Potential Interest in complete DIY LDR Passive Preamp Kit?
I'd like to hear from anyone who might be interested in a complete DIY LDR Passive Preamp kit. Have not decided to do so as yet hence this request for input.
The thought behind this is to be able to offer an all-inclusive DIY LDR passive preamp kit at a price point that would be attractive to those who are not likely to pop for our high end finished model, who also aren't interested in designing/sourcing their own DIY passive preamp project/parts, but who are up for putting together an all-inclusive kit.
All constructive thoughts/comments welcome.
Best,
Morten
I'd like to hear from anyone who might be interested in a complete DIY LDR Passive Preamp kit. Have not decided to do so as yet hence this request for input.
The thought behind this is to be able to offer an all-inclusive DIY LDR passive preamp kit at a price point that would be attractive to those who are not likely to pop for our high end finished model, who also aren't interested in designing/sourcing their own DIY passive preamp project/parts, but who are up for putting together an all-inclusive kit.
All constructive thoughts/comments welcome.
Best,
Morten
Possibly The Best DIY Preamp Available Today
Here's the kind of comments we get often from DIY customers.
Want to build you own preamp? That can be controlled via remote? That sounds utterly fantastic? Not sure which way to go? Go with our LDR3x.V2 Passive Preamp Controller. You won't be disappointed. Do it (yourself).
$259 - LDR3x.V2 Preamp Contoller Board
$59 - Display Module
$23 - Encoder Module
$25 - Apple Remote
Just provide your own 12 VDC power supply, an enclosure and your choice of RCA jacks and you'll have the best preamp you've ever heard. Or you can buy a power supply and jacks from us too if you want. And a 3 input relay board as well.
You don't need to believe me. Believe our customers.
Check it out: LDR3x.V2 Passive Preamp Controller | Tortuga Audio
Here's the kind of comments we get often from DIY customers.
Want to build you own preamp? That can be controlled via remote? That sounds utterly fantastic? Not sure which way to go? Go with our LDR3x.V2 Passive Preamp Controller. You won't be disappointed. Do it (yourself).
$259 - LDR3x.V2 Preamp Contoller Board
$59 - Display Module
$23 - Encoder Module
$25 - Apple Remote
Just provide your own 12 VDC power supply, an enclosure and your choice of RCA jacks and you'll have the best preamp you've ever heard. Or you can buy a power supply and jacks from us too if you want. And a 3 input relay board as well.
You don't need to believe me. Believe our customers.
Check it out: LDR3x.V2 Passive Preamp Controller | Tortuga Audio
Last edited:
Group Buy - Revised LDR3x.V2 Passive Preamp Controller Board - $199 Special
I'm planning a revised version of the LDR3x.V2 Passive Preamp Controller Board. This is a refinement of the V2 versus a new design. Think of it as the V2.1. The driver for this is to improve performance while also driving down the cost of a finished board.
The key refinements include:
1) Integration of simplified auto-calibration circuitry on to the main board - no more separate piggy-back auto-cal board.
2) Separate digital and analog power supplies
3) No direct use of external power source - everything gets regulated/filtered on the board
4) Related to 3), the V2.1 can accept a wider range of external supply voltages from 12-24 VDC (perhaps even higher) including unregulated.
5) 4 layer PCB board with separate power and ground planes
6) No audio signals passing through relay connections (on our LDRx/LDRxB preamps we already do this but it's done with a special version of our IO board).
7) Use of 3 separate linear regulators vs. existing single switch mode regulator.
All of that translates into a better overall design with quieter power supply that will hopefully yield improved performance. Getting everything on to a single board will go a long way to offsetting some of the cost increases related to items 1-7) such that the overall fully assembled cost of the board will still be less.
If you've been planning a DIY passive preamp around the LDR3x.V2, I'm extending a group volume price of $199 for the V2.1 version (vs. current V2 price of $259). To get this off the ground I need a group buy of at least 10 units but want to target 20+.
If you are interested please chime in here or send me a PM. And let your DIY audio buddies know. At this point I'm only looking to gauge interest and not a firm commitment. At some later point I may set this up as a pre-order on our website.
Enjoy!
Morten
I'm planning a revised version of the LDR3x.V2 Passive Preamp Controller Board. This is a refinement of the V2 versus a new design. Think of it as the V2.1. The driver for this is to improve performance while also driving down the cost of a finished board.
The key refinements include:
1) Integration of simplified auto-calibration circuitry on to the main board - no more separate piggy-back auto-cal board.
2) Separate digital and analog power supplies
3) No direct use of external power source - everything gets regulated/filtered on the board
4) Related to 3), the V2.1 can accept a wider range of external supply voltages from 12-24 VDC (perhaps even higher) including unregulated.
5) 4 layer PCB board with separate power and ground planes
6) No audio signals passing through relay connections (on our LDRx/LDRxB preamps we already do this but it's done with a special version of our IO board).
7) Use of 3 separate linear regulators vs. existing single switch mode regulator.
All of that translates into a better overall design with quieter power supply that will hopefully yield improved performance. Getting everything on to a single board will go a long way to offsetting some of the cost increases related to items 1-7) such that the overall fully assembled cost of the board will still be less.
If you've been planning a DIY passive preamp around the LDR3x.V2, I'm extending a group volume price of $199 for the V2.1 version (vs. current V2 price of $259). To get this off the ground I need a group buy of at least 10 units but want to target 20+.
If you are interested please chime in here or send me a PM. And let your DIY audio buddies know. At this point I'm only looking to gauge interest and not a firm commitment. At some later point I may set this up as a pre-order on our website.
Enjoy!
Morten
Ok. Looks like we have +3 so far. Keep em' coming!!
Also, we're back to a 6 layer board. Had to go with split power for the opamps which before only used single supply - which greatly limited choice of good/low-noise op amps.
Also, we're back to a 6 layer board. Had to go with split power for the opamps which before only used single supply - which greatly limited choice of good/low-noise op amps.
I'm planning a revised version of the LDR3x.V2 Passive Preamp Controller Board. This is a refinement of the V2 versus a new design. Think of it as the V2.1. The driver for this is to improve performance while also driving down the cost of a finished board.
The key refinements include:
1) Integration of simplified auto-calibration circuitry on to the main board - no more separate piggy-back auto-cal board.
2) Separate digital and analog power supplies
3) No direct use of external power source - everything gets regulated/filtered on the board
4) Related to 3), the V2.1 can accept a wider range of external supply voltages from 12-24 VDC (perhaps even higher) including unregulated.
5) 4 layer PCB board with separate power and ground planes
6) No audio signals passing through relay connections (on our LDRx/LDRxB preamps we already do this but it's done with a special version of our IO board).
7) Use of 3 separate linear regulators vs. existing single switch mode regulator.
All of that translates into a better overall design with quieter power supply that will hopefully yield improved performance. Getting everything on to a single board will go a long way to offsetting some of the cost increases related to items 1-7) such that the overall fully assembled cost of the board will still be less.
If you've been planning a DIY passive preamp around the LDR3x.V2, I'm extending a group volume price of $199 for the V2.1 version (vs. current V2 price of $259). To get this off the ground I need a group buy of at least 10 units but want to target 20+.
If you are interested please chime in here or send me a PM. And let your DIY audio buddies know. At this point I'm only looking to gauge interest and not a firm commitment. At some later point I may set this up as a pre-order on our website.
Enjoy!
Morten
Yes, assembly instructions that will be available in our online documentation. It's not there yet but it will be added here.
Group Buy - Revised LDR3x.V2 Passive Preamp Controller Board - $199 Special
As of this AM we are at 19 when combining diyAudio with AudioCircle so I'm going to assume we'll add a few more soon enough. Good enough to kick this off.
Timing & next steps.
I'll set this up on the website and let you know when that's done so you can go there and formally place and pay for your order. I figure another week or so of tweaking and double-checking the design before ordering the boards. Turn-around on board fabrication will be roughly 2-3 weeks. Getting them faster just drives up the cost. Once we have the boards we'll start stuffing boards and shipping. Adding that all up plus a little room for slippage and figure release/shipping starting mid December.
One additional feature of the V2.1 is the op amps will be socketed. The V2 uses 3 14 pin quad op amps with standard quad op amp pin out; 2 are used for controlling the LDRs and the 3rd only comes into play during auto-calibration otherwise is isolated from the audio signals. This opens up the possibility of exploring whether alternative op amps might improve performance. I'm agnostic on this topic. Specs like slew rates and bandwidth etc. shouldn't be relevant since we are only putting DC through the op amps. The only AC they see should be noise from the power supply. Yet every op amp contributes its own noise. Even though the audio signals are optically isolated, noise present on the control signals to the LDR's LED will be seen by the photoresistor and thus the audio signal. Response of the LDR's photoresistor is not instantaneous so they do act as natural filters. At what point such filtering renders any further improvement in control signal noise moot is something I'm curious about but have not had time to fully explore.
AudioCircle
1 - 33na3rd
1 - glynnw
2 - clefchef
1 - jtwrace (maybe)
2 - markn
1 - mikebarney
1 - golfrod
1 - krikor
2 - TrungT
2 - Mas
diyAudio
1 - Quirepace
1 - Do
1 - nilsjnesse
2 - justubes
As of this AM we are at 19 when combining diyAudio with AudioCircle so I'm going to assume we'll add a few more soon enough. Good enough to kick this off.
Timing & next steps.
I'll set this up on the website and let you know when that's done so you can go there and formally place and pay for your order. I figure another week or so of tweaking and double-checking the design before ordering the boards. Turn-around on board fabrication will be roughly 2-3 weeks. Getting them faster just drives up the cost. Once we have the boards we'll start stuffing boards and shipping. Adding that all up plus a little room for slippage and figure release/shipping starting mid December.
One additional feature of the V2.1 is the op amps will be socketed. The V2 uses 3 14 pin quad op amps with standard quad op amp pin out; 2 are used for controlling the LDRs and the 3rd only comes into play during auto-calibration otherwise is isolated from the audio signals. This opens up the possibility of exploring whether alternative op amps might improve performance. I'm agnostic on this topic. Specs like slew rates and bandwidth etc. shouldn't be relevant since we are only putting DC through the op amps. The only AC they see should be noise from the power supply. Yet every op amp contributes its own noise. Even though the audio signals are optically isolated, noise present on the control signals to the LDR's LED will be seen by the photoresistor and thus the audio signal. Response of the LDR's photoresistor is not instantaneous so they do act as natural filters. At what point such filtering renders any further improvement in control signal noise moot is something I'm curious about but have not had time to fully explore.
AudioCircle
1 - 33na3rd
1 - glynnw
2 - clefchef
1 - jtwrace (maybe)
2 - markn
1 - mikebarney
1 - golfrod
1 - krikor
2 - TrungT
2 - Mas
diyAudio
1 - Quirepace
1 - Do
1 - nilsjnesse
2 - justubes
The design uses 1% metal film throughout. Keep in mind that we aren't putting audio signals through any resistors other than the LDR photoresistors. The resistors used in the control circuit only see steady state DC. No PWM and certainly no audio level AC. They're used with the control op amps solely to limit the control voltages within practical limits used by LDRs. In the scheme of things using premium audio resistors within this context would arguably be gilding the lily. In fact I did use Dale resistors in early builds of the V1 and after some testing it just didn't make sense to continue.
Here's the kind of comments we get often from DIY customers.
Want to build you own preamp? That can be controlled via remote? That sounds utterly fantastic? Not sure which way to go? Go with our LDR3x.V2 Passive Preamp Controller. You won't be disappointed. Do it (yourself).
$259 - LDR3x.V2 Preamp Contoller Board
$59 - Display Module
$23 - Encoder Module
$25 - Apple Remote
Just provide your own 12 VDC power supply, an enclosure and your choice of RCA jacks and you'll have the best preamp you've ever heard. Or you can buy a power supply and jacks from us too if you want. And a 3 input relay board as well.
You don't need to believe me. Believe our customers.
Check it out: LDR3x.V2 Passive Preamp Controller | Tortuga Audio
Pardon my ignorance, I plan to use solely the remote for volume control, do I still need to get encoder module? Lastly, I assume the display module is optional and the board will work properly without it?
Therefore, the Apple remote is the only item required for a fully functional preamp.
Thank you for answering my questions.
Regards,
Good questions. This comes up often since there are multiple options.
Encoder - You don't have to have an encoder. There is one function performed by the encoder that can't be done via the remote. It's called remote "pairing" and this can only be initiated via the remote. This function can be emulated via temporary connection to the J2 header with a couple of wires so no worries. Pairing the remote is usually only done once unless you change remotes or replace the main controller chip.
Display Module - As with the encoder, you can live without a display module but life will be more confusing. Over time the control software has evolved with the idea of having visual/numerical feedback. Without this you may find the unit in a particular operating mode with no clue whats happening and think that the unit is being nonresponsive (can raise/lower volume) when really it's just in another mode that has to be cleared. I recommend using a display module but if not then you should definitely connect the Status signal to an LED otherwise you won't even now if the unit is on or off.
Good questions. This comes up often since there are multiple options.
Encoder - You don't have to have an encoder. There is one function performed by the encoder that can't be done via the remote. It's called remote "pairing" and this can only be initiated via the remote. This function can be emulated via temporary connection to the J2 header with a couple of wires so no worries. Pairing the remote is usually only done once unless you change remotes or replace the main controller chip.
Display Module - As with the encoder, you can live without a display module but life will be more confusing. Over time the control software has evolved with the idea of having visual/numerical feedback. Without this you may find the unit in a particular operating mode with no clue whats happening and think that the unit is being nonresponsive (can raise/lower volume) when really it's just in another mode that has to be cleared. I recommend using a display module but if not then you should definitely connect the Status signal to an LED otherwise you won't even now if the unit is on or off.
Thank you very much for answering my questions!
Regards,
We are currently only selling the V2 passive preamp controller as a completed and tested board, not as a bare board with a pile of parts that need to be solderd. I won't rule out a possible kit in the future but not today.
Hi, Morten
Great!! Save me some work - not that I hate soldering but I am sure you will do a much better job than me.
Regards,
Update on the LDR3x V2.1 Preamp Controller Etc.
I wanted to give everyone a brief update on the V2.1 and related product evolution so here goes.
1) The V2.1 board design is complete but waiting on arrival of 2 new components for final fit-up check and functional test. I expect to have that done by Nov 19th or so at which time I will proceed to order the boards.
2) We are going ahead with the DIY preamp kit - the LDR3.V2K. This will be available for pre-order at the same time the $199 V2.1 board special becomes available for pre-order. So you can choose whether to go with just the board or a complete kit. More to follow on that.
3) In addition to the LDR3.V2K kit, we are also going to offer an upgraded variant of the kit as a finished product - the LDR3.V2 (without the "K"). There will be a few differences between the kit and the finished product, both cosmetic and probably internally. However, both will utilize the same extruded aluminum box as our original LDR1/3/6 passive preamps at 6" wide x 3" tall x 8"deep but with new and different front/rear panels. More to follow on that as well.
4) Lastly there will be a price increase of our LDRx and LDR3xB Passive Preamps effective Jan 1st. If you've been jones'n for one of those, you still have time but the price will go up several $100 each starting in 2015.
None of this is on our website yet. An announcement with more details with be forthcoming via our Newsletter soon. If you're interested in the newsletter you can sign up here. Newsletter Subscription Signup | Tortuga Audio
Cheers,
Morten
I wanted to give everyone a brief update on the V2.1 and related product evolution so here goes.
1) The V2.1 board design is complete but waiting on arrival of 2 new components for final fit-up check and functional test. I expect to have that done by Nov 19th or so at which time I will proceed to order the boards.
2) We are going ahead with the DIY preamp kit - the LDR3.V2K. This will be available for pre-order at the same time the $199 V2.1 board special becomes available for pre-order. So you can choose whether to go with just the board or a complete kit. More to follow on that.
3) In addition to the LDR3.V2K kit, we are also going to offer an upgraded variant of the kit as a finished product - the LDR3.V2 (without the "K"). There will be a few differences between the kit and the finished product, both cosmetic and probably internally. However, both will utilize the same extruded aluminum box as our original LDR1/3/6 passive preamps at 6" wide x 3" tall x 8"deep but with new and different front/rear panels. More to follow on that as well.
4) Lastly there will be a price increase of our LDRx and LDR3xB Passive Preamps effective Jan 1st. If you've been jones'n for one of those, you still have time but the price will go up several $100 each starting in 2015.
None of this is on our website yet. An announcement with more details with be forthcoming via our Newsletter soon. If you're interested in the newsletter you can sign up here. Newsletter Subscription Signup | Tortuga Audio
Cheers,
Morten
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