My impressions of the Tortuga LDR3.V2

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TJHUB

My impressions of the Tortuga LDR3.V2
« on: 7 Feb 2015, 07:43 pm »
I'm not very good at this sort of thing, so please be understanding.

My system can be seen in detail under "Systems."  I updated it this morning, so everything is current including "System Pics 2015" in my gallery.

First a little history of my setup.  I used to run a Rogue Audio Perseus tube preamp in a dual duty 2-channel / HT setup.  The Perseus had HT-bypass, and sounded fantastic.  I had it since 2009, and never thought I'd part with it.  Then I moved into a different home last July.  I separated my 2-channel and HT systems into 2 separate rooms.  My wife came up with the idea of using the normal living room as a dedicated 2-channel room.  Who am I to complain?  So the living room is a dedicated 2-channel room, but I also hung a 50" plasma on the wall with a sound bar for occasional TV watching.  As a note, all the 2-channel gear is on dedicated power circuits.

Since I now had no need for a preamp with HT-bypass or multiple inputs, I decided to seek out a simpler single input preamp basically to function as a remote volume control.  This lead me to Tortuga Audio, and got me investigating passive preamps.  That's when I started to get nervous about many negative opinions of passives in general posted on various forums.

That's when I decided to try and run my setup without the Rogue.  To make this happen, I planned to use the digital volume control on my PC based music server (at the time J.River, but I switched to Foobar2000 with much better overall results).  This didn't work well at all because I would need to have the digital volume control at about 20% (or down 80%) resulting in rather poor sound quality.  That's when a really great guy I know, Big Red Machine, sent me his pair of Endler stepped attenuators to test. 

The stepped attenuators worked great.  Setting them where the digital volume control could be set at 100% for my preferred listening volume proved pretty incredible.  I had the best clarity I had ever heard from my system.  I was really happy with the tone, clarity, imaging, everything.  But it didn't take long to miss having a remote controlled preamp.  There is such a huge volume level difference in much of my library that I found there was no perfect setting for the stepped attenuators.  I always had either too much digital volume control or not enough volume.  I also really missed having a mute button for when the phone rang or my wife was yelling to me from another room.  All too often, I didn't get to the digital volume control or pause button fast enough.

I ordered the LDR3.V2 right after Thanksgiving.  This gave me plenty of time to tweak my system without using a preamp, and I did a fantastic job.  I was experiencing the best sound I've ever had from my setup.  I often wondered if it was worth $1,000.00 (pre-order pricing) for what would basically be a remote volume control.  I really didn't think so. 

Right before the LDR3.V2 showed up, I had the best transparency I'd ever heard.  I was convinced inserting a passive preamp would only slightly get in the way of what I had achieved.  After all, I have found that even the smallest pieces of wire could negatively affect the sound.  So I was pretty concerned to say the least.  Another thing that really had me concerned was that another really great guy I know loaned me a transformer based passive preamp, and I hated it.  The bigges and most unforgivable issue was that it sucked all of the life out of the music at any volume below almost too loud.  It was VERY disappointing.  But it also compressed the sound enough to make me just hate it.  I wasn't feeling too good about passives, and I was very concerned about my purchase.  Then I saw a thread here on AC in the Daedalus Audio forum where they were considering introducing their own passive preamp.  I only mention this because one poster commented about LDR based passives sounding the best while transformer based sucked the life out of the music unless at a high volume (paraphrasing here).  It was nice having someone else confirm my findings.

So yestereday, my Tortuga LDR3.V2 shows up.  I'm the typical 46 year old kid at Christmas.  I unbox the thing, connect it all up, and grab the remote.  I go to power it up, and nothing.  So this is when I realize that this is not a normal preamp that I'm used to.  Since nothing in the form of instructions are in the box, I go to the Torguga website for help.  I do think a manual, or even a simple startup guide, should be in the box, but the Tortuga website is very detailed in everything you need to know.  As a matter of fact, every question Morten answered in my many emails was found in detail on the website.  Anyone getting, or considering, a Tortuga preamp should read through the website first.  Having found my issue on the website, I paired the little Apple remote to the preamp.  I set the input to "1", and fired up my playlist of critical listen tracks.  That's when I was blown away.

Please understand that I am obsessed with my audio system.  I have invested 100's of hours into speaker placement, acoustic treatments, cables, and computer settings just since moving.  I have experimented with so many things to find the best combination to acheive the sound I desire.  Even though I know I will find further improvements, I'm very confident that I have something very special.  I have never heard a system anywhere that I've liked better.  My tone seems almost perfect, the bass from the 10" drivers in my Salk speakers is impressively articulate and forceful.  The midrange is smooth, clean, and analog sounding.  The treble ever so slightly left me wanting for more energy, but not from all tracks.  The imaging and sound stage is precise and gives a great sense of dimension.  I worked really hard for all of this.

So what did the LDR3.V2 do for the sound?  To my surprise, a sense of even more transparency.  There are details in the midrange and treble that are just more obvious now. The treble seems more extended, but there was absolutely no change in tone.  I don't know why this is possible.  I can't perceive a lower noise floor.  Vocals are even more realistic, and everything has increased texture and is more palpable.  But the best thing of all is the increased speed of transients.  Everything has an immediacy to it.  This even translates to the bass.  Kick drums have speed and an authority that is impressive.  There is a tremendous amount of quick energy there that just wows me on many tracks.  The music has real life and intensity.  It blows me away.  Easily the best I've heard.  And I don't perceive any loss of dynamics and any volume. 

It took less than a hour to familiarize myself with the rest of preamp's functions and settings.  It was slightly intimidating at first, but it works rather intuitively.  I didn't think I'd like the little Apple remote, but it's functional.  The overall function of the preamp is very good and draws only one complaint from me.  I really wish the volume control repeated as you increase/decease the volume instead of requiring a button push for each volume step.  In practical usage, this hasn't been a real issue, but I'd still prefer a repeating volume control. 

Overall, I couldn't be happier with the purchase.  I was worried I'd want to return it, leaving me to find a different solution, but you would have to pry this thing out my cold, dead hands before I'd give it up.  This is an amazing piece of audio gear.  I also realize that there are limits to passive preamp's, and I'm likely lucky to have the perfect mix of components to make it work so well.  A major component is the incredible flexibility of my music server with all of its various settings. 

Thanks for an incredible product Morten!   :thumb:

A pic of the LDR3.V2 in its new home:












33na3rd

Re: My impressions of the Tortuga LDR3.V2
« Reply #1 on: 7 Feb 2015, 08:34 pm »
Nice write up!

I've been curious how the Tortuga would mate with the Odyssey amps.
Now I have some idea, thank you!

rajacat

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Re: My impressions of the Tortuga LDR3.V2
« Reply #2 on: 7 Feb 2015, 08:50 pm »
deleted

robertopisa

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Re: My impressions of the Tortuga LDR3.V2
« Reply #3 on: 7 Feb 2015, 10:18 pm »
Thanks TJHUB, can you please comment also on the digital source? Where did you buy it?

Digital Source
Custom PC (S1200KPR/XEON CPU), Windows Server 2012 R2 (in core mode), AudiophileOptimizer, Foobar2000, and MonkeMote HD (on iPad). Single PC JPLAY in hibernation mode. Powered by a wide-input picoPSU/19V SMPS with LPS on PPA USB card and OS SSD

What are the two boxes to the sides of the PC?

http://www.audiocircle.com/index.php?action=gallery;area=browse;image=114491

TJHUB

Re: My impressions of the Tortuga LDR3.V2
« Reply #4 on: 7 Feb 2015, 10:46 pm »
Thanks TJHUB, can you please comment also on the digital source? Where did you buy it?

Digital Source
Custom PC (S1200KPR/XEON CPU), Windows Server 2012 R2 (in core mode), AudiophileOptimizer, Foobar2000, and MonkeMote HD (on iPad). Single PC JPLAY in hibernation mode. Powered by a wide-input picoPSU/19V SMPS with LPS on PPA USB card and OS SSD

What are the two boxes to the sides of the PC?

http://www.audiocircle.com/index.php?action=gallery;area=browse;image=114491

It's a custom build I did based upon early design ideas from JPLAY and High-End Audio PC.  I've been tweaking on it for the last year, testing linear power supplies and batteries.  There are actually 2 modified TeraDak linear power supplies and a 2TB USB buss powered drive for music storage.  The left linear PS powers the Paul Pang USB output card, and the right linear PS powers the operating system SSD.  The USB drive is used so that the PC operates in JPLAY's hibernation mode.   

I'm not sure what else I can say about it.  The story is long, and complicated. 

robertopisa

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Re: My impressions of the Tortuga LDR3.V2
« Reply #5 on: 7 Feb 2015, 11:16 pm »
Where did you buy the PC? I like the enclosure. (I am a computer scientist.)
Thanks
-R

It's a custom build I did based upon early design ideas from JPLAY and High-End Audio PC.  I've been tweaking on it for the last year, testing linear power supplies and batteries.  There are actually 2 modified TeraDak linear power supplies and a 2TB USB buss powered drive for music storage.  The left linear PS powers the Paul Pang USB output card, and the right linear PS powers the operating system SSD.  The USB drive is used so that the PC operates in JPLAY's hibernation mode.   

I'm not sure what else I can say about it.  The story is long, and complicated.

TJHUB

Re: My impressions of the Tortuga LDR3.V2
« Reply #6 on: 7 Feb 2015, 11:37 pm »
Where did you buy the PC? I like the enclosure. (I am a computer scientist.)
Thanks
-R

Quiet PC if I remember right. 

germay0653

Re: My impressions of the Tortuga LDR3.V2
« Reply #7 on: 27 Feb 2015, 01:54 pm »
Looks like a Streacom (www.streacom.com), correct?  HD-PLEX makes similar cases (www.hd-plex.com)

robertopisa

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Re: My impressions of the Tortuga LDR3.V2
« Reply #8 on: 27 Feb 2015, 04:04 pm »
Yes, it is. Probably with the nanoPSU. Hope he changed the switching AC/DC converter associated with the nanoPSU. I am following the same path :)

Looks like a Streacom (www.streacom.com), correct?  HD-PLEX makes similar cases (www.hd-plex.com)

TJHUB

Re: My impressions of the Tortuga LDR3.V2
« Reply #9 on: 28 Feb 2015, 12:35 am »
This thread is getting a little off topic...

I wanted to update my impressions of my LDR3.V2 after 3 weeks of ownership.  I can't say it wasn't a rocky road at times, but overall still great.  The rocky road came from trying various power supplies.  These included the original SMPS, a cheap linear, a better linear, an even better linear, and the replacement (linear? regulated?) whatever it is from Tortuga (thanks Morten!).  All I will say is power supplies did make a difference for me; some was good, some was different, some was bad.  I got myself lost in the woods with them, and had to start all over.   The good news is the replacement  from Tortuga is my favorite.

What made me think about updating this thread is that like any new audio component that gives you better sound, it quickly becomes "normal", and loses its new greatness.  That happened to me, and it wasn't until I listened without it, and went back to it that I was reminded of how great this little box really is.  But then something great happened. 

Last week Friday, I received a beta copy of the new JPLAY 6.  I can't tell you how excited I was to find out they had gone Open Home with the new version.  What's so great about that?  No need for JRiver or Foobar2000 on my source PC!  But the real magic became apparent upon first listen, and now has turned out to be nothing short of revolutionary for my setup.

JPLAY 6 (find out more at their forum), and JPLAYStreamer have brought an entire new level of transparency, imaging, and depth to my sound.  It's really remarkable, and as I tweak on all of the adjustments of my PC, I'm finding new levels of amazing sound improvements.  What's so great is that the Tortuga preamp seems to be passing through all the magic.  I mean every little detail.  The dynamics can be scary on some tracks, the energy coming off the 10" drivers in my Salk's is just damn fun.  There's something just awesome when the bass is super tight, defined, transparent, and visceral.  The midrange and treble clarity is the best I've had.  Vocals are extremely realistic, and the imaging is just pinpoint.  I guess what I'm trying to say here is that the Tortuga seems to be keeping pace with my source improvements in every way.  Just awesome...

jtwrace

Re: My impressions of the Tortuga LDR3.V2
« Reply #10 on: 28 Feb 2015, 12:44 am »
Cool.   :thumb:   So what's different about the new PS compared to the others?  Also, I thought I remember Morten saying that the PS didn't matter since it wasn't in the circuit per se. 

TJHUB

Re: My impressions of the Tortuga LDR3.V2
« Reply #11 on: 28 Feb 2015, 12:51 am »
Cool.   :thumb:   So what's different about the new PS compared to the others?  Also, I thought I remember Morten saying that the PS didn't matter since it wasn't in the circuit per se.

I heard a loss of clarity with one, and another tightened up the timbre so much, my bass became anemic.  A cheap, adjustable linear I have, and the replacement from Tortuga seem to have no sonic effect, so they are my favorites.  The replacement from Tortuga is smaller, so it got to keep the job powering the preamp.

ThuanDB

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Re: My impressions of the Tortuga LDR3.V2
« Reply #12 on: 28 Jun 2015, 04:57 pm »
Hello from the JPLAY club.  Thanks for sharing your impressions.  My LDR will hopefully be shipped out soon.  I can't wait to listen to JPLAY 6.1 with the LDR in the audio path.

tortugaranger

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Re: My impressions of the Tortuga LDR3.V2
« Reply #13 on: 29 Jun 2015, 02:07 pm »
Hello from the JPLAY club.  Thanks for sharing your impressions.  My LDR will hopefully be shipped out soon.  I can't wait to listen to JPLAY 6.1 with the LDR in the audio path.


Welcome. Your unit will ship out later this week.

ThuanDB

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Re: My impressions of the Tortuga LDR3.V2
« Reply #14 on: 29 Jun 2015, 04:38 pm »
Thanks Morten. As for the LDR PSU, in addition to the stock PSU, can I try a 12v rechargeable battery?

tortugaranger

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Re: My impressions of the Tortuga LDR3.V2
« Reply #15 on: 29 Jun 2015, 05:51 pm »
Thanks Morten. As for the LDR PSU, in addition to the stock PSU, can I try a 12v rechargeable battery?

No problem running the unit on a 12 V battery. The power jack is 5.5 mm outer barrel with a 2.1 mm center pin. Plugs can be 2.1 or 2.5. A 2.5 plug will fit into the jack but probably make intermittent connection so beware. The most important thing is to make sure the center pin is +positive.

I recently tested a unit using a 10 Ah 12 V sealed lead acid battery. I left it on for 3 days and the voltage had dropped only 0.5 volts so the current draw is low enough to make using a battery very practical.

Based on some testing with that battery, I'm currently of the opinion that running the unit on battery will not result in a discernible improvement. That's my view based on some test results but don't take that as definitive proof that a battery won't help. Our test rig is far from hi-end performance and is more a work horse that can take daily abuse without much downside or risk of failure.

What I've determined so far from testing is that our current use of an on-board 5V dc-dc switch mode regulator may be a limiting factor in reducing the total noise signature within the board followed by the fact that there's a microcontroller on the same supply that's running at 4 MHZ. Between the switching PS and the microcontroller there's roughly +/-10 mV of high frequency hash that does not go away when using a battery or a decent regulated linear 12 V supply.

When I swapped the switching 5 V regulator for a cheap LM7805 linear regulator, running on battery did cut the high frequency hash by roughly 50%. I attribute this reduction to the absence of the switching noise which is up in the 2-300 kHz range as I recall.

All of which begs the question, if the noise that is present is all in the 100's of kHz to several MHZ range, then how can reducing this possibly have any bearing on audio quality? I don't have a definitive answer but reason would suggest is shouldn't matter. Yet, the reason we went with the way more expensive 5 V switching regulator back when is several folks were convinced it improved the sound over the linear regulator and I was too.

One thing I can say for sure is using an LM7805 linear  regulator with an external 12 V battery definitely improved the speed of the auto-calibration process. Since auto-cal is a closed loop instrumentation measurement circuit involving 3 op amps and 2 DACs which are subjected to both 5 V and 12 V power, it shouldn't be surprising that the less noise there is the better it works. That's all positive.

However, during normal operation and control of the LDRs any noise present on the LDR control signal can only be "seen" by the audio signal by being transmitted by light from the LED to the photoresistor within each LDR. LDR's have an inherent reaction time constant of a few milliseconds whereas this noise is a few orders of magnitude higher in frequency and therefore should be effectively filtered out by the LDRs.

We are looking into this a but further and may well decide to return to using a linear 5 V linear regulator as a result but too early to tell on that.

ThuanDB

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Re: My impressions of the Tortuga LDR3.V2
« Reply #16 on: 29 Jun 2015, 07:55 pm »
Hi Morten,

I appreciate your thoughts on this PSU matter.  It's great to know that there are options, and I bet Tortuga will keep pushing the envelope.  I'm excited upon anticipation of the LDR preamp.

P.S.  I sincerely hope the stock PSU is good enough that I won't need to bother trying a battery.  Your tip on the choice between 2.1mm and 2.5mm us spot on.  Thanks again Morten.

Updates:  the unit shipped 7/6 and arrived 7/8 in usps mail locker.  I like the message, "Carrier - Leave at door if no response", it worked well as he put in the locker instead of leaving me only a piece of paper notice.  Very well and professionally packed, 6-dimensional buffered from outer box's walls.  Thank you Morten.
« Last Edit: 8 Jul 2015, 11:04 pm by ThuanDB »

ThuanDB

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Re: My impressions of the Tortuga LDR3.V2
« Reply #17 on: 12 Jul 2015, 02:35 am »
The LDR3.V2 has been in my room for a mere 3-4 day period, but I like it a lot.  I like the flawless Apple remote control (lack of repeating adjustment is fine with me), the 5 user adjustable input impedance presets, and its audio performance.  From now on, the LDR will be my reference tool used to judge other preamps and components in the audio chain.  For instance, my trusty Dodd Audio VGP variable gain preamp proves to be close to the LDR in transparency and tonality.  Both preamps are pleasant to listen to, with similar full body midrange, sweet highs, and sufficient lows.  The LDR is superior, however, in rendering all those ranges in an even lower noise floor canvas, resulting in more organic sound overall, higher volume listening desire, and longer listening session before listening fatigue sets in.  The words "chameleon", "rediscovering familiar music", "walls of enveloping sounds", "vocal solidity", "dynamic", and "true to the source" come to mind.

It's like driving a sport car, rough and bumpy when that's the road condition, but an immense joy and pleasure when the road is at least decent.  Luckily, the various music tracks I have collected are mostly decent sounding.  What values most is, the LDR lets the music get thru without editorializing yet manages to sound amazingly good.  Mission accomplished, Morten.  Congratulations, and thank you.

P.S.  Mine came with JAMECO ReliaPro 12v 500mA stock power supply and Neotech solid silver wiring option.  Hopefully, the already high SQ will improve further with the later break-in.

The LDR came with a 5-page document explaining its operations, plus a Tortuga business card in case the user needs to contact.  I find the package complete and professional.  Moreover, Morten responds to my emails inquiring about his product promptly and helpfully.  Highly recommended, both on an excellent product and customer service.
« Last Edit: 15 Jul 2015, 03:02 am by ThuanDB »