Pass B1

@ Quad: Someone in AC has a spare dvb-projekt kit that you are talking of and is willing to part with it. Do you think it is a worthy buy?
 
I think making an LDR is Linuxguru's next pet project, but he never seems to get around to it ...:lol:

Why don't we check with him?

--G0bble
 
@ Quad: Someone in AC has a spare dvb-projekt kit that you are talking of and is willing to part with it. Do you think it is a worthy buy?

I guess it depends on how much he wants for it, and the shipping etc.
It is a very simple board, so I guess local fabrication will be very economical.
As Omishra wrote, other than the LDRs, the rest of the components
are rather commodity stuff and will cost just about Rs 50-100 locally.
 
I think making an LDR is Linuxguru's next pet project, but he never seems to get around to it ...:lol:
OIC. I didn't know that.:rolleyes:
Why don't we check with him?
Will surely call him.
I guess it depends on how much he wants for it, and the shipping etc.
It is a very simple board, so I guess local fabrication will be very economical.
As Omishra wrote, other than the LDRs, the rest of the components
are rather commodity stuff and will cost just about Rs 50-100 locally.

Yeah, I pinged him. Let's see, I'm interested because he is also giving matching LDRs which are difficult to get I'm told.
 
Check here for the gerbers.

Optical Volume Control Professional PCB - Page 37 - diyAudio

ovcbom.jpg

Hi,
This PCB can be made within Rs100.

Regards,
Sachin
 
Hi,
We are working to reduce its cost by substituting parts by same quality.I can only tell the cost of PCb and matched JFETs 330+200(Approx).
Total cost could be around RS 3000 IMO.

regards,
Sachin
 
Hi,
We are working to reduce its cost by substituting parts by same quality.I can only tell the cost of PCb and matched JFETs 330+200(Approx).
Total cost could be around RS 3000 IMO.

regards,
Sachin

So this total cost means, PASS B1 (Stereo) + LDR Stereo Volume Control.
BTW, today I will look into the PCB diagram provided by quad. Looks nice. Still I feel single sided PCB will be sufficient for this.
 
BTW, today I will look into the PCB diagram provided by quad. Looks nice. Still I feel single sided PCB will be sufficient for this.

Om, yes, it should be doable on a single sided board as it's a really
simple circuit.
dvb_projekt went for double sided to separate the control path
from the signal path by using different layers for them.

In an offline conversation, Linuxguru suggested looking at
the "Poor Serbian Man's Attenuator, as it is a much better solution
and he also has a buffer board too.

The Poor Serbian Man's Optical Attenuator - diyAudio

Poor Serbian Man Optical Volume Control - diyAudio

One nice tip from this thread is to mount the LDRs on the copper
side, and use an aluminium plate as a thermal coupling
for temperature equalization.
** Imp to note that the LDR diode orientation must be maintained correctly if doing this **

This is to counter a critical issue with LDRs which show significant drift
with temperature.
The original lightspeed uses a wax based potting for thermal coupling
of the LDRs.
 
LightSpeed LDR board

Hi all,
Please have a look of LightSpeed LDR board modified by Prasad(Quad) and Omishra.Suggestions welcome

newldrbrd.png

By sachu888 at 2011-10-31

Regards,
Sachin
 
A beautiful, well-constructed speaker with class-leading soundstage, imaging and bass that is fast, deep, and precise.
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