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Tortuga Audio Newsletter | September 2013 | Tortuga Audio
Tortuga Audio Newsletter | September 2013 | Tortuga Audio
Revised Pricing/Structure for LDR3x DIY Passive Preamp Board
Now that the LDR3x can be fully controlled via the Apple Remote, we've modified our pricing structure so that you can purchase the LDR3x without the Tortuga Audio custom IR remote and thus save yourself some cash especially if you already have an Apple Remote.
As of 10.6.13, pricing for the LDR3x Master & Slave boards is as follows.
$199 - Unbalanced master board without remote
$249 - Unbalanced master Board with Tortuga Audio Remote
$325 - Balanced master & slave boards without remote
$375 - Balanced master & slave boards with Tortuga Audio Remote
Please note that any LDR3x sold after 10.6.13 will work interchangeably with both the Apple Remote and the Tortuga Audio remote. You don't have to do any special programming or change any settings for either remote to work.
Tortuga Audio does NOT sell the Apple Remote. It's readily available online and at brick-mortar stores like Best Buy or Apple stores and retails for ~$20.
Link To Website/Store: LDR3x DIY Preamp Controller Board | Tortuga Audio
Now that the LDR3x can be fully controlled via the Apple Remote, we've modified our pricing structure so that you can purchase the LDR3x without the Tortuga Audio custom IR remote and thus save yourself some cash especially if you already have an Apple Remote.
As of 10.6.13, pricing for the LDR3x Master & Slave boards is as follows.
$199 - Unbalanced master board without remote
$249 - Unbalanced master Board with Tortuga Audio Remote
$325 - Balanced master & slave boards without remote
$375 - Balanced master & slave boards with Tortuga Audio Remote
Please note that any LDR3x sold after 10.6.13 will work interchangeably with both the Apple Remote and the Tortuga Audio remote. You don't have to do any special programming or change any settings for either remote to work.
Tortuga Audio does NOT sell the Apple Remote. It's readily available online and at brick-mortar stores like Best Buy or Apple stores and retails for ~$20.
Link To Website/Store: LDR3x DIY Preamp Controller Board | Tortuga Audio
Hello all,
I wanted to give my own comments on LDR technology but especially Tortuga's own LDR3x product.
For the past 20 years I have been involved in Hi-Fi both as a DIY hobby and commercial products. I would say the past 6 years have been 95% DIY and I'm not going back. I have owned many high end gears which have now all been replaced by DIY projects. In that time frame I have had the chance to test or audition some pretty good preamps and also attenuator sur as Goldpoint (Used in my balanced DCB1), DACT, Kozmo, which sounded mostly the same maybe some really minor differences, TVC which I personally dislike since I find they are thin and color the sound (This is per my own taste, I am not making a debate here) and my favorite up to now was my AMB delta 1 R2R Shunt Ladder configured in balanced mode.
Now I'm far from an esoteric person and a lot of times I read about a bunch bull about audio. I have read a lot about LDRs and even one guy from Goldpoint told me he would go with a DACT (his competitor) before buying into this technology, so I waited... Then read about the matching issues at different volume levels and just gave up... Gave up until now and this because Tortuga had found an interesting way to plot an almost perfect logarithmic curve using manual matching of LDRs along with the most important part which is computer assistance in analyzing each steps of each LDRs and create a perfect curve then transfer this data on the LDR3x. This is a per board configuration since no LDRs are the same, so yes it is hard work but hard work that pays off big time!
This was what was missing for me to dive in! So I asked Morten to send one over for testing and to convince me as well... I'm sure he knew I was going to buy one in the end which I gladly did and will probably buy another one in balanced!
On the first piece I played from the Jorane album "Dix" I was confused but in a good way, I was having a hard time explaining in words what I was hearing, it just felt so clean, natural and timbres to die for, to take what someone else had already said which I thought was yet another propaganda, "Let me state up front that the LDR1 is the most pure, neutral, transparent, noise-free and grain-free component I have ever heard." and he was totally right on the spot. I would also add to this a fluidity in complex passages I had not heard before, it is as if someone had removed a veil in front of me. My friend and I were both totally impressed and trust me, I have tried many gears before.
So Morten and all the Tortuga Audio Team, I have only praises to give you. Keep up the good work, these are amazing products!
Do
I wanted to give my own comments on LDR technology but especially Tortuga's own LDR3x product.
For the past 20 years I have been involved in Hi-Fi both as a DIY hobby and commercial products. I would say the past 6 years have been 95% DIY and I'm not going back. I have owned many high end gears which have now all been replaced by DIY projects. In that time frame I have had the chance to test or audition some pretty good preamps and also attenuator sur as Goldpoint (Used in my balanced DCB1), DACT, Kozmo, which sounded mostly the same maybe some really minor differences, TVC which I personally dislike since I find they are thin and color the sound (This is per my own taste, I am not making a debate here) and my favorite up to now was my AMB delta 1 R2R Shunt Ladder configured in balanced mode.
Now I'm far from an esoteric person and a lot of times I read about a bunch bull about audio. I have read a lot about LDRs and even one guy from Goldpoint told me he would go with a DACT (his competitor) before buying into this technology, so I waited... Then read about the matching issues at different volume levels and just gave up... Gave up until now and this because Tortuga had found an interesting way to plot an almost perfect logarithmic curve using manual matching of LDRs along with the most important part which is computer assistance in analyzing each steps of each LDRs and create a perfect curve then transfer this data on the LDR3x. This is a per board configuration since no LDRs are the same, so yes it is hard work but hard work that pays off big time!
This was what was missing for me to dive in! So I asked Morten to send one over for testing and to convince me as well... I'm sure he knew I was going to buy one in the end which I gladly did and will probably buy another one in balanced!
On the first piece I played from the Jorane album "Dix" I was confused but in a good way, I was having a hard time explaining in words what I was hearing, it just felt so clean, natural and timbres to die for, to take what someone else had already said which I thought was yet another propaganda, "Let me state up front that the LDR1 is the most pure, neutral, transparent, noise-free and grain-free component I have ever heard." and he was totally right on the spot. I would also add to this a fluidity in complex passages I had not heard before, it is as if someone had removed a veil in front of me. My friend and I were both totally impressed and trust me, I have tried many gears before.
So Morten and all the Tortuga Audio Team, I have only praises to give you. Keep up the good work, these are amazing products!
Do
Audiophilia.com Review of the LDR1 Passive Preamp
Audiophilia.com just published their review of our LDR1 Passive Preamp. I think the review characterizes the essence of the LDR1 (and our LDR family of preamps generally) while avoiding offering much by way of personal opinions or comparisons. Just the facts ma'am.
Tortuga Audio LDR1 Passive Preamplifier ? Audiophilia
Audiophilia.com just published their review of our LDR1 Passive Preamp. I think the review characterizes the essence of the LDR1 (and our LDR family of preamps generally) while avoiding offering much by way of personal opinions or comparisons. Just the facts ma'am.
Tortuga Audio LDR1 Passive Preamplifier ? Audiophilia
Improved Impedance & Performance
Hi All,
Thought I'd share some interesting evolving news regarding our LDR based passive preamp design.
To optimally transfer the audio signal (voltage!) from source to load, contemporary designs take an impedance bridging approach whereby low Z sources (<1k - CD, DAC etc.) are connected ("bridged") to relatively high Z loads (preamp/amp > 15k) rather than trying to actually match the Z's. If this ratio gets too low, the sound can begin to lose dynamics and sound flat.
Historically, implementing an LDR based attenuator by conventional analog means (using a stereo pot to regulate the LDRs) results in a suboptimal impedance (Z) profile wherein the Z can get quite low (<1k) in the middle of normal listening range; quite the opposite of what you want. A considerable body of online discussion regarding the merits of LDR based preamps touches on this subject of "impedance mismatch". To mitigate this, LDR based passive preamp designers (including Tortuga Audio) have recommended a load to source Z ratio of 100:1 or greater. Even so, there are instances where an LDR passive preamp is not a great fit between certain sources and amps. And although Tortuga Audio's LDR preamp design utilizes digital control, to date we have largely emulated the LDR control achieved by a conventional pot. So while our focus to date has been on taming the variable and nonlinear LDRs and perfecting channel matching via software based control (which we have definitely achieved!), the impedance mismatch issue has largely remained unresolved.
That is about to change! Using test data, post testing data manipulation, and a revised software control design, we have now achieved an effectively fixed input impedance of ~20k over 90-95% of the attenuation range with impedance increasing above this level near zero and max volume (in order to achieve a nominal 0-60dB attenuation range).
What this means is while our LDR passive preamps already sounded great and we have a growing base of very satisfied customers, our LDR passive preamps are going to get even better going forward. Raising and fixing the input impedance to roughly the equivalent of a 20k potentiometer will both improve the audio dynamics and open up the application of our LDR passive preamp products to a much wider range of source-amp combinations including both tube and solid state types.
More on this as we work out the final details but we hope to begin shipping units with this upgraded design within the next 30 days or so.
Cheers,
Morten
Hi All,
Thought I'd share some interesting evolving news regarding our LDR based passive preamp design.
To optimally transfer the audio signal (voltage!) from source to load, contemporary designs take an impedance bridging approach whereby low Z sources (<1k - CD, DAC etc.) are connected ("bridged") to relatively high Z loads (preamp/amp > 15k) rather than trying to actually match the Z's. If this ratio gets too low, the sound can begin to lose dynamics and sound flat.
Historically, implementing an LDR based attenuator by conventional analog means (using a stereo pot to regulate the LDRs) results in a suboptimal impedance (Z) profile wherein the Z can get quite low (<1k) in the middle of normal listening range; quite the opposite of what you want. A considerable body of online discussion regarding the merits of LDR based preamps touches on this subject of "impedance mismatch". To mitigate this, LDR based passive preamp designers (including Tortuga Audio) have recommended a load to source Z ratio of 100:1 or greater. Even so, there are instances where an LDR passive preamp is not a great fit between certain sources and amps. And although Tortuga Audio's LDR preamp design utilizes digital control, to date we have largely emulated the LDR control achieved by a conventional pot. So while our focus to date has been on taming the variable and nonlinear LDRs and perfecting channel matching via software based control (which we have definitely achieved!), the impedance mismatch issue has largely remained unresolved.
That is about to change! Using test data, post testing data manipulation, and a revised software control design, we have now achieved an effectively fixed input impedance of ~20k over 90-95% of the attenuation range with impedance increasing above this level near zero and max volume (in order to achieve a nominal 0-60dB attenuation range).
What this means is while our LDR passive preamps already sounded great and we have a growing base of very satisfied customers, our LDR passive preamps are going to get even better going forward. Raising and fixing the input impedance to roughly the equivalent of a 20k potentiometer will both improve the audio dynamics and open up the application of our LDR passive preamp products to a much wider range of source-amp combinations including both tube and solid state types.
More on this as we work out the final details but we hope to begin shipping units with this upgraded design within the next 30 days or so.
Cheers,
Morten
Updated LDRx Impedance Curve
This is what the new impedance curve looks like superimposed with the attenuation curve which hasn't changed. The bathtub shaped impedance is caused by the Z rise as volume approaches zero or max. These rises are need to to achieve the full attenuation range. Most listening is done at the bottom of the bathtub so to speak where the impedance hovers around 20k. This is where the raised impedance floor will have the most positive impact on dynamics.
This is what the new impedance curve looks like superimposed with the attenuation curve which hasn't changed. The bathtub shaped impedance is caused by the Z rise as volume approaches zero or max. These rises are need to to achieve the full attenuation range. Most listening is done at the bottom of the bathtub so to speak where the impedance hovers around 20k. This is where the raised impedance floor will have the most positive impact on dynamics.
More update on the HiZ LDR Preamp Improvements
Here's an updated look into the new HiZ attenuation and input impedance curves after further refinement of the test data processing logic/software. Managed to get rid of the impedance rise near max volume so no more bathtub shape. By the time the unit is in normal listening levels the impedance is leveled out around 20k.
The squiggles in the lines are caused by quantization effects. The design employs an 8 bit voltage divider so the full range of each LDR is captured via testing using 256 samples and we end up not using the bottom first 10. The quantization of the audio taper curve is small enough that you can't hear it. A few tenths of a dB at most. One consequence of this is I had to give up on bending the attenutation curve towards full volume - just ran out of resolution. Could fix that by going with a higher resolution 10 or 12 bit voltage divider on the next hardware iteration but I think that would be overkill.
After doing some extensive listening to this "HiZ" upgrade the overall improvement in fullness, dynamics and overall musicality and involvement is undeniable. And the LDR openess, clarity and resolution are still there in spades just as before - only better! I think this is going to raise the bar on passive preamps and give actives a real run for their money.
I am really pumped about this!!
Here's an updated look into the new HiZ attenuation and input impedance curves after further refinement of the test data processing logic/software. Managed to get rid of the impedance rise near max volume so no more bathtub shape. By the time the unit is in normal listening levels the impedance is leveled out around 20k.
The squiggles in the lines are caused by quantization effects. The design employs an 8 bit voltage divider so the full range of each LDR is captured via testing using 256 samples and we end up not using the bottom first 10. The quantization of the audio taper curve is small enough that you can't hear it. A few tenths of a dB at most. One consequence of this is I had to give up on bending the attenutation curve towards full volume - just ran out of resolution. Could fix that by going with a higher resolution 10 or 12 bit voltage divider on the next hardware iteration but I think that would be overkill.
After doing some extensive listening to this "HiZ" upgrade the overall improvement in fullness, dynamics and overall musicality and involvement is undeniable. And the LDR openess, clarity and resolution are still there in spades just as before - only better! I think this is going to raise the bar on passive preamps and give actives a real run for their money.
I am really pumped about this!!
Improved HiZ (high impedance) LDR preamp control software released
We start shipping LDR passive preamps with the new HiZ (high impedance) software this week.
Here's a link to the announcement we put out over the weekend: New HiZ Control Software Yields Major Improvement To LDR Passive Preamps | Tortuga AudioTortuga Audio
Cheers,
Morten
We start shipping LDR passive preamps with the new HiZ (high impedance) software this week.
Here's a link to the announcement we put out over the weekend: New HiZ Control Software Yields Major Improvement To LDR Passive Preamps | Tortuga AudioTortuga Audio
Cheers,
Morten
My Review of the LDR1
This is part 1 of a review of the Tortuga Audio LDR1 passive volume control, or passive preamp, as some like to call it.
Tortuga Audio | Handcrafted audio gear for music loversTortuga Audio
There was a delay in getting a newly implemented control software chip due to refinements that were required after beta testing. Part 2 will consist of a comparison between the original chip and the new chip. I felt compelled to post my thoughts while they were fresh in, what little is left of, my mind.
My system consists of a Sony BDP S580 BluRay player hooked up via a 15ft length of DH Labs SilverSonic D75 coax BNC/RCA adapter->BNC to a Bryston BDA-1 DAC(Mojo Audio PC). The single ended out then goes to Creek OBH-12 passive pre via a 26" pair of Sweet Spot Reveal "Silver" interconnects then from the Creek to a pair of W4S SX500 mono amps(W4S P-1 PCs) via a 3ft pair of Grover Huffman ICs. A 3ft pair of Anti-Cables go from the amps to Aether Audio Black Boxes, Aether Audio Timepiece Minis and VMPS Super tweeters(facing backwards). The amps are plugged into the wall, and eveything else in plugged into an APC S15 power conditioner and Belkin PureAV PF60.The LDR1 replaces the Creek.
I have not used an active pre in almost 20 years. My system is optimized for use with a passive pre. The Bryston DAC was selected because of its 2.3V, 50ohm, discrete analog output, and reliability. The W4S amps were chosen for their high gain, low noise and distortion, and relatively high, for ICE power type amps, input impedance of 60k ohms. ICs are short and low capacitance. No accommodations were made to substitute the Creek with the Tortuga.
I've been on the hunt for a replacement for the Creek for some time. To be sure, the Creek is an entry level passive but offers 3 input switching and remote so it met my needs. The replacements that I have considered over the years all have some perceived weakness. Mostly they offered no, to me, significant increase in sound quality commensurate with their price. AFAIK, there are only 3 methods of implementing passive pres; resisters, transformers, and light dependent resisters. Each method has its assets and liabilities. It wasn't until the Tortuga came along that I felt there was something that minimized the minuses and maximized the pluses and justified the asking price. I jumped at the opportunity to secure a spot on the audition tour that was offered.
I received the unit on Halloween. Trick or treat? It is housed in a nondescript black case with a window for the infrared remote receiver, blue lettering, a black knurled knob, and an on/off blue LED that some might find too bright. After substituting the LDR1 for the Creek I got no sound. I called Morten to see what could possibly be wrong. He indicated that there was not much that could go wrong. When installing the unit I had double checked that I had made the correct input/output connections, as I have made that mistake in the past. While on the phone it occurred to me that maybe I had forgotten to turn my amps back on. That, indeed, was the case. How embarrassing. I had a nice chat with Morten, indicated all was well, and he could not have been more cordial. I had tricked myself and now for the treat.
It became immediately apparent that the LDR1 was a more transparent component than the Creek. At 3 times the price, one should expect that. What they had in common was the black background, low/no distortion, and wide sound stage. The LDR1 improves on the Creek in a number of different areas.
Leading edge attack transients are more delineated throughout the frequency range. This was most noticeable with all types of percussion. Snare, cymbals, toms, and kick had much more snap and precision.
The mid-bass on down seemed to gain a few extra db of authority. Not lumpy mind you, but a smooth fullness contributing a sense of realism to whatever instrument was in that range. The extra degree of sub 40hz info gave an increased sense of acoustic space.
Low level detail increased to a great degree. Previously obscured detail was laid bare. Each instrument and voice gained, not only an extra dimension in space but, resolution giving a sense of the artists emotional intent.
It seemed like the LDR1 was letting more signal through. I was listening at levels above my usual, 85db-95db, to levels of 100bd+ as everything just sounded so good. Some discs which I had been able to turn up all the way with the Creek, and in theory should be the same as a bypass, were needed to be restrained a bit as not to push the amps, and/or speakers, past their limits.
There was a greater sense of dynamics, compered to the Creek, at all volume levels. Greatly anticipating the new chip to see if this is expanded.
If I were to change anything I would give some sense of the volume going up and down other than just the aural evidence. As it is the blue LED flashes slowly when either the volume is all the way up, or all the way down. There is an enter button on the remote which causes the LED to flash rapidly and I would prefer this sense of feedback when raising and lowering the volume. This is the way the Creek works but this is by no means a deal breaker for me. I would also like a less bright LED, but, again, not a deal breaker.
I listen to a wide variety of music. I pulled out discs that I had not listened to in years and probably listened to more music, since receiving the LDR1, than I had listened to in the past 6 months. I was given a renewed sense of excitement that I had been missing for a long time. I can't think of higher praise. As a casualty of the part-time economy I shall have to find a way to acquire one of these.
Modify message
This is part 1 of a review of the Tortuga Audio LDR1 passive volume control, or passive preamp, as some like to call it.
Tortuga Audio | Handcrafted audio gear for music loversTortuga Audio
There was a delay in getting a newly implemented control software chip due to refinements that were required after beta testing. Part 2 will consist of a comparison between the original chip and the new chip. I felt compelled to post my thoughts while they were fresh in, what little is left of, my mind.
My system consists of a Sony BDP S580 BluRay player hooked up via a 15ft length of DH Labs SilverSonic D75 coax BNC/RCA adapter->BNC to a Bryston BDA-1 DAC(Mojo Audio PC). The single ended out then goes to Creek OBH-12 passive pre via a 26" pair of Sweet Spot Reveal "Silver" interconnects then from the Creek to a pair of W4S SX500 mono amps(W4S P-1 PCs) via a 3ft pair of Grover Huffman ICs. A 3ft pair of Anti-Cables go from the amps to Aether Audio Black Boxes, Aether Audio Timepiece Minis and VMPS Super tweeters(facing backwards). The amps are plugged into the wall, and eveything else in plugged into an APC S15 power conditioner and Belkin PureAV PF60.The LDR1 replaces the Creek.
I have not used an active pre in almost 20 years. My system is optimized for use with a passive pre. The Bryston DAC was selected because of its 2.3V, 50ohm, discrete analog output, and reliability. The W4S amps were chosen for their high gain, low noise and distortion, and relatively high, for ICE power type amps, input impedance of 60k ohms. ICs are short and low capacitance. No accommodations were made to substitute the Creek with the Tortuga.
I've been on the hunt for a replacement for the Creek for some time. To be sure, the Creek is an entry level passive but offers 3 input switching and remote so it met my needs. The replacements that I have considered over the years all have some perceived weakness. Mostly they offered no, to me, significant increase in sound quality commensurate with their price. AFAIK, there are only 3 methods of implementing passive pres; resisters, transformers, and light dependent resisters. Each method has its assets and liabilities. It wasn't until the Tortuga came along that I felt there was something that minimized the minuses and maximized the pluses and justified the asking price. I jumped at the opportunity to secure a spot on the audition tour that was offered.
I received the unit on Halloween. Trick or treat? It is housed in a nondescript black case with a window for the infrared remote receiver, blue lettering, a black knurled knob, and an on/off blue LED that some might find too bright. After substituting the LDR1 for the Creek I got no sound. I called Morten to see what could possibly be wrong. He indicated that there was not much that could go wrong. When installing the unit I had double checked that I had made the correct input/output connections, as I have made that mistake in the past. While on the phone it occurred to me that maybe I had forgotten to turn my amps back on. That, indeed, was the case. How embarrassing. I had a nice chat with Morten, indicated all was well, and he could not have been more cordial. I had tricked myself and now for the treat.
It became immediately apparent that the LDR1 was a more transparent component than the Creek. At 3 times the price, one should expect that. What they had in common was the black background, low/no distortion, and wide sound stage. The LDR1 improves on the Creek in a number of different areas.
Leading edge attack transients are more delineated throughout the frequency range. This was most noticeable with all types of percussion. Snare, cymbals, toms, and kick had much more snap and precision.
The mid-bass on down seemed to gain a few extra db of authority. Not lumpy mind you, but a smooth fullness contributing a sense of realism to whatever instrument was in that range. The extra degree of sub 40hz info gave an increased sense of acoustic space.
Low level detail increased to a great degree. Previously obscured detail was laid bare. Each instrument and voice gained, not only an extra dimension in space but, resolution giving a sense of the artists emotional intent.
It seemed like the LDR1 was letting more signal through. I was listening at levels above my usual, 85db-95db, to levels of 100bd+ as everything just sounded so good. Some discs which I had been able to turn up all the way with the Creek, and in theory should be the same as a bypass, were needed to be restrained a bit as not to push the amps, and/or speakers, past their limits.
There was a greater sense of dynamics, compered to the Creek, at all volume levels. Greatly anticipating the new chip to see if this is expanded.
If I were to change anything I would give some sense of the volume going up and down other than just the aural evidence. As it is the blue LED flashes slowly when either the volume is all the way up, or all the way down. There is an enter button on the remote which causes the LED to flash rapidly and I would prefer this sense of feedback when raising and lowering the volume. This is the way the Creek works but this is by no means a deal breaker for me. I would also like a less bright LED, but, again, not a deal breaker.
I listen to a wide variety of music. I pulled out discs that I had not listened to in years and probably listened to more music, since receiving the LDR1, than I had listened to in the past 6 months. I was given a renewed sense of excitement that I had been missing for a long time. I can't think of higher praise. As a casualty of the part-time economy I shall have to find a way to acquire one of these.
Modify message
Encoder board/assemby
We are now offering an encoder board/assembly for those DIY'ers who want to control their LDR3x preamp controller manually. Our encoder provides effectively all the same functionality as the remote.
Using the encoder board avoids the awkward soldering of multiple wires to the 5 tiny encoder pins.
It's priced at $23 which includes shipping via USPS Priority in the US. There's an additional shipping charge for international orders (best to order at the same time as the LDR3x board to avoid add'l shipping costs).
Over the next 30 days or so we'll also be introducing a 2 digit (8 segment) display module and a 3 input switching board.
Here's a link to the encoder page at the webstore: Encoder Board | Tortuga AudioTortuga Audio
We are now offering an encoder board/assembly for those DIY'ers who want to control their LDR3x preamp controller manually. Our encoder provides effectively all the same functionality as the remote.
Using the encoder board avoids the awkward soldering of multiple wires to the 5 tiny encoder pins.
It's priced at $23 which includes shipping via USPS Priority in the US. There's an additional shipping charge for international orders (best to order at the same time as the LDR3x board to avoid add'l shipping costs).
Over the next 30 days or so we'll also be introducing a 2 digit (8 segment) display module and a 3 input switching board.
Here's a link to the encoder page at the webstore: Encoder Board | Tortuga AudioTortuga Audio
Hi Morten,
In the announcement of the HiZ control software improvement for Tortuga Audio passive preamps, it is mentioned that it would be possible to retrofit the existing passive preamps with the new software.
Sorry if this has been asked already, but can you please share how will this upgrade be possible?
- Zia
In the announcement of the HiZ control software improvement for Tortuga Audio passive preamps, it is mentioned that it would be possible to retrofit the existing passive preamps with the new software.
Sorry if this has been asked already, but can you please share how will this upgrade be possible?
- Zia
HiZ Control Software Upgrade
Yes, for existing owners it's possible via a firmware upgrade which means replacing the existing microcontroller chip with a new one using the original board/preamp's test data. Of course, all new orders ship with the HiZ software included.
It's a bit lame having to do this by swapping chips. Future versions of the preamp products will have on board boat loaders and USB connections which will allow firmware updates/upgrades to be emailed out and updated via a PC/USB connection.
There's a modest cost for the HiZ upgrade. The HiZ upgrade pages on the website/store can be found via the following links:
for the LDR1/LDR6: HiZ Upgrade for LDR1&6 | Tortuga AudioTortuga Audio
for the LDR3x: HiZ Upgrade for LDR3x | Tortuga AudioTortuga Audio
Cheers,
Morten
Yes, for existing owners it's possible via a firmware upgrade which means replacing the existing microcontroller chip with a new one using the original board/preamp's test data. Of course, all new orders ship with the HiZ software included.
It's a bit lame having to do this by swapping chips. Future versions of the preamp products will have on board boat loaders and USB connections which will allow firmware updates/upgrades to be emailed out and updated via a PC/USB connection.
There's a modest cost for the HiZ upgrade. The HiZ upgrade pages on the website/store can be found via the following links:
for the LDR1/LDR6: HiZ Upgrade for LDR1&6 | Tortuga AudioTortuga Audio
for the LDR3x: HiZ Upgrade for LDR3x | Tortuga AudioTortuga Audio
Cheers,
Morten
Commentary on Improved LDR Preamp Performance
I thought I'd post some subjective thoughts on the performance improvement as a result of the higher impedance (HiZ) control software algorithm.
After a few weeks of nose-to-grindstone work on getting this upgrade polished and out the door I finally took time last night to do some critical listening on my main rig, not just the small test rig I use in the lab/office for development/testing. I realize that anything I say here will be viewed as self-serving and thus heavily discounted but if you can't blow your own horn then who will!
I'm really impressed by the improved audio quality. And I don't impress all that easily. There's now a more relaxed fullness that was missing. A more lush sound with a more natural tonal balance. And yes the dynamics are noticeably improved as well. The percussive pluck, pop and slam from strings to drum heads are now more clearly evident. What I wasn't expecting was the improved sound stage. It seems wider and more even. Love that. Overall, a very satisfying sound!
While the importance of impedance (matching) has long been recognized, conventional implementations of LDR based passive preamps have fallen short on optimizing impedance. I'm quite pleased to report that we've broken past that barrier and have set the bar at a much higher level. This has only been possible through software based digital control of an analog system. This hybrid approach has allowed us to free LDRs from the limitations of analog control and implement a programmed impedance and attenuation schedule that more closely emulates the voltage divider characteristics of conventional attenuation methods while retaining all of the wonderful audio characteristics of LDRs.
Whether you're a DIY tinkerer or an seasoned aficionado of audiophile gear, I invite you to give us a try. Especially if you were holding back, not quite convinced that passives, and especially LDR based passives, was a wise choice for you.
When it all comes together, this obsession with audio can be a thing of beauty!
Cheers!
Morten
I thought I'd post some subjective thoughts on the performance improvement as a result of the higher impedance (HiZ) control software algorithm.
After a few weeks of nose-to-grindstone work on getting this upgrade polished and out the door I finally took time last night to do some critical listening on my main rig, not just the small test rig I use in the lab/office for development/testing. I realize that anything I say here will be viewed as self-serving and thus heavily discounted but if you can't blow your own horn then who will!
I'm really impressed by the improved audio quality. And I don't impress all that easily. There's now a more relaxed fullness that was missing. A more lush sound with a more natural tonal balance. And yes the dynamics are noticeably improved as well. The percussive pluck, pop and slam from strings to drum heads are now more clearly evident. What I wasn't expecting was the improved sound stage. It seems wider and more even. Love that. Overall, a very satisfying sound!
While the importance of impedance (matching) has long been recognized, conventional implementations of LDR based passive preamps have fallen short on optimizing impedance. I'm quite pleased to report that we've broken past that barrier and have set the bar at a much higher level. This has only been possible through software based digital control of an analog system. This hybrid approach has allowed us to free LDRs from the limitations of analog control and implement a programmed impedance and attenuation schedule that more closely emulates the voltage divider characteristics of conventional attenuation methods while retaining all of the wonderful audio characteristics of LDRs.
Whether you're a DIY tinkerer or an seasoned aficionado of audiophile gear, I invite you to give us a try. Especially if you were holding back, not quite convinced that passives, and especially LDR based passives, was a wise choice for you.
When it all comes together, this obsession with audio can be a thing of beauty!
Cheers!
Morten
Ooh, just what I was looking for! Is it big and impressive looking ;-) Or, better still, can you split the controller board from the display itself so that we can select colour/size etc?
Looks like I'll be upgrading the firmware chip at the same time then ;-)
The display size (height of numbers) is a nominal 0.56 inch. Not what I'd call BIG but certainly adequate and not atypical of 7 segment display sizes. That size is fixed for this iteration display module.
It's a separate module from the LDR3x board and has a 2x5 IDC header interface. It's not pin for pin compatible with the current version of the LDR3x board which has provisions for a 2x7 IDC header. So you'll need to use 5 individual female IDC jumpers between the LDR3x and the DispMod.
It communicates with the LDR3x via SPI protocol (serial). So there's 5 connections between the DispMod and the LDR3x: clock, data, select, +5V & ground.
It also provides for ganging 2 display modules together such that one shows left channel step and the other the right channel step. Connected via a 2x5 IDC ribbon cable.
Hadn't planned on offering different color options but no reason that couldn't be added. Blue, red, green & yellow are available of the particular make/model we're using. Standard will be blue.
And yes, it will require a firmware (chip) upgrade. A PITA but there it is.
Final (hopefully) prototype board should arrive today. Assuming that design/board tests out ok, then it's another 2-3 weeks for production boards so I figure by end of the year or early Jan it should be available.
This is part 2 of a review for the Tortuga Audio LDR1 passive preamp. I was able to audition the LDR1 for a full month before receiving the updated software chip. There had been a delay in sending out the chip as it was discovered there were certain anomalies with Class D amps. Once those were resolved the chip was sent out. Since I have W4S Class D amps, it was reassuring that this was checked out. Having the LDR1 for so long made it easy to hear the difference between the old software and the new software.
The only difference in actual operation of the pre was that now when the volume was raised or lowered, the LED fast flickers. Tortuga had incorporated my suggestion. Nice!
The purpose of the new software was to increase and optimize the input impedance thus resulting in better dynamics especially at lower volumes. In actual practice it did much more than that. Dynamically there was a sense of increased transient response though not nearly as significant as the difference between my old passive and the old software. At lower volumes it was difficult for me to detect a significant increase in dynamics across the board. What was significant was a marked increase in low level detail, even at lower volumes. But the most improvement came in rendition of sound stage. At all volumes there was an expansion of width and depth as well as a greater perception of space. There was a smoothness to the presentation that gives a greater sense of reality, especially in live recordings.
My GUESS as to whats going on is that the precision of the channel balance that the original software pioneered is further enhanced and made more apparent by the impedance optimization. Those spacial cues that are embedded in the phase relationships are made more precise by the channel matching and brought to the fore by the impedance refinement. Again, just a guess on my part.
Having sent the unit on to the next participant on the tour, and going back to my previous pre, I noticed that the texture of instruments and voices are less refined. The subtle emotional nuances are less. There is a flattening of the sound stage and the sound sticking more to the speakers. Harrumph.
Having worked in live sound for a few years and maintaining an interest in audio as a hobby for 40 years, I have come to appreciate that everyone comes to different conclusions as to what they hear and thus how they want their audio to be reproduced. Its a trial and error process hopefully with correlations between what is heard and what can be measured. That has been my experience anyway. What I have found is that low distortion, high signal to noise ratio, and flat frequency response are the preeminent determinants as to whether I will like a certain component. Others have come to different conclusions.
The very nature of the recording process manipulates the sound running it through various circuits with all kinds of deleterious as well as beneficial effects, some recordings more than others. Some are of the opinion that since this is the case why not use every means at our disposal to manipulate the sound, when reproducing, to achieve pleasing results. Those that use passive preamps take an opposing view. The last thing we want to do is use anything that will obscure the waveform as its delivered by the source medium. The fewer circuits the better. While I have not personally auditioned a lot of passive pres, I can say that the LDR1 is as a transparent component as I have ever encountered. I will be curious of the findings of the rest of the tour participants as to how the LDR1 performs with their systems. Thanks to Tortuga for sponsoring the tour.
The LDR1 tour is a being conducted for members of the Audiocircle forum who responded to a thread in the Tortuga Audio sub-forum. You can follow it here.
LDRx Passive Preamp Tour
The only difference in actual operation of the pre was that now when the volume was raised or lowered, the LED fast flickers. Tortuga had incorporated my suggestion. Nice!
The purpose of the new software was to increase and optimize the input impedance thus resulting in better dynamics especially at lower volumes. In actual practice it did much more than that. Dynamically there was a sense of increased transient response though not nearly as significant as the difference between my old passive and the old software. At lower volumes it was difficult for me to detect a significant increase in dynamics across the board. What was significant was a marked increase in low level detail, even at lower volumes. But the most improvement came in rendition of sound stage. At all volumes there was an expansion of width and depth as well as a greater perception of space. There was a smoothness to the presentation that gives a greater sense of reality, especially in live recordings.
My GUESS as to whats going on is that the precision of the channel balance that the original software pioneered is further enhanced and made more apparent by the impedance optimization. Those spacial cues that are embedded in the phase relationships are made more precise by the channel matching and brought to the fore by the impedance refinement. Again, just a guess on my part.
Having sent the unit on to the next participant on the tour, and going back to my previous pre, I noticed that the texture of instruments and voices are less refined. The subtle emotional nuances are less. There is a flattening of the sound stage and the sound sticking more to the speakers. Harrumph.
Having worked in live sound for a few years and maintaining an interest in audio as a hobby for 40 years, I have come to appreciate that everyone comes to different conclusions as to what they hear and thus how they want their audio to be reproduced. Its a trial and error process hopefully with correlations between what is heard and what can be measured. That has been my experience anyway. What I have found is that low distortion, high signal to noise ratio, and flat frequency response are the preeminent determinants as to whether I will like a certain component. Others have come to different conclusions.
The very nature of the recording process manipulates the sound running it through various circuits with all kinds of deleterious as well as beneficial effects, some recordings more than others. Some are of the opinion that since this is the case why not use every means at our disposal to manipulate the sound, when reproducing, to achieve pleasing results. Those that use passive preamps take an opposing view. The last thing we want to do is use anything that will obscure the waveform as its delivered by the source medium. The fewer circuits the better. While I have not personally auditioned a lot of passive pres, I can say that the LDR1 is as a transparent component as I have ever encountered. I will be curious of the findings of the rest of the tour participants as to how the LDR1 performs with their systems. Thanks to Tortuga for sponsoring the tour.
The LDR1 tour is a being conducted for members of the Audiocircle forum who responded to a thread in the Tortuga Audio sub-forum. You can follow it here.
LDRx Passive Preamp Tour
DM1 Display Module
We are pleased to announce the pre-release of our DM1 Display Module which we anticipate will be ready to ship by Januaray 6, 2013 (just waiting on the boards to be fabricated).
The Display Module ("DM1") is 2 digit (0.56 inch tall), 7-segment numerical LED display board (1.8 x 1.8 inches) that can be interfaced with the LDR3x Preamp Controller Board to provide numerical/visual feedback of volume level and status of the LDR3x.
You can use just a single module (master) or dual modules (master/slave) for left/right channel display. And they come in blue, green, yellow and red.
Pricing is as follows:
$59 - Single Display (right channel/master only)
$39 - Add 2nd Display Later (left channel/slave)
$89 - Dual Displays Purchased Together (left/right - master/slave) - $10 discount
$20 - LDR3x Firmware Upgrade (required for all LDR3x units purchased prior to 12.18.13; included with all new LDR3x)
You can now pre-order the DM1 and/or find a lot more info on the DM1 on our website/store: Display Module DM1 | Tortuga AudioTortuga Audio
Pre-order means you can order one now but won't have to pay until the DM1 is released and ready to ship.
Happy Holidays! :thumb:
We are pleased to announce the pre-release of our DM1 Display Module which we anticipate will be ready to ship by Januaray 6, 2013 (just waiting on the boards to be fabricated).
The Display Module ("DM1") is 2 digit (0.56 inch tall), 7-segment numerical LED display board (1.8 x 1.8 inches) that can be interfaced with the LDR3x Preamp Controller Board to provide numerical/visual feedback of volume level and status of the LDR3x.
You can use just a single module (master) or dual modules (master/slave) for left/right channel display. And they come in blue, green, yellow and red.
Pricing is as follows:
$59 - Single Display (right channel/master only)
$39 - Add 2nd Display Later (left channel/slave)
$89 - Dual Displays Purchased Together (left/right - master/slave) - $10 discount
$20 - LDR3x Firmware Upgrade (required for all LDR3x units purchased prior to 12.18.13; included with all new LDR3x)
You can now pre-order the DM1 and/or find a lot more info on the DM1 on our website/store: Display Module DM1 | Tortuga AudioTortuga Audio
Pre-order means you can order one now but won't have to pay until the DM1 is released and ready to ship.
Happy Holidays! :thumb:
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Customer Feedback on our LDRx Passive Preamp
Received this wonderful note over Christmas from a customer in Portugal who finally finished his DIY LDR3x preamp project. Thought I'd share. Here it is verbatim (with permission).
"CONGRATULATIONS, MORTEN! The LDRx is quite a revelation with exceptional musical qualities!I must stress that I've been using a Vishay bulk foil plus Holco shunt resistors,silver wired stepped attenuator for the last 20 years(Audio Synthesis' PASSION) and that this unit was highly rated. Indeed, it is a very, very good passive control unit and I've been quite satisfied with it. Well, it is quite an achievement that the LDRx does everything better in a clear audible way!The music simply sounds fuller,warmer with more body and detail.Everything sounds more natural as if no electronic gear is being used. No small achievement in a system that combines a digital source, a digital 3 way crossover, solid state amplification and an all dipole loudspeaker arrangement comprising Quad's ESL63 electrostatics, a pair of Volt bass/mid drivers and a Gradient subwoofer. No nasty boxes at all! I enclose a picture of my LDRx in all its glory,showing its guts and surrounded by Flower Power. Well,what can I say? Thank you, Morten and Merry Christmas!" - Francisco Fragoso
Merry Christmas indeed!
Received this wonderful note over Christmas from a customer in Portugal who finally finished his DIY LDR3x preamp project. Thought I'd share. Here it is verbatim (with permission).
"CONGRATULATIONS, MORTEN! The LDRx is quite a revelation with exceptional musical qualities!I must stress that I've been using a Vishay bulk foil plus Holco shunt resistors,silver wired stepped attenuator for the last 20 years(Audio Synthesis' PASSION) and that this unit was highly rated. Indeed, it is a very, very good passive control unit and I've been quite satisfied with it. Well, it is quite an achievement that the LDRx does everything better in a clear audible way!The music simply sounds fuller,warmer with more body and detail.Everything sounds more natural as if no electronic gear is being used. No small achievement in a system that combines a digital source, a digital 3 way crossover, solid state amplification and an all dipole loudspeaker arrangement comprising Quad's ESL63 electrostatics, a pair of Volt bass/mid drivers and a Gradient subwoofer. No nasty boxes at all! I enclose a picture of my LDRx in all its glory,showing its guts and surrounded by Flower Power. Well,what can I say? Thank you, Morten and Merry Christmas!" - Francisco Fragoso
Merry Christmas indeed!
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