JLH Class A

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Ray P
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JLH Class A

Post by Ray P » Thu Feb 20, 2014 8:14 pm

My first venture into DIY audio was a Hart kit of a John Linsley Hood 80W mosfet design - and very nice it was too!

JLH lived just outside of Taunton (where I live) and I was fortunate to meet him a couple of times. He was a true British eccentric and quite humble.

So I've always had a soft spot for JLH and his amps and I've long harboured thoughts of building his class A design, originally published in 1969 and updated in 1996 (with further updates here;

http://sound.au.com/tcaas/index-0.htm

Anyway, I was idling away a little time last evening and stumbled across this;

http://www.siliconray.com/free-jlh-2005 ... board.html

I found a thread on the boards over on DIY Audio and, whilst there seem to have been some issues with counterfeit components, there are some positive comments about the amp and the PCBs seem to be very well regarded. So, for the grand sum of around a tenner (mostly shipping) I've ordered a pair of amp PCBs and a pair of the power supply PCBs too. For that cost the risk is low and who knows, the boards might be OK. I'll update in due course.

Any other takers?

Ray

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Ray P
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Post by Ray P » Sat Mar 01, 2014 10:33 am

I got a package from Hong Kong.

I'm a bit ambivalent about component quality; never quite sure what you're getting from China so the caps, transistors will go in the bin; but the PCBs are nice quality. Four boards, delivered from hallway around the world, for a tenner isn't bad by in my book.

No immediate plans to build the amp just now but in due course...

Ray

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colin.hepburn
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Post by colin.hepburn » Sat Mar 01, 2014 3:54 pm

Yep this boards have been changes a bit at the output compare your schematic with the original which I got emailed to me directly from Geoff moss which is a headphone copy of the speaker amp version see headphone schematic :)
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pre65
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Post by pre65 » Sun May 03, 2015 1:19 pm

Can I ask Ray if he got these amps up and running ?
People are like stained-glass windows. They sparkle and shine when the sun is out, but when the darkness sets in, their true beauty is revealed only if there is a light from within
Dr Elisabeth Kubler-Ross

G-Popz THE easy listening connoisseur. (Philip)

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