JLH amp pcb

Khron · 10th December 2007, 01:31 PM

Greetings everyone...

I'm keen on building a pair of (updated) JLH amps to drive the tweeters in my bi-amped system. I've devised a pcb for them, and i'm currently seeking validation and maybe some tips for improving the layout.

The schematic can be found at this site .

I'm attaching the current layout here.

jmateus · 10th December 2007, 01:54 PM

Nice PCB
What kind of outputs are you considering for this design?

Khron · 10th December 2007, 02:00 PM

Following some recommendations from that site, i was considering MJL21194's. It's said to oscillate if faster devices are used.

PS: another reason is that i can source some as samples from OnSemi

pilli · 10th December 2007, 03:15 PM

Have you already seen this site?

http://members.shaw.ca/paul.r.brown/...%20Moss%20JLH/

_

Khron · 10th December 2007, 03:27 PM

I think i stumbled upon that page sometime, but the board is quite big. It says somewhere that the board is 160x100mm. Mine is about 1/4 that size (around 85x50mm), and in don't really have any huge cases available at the moment

Nico Ras · 10th December 2007, 03:36 PM

Quote:

Originally posted by Khron
Greetings everyone...

I'm keen on building a pair of (updated) JLH amps to drive the tweeters in my bi-amped system. I've devised a pcb for them, and i'm currently seeking validation and maybe some tips for improving the layout.

The schematic can be found at this site .

I'm attaching the current layout here.

Personally, I would move the caps to the other side of the power transistors so that the feedback path is much shorter.

Kind regards
Nico

Nico Ras · 10th December 2007, 03:42 PM

If you are going to use it for your tweeters only, why need to double up on the power transistors, one pair would be more than adequate for 10 watts or so.

Regards

Nico

Nico Ras · 10th December 2007, 03:54 PM

Experimented with this one using Mosfets some weeks ago. Sounds great and good for about 12 watts.

I have no idea why use CCS they make neither sonic nor measurable difference.

Nico Ras · 10th December 2007, 04:14 PM

Then what about this, which includes your HF filter. The output cap is also nice for protecting your delicate tweeter against dc.

Ciao

Khron · 10th December 2007, 04:15 PM

I took your advice and moved the caps. I had a bit of work uniting the grounds, but i hope i haven't messed it up more than it was before

10th December 2007, 01:54 PM	#2
jmateus diyAudio Member Join Date: Mar 2003 Location: US, New Jersey	JLH amp Nice PCB What kind of outputs are you considering for this design? __________________ JLH 2005, Cyrus and so on...

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10th December 2007, 02:00 PM	#3
Khron diyAudio Member Join Date: Jul 2005 Location: Finland	Following some recommendations from that site, i was considering MJL21194's. It's said to oscillate if faster devices are used. PS: another reason is that i can source some as samples from OnSemi

10th December 2007, 03:15 PM	#4
pilli diyAudio Member Join Date: Aug 2006	Have you already seen this site? http://members.shaw.ca/paul.r.brown/...%20Moss%20JLH/ _

10th December 2007, 03:27 PM	#5
Khron diyAudio Member Join Date: Jul 2005 Location: Finland	I think i stumbled upon that page sometime, but the board is quite big. It says somewhere that the board is 160x100mm. Mine is about 1/4 that size (around 85x50mm), and in don't really have any huge cases available at the moment

10th December 2007, 03:42 PM	#7
Nico Ras diyAudio Member Join Date: Nov 2005 Location: Amanzimtoti - East Coast of South Africa	If you are going to use it for your tweeters only, why need to double up on the power transistors, one pair would be more than adequate for 10 watts or so. Regards Nico

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