AudioCircle
Industry Circles => Tortuga Audio => Topic started by: tortugaranger on 18 Feb 2020, 09:53 pm
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(https://www.tortugaaudio.com/images/ldr300x_frontview_open_800px.jpg)
Hi All,
For the past several years we’ve been selling variation of our LDR3 Passive Preamp first with our V2 board and later our newer V25 board. Eventually we added the OLED display. We’ve used the same powder coated heavy duty extruded aluminum case, Cardas jacks, machined aluminum panels, acrylic inlays etc. Parts and fabrication costs for this model have been on the high side for us and so we’ve priced the LDR3 at $1195 all this time.
In a few weeks, hopefully before the end of March, we’ll be introducing a replacement model for the LDR3, the LDR300x. While the internals of the LDR300x configured as a passive preamp will not change very much the externals will.
We are moving to a newer, lighter, smaller enclosure with newer and smaller front/rear panels. We are doing away with the machined aluminum front panel which was an expensive bear to fabricate and going instead with a dark acrylic lens. We’re also dropping the costly Cardas jacks.
The net result of all these mostly external changes is that going forward we’ll be able to offer the new LDR300x as a passive preamp at the remarkable price point of $789. Moreover, by also optionally leaving out the OLED display and only providing a simple status LED along with reduced functionality/features we will be offering a “no display” passive version for only $599.
Wait, there’s more!
Some of you may recall the LDR300 Buffered Preamp (without the “x”) that we released in the fall of 2018 and then discontinued in the spring of 2019. I won’t rehash that story here but we never stopped messing with the design of the buffer circuit used in the original LDR300. In fact we’ve improved upon it and are making it an optional part of the LDR300x. This means you can order the LDR300x as either a passive preamp or as an active preamp. Externally the active version looks and behaves the same as the passive version but the active version now has the new SSPB.V2 Preamp Buffer board.
The SSPB is more than just a JFET buffer, it also has a proper gain stage based on the LME49720 audio op amp with adjustable plug-in gain modules for running at unity (1x), +6dB or +12dB. Don't care for the LME49720? No problem. The dual op amp is socketed so you can go ahead and try alternative dual op amps if you like.
The active version of the LDR300x is priced at $995 and is one sweet sounding preamp.
More info on the LDR300x can be found here in an article we just published. https://www.tortugaaudio.com/ldr300x-preamp-coming-soon-in-passive-and-active-versions/ (https://www.tortugaaudio.com/ldr300x-preamp-coming-soon-in-passive-and-active-versions/)
We'll be adding more info on the LDR300x as we get closer to a release date.
We also plan to organize a tour for the LDR300x and this time we're going to ship both a passive and an active version so tour members can try both.
Cheers,
Morten
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This is great news Morten! I like the idea of a modular design, and the more aggressive pricing will likely attract many more to give these excellent sounding Tortuga products a try.
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Any news on this and might there be one to try out?
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Yes, I'd definitely be interested in auditioning one. I'm looking for a replacement for my current preamp.
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Any news on this and might there be one to try out?
We are diligently working on the 300x. The critical path item is completing the development of the new ePot.V3 Preamp Controller which will be at the heart of the new preamp model. We recently took one more time consuming step to improving the V3 by converting all of our code from C to object oriented C++. For most that won't mean anything but it's yet another step in raising the quality bar of the underlying software tech that runs our preamps. That decision set back our timeline by 2-3 weeks but now was the best time to do it. Realistically we are now talking about a mid-late June release. The good news is that we are more than 90% done with the work on the V3. I hope to freeze the hardware design over the next week or so which will let us proceed with ordering boards.
We WILL be organizing a tour for the 300x so more on that as we get closer to the release date. Tours are slow moving trains so if you wish to participate in the tour that will likely means months before your turn with a demo unit. The fastest way to try one out will be to buy one and take advantage of our 30 day in home audition and 100% refund policy if you're not satisfied.
Cheers,
Morten
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Thanks for the update!
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Shouldn't the two versions be called the LDR300a and LDR300p?
For the tour, will you be sending both versions together to each person at the same time?
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Shouldn't the two versions be called the LDR300a and LDR300p?
For the tour, will you be sending both versions together to each person at the same time?
Good question. It comes down to both a matter of design philosophy and a practical/cost question.
As conceived this overall model could have the following variations: 1) passive - no display (LED only), 2 passive with OLED display, 3) buffered (active) with OLED. If we offered 2 or all 3 as its own model then we'd need 3 different versions of rear panel with its own model labeling. If it's only 300x then there's only 1 rear panel to design and fabricate. This keeps the cost down. Labeling doesn't make anything sound better so why make it cost more? Ok, then so how does anyone know what specific version they have in their hand? Well, it it has only a blinking LED then it's a passive 300x. If it has an OLED display then go down the display menu until you see "Version", click on it and it will tell you what it is.
Now suppose someone buys a low cost passive version with a blinking LED and later decides he wants both an OLED display and a buffer added. No problem. Nothing needs to change externally. All the mods are done internally and the rear panel doesn't have to be changed out. Flexible, least cost approach. They are all variations on the 300x model. X for fleXible.
It gets even more "interesting" when you introduce our new non-LDR plug-in discrete thin-film switched attenuator module that you can plug into the preamp controller board in lieu of an LDR module and now you have a non-LDR preamp that can be passive or active. It's still a 300x. Query the OLED display menu to find out it's a TA300x.DA for Discrete Active or LA for LDR Active or DP for Discrete Passive or LP for LDR Passive. In fact we may well actually end up calling this the TA300x given that it's no longer locked in to being an LDR preamp. Cool beans! :thumb:
Cheers,
Morten
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Gotcha!
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Any updates on release date for the active preamp?
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Any updates on release date for the active preamp?
The critical path to answering that question is getting the ePot.V3 controller board finished. Thought we were done the last week of May but I wasn't satisfied with the power supply arrangement so we're now going through a couple of iterations on different PS designs. Next round of prototype boards due to arrive next week. If that goes well we can place production orders by mid June which would mean a possible release in mid-late July. This is pretty much taking 100% of our time currently so we on it like stink. As soon as we get the V3 wrapped up we'll be able to give a more accurate update but for planning purposes late July or early August looks doable.
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Thanks for the update. Might you have an idea of the size of the enclosure? Need to plan some space
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Thanks for the update. Might you have an idea of the size of the enclosure? Need to plan some space
That part of the cake is baked.
Width: 6.125"
Height: 2.5" including feet (2" nominal enclosure)
Depth: 9.5"
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Any updates? Just wondering if you are still on track for your planned release dates.
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Any updates? Just wondering if you are still on track for your planned release dates.
The V3 controller designs are done and hardware has been ordered. We expect to have production V3 hardware in hand around the 1st week of August. We need that hardware to produce the new TA300x. The only part of the TA300x we don't physically have yet aside from the V3 is the rear panel but we'll have those by the time the V3 boards arrive. So adding all of that up it looks like around mid-August is looking feasible. Let's just say "August" for sure whether that's early, mid or late I've given up trying to forecast these things. The good news is there are very few remaining uncertainties.
We'll be standing up the TA300x product page on our website soon for pre-ordering.
Cheers,
Morten
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First day of August, wondering when the TA300x Active might be available?
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First day of August, wondering when the TA300x Active might be available?
By way of update we started production of both the ePot.V3 Mini and Max boards this past week. Official release of the V3 attenuator/controllers is scheduled for mid-August and it looks like we'll meet that target with maybe a 1 week slippage since we are still putting final touches on the firmware.
Release/availability of the V3 Max is THE critical path item to getting the TA300x ready to go. We have raw rear panels for the TA in house now and will be prepping and shipping those out to the anodizer this coming week with a 1 week turnaround. Aside from the V3 Max, the rear panels are the last thing we need to start producing the TA300x. Rolling that all up I'd say it's still possible we could release the TA300x by the end of August and it that slips it might spill into early September but somewhere in that time frame is realistic.
I'd expected to stand up the TA300x product page on the website by now but have been consumed with getting the new V3 controller ready which takes precedence over everything else right now. That said I'm committed to get the product page up and going before this week is out. It's time.
Cheers,
Morten
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Just curious on the status of the product page. Hoping you are making progress!
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Just curious on the status of the product page. Hoping you are making progress!
We are on track to being shipping ePot.V3 Mini boards this week and to start producing the Max boards. The Max boards are needed for the TA300x. We are also waiting on getting the rear panels back from the anodizer which should be done by the of the week so I expect we'll have both panels AND Max boards by next week which means we'll likely be ready to produce TA300x units be the end of the month. I wanted to get some production unit pics of the TA300x before standing up the product page and we need the rear panels for that. So probably next week for the product page.
Cheers,
Morten :thumb:
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Hi All,
We are pleased to finally stand up the product page for the new LDR300x.V3 Passive or Active Preamp. What's missing are decent product photos but those are in the works and will be available next week. We are accepting orders but will not likely be shipping units until the end of August.
I will be organizing a tour for the LDR300x soon as well.
While it's the ultimate self-serving statement I'm really VERY pleased with the sound of this preamp. I mean I REALLY like it A LOT. I get distracted listening to it here in our shop. No doubt in my mind the ePot.V3 is THE best attenuator/controller we've ever designed.
Here's the link: [url]https://tortugaaudio.com/products/passive-preamps/ldr300x-v3-preamp/
Cheers,
Morten :thumb:
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Good news, is the pre-order discounted? I also see options for capacitor upgrades. Can those be done at a later time? Finally, is a remote included? Don't see a TA option either.
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Good news, is the pre-order discounted? I also see options for capacitor upgrades. Can those be done at a later time? Finally, is a remote included? Don't see a TA option either.
Pre-order discount - Given the relative aggressive pricing there's really no room for discounting these preamps. I did consider this since it's been customary to offer pre-order discounts.
Capacitor upgrades - Yes, these can be done down the road. It does require carefully removing and reinstalling soldered components but quite doable.
Remote control - Yes, all of our preamps are always remote control. We are, after all, civilized ;)
TA Option - By this I assume you mean the discrete attenuator option in lieu of the LDR. After much back and forth on this I won't mince words. The LDR approach remains the better sonic option. I'd expected less of a difference and I'm actually quite agnostic as to which is better but so far the LDR wins so we are leading with what sounds better until something else comes along that beats it. I'm looking into an alternative discrete attenuator topology which may sound better than the logarithmic/ladder approach we currently have. We'll have to see how that goes.
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Alright, appreciate the response. Purchase made, glad you reduced the level of options :) Now I need to find a new phono stage!
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Here's our first batch of product pics for the LDR300x.V3 Preamp.
Still need to get one made with the unit powered on with the OLED display showing.
We've started shipping these. :thumb:
LDR300x.V3 Preamp | Active or Passive | https://tortugaaudio.com/products/passive-preamps/ldr300x-v3-preamp/ (https://tortugaaudio.com/products/passive-preamps/ldr300x-v3-preamp/)
(https://tortugaaudio.com/images/LDR300xV3_frontview_with_remote_1b.jpg)
(https://tortugaaudio.com/images/LDR300xV3_frontview_1.jpg)
(https://tortugaaudio.com/images/LDR300xV3_sideview_1.jpg)
(https://tortugaaudio.com/images/LDR300xV3_rearview_1.jpg)
(https://tortugaaudio.com/images/LDR300xV3_rearview_2.jpg)
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Here's a decent pic of the LDR300x.V3 Active Preamp internals all dressed with VCAP reference series copper teflon output coupling caps. Amazing natural detailed sound.
https://tortugaaudio.com/products/passive-preamps/ldr300x-v3-preamp/ (https://tortugaaudio.com/products/passive-preamps/ldr300x-v3-preamp/)
(https://tortugaaudio.com/images/ldr300x.v3_topview_internals.jpg)
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A musical interlude (click on youtube video link) for our Tortuga Audio mascot hard at work keeping our OLED display healthy.
The screensaver kicks in automatically after 15 minutes of no control activity when the unit is on.
The slight flicker seen in this video is an artifact of fluorescent lighting interacting with the camera.
It actually doesn't flicker at all.
Enjoy!
Morten
https://youtu.be/eGbH_h8wd5w (https://youtu.be/eGbH_h8wd5w)
(https://tortugaaudio.com/images/ldr300x.v3_frontview_OLED_1.jpg)
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Looking good Morten.
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Sign me up for the west coast leg of the tour! If hawaii counts as west coast. Great job on keeping price low and your programming of the settings is impressive. What's next, software tone controls? ;)
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I've had mine for about a week now and can say this pre-amp is an amazing little device. While I can use it in pure passive mode, the active buffer really gives the music some weight and body. It is three preamps in one if you consider all the settings (assuming you purchase the active model - pure passive, active buffered, active with 6 db gain). Need to fine tune my setup as it is very revealing and I have found a number of areas in my system that needed tweaking or correcting. I'm giving it a little more time to burn in before a proper review but it replaced a preamp that was 4 times the cost with very expensive tubes and I am not missing it.
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I've had mine for about a week now and can say this pre-amp is an amazing little device. While I can use it in pure passive mode, the active buffer really gives the music some weight and body. It is three preamps in one if you consider all the settings (assuming you purchase the active model - pure passive, active buffered, active with 6 db gain). Need to fine tune my setup as it is very revealing and I have found a number of areas in my system that needed tweaking or correcting. I'm giving it a little more time to burn in before a proper review but it replaced a preamp that was 4 times the cost with very expensive tubes and I am not missing it.
This is great to hear! I'm looking forward to auditioning the LDR300x in the coming weeks to determine if it's enough of an upgrade to displace my 6 year old Tortuga passive...
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I just noticed I missed out on the tour again for yet another generation of preamps :cry:
Morten you're so good at programming the settings through the screen did you ever think of adding a DAC module to the preamp? Like I know soekris has a small oem dac module board.. and the orchard audio guy has his pecan pi dac boards available
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I just noticed I missed out on the tour again for yet another generation of preamps :cry:
Morten you're so good at programming the settings through the screen did you ever think of adding a DAC module to the preamp? Like I know soekris has a small oem dac module board.. and the orchard audio guy has his pecan pi dac boards available
There's room on the tour. No worries. As for DACs I'm biased towards DACs being standalone components and am unclear on whether there would be demand for an integrated DAC/preamp. I'm broadly aware of the soekris DAC and believe ladder types are the way to go. Do you believe a visual front end for an OEM DAC board would be of interest and if so what functionality should it have?
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As we gain more runtime on the new LDR300x we've been refining not only the control firmware but have also been tweaking the SSPB.V2 gain/buffer board used in the active version of the preamp. One thing we've noted from day 1 is that the LDR300x has a noticeable bass boost especially in the active configuration. It's pleasant and not boomy but I've wondered about it. We've been using the LME49720 audio op amp in the active LDR300x all along and until recently haven't really taken the time to explore alternatives. Fortunately, the dual channel op amp is a plug-in PDIP8 type so it's easy enough to swap out the LME49720 for alternatives.
Today we swapped out the LME49720 and tried a good old TL072 JFET op amp. To our pleasant surprise the change was an overall positive mode. The base boost was dialed back while everything continued to sound marvelous if not actually a tad bit better. My tech thought so right away. Moreover, the TL072 exhibited very stable unity-gain operation - arguably better than the LM49720 which tended towards some low level motor-boating with low/zero gain.
Based on the success with the TL072, which was first released back in 1978 believe it or not, we are going to try a few other alternatives op amps and report back on results. As things stand this moment I'm going to switch over production units to the TL072 unless we find something better after trying a few others.
I'll report back on findings after we've tried some others.
The other tweak we've been testing is running the LDR300x with direct coupled output. Direct coupled means we don't use output coupled capacitors ..... at all!! For this to work we have to ensure that the DC offset on the output signals are near zero (just a few millivolts). We baked this capability into the design of the SSPB.V2 board but until recently haven't focused on it. The use of a split voltage power supply together with adjustable JFET buffer current allows us to literally dial in zero DC offset using trim pots. What we're finding is that once trimmed out, the DC offset remains quite stable and resumes near zero levels after power up each time. Running without output/blocking caps yields the best possible sound quality since the best coupling capacitor is no capacitor at all provided the DC offset is small and stable. Anyone with an existing unit can implement this themselves using jumper wires, a volt-ohm meter, and a thin bladed screwdriver.
Between the op amp optimization and the direct coupled output, the active version of the LDR300x is evolving into a truly great sounding preamp.
Cheers,
Morten
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nice to see active development! I love when these tweaks come stock. what next, power supply regulator rolling or mumetal shielding and vibration damping? :)
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Is there room within the preamp enclosure to use a Burson V6 Vivid or Classic opamp? Those are supposed to be the cat's meow for opamps and they would be a direct substitute for the ones you are using.
L.D.
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Is there room within the preamp enclosure to use a Burson V6 Vivid or Classic opamp? Those are supposed to be the cat's meow for opamps and they would be a direct substitute for the ones you are using.
L.D.
I'm reasonably sure a Burson would fit width-wise. I did a quick measurement and the distance from top of current chip to top of enclosure is almost 1 inch whereas the Burson needs 1.14 inches. If I subtract the thickness of the existing chip we are probably right at the 1.14 inch height. Worst case scenario remove the plastic case from around the Burson op amp and I'm sure that the discrete boards would fit. I'm going to give this a try as well and report on the results. Good suggestion!
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We tried several alternative op amps today. We agreed the OPA2134 stood out. All the others sounded good/similar while the OPA2134 was more refined. That's not a big surprise as the OPA2134 has a great reputation. We may still try some others but for now will likely stay with the OPA2134 going forward. The OPA2134 is rock solid at unity gain while the LME49720 would sometimes exhibit some low level motor boating (oscillation).
The others we tried included:
LME49720 (our original choice during the design and initial production)
NE5532 - considered a more modern replacement for TL072
TL072
TLE2072 - a modern version of the TL072
As we gain more runtime on the new LDR300x we've been refining not only the control firmware but have also been tweaking the SSPB.V2 gain/buffer board used in the active version of the preamp. One thing we've noted from day 1 is that the LDR300x has a noticeable bass boost especially in the active configuration. It's pleasant and not boomy but I've wondered about it. We've been using the LME49720 audio op amp in the active LDR300x all along and until recently haven't really taken the time to explore alternatives. Fortunately, the dual channel op amp is a plug-in PDIP8 type so it's easy enough to swap out the LME49720 for alternatives.
Today we swapped out the LME49720 and tried a good old TL072 JFET op amp. To our pleasant surprise the change was an overall positive mode. The base boost was dialed back while everything continued to sound marvelous if not actually a tad bit better. My tech thought so right away. Moreover, the TL072 exhibited very stable unity-gain operation - arguably better than the LM49720 which tended towards some low level motor-boating with low/zero gain.
Based on the success with the TL072, which was first released back in 1978 believe it or not, we are going to try a few other alternatives op amps and report back on results. As things stand this moment I'm going to switch over production units to the TL072 unless we find something better after trying a few others.
I'll report back on findings after we've tried some others.
The other tweak we've been testing is running the LDR300x with direct coupled output. Direct coupled means we don't use output coupled capacitors ..... at all!! For this to work we have to ensure that the DC offset on the output signals are near zero (just a few millivolts). We baked this capability into the design of the SSPB.V2 board but until recently haven't focused on it. The use of a split voltage power supply together with adjustable JFET buffer current allows us to literally dial in zero DC offset using trim pots. What we're finding is that once trimmed out, the DC offset remains quite stable and resumes near zero levels after power up each time. Running without output/blocking caps yields the best possible sound quality since the best coupling capacitor is no capacitor at all provided the DC offset is small and stable. Anyone with an existing unit can implement this themselves using jumper wires, a volt-ohm meter, and a thin bladed screwdriver.
Between the op amp optimization and the direct coupled output, the active version of the LDR300x is evolving into a truly great sounding preamp.
Cheers,
Morten
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As we gain more runtime on the new LDR300x we've been refining not only the control firmware but have also been tweaking the SSPB.V2 gain/buffer board used in the active version of the preamp. One thing we've noted from day 1 is that the LDR300x has a noticeable bass boost especially in the active configuration. It's pleasant and not boomy but I've wondered about it. We've been using the LME49720 audio op amp in the active LDR300x all along and until recently haven't really taken the time to explore alternatives. Fortunately, the dual channel op amp is a plug-in PDIP8 type so it's easy enough to swap out the LME49720 for alternatives.
Today we swapped out the LME49720 and tried a good old TL072 JFET op amp. To our pleasant surprise the change was an overall positive mode. The base boost was dialed back while everything continued to sound marvelous if not actually a tad bit better. My tech thought so right away. Moreover, the TL072 exhibited very stable unity-gain operation - arguably better than the LM49720 which tended towards some low level motor-boating with low/zero gain.
Based on the success with the TL072, which was first released back in 1978 believe it or not, we are going to try a few other alternatives op amps and report back on results. As things stand this moment I'm going to switch over production units to the TL072 unless we find something better after trying a few others.
I'll report back on findings after we've tried some others.
The other tweak we've been testing is running the LDR300x with direct coupled output. Direct coupled means we don't use output coupled capacitors ..... at all!! For this to work we have to ensure that the DC offset on the output signals are near zero (just a few millivolts). We baked this capability into the design of the SSPB.V2 board but until recently haven't focused on it. The use of a split voltage power supply together with adjustable JFET buffer current allows us to literally dial in zero DC offset using trim pots. What we're finding is that once trimmed out, the DC offset remains quite stable and resumes near zero levels after power up each time. Running without output/blocking caps yields the best possible sound quality since the best coupling capacitor is no capacitor at all provided the DC offset is small and stable. Anyone with an existing unit can implement this themselves using jumper wires, a volt-ohm meter, and a thin bladed screwdriver.
Between the op amp optimization and the direct coupled output, the active version of the LDR300x is evolving into a truly great sounding preamp.
Cheers,
Morten
So are the expensive capacitors no longer needed in Active mode? Just wondering as I am still enjoying the unit and waiting for the chassis upgrade.
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So are the expensive capacitors no longer needed in Active mode? Just wondering as I am still enjoying the unit and waiting for the chassis upgrade.
From what we've been observing it looks like the design can maintain a stable low DC offset which allows running the active/buffer board without coupling capacitors - cheap or expensive. It's up for debate whether there's a discernable sound quality difference between running without any cap vs. running with a high quality cap but I submit "no cap" is better than the "best cap" provided you can maintain a low DC offset at the output.
Swapping out different input/gain op amps has a more noticeable impact on sound quality. Not so much better vs. worse as in different where it comes down to preferences as much as anything. After going back and forth I'm currently liking the TL072 the best. Vivid mid range with plenty of high frequency "air". In systems that already tend towards bright, the TL072 may not be ideal and the more laid back BurrBrown OPA2134 may work better. These are 8 pin DIP plug-in dual op amps so it's easy enough to try alternatives to see which you prefer. The biggest challenge is patiently inserting the 8 pin DIP into the socket without bending the pins.
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I ordered a pair of Burr Brown OPA2134, I haven't opened up my preamp but is there one or two that need to be replaced?
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I ordered a pair of Burr Brown OPA2134, I haven't opened up my preamp but is there one or two that need to be replaced?
Just one is needed. They are dual channel op amps.
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Just one is needed. They are dual channel op amps.
I swapped out the op amp with the Brown Burr and gave it a listen, not critical but didn't hear anything that caused concern. For the most part, swapping this out is like an adult version of Operation. If your intent is to let people "roll" their own, perhaps a socket that is a little easier to use. I've done this before with a Sutherland phono preamp and the sockets in that until had more user friendly opamp sockets.
Waiting on a few other changes to my system to settle down before I give a critical review.
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I swapped out the op amp with the Brown Burr and gave it a listen, not critical but didn't hear anything that caused concern. For the most part, swapping this out is like an adult version of Operation. If your intent is to let people "roll" their own, perhaps a socket that is a little easier to use. I've done this before with a Sutherland phono preamp and the sockets in that until had more user friendly opamp sockets.
Waiting on a few other changes to my system to settle down before I give a critical review.
Yes, the op amp is not exactly located where there's a lot of room - pulling out the 2 socketed gain modules on either side helps open up the access. As to the socket itself, the term "user friendly" and most any DIP socket do not go well together. That said, we do use a very high quality milled/machined socket made with BeCu - not a cheap socket. Doesn't mean it's easy - pins have to aligned just so - same as any DIP socket.
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Well, I've placed an order for the active version. I believe this will be a worthy successor to the Dacgear LDR Pre Mk2 I currently run in my main system as I bi-amp. I'll move the Dacgear to my second system.
If it sounds at all Bright I'll order a Burr Brown OPA or maybe Burson V6 Vivid.
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Will a Sonic Imagery Labs 994Enh-Ticha work and fit inside this unit? It's physically wider than taller discrete OPAMPS like the Burson.
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Will a Sonic Imagery Labs 994Enh-Ticha work and fit inside this unit? It's physically wider than taller discrete OPAMPS like the Burson.
I've not measured this but eye-balling the available space and looking at that Sonic Labs unit online my guess is it will fit just barely. May have to push the adjacent trim pot out of the way a little. Worst case scenario you end up with a 8DIP pin socket extender to raise the effective opamp socket up high enough but I don't think that will be necessary.
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Mmm, I think I'll give it a go. From what I've read it sits between the Burson V6 Classic and Vivid in terms of sonics. Sounds interesting as each of those OPAMPS do something I like though neither quite do it all for me. Better than Sparkos though which are a little bright and thin in comparison.
I'm really looking forward to getting your active pre in place. :)
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Recieve d it today. Upon first powering on I was a little disappointed vs my DACGEAR LDR h as it's getting some time on it things seem to be improving. Makes sense I guess as there are active components should benefit from burn in.
One other this n be I noticed is when using my the volume knob it's sometimes unresponsive though there appears no such issues with the be remote?
I'll listen some more later and see if I can get a better feel for it. More use needed to evaluate.
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Ok, now it's has a bit more warm up and I've been able to have a bit more of a listen I note the following ad improvements over my DACGEAR LDR Pre MK2:
1. Noticeably improved dynamics (contrast between quiet and loud)
2. Improved decays, especially high hats
3. Bass initially seems less, then I notice bass notes and instrumentation I've never heard before. It's more transparent.
4. An overall more natural sound though reveals more flaws in recordings. Overall everything sounds better though warts and all.
5. An ever so slightly smoother and more natural presentation
Overall with minimal burn in this is a noticeable improvement. It won't be going back. Now to reprogram my Logitech Harmony remote. ;)
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Ok, now it's has a bit more warm up and I've been able to have a bit more of a listen I note the following ad improvements over my DACGEAR LDR Pre MK2:
1. Noticeably improved dynamics (contrast between quiet and loud)
2. Improved decays, especially high hats
3. Bass initially seems less, then I notice bass notes and instrumentation I've never heard before. It's more transparent.
4. An overall more natural sound though reveals more flaws in recordings. Overall everything sounds better though warts and all.
5. An ever so slightly smoother and more natural presentation
Overall with minimal burn in this is a noticeable improvement. It won't be going back. Now to reprogram my Logitech Harmony remote. ;)
1. Noticeably improved dynamics (contrast between quiet and loud)
Even with the solid state active/buffer output stage these preamps have a dead quiet background. I get this comment often.
2. Improved decays, especially high hats
I think this is related to #1 in that subtle details are more clearly present and unlikely to be masked.
3. Bass initially seems less, then I notice bass notes and instrumentation I've never heard before. It's more transparent.
Bass is one area that where we usually get consistent comments about bass being noticeably strong but not overly so.
4. An overall more natural sound though reveals more flaws in recordings. Overall everything sounds better though warts and all.
"Natural sounding" is probably the THE most common comment we get on our LDR preamps. But you hear what's there....like it or not. Can't hide from the recording quality.
5. An ever so slightly smoother and more natural presentation
That was my own personal impression the first time I started working with LDR attenuation.
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My only real gripe is that the volume knob when used is regularly unresponsive for a second or two. I believe this is a firmware bug.
Another is settings seem to be lost if the unit is powered down
My work around for this is to never turn it off, and this is a valid work around due to the user replaceable nature of your LDR modules. It also simplified my systems operation which makes my wife happy. :)
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My only real gripe is that the volume knob when used is regularly unresponsive for a second or two. I believe this is a firmware bug.
Another is settings seem to be lost if the unit is powered down
My work around for this is to never turn it off, and this is a valid work around due to the user replaceable nature of your LDR modules. It also simplified my systems operation which makes my wife happy. :)
** Updated **
I'm curious to know more about these issues (response delay from volume knob & lost settings) since we have no evidence of this happening in any units we're currently building/commissioning and are not receiving similar complaints from others. Not saying these problems aren't real, only that we're ignorant of this happening. Any further info, pics, video etc you can provide documenting this will be appreciated and may prove helpful getting it resolved.
We found the root cause of the lost settings. Maybe also the delayed response. We made a fairly significant firmware update just before your unit was shipped. It's clear now that we managed to introduce a bug that we did no observe so we didn't catch it. It's clear now what happened and a fix is being prepared.
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Excellent, thanks so much Morten for your (rather exceptional) response to this. :)
I look forward to the updated firmware. I had read about your incredible support, but to experience it is another thing entirely. Better than I’ve ever experienced before. :)
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Here’s a short video of the volume knob issue Morten. In my mind definitely a firmware issue rather than hardware based on the units observed behaviour. I.e. The volume knob will wake it up but there's a delay before it will accept volume change. The bug doesn't seem to affect control via the remote thankfully.
https://drive.google.com/file/d/1crMqpzeiSu26mGYW2FONzZQ8tkfxk23E/view?usp=drivesdk
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Another quick question, I've been trying to train my Logitech Harmony One to work with the Tortuga with no success currently. Is the Tortuga currently locked to the Apple Remote it shipped with? If so is there a way for me to remove this lock?
Cheers
Matt
EDIT: Never mind. I was being lazy. Found this: https://www.audiocircle.com/index.php?topic=174645.0
EDIT2: Just replicated the volume lag with the remote though that’s a one off so far. Matt not happen again.
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Here’s a short video of the volume knob issue Morten. In my mind definitely a firmware issue rather than hardware based on the units observed behaviour. I.e. The volume knob will wake it up but there's a delay before it will accept volume change. The bug doesn't seem to affect control via the remote thankfully.
https://drive.google.com/file/d/1crMqpzeiSu26mGYW2FONzZQ8tkfxk23E/view?usp=drivesdk (https://drive.google.com/file/d/1crMqpzeiSu26mGYW2FONzZQ8tkfxk23E/view?usp=drivesdk)
Thanks for the video. Videos like this can be very helpful in sorting through odd behaviors. This video shows that the display timeout feature has been enabled where the display turns off after a defined number of seconds. Turning the volume knob turns the display back on and resets the display timeout timer. I discovered that the user adjustable timeout value was not being properly saved which caused a brief delay in responding to further control inputs. Since correcting this I've not been able to reproduce the delay behavior so I'm thinking this bug will be resolved in the next firmware update.
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Excellent, thanks Morten. I look forward to the next update. Things have improved more with further burn in of the active components with sonics improving to a point where things are now sounding outright magical. I’m now extremely happy with the unit. Particularly with a fix for the volume delay on the way. :)
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Well it seems the Sonic Imagery 994Enh-Ticha was too big to fit so I’ve ordered a DIP8 socket extender. I’ll try it once recieved.
I did have some Sparkos SS3602 discrete OPAMPS on hand and tried them for a day. Overall they were too clean and sounded unnatural. The TL072 that is standard in the unit is noticeably better so it’s back in place. I kind of wish I still had a Burson V5i-D on hand. They’rea semi discrete FET based OPAMP and that could work rather well. I’m not really a fan of the Burson V6 finding the Vivid and Classic to be polar opposite of each other. Not really that well balanced.
Anyway Even if the Sonic Imagery isn’t an improvement it’s no big deal when things already sound this good. :)
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Well it seems the Sonic Imagery 994Enh-Ticha was too big to fit so I’ve ordered a DIP8 socket extender. I’ll try it once recieved.
I did have some Sparkos SS3602 discrete OPAMPS on hand and tried them for a day. Overall they were too clean and sounded unnatural. The TL072 that is standard in the unit is noticeably better so it’s back in place. I kind of wish I still had a Burson V5i-D on hand. They’rea semi discrete FET based OPAMP and that could work rather well. I’m not really a fan of the Burson V6 finding the Vivid and Classic to be polar opposite of each other. Not really that well balanced.
Anyway Even if the Sonic Imagery isn’t an improvement it’s no big deal when things already sound this good. :)
I tried numerous alternatives to the TL072 but kept coming back to it. Even very pricey well regarded audio-centric op amps did not clearly outperform the TL072 which is considered a general purpose low-noise JFET op amp that started life all the way back in 1978. Curious to get your take on any of the discrete opamps, none of which Iv'e tried yet in this application.
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Yes, the Sparkos was a bit of a let down though to be fair I’ve never much liked their sound. The next discrete I’ll try is the Sonic Imagery 994Enh-Ticha, maybe a SX45B as well though then I’ll call it a day. A fair chance the TL072 will be the victor.
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Ah, I changed the Supra CAT8 cable on my Roon end point for an Acoustic Revieve R-AL1 and I've the additional clarity I was looking for without losing any of the naturalness of the TL072. Basically the Tortuga was just letting through a slight muddiness caused by the Supra CAT8.
I kind of wish I hadn't bothered ordering the Sonic Imagery 994Enh-Ticha OPAMP now as it's just unnecessary. I'll still try it when I've the DIP8 extender but I can't imagine things improving from here.
I'll get a Synergistic Research Orange Quantum fuse for my DAC now instead, maybe for my amp and Mutec as well.
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Ok, I received my DIP8 extender and have installed the Sonic Imagery 994Enh-Ticha OPAMP. First impressions are a slight improvement in clarity and dynamics, though without giving up the musicality and naturalness that the TL072 brought. It shares a similar richness as well with better top end extension and seems to have slightly better bass. Considering that this is the benefit it brings with zero burn in I expect it should continue to improve, though you never know in this hobby. It could go the other way as well. I'll report back in a few weeks and see if it remains installed in the 300x. I’ve been tricked into thinking things are better before.
I note this OPAMP seems to have less gain. It’s clearly a little constricted just now too as the stock OPAMP started off. It has potential though. That said, things were sounding so good with the fully burned in TL072 that I might not have the patience to wait for burn in. At a certain point of enjoyment, what’s the point of potential improvement when it’s already incredible? Course I might just wait too. :)
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One thing that is really noticeable with this OPAMP vs any other I’ve tried is the only blackness sound comes from where there’s no sound in the recording (basically modem digital recordings with no tape hiss). It’s particularly striking when instruments start on one speaker to be followed by other instruments on the other. I’ve never heard anything like it before. That said it has started a bit warm and can sound muddy at lower playback volume though nothing noticeable at higher levels. More burn in required before I can judge.
Still, there’sa certain colouration that the TL072 has which was very pleasant that I miss, though the improvements in nearly every other area make the Sonic Imagery 994Enh-Ticha discrete OPAMP the better sounding OPAMP but it’s still a tough choice. I may never be able to decide until I switch the TL072 back in a few weeks.
EDIT: Ordered an Orange discrete JFET OPAMP to try with the Tortuga. It seems that the Sonic Imagery 994Enh-Ticha is that bit better than the stock TL072 in every aria, but lacks that special sense of being at the performance. That magical element.
I figured maybe I need to try another FET based solution so the Orange Discrete OPAMP is now in the way.
This really says a lot on the choice of the TL072 that to my ears it’s still ahead of some very nice discrete OPAMPS.
I’ve swapped the TL072 back in and will see if it still has that special something in comparison when I have a listen later tonight. :)
EDIT2: Despite everything the 994 does right, the TL072 remains more lifelike giving the impression of being there at the performance. The 994 can only do this with the very best recordings. I think it may be more accurate however I prefer the presentation of the TL072. I think I’ll try the Orange JFET discrete OPAMP though after that I’m done trying different OPAMPS irrespective of what sounds best so it will be down between the Orange and TL072.
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One thing that is really noticeable with this OPAMP vs any other I’ve tried is the only blackness sound comes from where there’s no sound in the recording (basically modem digital recordings with no tape hiss). It’s particularly striking when instruments start on one speaker to be followed by other instruments on the other. I’ve never heard anything like it before. That said it has started a bit warm and can sound muddy at lower playback volume though nothing noticeable at higher levels. More burn in required before I can judge.
Still, there’sa certain colouration that the TL072 has which was very pleasant that I miss, though the improvements in nearly every other area make the Sonic Imagery 994Enh-Ticha discrete OPAMP the better sounding OPAMP but it’s still a tough choice. I may never be able to decide until I switch the TL072 back in a few weeks.
EDIT: Ordered an Orange discrete JFET OPAMP to try with the Tortuga. It seems that the Sonic Imagery 994Enh-Ticha is that bit better than the stock TL072 in every aria, but lacks that special sense of being at the performance. That magical element.
I figured maybe I need to try another FET based solution so the Orange Discrete OPAMP is now in the way.
This really says a lot on the choice of the TL072 that to my ears it’s still ahead of some very nice discrete OPAMPS.
I’ve swapped the TL072 back in and will see if it still has that special something in comparison when I have a listen later tonight. :)
EDIT2: Despite everything the 994 does right, the TL072 remains more lifelike giving the impression of being there at the performance. The 994 can only do this with the very best recordings. I think it may be more accurate however I prefer the presentation of the TL072. I think I’ll try the Orange JFET discrete OPAMP though after that I’m done trying different OPAMPS irrespective of what sounds best so it will be down between the Orange and TL072.
Interesting feedback/info. In my view, the subtle, and sometimes not so subtle, differences with various audio op amps (and other components) more often than not comes down to personal preferences rather than some objective continuum of good, better, and best. The only way to develop a keen sense of this is to do what you're doing - try different op amps - live with their sound for a while - and then switch to another op amp and give that one some time. Yes, it's an inherently imperfect subjective approach but since we experience music subjectively (our ears/brain do not "hear" the same as measurement instrumentation) the question of which is "better" objectively (measured results) isn't particularly meaningful except as an engineering design guide/reference. This is evident in the many online audio forum debates over which op amp is preferred in audio applications - yes, there's the collection of usual preferred suspects but rarely is there a consistent overall winner across all hardware designs.
Said differently, there's the op amp that should sound the best (measures best), and then there's the op amp that you enjoy listening to the most. They're rarely the same. Makes for a fun hobby. And endless debate.
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Yes, the differences between OPAMPS are far more noticeable with extended listening over time. To date your choice of TL072 is the ebst I've heard by a fair margin. I'll give the Orange discrete JFET OPAMP a try though I rather suspect at this point that my favourite will remain the TL072. Interestingly I found the LDR300x V3 a bit dull though once burned in it's just gorgeous. :)
EDISt: Damn, I just can’t figure out which OPAMP I prefer. With many recordings the 994 is clearly better sounding….. especially with Billie Holliday, John Lee Hooker etc. furthermore I suspect it’s still burning in a bit….. On the other hand the top end of the TL072 is just beautiful.
So yeah the 994 is back in again. More burn in needed maybe?
Another difference I’m noticing is that the 994 is wonderfully open sounding whereas the TL072 has a slightly tube like effect going on, tough sounding less open than the best tubes. The TL072 is a bit brighter and tends to accentuate sibilants a bit more whereas the 994 is a little warmer which hurts playback clarity at lower volume in comparison. With some luck the slight warmth will die down a bit though now I notice it perhaps I can switch around some of my RCA leads to get the desired effect. Guess I’ll see.
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It’s time I mention that I’m powering my unit with a 12v 15a Teradak linear power supply. I mention this as tonight I replaced the standard DC umbilical with a new umbilical using Oyaide DC plugs and pure silver writing. The initial change is very constricted sounding though I know that will improve in time. I then switched the 2A fast blow fuse for an Aucharm branded 1a pure silver fast blow fuse which really had an enormous impact on overall sound massively opening up the soundstage. Initially sound was tilted towards treble and bass disappeared though over the past few hours the sound has started to balance out. The constricted sound immediately disappeared as well which I found interesting. This is not an expensive fuse by any means. It tells me the unit is sensitive to the quality of supplied power which was an unexpected result given that this unit has no gain. I should try the stock switching supply one of the days for comparison.
I’ve also ordered a Staccato OSH OPAMP which I’m pretty keen to try. Everything I’ve read indicates that it will at least equal the Sonic Imagery 994Enh-Ticha so it will be very interesting to try. Some of the descriptions I've read could as easily have been about the 994. The Orange discrete on the other hand is apparently not that detailed so I might get around to trying it….. or not. :)
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Ok, I received the Staccato OSH-DHb OPAMP this morning and have installed it.... Right out of the box this OPAMP better than anything else I've tried before. It was as large an improvement again as the Sonic Imagery 994Enh-Ticha was over the TL072. Where to my ears the 994Enh-Ticha combined the best attributes of the Burson V6 Vivid and Classic OPAMP's (The better transients of the Vivid with the timbre and naturalness of the Classic and better musicality of each) the OSH-DHb improves on those areas and adds the excellent detail of the Sparkos OPAMPS while remaining musical rather than the clinical sound of the Sparkos.
This from an OPAMP that isn't even an hour warmed up is impressive. It also seems louder so I need to set the volume lower overall.
Anyway, I've zero inclination to try anything else at this point as to my mind the Tortuga LDR300x V3 with these tweaks results in sonic perfection.
Tweaks have included:
TeraDak 6V 5A linear power supply + 1A fast blow Aucharm silver fuse
Pure silver DC umbilical with Oyaide connectors
OPAMP extender + Staccato OSD-DHb discrete Dual OPAMP
I may out of interest compare the stock switching power supply and see if the power supply tweaks I made have any sonic impact as the switching supply doesn't have any fuse so is not limited in that way. Yes a fuse change impacted the sound, though is the linear power supply itself an improvement over the stock switching power supply? It was interesting to me though that changing the fuse in the power supply made quite a large and noticeable improvement.
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I’ve had my mind blown listening tonight. Track after track of pure magic. Staccato OPAMPS must be burning in. I’d even say it’s a must have upgrade at this point. Just spectacular :D
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I'm making a cosmetic change to the LDR300x.V3 preamp clam shell case. When I receive our next batch of raw cases from our supplier, I'm going to have them powder coated instead of anodized. Anodizing looks great when all the prep work is done right but I was less than thrilled with the results of the first batch which we're almost out of now. So this next batch will black powder coated for a more even and elegant look and feel. Will announce when those are ready to be used in new builds/orders. That is all. Carry on. :thumb:
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will they be available in limited edition colors too? ;)
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Morten - Tortuga owners are well aware that you spend countless hours carefully investigating upgrade paths for your products, but one can't read Mjw21a's impressions above without wondering if the tweaks he's made really do propel the LDR300x to the next level of finesse he experienced. He obviously loved the LDR300x enough to try various tweaks to bring out its full potential.
I appreciate the cosmetic changes to the case, but would you consider making the Staccato OSH-DHb OPAMPs and 1A fast blow Aucharm silver fuses standard on the LDR300x? or maybe an upgrade option? of course you trust your ears and Mjw21's findings may be subjective, but again, reading his excitement over the increased "magical" sound quality he was apparently able to achieve is hard to ignore.
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will they be available in limited edition colors too? ;)
Actually I do intend to discuss having a few of the new cases finished in a deep candy apple red gloss. It will depend on how creative and cooperative I find my local powder coat service provider. :thumb:
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Morten - Tortuga owners are well aware that you spend countless hours carefully investigating upgrade paths for your products, but one can't read Mjw21a's impressions above without wondering if the tweaks he's made really do propel the LDR300x to the next level of finesse he experienced. He obviously loved the LDR300x enough to try various tweaks to bring out its full potential.
I appreciate the cosmetic changes to the case, but would you consider making the Staccato OSH-DHb OPAMPs and 1A fast blow Aucharm silver fuses standard on the LDR300x? or maybe an upgrade option? of course you trust your ears and Mjw21's findings may be subjective, but again, reading his excitement over the increased "magical" sound quality he was apparently able to achieve is hard to ignore.
Thanks for the reminder on the Staccato opamps. I need to order some to try and will let you all know what I think after hearing them in service.
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Thanks for the reminder on the Staccato opamps. I need to order some to try and will let you all know what I think after hearing them in service.
I've been in contact with Jakub Honkisz, the founder of Staccato, which is based in eastern Poland. I've ordered one of their discrete op amps for evaluation. If all goes well I will probably order a batch for resale.
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Officially registering my interest in an ldr300x in the red case, active with gain :)
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Officially registering my interest in an ldr300x in the red case, active with gain :)
Raw cases shipment arrived yesterday so I'll be getting them powder coated soon. I'll let you know if/when I get the red ones.
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lol I should buy a ferrari badge off ebay to get ready to apply it to the preamp :D
https://www.ebay.com/itm/363481711224?_trkparms=ispr%3D1&hash=item54a132c278:g:TbcAAOSwvZRgRuuT&amdata=enc%3AAQAGAAAA4BiJ3LsYzdVZlMha385Tq9zGtkBEvPLbCV9%2BBp%2BJV04iZWWPt3QyP25fgc0ZMIo58JxC8Af2ChVQLayjJfWp29WfmH2P3oWXYyY7XM8BeYGjLV7oDU54Fr3I4XaCiuvBHFnoNDHn2b0ZaipSnjTS5a4JYPhUxPD%2Bjl2DnV5%2FRNXR5oduotdXWVFxf2IFGc0eutHcu9u4CYW28MwKisBwAPEmkLoowT%2B5Ftzzwaij5MIDjmHwaw%2FTbnQsR%2FQLKh7Y1KAzzQNkl0l5iKRiYapuaUXbAH5kTwwI3Eh%2BNSumbpvC%7Ctkp%3ABFBM3vbg54Fg (https://www.ebay.com/itm/363481711224?_trkparms=ispr%3D1&hash=item54a132c278:g:TbcAAOSwvZRgRuuT&amdata=enc%3AAQAGAAAA4BiJ3LsYzdVZlMha385Tq9zGtkBEvPLbCV9%2BBp%2BJV04iZWWPt3QyP25fgc0ZMIo58JxC8Af2ChVQLayjJfWp29WfmH2P3oWXYyY7XM8BeYGjLV7oDU54Fr3I4XaCiuvBHFnoNDHn2b0ZaipSnjTS5a4JYPhUxPD%2Bjl2DnV5%2FRNXR5oduotdXWVFxf2IFGc0eutHcu9u4CYW28MwKisBwAPEmkLoowT%2B5Ftzzwaij5MIDjmHwaw%2FTbnQsR%2FQLKh7Y1KAzzQNkl0l5iKRiYapuaUXbAH5kTwwI3Eh%2BNSumbpvC%7Ctkp%3ABFBM3vbg54Fg)
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I've been in contact with Jakub Honkisz, the founder of Staccato, which is based in eastern Poland. I've ordered one of their discrete op amps for evaluation. If all goes well I will probably order a batch for resale.
I wish I had better news but the first problem is there's insufficient room for the Staccato to fit without some type of socket extender. The other bit of bad news is I managed to fry the regulator in the process of trying to fit it in and then cobble together an adapter. The Staccato may ultimately prove to be excellent for this application but it will require a redesign of the SSPB.V2 board to accommodate...something that will have to go on the back burner for now.
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An extender like this? https://www.ebay.com/itm/273516806027
Hmm how did that other ldr preamp owner use it if it doesn't fit?
Lol any news from the powder coat guy on colors?
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An extender like this? https://www.ebay.com/itm/273516806027
Hmm how did that other ldr preamp owner use it if it doesn't fit?
Lol any news from the powder coat guy on colors?
Those look to be the actual socket extenders I used yes. None of the discrete OPAMPS I used would fit without it. The Staccato OPAMPS in particular have large cooling heat sinks though never seem to run that warm really so airflow was never an issue.
Morten, I hope everything is still well? I ask as I looked at your site recently and all fully built units are in the archived section including your beautiful LDR3000x V3. If a version were available with 71A DHT tube buffer I'd certainly have pulled the trigger on one by now. I did change to an icOn 4PRO after hearing another Slagleformer unit in my system. A friend brought over a Slageformer kit pre and it was just a touch ahead in terms of soundstage depth though otherwise very comparable hence I sourced the icOn. That said I believe a little extra tubey goodness with LDR attenuation up front such as your LDR3000x V3 provides a very compelling argument ;)
Really though since I had the LDR300x V3, every single component in my system has changed. Streamer, DAC, Pre, power amp, sub, speakers etc. Lots of change in that time frame. The Absolute Audio Labs SIT-A15 power amp is a very special unit. :)
The fully tricked out LDR300x V3 Active remains the best sounding LDR pre I've heard to date and I've a sneaking suspicion the LDR3000x V3 with tube output would actually better the rather excellent icOn 4PRO Unbalanced Slagleformer pre I'm now running. Perhaps more a change in flavor with the addition of the tubes. That the LDR300x V3 competes so closely after tweaks with the icOn for a fraction of the cost is a testament to it's design.
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Hi All,
Before shutting down all development and order fulfillment work prior to moving to Oregon, I managed to squeeze in a prototype of a future updated variation on my LDR300x.V3 Active/Passive Preamp. Even though I stopped building/selling new finished preamps as of a year ago, I haven't stopped working on the underlying tech or possible future limited production runs.
The photo below shows a potential prototype of what may become an LDR300LA.V4 Linear Active Preamp. The preamp shown here uses the current ePot.V3 Max preamp attenuator/controller board with the addition of a new plug-in solid state buffer/gain board that plugs directly into the V3 board socket where the LDR module would normally go. Instead the LDR module gets plugged into the solid state buffer/gain board. Thus the board on the right is actually a 3 tiered V3-buffer-LDR arrangement.
The board on the left is a new split voltage (+12/-12V) linear DC power supply which powers both the new solid state buffer/gain board as well as the V3 attenuator/controller board. The power supply board runs off AC mains and uses a low noise toroidal transformer. It's a 2 stage design with an unregulated stage followed by a regulated stage. After rectification it uses linear regulators together with high quality polypropylene as well as Elna silk caps bypass caps for high quality low noise split voltage power. The solid state buffer/gain board is direct coupled - no audio coupling caps in either the input or output audio signal path. It has trimmer pots for dialing in near zero DC offset.
The unit shown below actually belongs to a customer who was willing to to allow his existing LDR300x.V3 to be modified.
I confess I'm rightly impressed with sound quality from this LD300LA prototype. The sound is full and dynamic while retaining the inherent sweetness of LDR attenuation and without adding any noticeable coloration. The gain stage uses plug-in gain resistor modules - this one is set up with +6 dB gain. It can handle up to +12 dB gain but note that pumping up the gain if you don't need it only introduces more noise with no additional benefits. I found myself running this at around step 60 out of 100 whereas in unity passive mode I would normally listen to an LDR300x at around step 70-75.
I'm hoping to pick up work on this once I'm up and running in Oregon later this year. I've gone through several iterations on the new ePot.V4 as well and want to get that finished and released first and then integrate the V4 into the final configuration of this LDR300LA. Probably won't have that all ready by year's end but it's a goal of mine to give it a go.
Cheers,
Morten
(https://tortugaaudio.com/images/LDR300LA.V3_July2023_prototype.jpg)
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Hi Morten. Looks cool. PM from me.
Randy
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I am in the same boat - miss my Tortuga preamp that I foolishly sold - if you ever get to producing a small run of these I will be in line. Will keep watching here into fall and winter hoping this is the case.
David in Victoria
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Oh Man, I an excited about this.
Not only am I excited for you on this move but also for the updated preamp. I am glad you are still devloping V.4.
I am excited that you are moving to Oregon(ORYGUN LOL) because I live in Dallas near Salem. I may want to come see you after you get setteled in.
Anyway this is all very cool and exciting,
Wayne in Oregon
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"I haven't stopped working on the underlying tech or possible future limited production runs. "
ooh, very exciting
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"I haven't stopped working on the underlying tech or possible future limited production runs. "
ooh, very exciting
Agreed, and welcome to the Pacific NW, where extreme temperatures are rare.... and hurricanes are non-existant