[tortugaranger]

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) 6 layer PCB board with 3 power planes in addition to ground plane
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 multiple low drop out, low noise 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
 

[33na3rd]

I'm interested!

[glynnw]

Count me in.

[ClefChef]

Ill take 2 please.

[rajacat]

I have the LDR3x.V2 from the first group buy. Is there any way that that board can be updated to eliminate the relays?
I still haven't assembled the kit.

[jtwrace]

I might be depending on timing. 


When will the constant progress slow down though?  I do worry about the improvements that obsolete the previous generation so quickly. 

[tortugaranger]

I have the LDR3x.V2 from the first group buy. Is there any way that that board can be updated to eliminate the relays?
I still haven't assembled the kit.

Relays are still needed to connect in the auto-cal circuitry which otherwise remain disconnected from the audio signals during normal use. On the V2 these relays also isolate the input & output when auto-cal is enabled so the audio signals are always going through the relay circuit (which is not energized during normal use). The V2.1 will not isolate the input & output during auto-cal so you'll have to either disconnect the audio cables during auto-cal or have an interposing relay board that does this for you (which will require more relays ...or....you can use LDRs as switches).

You can bypass the input/output around the relays on the existing V2 by bridging a solder connection across pins O & Ox and I & Ix on both J13R and J13L of the piggy back board.

[markn]

I'm in for sure, will be my third unit!!!


Mark

markn1@mindspring.com

[tortugaranger]

When will the constant progress slow down though?  I do worry about the improvements that obsolete the previous generation so quickly.

Leaving aside commercial considerations, that's an interesting philosophical question.  Should incremental improvements be made simply because they can? Personally I don't think you can ever afford to stand still. You're either moving forward or you're falling behind. I've never liked that old saying of "if it ain't broke don't fix it".

That said, the V2.1 will hardly obsolete the V2. While I believe the V2.1 will be an inherently more robust version and that it has the potential for better performance, that's to be seen. No small part of the V2.1 is to reduce the time and effort required produce a board ...and thus reduce its cost. That almost always makes sense.

At this point I don't anticipate a major redesign (a V3 if you will) any time soon. There will definitely be refinements to the V2 software which I believe has room for improvement...and aside from the hassle factor of uploading it into the board (which can be done with a PC and a USB cable)...the software is free!! 

[robertopisa]

Ouch... I just finished assembling the two enclosures for my DIY balanced volume attenuator...

Morten, will the footprint of the board be the same as the current version? I would like not to rewire everything. For balanced, do I need two boards?

Thanks
-R

[robertopisa]

Sorry Mortem, can you please comment more on what happens if we bridge the pins below? Is the analog signal currently going through also the relays (besides the LDRs)?

Thanks
Roberto

You can bypass the input/output around the relays on the existing V2 by bridging a solder connection across pins O & Ox and I & Ix on both J13R and J13L of the piggy back board.

[tortugaranger]

Ouch... I just finished assembling the two enclosures for my DIY balanced volume attenuator...

Morten, will the footprint of the board be the same as the current version? I would like not to rewire everything. For balanced, do I need two boards?

Thanks
-R

The V2.1 is currently 0.2" inches longer than the V2 but the mounting holes will be kept the same. But honestly there's no reason to replace your V2's. Enjoy!

[jtwrace]

Leaving aside commercial considerations, that's an interesting philosophical question.  Should incremental improvements be made simply because they can? Personally I don't think you can ever afford to stand still. You're either moving forward or you're falling behind. I've never liked that old saying of "if it ain't broke don't fix it".

That said, the V2.1 will hardly obsolete the V2. While I believe the V2.1 will be an inherently more robust version and that it has the potential for better performance, that's to be seen. No small part of the V2.1 is to reduce the time and effort required produce a board ...and thus reduce its cost. That almost always makes sense.

At this point I don't anticipate a major redesign (a V3 if you will) any time soon. There will definitely be refinements to the V2 software which I believe has room for improvement...and aside from the hassle factor of uploading it into the board (which can be done with a PC and a USB cable)...the software is free!! 

OK.  Yes, I agree, standing still doesn't do anyone any good.  However, some sort of plan that explains the upgrade path how JRiver set out is pretty cool.  Not saying that you should do the same it's just that every year or so a new upgrade is great but I thought it was only a few months ago since the last upgrade board.  That's all. 

[rajacat]

I might be depending on timing. 


When will the constant progress slow down though?  I do worry about the improvements that obsolete the previous generation so quickly.

I'll have to admit that I'm disappointed that a new, improved version has come along even before I assembled the old one.
I've been building new speakers thus put the LDR on the back burner. I not only bought the basic board but the IO3relay board and the DM1 display module.

Hmm... I wonder when the next upgrade will come? I guess the lesson from this is don't be an early adopter although this could discourage the introduction of new products financed by group buys.

[tortugaranger]

I'll have to admit that I'm disappointed that a new, improved version has come along even before I assembled the old one.
I've been building new speakers thus put the LDR on the back burner. I not only bought the basic board but the IO3relay board and the DM1 display module.

Hmm... I wonder when the next upgrade will come?

Jeeez, you guys are killing me here. The V2.1 isn't going to be some grand break-through got-to-have-it-or-else upgrade. It will NOT obsolete your V2 or make your IO3 relay board or DM1 display modules incompatible or obsolete. I'm just trying to find a way to make a better product for less. That simply can not be a wrong thing to do....ever.

[tortugaranger]

Sorry Mortem, can you please comment more on what happens if we bridge the pins below? Is the analog signal currently going through also the relays (besides the LDRs)?

Thanks
Roberto

In the V2 the audio input/output signals pass through normally closed relay contacts (relay not energized). If you bridge those 4 pair of pins, the audio I/O will bypass the relays. And if you bridge them then during auto-cal you'll need to isolate (disconnect) your audio cables from your preamp unless you use an I/O board that isolates the inputs automatically but you'll still need to disconnect the output. Auto-cal doesn't need to be run often so it's not that big of a PITA.

[robertopisa]

Thanks Morten for the clarification! When you say disconnect audio cables, do you actually mean that the source and the amp are turned off, or is it really an electrical disconnection? Either case would be not a big issue for me.
-R

Edit: Rereading above, it seems that cables should be physically disconnected. The only issue I see is that if I inadvertently press the ENTER button of the Apple IR when the Tortuga is stand-by, it will start the autocal.

In the V2 the audio input/output signals pass through normally closed relay contacts (relay not energized). If you bridge those 4 pair of pins, the audio I/O will bypass the relayis. And if you bridge them then during auto-cal you'll need to isolate (disconnect) your audio cables from your preamp unless you use an I/O board that isolates the inputs automatically but you'll still need to disconnect the output. Auto-cal doesn't need to be run often so it's not that big of a PITA.

[rajacat]

Jeeez, you guys are killing me here. The V2.1 isn't going to be some grand break-through got-to-have-it-or-else upgrade. It will NOT obsolete your V2 or make your IO3 relay board or DM1 display modules incompatible or obsolete. I'm just trying to find a way to make a better product for less. That simply can not be a wrong thing to do....ever.

OK, I understand your point of view. If you can make it better and cheaper, that's good. You have good intentions and you're developing your product as you go along.
Nevertheless, its the audionervosa that most audiophiles have that drives many purchases. The very fact that the LDR will probably replace my perfectly good active pre is motivated by the desire to attain the small, incremental improvement that it will provide. This same OCD behavior also manifests itself by the frustration of trying to keep up with the cutting edge which has become a moving target. 
It might not seem that way but I'm not complaining, just frustrated and a bit disappointed. Actually, I believe you have a GREAT product and excellent customer service.

[markn]

Jeez, what a bunch of whiners...

This is a KILLER product offered at a great price, enjoy!

[mikebarney]

I would be interested in one board.
Mike