GB for DC coupled B1 buffer with shunt PSUs

[cHoc]

Originally Posted by Salas

20-25k is acceptable. 22k is the centre value.

Is it also possible to go outside those values, eg a 50K ALPS??
I can get an 20K ALPS, but at 2 times the cost of a 50K. (different shop, different prices.....)

[AlanElsdon]

Originally Posted by woodturner-fran

Alan,

would you give us some more details or even photos of how you set it up?

My set of LDRs need a 500k pot, but thats not anywhere in the signal chain, it just controls the current going to either the series or shunt LDRs (as I understand it). Some LDRs are more sensitive and so need much less current for a given resistance, hence some batches need a 100k pot and others a 500k pot with say a 5V supply.

Fran

Fran,

I will send a pm with details.

Alan

[Salas]

Originally Posted by cHoc

Is it also possible to go outside those values, eg a 50K ALPS??
I can get an 20K ALPS, but at 2 times the cost of a 50K. (different shop, different prices.....)

Don't. It will work but we don't want such impedance. It will hinder the quality you can attain. In any case if you must, you should make the 220k resistor a 520k one.

[Salas]

Originally Posted by fingerx

Lightspeed volume use 100K opticoupler in series and 100K shunt to GND, somebody said that almost equal to 10K pot. Any changes if I prefer to use Lightspeed?

I saw there are 12V*2 & 15V*2 50VA power transformer can be use, in fact, which one is more suitable?

No changes if you use the Lightspeed and it is between 10-20k.

2X15V TX is safer for low mains and Vin-Vout margin. Recommended.

[Salas]

Originally Posted by korben69

Here's modified V3.1 BOM according to your suggestions/wishes :
a) BC550 and 560 alternatives added.
b) BOM Name : DC Coupled B1 Shunt PSU
c) Recommended Caps list : Nichicon added
d) 1N4001 Qty for Mezmerize : 7 units for Mezmerize
e) Rotary Switch for Mezmerize + Pin header for wiring

Nice to read from you

P.S. What about inputs / output pins?

[woodturner-fran]

Yep, input'ouput headers would be really great. See the ones used here:



I don't know part numbers etc, but I'll email the TPA lads and I'm sure they'll give that info. What is the pin spacing on the current board does anyone know?

More later.
Fran

[korben69]

I've found Female and Male parts & refs at farnell's :
Male
http://fr.farnell.com/tyco-electroni...581?Ntt=588581
Female
http://fr.farnell.com/tyco-electroni...38?Ntt=1098438
Yes red color, why not ?

Footprint is 2.54mm, straight parts not 90°.
Is it Ok ?

Hummm just wondering... BOM v3.2 ?

[ichiban]

I was in on the failed group buy and I am interested in the new one.
Waiting for a WIKI page, will there be one?
I've tried listing WIKIs but keep getting a request
for name/password? My guess is the WIKIs aren't
functioning yet, since the web site update?

[korben69]

For the 16 x green Led ref, I think this one is more accurate :
http://www2.mouser.com/ProductDetail...7;2fVeh5DEs%3d
It shows 1.9 to 2.5v vs 2.2 to 2.5.
Your opinion ?

[Tea-Bag]

Originally Posted by ichiban

I was in on the failed group buy and I am interested in the new one.
Waiting for a WIKI page, will there be one?
I've tried listing WIKIs but keep getting a request
for name/password? My guess is the WIKIs aren't
functioning yet, since the web site update?

I am trying to resurrect a new GB, but want to ensure the boards will fit on the correct parts, as shown in the pics that Sala's posted a few days ago.

I am planning on getting a few boards to start, lettting a few people build them, and if all goes well, order more according to demand. It wont probably be a lightening fast process. I am doing a 'second beta' of what XaudioX had previously done. We need to be sure the new pcb works. One thing I can say, I am not too interested in any changes to the current effort, unless the entire army of DIYaudio guys protest, or Salas.