GB for DC coupled B1 buffer with shunt PSUs - Page 61 - diyAudio
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Old 2nd September 2009, 11:18 AM   #601
cHoc is offline cHoc  Netherlands
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Quote:
Originally Posted by Salas View Post
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.....)
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Old 2nd September 2009, 11:43 AM   #602
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Quote:
Originally Posted by woodturner-fran View Post
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
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Old 2nd September 2009, 12:24 PM   #603
Salas is offline Salas  Greece
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Quote:
Originally Posted by cHoc View Post
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.
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Old 2nd September 2009, 12:28 PM   #604
Salas is offline Salas  Greece
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Quote:
Originally Posted by fingerx View Post
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.
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Old 2nd September 2009, 12:34 PM   #605
Salas is offline Salas  Greece
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Quote:
Originally Posted by korben69 View Post
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?
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Old 2nd September 2009, 01:10 PM   #606
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Yep, input'ouput headers would be really great. See the ones used here:

Click the image to open in full size.

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
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Old 2nd September 2009, 04:54 PM   #607
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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 ?

Last edited by korben69; 2nd September 2009 at 05:02 PM.
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Old 2nd September 2009, 05:13 PM   #608
ichiban is offline ichiban  United States
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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?
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Old 2nd September 2009, 05:14 PM   #609
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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 ?
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Old 2nd September 2009, 05:26 PM   #610
Tea-Bag is offline Tea-Bag  United States
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Quote:
Originally Posted by ichiban View Post
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.
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