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Light Dependant Resistor 3 Input Preamp Kit

What is reasonable to pay for a LDR 3 input Kit

  • $150.00

    Votes: 33 80.5%

  • $180.00

    Votes: 5 12.2%

  • $300.00

    Votes: 3 7.3%
  • Total voters
    41
Jump to Latest
C

Chris Daly

Member
Joined 2004
Our customers receive update boards without cost, There have been three revisions, and we are working through backlog to update all of our customers with our latest board.

Your comments regarding prior boards are unfounded suggest you peek at
http://www.lencoheaven.net/forum/index.php?topic=13947.45

We did have difficulty with a darlington transistor that was found to be too slow affecting three customers who were advised and new boards provided. Marco who contributes to the forum wanted to update his own board, and we have offered him the latest boards at post 61, which we are following up with.
Cheers / Chris
 
C

Chris Daly

Member
Joined 2004
Rush said:
Chris,

Is there any DC on the output? Can this be connected to an F5 without a coupling capacitor?
Same question for the input, if there is DC on the output of a DAC, what is necessary?

Rush
Click to expand...

Hi Rush
Our circuit has no DC on its signal outputs or inputs. So Yes you can connect to any piece of audio equipment including the excellent F5.

Your post suggests you want to entirely connect without any form of coupling.
the subject is looked at here; DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit

The TDA1541 stands as an interesting example where one channel as a result of internal design has higher current than the other channel and can be canceled prior to the i/v stage, in theory if very carefully done relieving the circuit of an output capacitor
Discussed and implemented by Ben Duncan there may be reprints available of his article Supertuning CD see reference 3 in my article overcoming deficiencies of SPDIF.
The Deficiencies of SPDIF as a Digital Transmission Method

if you are seeking the best audio resolution our kits are a great place to start. From experience you should also look at companding like DBX to increase the dynamic range of CD,, and generally reducing distortion which you are doing from sources amplifiers and loudspeakers.

We look forward to assisting you.:)

Cheers / Chris
 
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Rush

Rush

Member
Joined 2009
Chris Daly said:
Hi Rush
Our circuit has no DC on its signal outputs or inputs. So Yes you can connect to any piece of audio equipment including the excellent F5.

Your post suggests you want to entirely connect without any form of coupling.
the subject is looked at here; DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit

The TDA1541 stands as an interesting example where one channel as a result of internal design has higher current than the other channel and can be canceled prior to the i/v stage, in theory if very carefully done relieving the circuit of an output capacitor
Discussed and implemented by Ben Duncan there may be reprints available of his article Supertuning CD see reference 3 in my article overcoming deficiencies of SPDIF.
The Deficiencies of SPDIF as a Digital Transmission Method

if you are seeking the best audio resolution our kits are a great place to start. From experience you should also look at companding like DBX to increase the dynamic range of CD,, and generally reducing distortion which you are doing from sources amplifiers and loudspeakers.

We look forward to assisting you.:)

Cheers / Chris
Click to expand...

You know, we all want to couple stages without any caps if possible.

I read the information provided in the links, didn't help much as I didn't mention which source (pre-amp, QB9, CD, ETC.)

The current setup is a DCB1 before and after the volume and then the F5. If there is 7 mil volt on the output of the DCB1, then there will be a 7 mil volt on the output of your LDR, correct? I take it, you aren't using a buffer on your output. I don't want 7 mil volts on the input of my F5, so I would need to cap couple to the F5. Right?

Rush
 
C

Chris Daly

Member
Joined 2004
Rush said:
You know, we all want to couple stages without any caps if possible.

I read the information provided in the links, didn't help much as I didn't mention which source (pre-amp, QB9, CD, ETC.)

The current setup is a DCB1 before and after the volume and then the F5. If there is 7 mil volt on the output of the DCB1, then there will be a 7 mil volt on the output of your LDR, correct? I take it, you aren't using a buffer on your output. I don't want 7 mil volts on the input of my F5, so I would need to cap couple to the F5. Right?

Rush
Click to expand...

Hi Rush
Coupling small amounts of DC as a result of the use of no caps through to the F5 circuit is a question for Nelson who will assist answering on the forum or by sending him a PM . His F5 manual gives suggestion that the inward R9 1k resistor greatly assists the F5 amp to live in the real world of offsets, wrong connections and input overloads. Its great you want to preserve what is a excellent design, and not involve caps.

Whilst Nelson is answering, and you can refer him to this thread. allow me to measure small DC parameters to see if the stereo Coffee LDR L pad lessens any such voltages, it would suggest straight away it will indeed do that, firstly acting on any voltage then as a current and also to a degree as a voltage divider - all good indications of dissipation and lessening the problems associated with direct coupling. I will reply once I have that information.

For our customers reading this, there is normally in all audio equipment a capacitor placed
at the output of the source and at the input of the load ( the power amp ) Rush is asking what happens when there is very small amounts of DC, as he requires the benefit allowed by the F5 amp in its design of having no capacitors at all.

Cheers / Chris
 
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Rush

Rush

Member
Joined 2009
Chris Daly said:
Hi Rush

In answer to your question The effect of running 17mv through at normal listening level is to divide by approximately 4 that value. So there is benefit in using a L pad . Did you receive reply from Nelson ?

Cheers / Chris
Click to expand...

I have read the F5 and F5T threads from beginning to end. I don't need to know anymore information about the F5.
I don't see a schematic for your product, unlike Nelson Pass who publishes his schematics, so I see no reason to ask Mr. Pass anything about his F5 and I certainly am not going to ask him about your commercial product with no shared schematic.

Thanks,

Rush
 
G

godfrey

Member
Joined 2009
Rush said:
Is there any DC on the output?
Click to expand...
If there is DC at the input, then there will be DC at the output. The fact that it took Chris several days to figure that out should tell you everything you need to know about his understanding of electronics in general and his own products in particular. Best not to bother him with technical questions, IMHO.

BTW, the DC will be attenuated by the same amount as the audio signal.

Chris Daly said:
Our circuit signal side, is a simple L pad. You can assume 100k resistors overall on each branch, In practice normal listening levels are approx 12k series and 3.4k shunt per channel .
Click to expand...
Interesting arithmatic. Somehow 12K plus 3.4k adds up to 100K?:confused:

Rush said:
I don't see a schematic for your product....
Click to expand...
He has published some of his previous designs in this thread. That was a couple of years ago so I expect he's "refined" his designs a bit since then, but the basic principles will still be the same.

Anyway, the feedback he got at the time from knowledgable people was quite enlightening. For example:
DF96 said:
This might be what you could get if a 6-year-old child was given an ECAD program and asked to draw a circuit.
Click to expand...
gootee said:
I hate to have to be the one to break this to you, Chris, but voltage and current are not independent of each other. There's an enormous body of work (work, not just hand-waving and talking) called Physics, where (along with many other things) the laws of electricity have been discovered and studied. You should check it out, sometime.
Click to expand...
SY said:
You've been told repeatedly by experienced people that your designs don't make sense, the explanations are gibberish, your target (other than selling stuff to the gullible) is unclear, and that these are bad circuits, "designed" in complete defiance of basic electronics. Perhaps you expect people to fix your "designs" for free so that you can enjoy the sales unencumbered by the necessity of design costs, but expect that this will be pointed out and vigorusly so.
Click to expand...
 
C

Chris Daly

Member
Joined 2004
Hi
Our products speak for themselves, and our customers continually praise what we do:


A++++++ Excellent seller, great communication !!!!
great seller
As advertised, quick delivery, Thanks
Excellent service, great product
Exlnt packaging & rapid ship! Great product, excellent communication & support!
Excellent trade, Chris is a wonderful person and went out of his way to help me assemble this preamp and it sounds very nice. Thanks very much Chris,
I´m really happy with this little preamp, and it will be staying in my system. Looks like the Transcendent Sound Grounded Grid will be up for sale soon

Approx 100k usable resistance is the L pad range and 12k series and 3.4k shunt is normal listening level. There is total quiet at lowest volume, unlike any other LDR product that we know of.

If Godfrey would similarly like to be our customer we would be glad to assist.

Cheers / Chris
 
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J

J Leng

Member
Joined 2008
Hi All,

I would like to say how amazing Chris's help has been, not only has he sent me 4 power boards over the past 6 months, he has just sent another main board as I was experiencing balance problems.
The new boards have really improved the dynamics and the ability to follow the music in load passages.
Thanks again Chris
 
C

Chris Daly

Member
Joined 2004
It is well known our Stereo Coffee kits provide very well matched LDR's.
stereo coffee items - Get great deals on items on eBay Stores!

The result being for you excellent Left to Right stereo separation. We are also finding the NSL32SR2s part is improving We buy in lots of 50 and there is improving consistency. Nevertheless we carefully match LDR's for each kit we sell, as you want this part very well matched for good audio.

But there is more to good audio performance and stereo separation as the DC current source has to be capable of providing equal division of current to each LDR at all volume settings. With current regulation to the shunt and series anodes we achieve very good control of the NSL32SR2S. Each board we build is individually tested and has to pass our listening tests. Our ESL57's are always left on to assess each board. We also use the wonderful Gale GS401a loudspeakers. :)

Each control board update we have done has been getting better in this area, and we remain committed to providing you now and in the future the best audio performance at low cost from our Stereo Coffee LDR kits.

Cheers / Chris
 
C

Chris Daly

Member
Joined 2004
Hi
Thanks to those DIY members who assisted with the poll. We will keep it running.

The message is clear you want and expect a LDR 3 input kit for $150.00
So we have reduced our prices

items in stereo coffee store on eBay!

as well our single input model is now lower in cost.:)

Postage costs are free if you are in NZ , and our flat rate is $17.00 anywhere in the world.

Cheers / Chris
 
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