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new batch of mini Aleph amplifier and PSU boards

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My amp boards arrived ages ago now I'm planning the build. I want to make mini aleph mono blocks heatsinked to aluminium cases I already have. I estimate cases to have 2*C/watt thermal resistance but that is just a guess. If I make mono blocks then that would be 4 of these heatsinks in total.

BTW my cases are the fairly well known "galaxy max" from italy:

An externally hosted image should be here but it was not working when we last tested it.


Do you think that would be enough heatsink? (my case is not the exact one in the picture)

How much power does a mini aleph dissipate?
 
Aleph construction info !

BrianGT> With there still being so much interest in amps constructed using your wonderful pcb's If possible could you post some construction details for various Aleph versions ect... Something like what you offer for the chip amps pdf posted at your site ! Im sure this would help a great number of people who are new to DIY my-self included. Again many thanks for those beutiful black pcb's !
 
Retired diyAudio Moderator
Joined 2002
I just spotted this old thread.

Here is the BOM parts list from the old diyamps.com website:
http://www.chipamp.com/diyaudio/mini-A.xls

and as for the schematic, if you drop me an e-mail, I can send it to you.

I have a new batch of boards, and put them up at 20% off the original price of $9, making them $7.20 until the end of the month for the set, which includes 2 main amplifier boards and 4 output boards.

I am looking to start a gallery of finished amplifiers made with the boards. If you have any pics of your finished amp, e-mail them to me, and I can add them to my gallery. If I get 5 people to send me pictures from their build, I will randomly pick one of them and send them off a free pcb set :) I like seeing how people choose to implement their amplifiers.

--
Brian
 
Aleph-X PCB any left

Hi BrianGT. Do you have any Aleph-X PCB left, see image. Thanks...
 

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Hi !
I'm building a standard Mini-A using BrianGT's boards (Amp+PSU) with a 2x12V toroid, hoping 15v at the rails. I need about 10W.

I was wondering about some questions :
1° - A strap is required for R3 and R12. Please confirm.
2° - Could the PSU board be fed with 2 Leds and a single 10K R ? Please confirm.
3° - I'm planning to use 2x(22000µF/10000µF/3K3/10000µF) in this order. I'm right or not ?
Would it be a better solution with 22000µF/22000µF/3K3/10000µF ?

Nice to read from the expert ! ;)
 
I have built one of these - I can show some pics if that would be any help?

An externally hosted image should be here but it was not working when we last tested it.


1. Don't know about R3 and R12.
2. With 12V rails about 2-3K is enough for a single resistor. Maybe 1K -1.5K if the LEDs are in series. There are online LED resistance calculators..... see here:
http://led.linear1.org/1led.wiz
3. I would have thought that 3k3 is way too high for the PS resistor - should this not be much smaller, something like 0.33R? My caps are 15000, 15000, 0.33R (I think) and then 15000 again. 25V caps.


Also, I don't think you will get 15VDC out of a 12V transformer - but you might get close (esp under load).




Fran
 
Hi woodturner-fran and john65b

Yes you're right, my mistake, 3K3 is the bleeder resistor value...
I was wondering about 0.47R or 0.33R/3W for the PSU resistor.

What is your opinion about caps order and amount ?
1° - 22000µF/10000µF/0.47R/10000µF
2° - 22000µF/22000µF/0.47R/10000µF

Nice to see you care ;)
 
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