JL Hood schematic circa 1985?

pmkap · 12th July 2003, 01:58 AM

Would anyone know where I can find the schematic, etc... first published in Electronics Digest, Winter 1985. Geoff Moss's 'Class A Website' is MIA, and Google hasn't shown it.

I'm specifically interested in the feedback network.

Thanks in advance.
Paul

Nisbeth · 12th July 2003, 09:23 AM

Which schematic (from Geoff Moss' site) is it you're interested in, specifically? I think I saved most of it to my HD after the last update. If you want I'll look for it

/U.

pmkap · 12th July 2003, 04:36 PM

Nisbeth,

I'm not sure which schematic it is, whether its MOSfet or BJT....
I only know it uses an unusual feedback scheme with the typical electrolytic to ground replaced with a series film cap (with a topological change).

The schematic was referenced in an aritcle in Audio Amateur 1996, issue 1. by Richard Guest, 'On Power Amplifier Feedback Networks". It uses the typical JLH Cdom 5pf from the Vas collecter to the feedback node, 150k & 1.2k resistors, and 9.4mmf cap.

So I actually know the confiuration and values of the feedback scheme, but I don't know the context in which it was implemented.

Thanks,
Paul

pmkap · 13th July 2003, 12:30 AM

Nisbeth,

Thanks for your kind offer. Geoff just emailed me a scan of the circut.

Thanks again,
Paul

Audiofanatic · 13th July 2003, 11:04 AM

Quote:

Originally posted by pmkap
Nisbeth,

Thanks for your kind offer. Geoff just emailed me a scan of the circut.

Thanks again,
Paul

Hi Geoff,

Would it be possible for you to e-mail me the schematic too?

Thanks in advance,

Audiofanatic

rchua77 · 18th July 2003, 05:29 PM

Hi,

could anyone email me the updated latest schematic of the JLH SE BJT amplifier? Been looking for it on the web but the site seems to have closed down. email addy is rchua77@hotmail.com

Regards
Chua

12th July 2003, 01:58 AM	#1
pmkap diyAudio Member Join Date: Aug 2001 Location: NYC	JL Hood schematic circa 1985? Would anyone know where I can find the schematic, etc... first published in Electronics Digest, Winter 1985. Geoff Moss's 'Class A Website' is MIA, and Google hasn't shown it. I'm specifically interested in the feedback network. Thanks in advance. Paul

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12th July 2003, 09:23 AM	#2
Nisbeth diyAudio Member Join Date: Jan 2001 Location: Denmark	Which schematic (from Geoff Moss' site) is it you're interested in, specifically? I think I saved most of it to my HD after the last update. If you want I'll look for it /U.

12th July 2003, 04:36 PM	#3
pmkap diyAudio Member Join Date: Aug 2001 Location: NYC	Nisbeth, I'm not sure which schematic it is, whether its MOSfet or BJT.... I only know it uses an unusual feedback scheme with the typical electrolytic to ground replaced with a series film cap (with a topological change). The schematic was referenced in an aritcle in Audio Amateur 1996, issue 1. by Richard Guest, 'On Power Amplifier Feedback Networks". It uses the typical JLH Cdom 5pf from the Vas collecter to the feedback node, 150k & 1.2k resistors, and 9.4mmf cap. So I actually know the confiuration and values of the feedback scheme, but I don't know the context in which it was implemented. Thanks, Paul

13th July 2003, 12:30 AM	#4
pmkap diyAudio Member Join Date: Aug 2001 Location: NYC	Nisbeth, Thanks for your kind offer. Geoff just emailed me a scan of the circut. Thanks again, Paul

18th July 2003, 05:29 PM	#6
rchua77 diyAudio Member Join Date: Jul 2003 Location: Back in Singapore	Hi, could anyone email me the updated latest schematic of the JLH SE BJT amplifier? Been looking for it on the web but the site seems to have closed down. email addy is rchua77@hotmail.com Regards Chua