LDR3000T.V25 Tube Preamp

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tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #20 on: 23 Jul 2019, 09:33 pm »
Just a brief update on LDR3000T development as we roll towards our Sept 15th release. Very busy the past week+. Here are the highlights.

1) Completed the CNC machining code and jigs for modifying our standard extruded aluminum enclosures into double-wide boxes.
2) Cut our first rear panel for fit-up
3) Completed mock-up and fit-up of rear panel input/output interface board
4) Confirmed alignment of both the V25 controller boards and the new tube buffer board within the casework and with the input/output interface board
5) Finalized layout of the new tube buffer board and ordered prototype PCBs
6) Finalized layout of input/output interface board and ordered prototype PCBs
7) Updated bill of materials
8) Completed CAD work on front panel - ready to order 1st set of blanks

As you can tell from the above we are now deep into finalizing and fine-tuning the enclosure layout and component fit-up. For once we didn't run into any egregious obstacles all last week and kept the swearing to a minimum. In about 2 weeks or I think we'll have our first fully assembled LDR3000T  that we can live test as an assembly and not just as stand alone components on a test bench. Won't have pretty finished boxes and panels until later in August but that's typical. Probably order 1st set of panels by the end of this week. They won't be anodized yet though. Still have prep and machining to do before that. Busy busy! 

Cheers,
Morten :thumb:

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #21 on: 6 Aug 2019, 01:41 pm »
Hi All,

Just a reminder that the LDR3000T Tube Preamp is currently available for pre-order at a substantial 30% discount off. That level of discount expires at the end of August 15th a week from now. After that the discount drops to 20% until its planned release date of Sept 16.

We are making great progress on finishing up development work. This model will be are most sophisticated engineered design to date. Which means we are putting way more time and effort into the finer  points of the design and ease of assembly which should make for smoother production.

This is going to be a fabulous preamp!

More info including pre-order here:  https://www.tortugaaudio.com/product-category/active-preamps/

kernelbob

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Re: LDR3000T.V25 Tube Preamp
« Reply #22 on: 9 Aug 2019, 06:24 pm »
Hi all.

Before you place an order for your Tortuga LDR300T, I urge you to consider discussing with Morton the option of absolute polarity/phase inversion on your unit.  I've been using a Tortuga LDRxB balanced controller for years now which includes that option.

When you have the capability of switching the setting from the listening position, the difference is easily identifiable.  Since there is no consistency between various labels or recordings, the correct setting needs to be selected by ear.  Fortunately, it only takes a second or two to check which polarity/phase setting is correct.  The correct setting will, on well recorded & well mastered sources, have deeper, better articulated bass.  The midrange will be better integrated.  Soundstaging will be more focused with clearer placement of instruments.  At the incorrect setting (for that recording) the upper midrange will sound a bit too forward or pronounced and the bass will be leaner & more rounded.  These differences are consistent across recordings, though the correct setting varies depending on polarity/phase of the recording itself-- and they do vary.

Once you get used to having this capability, you won't want to be without it.  You'll often be able to determine if a recording's polarity/phase setting needs to be reversed without even having to test the other setting.  Sort of the equivalent of having absolute pitch-- absolute absolute phase detection. 

The "Phase" status is indicated on the LDR display panel and can be selected using the remote.  No special software version is needed.  Note that this feature only is only available for Tortuga units supporting balanced inputs.

Happy listening,
Robert

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #23 on: 9 Aug 2019, 06:43 pm »
Hi all.

Before you place an order for your Tortuga LDR300T, I urge you to consider discussing with Morton the option of absolute polarity/phase inversion on your unit.  I've been using a Tortuga LDRxB balanced controller for years now which includes that option.

When you have the capability of switching the setting from the listening position, the difference is easily identifiable.  Since there is no consistency between various labels or recordings, the correct setting needs to be selected by ear.  Fortunately, it only takes a second or two to check which polarity/phase setting is correct.  The correct setting will, on well recorded & well mastered sources, have deeper, better articulated bass.  The midrange will be better integrated.  Soundstaging will be more focused with clearer placement of instruments.  At the incorrect setting (for that recording) the upper midrange will sound a bit too forward or pronounced and the bass will be leaner & more rounded.  These differences are consistent across recordings, though the correct setting varies depending on polarity/phase of the recording itself-- and they do vary.

Once you get used to having this capability, you won't want to be without it.  You'll often be able to determine if a recording's polarity/phase setting needs to be reversed without even having to test the other setting.  Sort of the equivalent of having absolute pitch-- absolute absolute phase detection. 

The "Phase" status is indicated on the LDR display panel and can be selected using the remote.  No special software version is needed.  Note that this feature only is only available for Tortuga units supporting balanced inputs.

Happy listening,
Robert

I would add the following clarifications to Robert's note:

1) Phase reversal does not come enabled on stock units. We have to do some special wiring to enable this.

2) In order to enable the phase reversal feature on any of the 3 balanced inputs we have to "steal" one of the 3 unbalanced/RCA inputs. Hence if you wished to have phase reversal on XLR input #1, we would have to steal RCA input #4 (leaving 5 and 6 available).

Cheers,
Morten  :thumb:

Goosepond

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Re: LDR3000T.V25 Tube Preamp
« Reply #24 on: 9 Aug 2019, 06:49 pm »
Hi Morten,

Is this upgrade an added cost?

Thanks,

Gene

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #25 on: 9 Aug 2019, 07:11 pm »
Here's our first published pic of the internals of the LDR3000T. Sausage making at its finest.

Here we are doing some early live music listening tests with all the hardware bits plugged together. The LDR attenuator boards are near the top and the upside down tube buffer board is on the bottom. The toroidal power transformer is under the buffer board so it isn't visible. The display assembly is out of the frame to the right. Without a doubt this is one fine sounding preamplifier. We didn't get much work done the rest of the afternoon because we just kept playing music. My tech Andy said he got goosebumps! 

At this point everything is done by way of development work with the exception of confirming the final cathode resistor values for 0 dB and +6 dB gain. The cathode resistors are going to be plug-in so you can flip them around to go from 0 dB to +6 dB. By having them plug-in it will also be simple to make up resistor modules with other values for different tubes/gains.

Also, please note that the main components are all plug-in modular. So if we come up with a better LDR preamp controller/attenuator, it's replaceable. Same for the tube/buffer board. Same for the display module. Cool beans.

Production circuit boards and enclosure front/rear panels are all on order. If we're not careful we might actually be ready to build and ship starting on the planned Sept 16th release date.  :o


tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #26 on: 9 Aug 2019, 07:30 pm »
Hi Morten,

Is this upgrade an added cost?

Thanks,

Gene

By upgrade I'm assuming you mean the phase reversal feature that KernelBob mentioned recently.  At this point we do NOT plan to charge additional for this feature. The firmware work has already been done including the control interface. It does require some additional wiring during the assembly process but I'm not sure it's enough additional work to warrant a charge so we'll see how that goes. One remaining quandry is what to do about the RCA jack/input that gets stolen per each XLR input that has phase reversal. We'll probably just leave the jack installed but not connected. Ultimately that will allow for the phase reversal feature to be removed if so desired and the RCA input functionality to be restored.

Goosepond

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Re: LDR3000T.V25 Tube Preamp
« Reply #27 on: 9 Aug 2019, 09:13 pm »
Yes, the phase reversal feature implementation is what I was asking about.

Thanks,

Gene

kernelbob

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Re: LDR3000T.V25 Tube Preamp
« Reply #28 on: 16 Aug 2019, 09:47 pm »
Hi all,

If and when you get your Tortuga LDR3000T with the polarity/phase inversion option (or in the LDRxB for that matter), it will take a several weeks for it to reach its performance plateau as is common for any high-end unit.  As the components and wiring settle in, the sound will improve in various ways.  A key area is in low (and really low) bass frequencies.

In a concert hall, much of the sound that the ear/brain uses for spatial cues is in the lower frequencies.  That deep bass is one area where the difference in the absolute polarity/phase selection is significant.  Same for that upper midrange balance that I mentioned in my previous post.

So, out of the box, if you don't notice a clear difference when switching between absolute polarity/phase settings, be patient.  Do exercise both the "normal" and "inverted" settings, since you'll need to exercise both signal paths.

Regards,
Robert

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #29 on: 20 Aug 2019, 06:57 pm »
Hi All,

August is ripping right along and Sept 16 will be here sooner than we think. The good news is we now have production circuit boards for everything and have started putting together sub-assemblies. The front and rear panels have been cut and are being shipped out to us today....here by the end of the week. That gives us roughly a week to custom machine the font panel blanks (which we do here ourselves) and to prep the rear panels before sending them out to get anodized. So at this point the front/rear panels remain the critical path but we expect to have them ready on time. Various parts are arriving daily and probably the only parts yet to order are the VCAP coupling capacitors which can be here within 2-3 days of placing an order.

As a reminder, the LDR3000T is officially our first integrated active LDR preamp that includes balanced LDR attenuation, a hybrid tube input/gain stage and a JFET output stage. It's core design is based around our proven 4th generation LDR.V25 preamp controller/attenuator and our second generation TPB.V2 tube preamp buffer which when combined in a tightly integrated package sound nothing short of fantastic.

The LDR3000T is now available for pre-order. Pre-order means you purchase and pay for it now but it doesn't ship until starting after September 16th. Orders will ship in the sequence they came in. We'll be ramping up production as we go along so we won't be shipping every unit ordered on day one. The 20% pre-order discount continues to run from now up until the scheduled Sept 16th release date.

More info on the LDR3000T can be found here:  https://www.tortugaaudio.com/products/active-preamps/ldr3000t-v25-tube-preamp/

Our biggest problem at the moment is we're not getting much work done because we're listening to a bench test unit playing various classic rock tunes and it's giving us goosebumps (yes, goosebumps!!). And that's  through a crappy DAC, a crappy amp and cheap-ass speakers (we brutalize our bench audio gear so no high-end gear to be found for development/testing). And STILL it sounds awesome!!

In other news the US is reportedly having a heat wave in the 90's and everyone is complaining. To which we Floridians with our daily 90+ weather every single day for almost 6 months think....say what?

Stay cool bredren!  :thumb:
Morten
« Last Edit: 20 Aug 2019, 11:46 pm by tortugaranger »

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #30 on: 28 Aug 2019, 02:25 pm »
Hi All,

We now have literally 20 days left until the release of the LDR3000T.V25 Tube Preamp and at this point I see no reason why we can't hit the Sept 16th release date and start shipping that week.

The critical path is getting the front/rear panels prepped and anodized. We now have our first batch of raw panels in house and all the rear panels have already  been prepped and are ready for anodizing. The front panels still need to be machined which we started yesterday.

One detail that we're still working through is which encoder make/model we're going to use. In addition to the model we've been using we've been evaluating 3 others. The 4th encoder model arrives tomorrow at which time we'll make a final decision. They all work the same electronically but it comes down to which one "feels right" and has the most robust build. Details details details. Depending on final choice we may have to tweak the front panel CNC machining so it's time to make a decision.

Once the front panels have been machined it takes roughly a 7 day turn around for anodizing. Once we have the anodized panels we'll be start final assembly. Meanwhile sub-assemblies are being made and last minute parts are being ordered and are arriving daily.

Also, as soon as we have our first fully assembled production build we'll be be sticking it in our light box and taking photos and posting them. I know you're interested in seeing the real thing as are we.

Someone recently got up in my grill because at least one of the electronic components we use was made in China. Yet we claim our equipment is made in the USA. Gotcha! Nonsense I say. It's literally impossible in today's world to source 100% of electronics from US manufacturers. That world no longer exists. What is possible is to source most, if not all, of your supplies from domestic suppliers,  do all of your own coding, do much of your own machining, and do essentially all of your own assembly and shipping. That is what we do. We're about as made in the USA as you can get these days.

More info on the LDR3000T can be found here:  [url]https://www.tortugaaudio.com/products/active-preamps/ldr3000t-v25-tube-preamp/[url]

Just a reminder that the 20% pre-order discount runs through Sept 15th. Get your order in early!!

Cheers,
Morten


jeffrt

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Re: LDR3000T.V25 Tube Preamp
« Reply #31 on: 2 Sep 2019, 02:03 pm »
I see there's a choice between 6H30Pi tubes and 6922s. From what I know/read/have learned, they're not a direct substitution one for the other. So a unit designed to work on 6H30s may or may not work with 6922 tubes.

If I order a unit with 6H30Pi tubes, will I be able to SAFELY substitute 6922/6DJ8/7308/CCA tunes for the 6H30pi tubes?

Thanks.

I.Greyhound Fan

Re: LDR3000T.V25 Tube Preamp
« Reply #32 on: 2 Sep 2019, 09:03 pm »
I see there's a choice between 6H30Pi tubes and 6922s. From what I know/read/have learned, they're not a direct substitution one for the other. So a unit designed to work on 6H30s may or may not work with 6922 tubes.

If I order a unit with 6H30Pi tubes, will I be able to SAFELY substitute 6922/6DJ8/7308/CCA tunes for the 6H30pi tubes?

Thanks.

Go with the 6922 tubes.  There is no tube rolling with the 6h30's  unless you want to pay hundreds for the rare NOS 6h30's.  My BAT preamp uses 8 of them.  They are not a warm and fuzzy tube.  They are very neutral but they are very durable.

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #33 on: 2 Sep 2019, 09:16 pm »
I see there's a choice between 6H30Pi tubes and 6922s. From what I know/read/have learned, they're not a direct substitution one for the other. So a unit designed to work on 6H30s may or may not work with 6922 tubes.

If I order a unit with 6H30Pi tubes, will I be able to SAFELY substitute 6922/6DJ8/7308/CCA tunes for the 6H30pi tubes?

Thanks.

The LDR3000T is designed around the 6H30 which due to its relative high heater current requirement makes it possible to also use most any of the 6922 et al family of tubes which have much lower current requirements.

Said differently, the tube you choose when buying a LDR3000T does not alter the preamp design or model type.


The 6H30 is a very neutral tube whereas the 6922s et al tend to be warmer depending on specific model and brand. You have a huge selection of 6922 family brands including NOS but as was already pointed out by Greyhound Fan with 6H30 your choices are 2 current brands plus a very expensive NOS Russian military version.



I.Greyhound Fan

Re: LDR3000T.V25 Tube Preamp
« Reply #34 on: 2 Sep 2019, 10:32 pm »
The 2 current brands of 6H30's are made in the same factory and are the same tube except one has gold pins.  They are supposed to  sound the same.  I use the gold pins.

Lots of choices for the 6922 and its variants.  I own a piece of gear that uses them and some are spectacular and others not so much.
It allows you to tailor the sound to your liking. Especially the NOS tubes.

jeffrt

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Re: LDR3000T.V25 Tube Preamp
« Reply #35 on: 3 Sep 2019, 02:23 pm »
The LDR3000T is designed around the 6H30 which due to its relative high heater current requirement makes it possible to also use most any of the 6922 et al family of tubes which have much lower current requirements.

Said differently, the tube you choose when buying a LDR3000T does not alter the preamp design or model type.


The 6H30 is a very neutral tube whereas the 6922s et al tend to be warmer depending on specific model and brand. You have a huge selection of 6922 family brands including NOS but as was already pointed out by Greyhound Fan with 6H30 your choices are 2 current brands plus a very expensive NOS Russian military version.
I understand the choices for 6H30s and 6922s. I understand the sonic differences.

What  I need to know is if I order the preamp with 6H30, will it then be safe to use 6922s in this preamp?

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #36 on: 3 Sep 2019, 03:00 pm »
What  I need to know is if I order the preamp with 6H30, will it then be safe to use 6922s in this preamp?

YES!

By virtue of the fact that the 6H30 sets the bar quite high on the power supply current capacity, the entire 6922 family of tubes can be substituted safely because they draw far less current and are otherwise pin compatible.

jeffrt

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Re: LDR3000T.V25 Tube Preamp
« Reply #37 on: 3 Sep 2019, 07:18 pm »
YES!

By virtue of the fact that the 6H30 sets the bar quite high on the power supply current capacity, the entire 6922 family of tubes can be substituted safely because they draw far less current and are otherwise pin compatible.

Thank you very much.

SonnyB

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Re: LDR3000T.V25 Tube Preamp
« Reply #38 on: 3 Sep 2019, 08:38 pm »
Apologies in advance for three really dull questions but:

1. Are you still on schedule to start shipping on the 16th (now less than a fortnight).

2. Assuming you start shipping then, by very roughly when would you expect to ship, say, all the units you’ve sold up to now?

3. Are you able to say how tall the unit will be, great including tubes?

Cheers.

tortugaranger

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Re: LDR3000T.V25 Tube Preamp
« Reply #39 on: 4 Sep 2019, 01:50 pm »
Apologies in advance for three really dull questions but:

1. Are you still on schedule to start shipping on the 16th (now less than a fortnight).

2. Assuming you start shipping then, by very roughly when would you expect to ship, say, all the units you’ve sold up to now?

3. Are you able to say how tall the unit will be, great including tubes?

Cheers.

Start of Shipping:  As things stand now we actually expect to begin shipping LDR3000Ts the week of Sept 16. It's going to be tight but we believe we'll be ready. Even if we slip a week or so that would be an all time record breaking accomplishment for us.

Time To Ship All Pre-Orders to date:  Probably will take a couple of weeks to build, commission and ship the whole bunch but that's a very soft projection.  We have sufficient parts and subsystems built already to handle the preorders we have so far so not expecting significant delays.

LDR3000T Height:  Feet are 0.5 inch, enclosure is 3 inches (without tubes) and the taller 6H30 tubes project approximately 2.25 inches above the enclosure. Add that all up and figure on 5.75 inches but I'd recommend you plan on 6 inches to give yourself some margin.