JLH 75 Watt amp - Does anyone have the original article?

[jez]

I would be very interested to read the original Hi-Fi News article/s on the JLH 75 Watt amp.
The actual schematic is readily available, but I have never seen the full original article.... I would guess that it should provide considerable insight into the thinking of JLH regarding his design decisions and into the general thinking of the era in this matter.
So.... anyone got the above article and willing to scan it and put it up on this site? or even PM me on the matter?

[AndrewT]

the 80W that came a few years later is also a good read.
Some have criticised his foldback regulator's performance.

Is there anything in the site dedicated to JLH's designs?

[jez]

Hi Andrew,
Hmm.... we could well live only about 40 or 50 miles away from each other, just about neighbors in the context of this site!

There is the class a amplifier site:

The Class-A Amplifier Site - JLH Articles

Which is a treasure trove of JLH material (and much more!)
I believe Geoff is a member on this site actually...

I am familiar with most of JLH's work and have various copies of the schematic for the amp, BUT I have never seen the actual article/series in Hi-Fi News (1972?). It would be interesting to read this and get some background on this seminal design.

[seroxatmad]

Hi

I have the article i can scan for you.

John

[nigelwright7557]

Maplin electronics used to sell a kit for a JLH 50 watt amplifier.

I built one and it sounded very good.

[jez]

John,
Thanks for the offer to scan the articles for me. Most appreciated. I look forward to reading it.
And in reply to your P.M. no I didn't study at Durham.....

[AndrewT]

Hi Serox,
could you turn on contacts.
I would like to send my Email address.

[seroxatmad]

Hi Andrew

I have added you as a friend and sent you my email address. My contacts are on i think...

I actually have a few articles i collected around 80s/early 90s I will make a list and scan any people are interested in.

John

P.S I cant find the early copy of the JLH 75W amp but will keep looking...only the 1985 version (d) below. I should have a Gramaphone? review of it some were which sang its praises above a Naim Audio amp!


These are available I will scan ASAP and add them to my website for people to download:

a) Class One Sound Amplifier - Everyday Electronics Jan 1989 - Graham Nalty
b) The PE 30 Plus 30 - Practical Electronics Feb-Apl 1987 - Graham Nalty
c) Virtuoso Power Amplifier - ETI April 1988 - Graham Nalty
d) Audio Design Amplifier - Electronics Digest - John Linsley Hood
e) System A Amplifier - Electronics Digest Winter 1985/1986 - Stan Curtis (Pre and Power class-a)
f) Mosfet Amplifier - Maplin Magazine Dec 1990 - Dave Goodman
g) HexFet Amplifier upgrade - Elektor Electronics Sept 1995 - T Giesberts
h) Robust AF Power Amplifier - Elektor Electronics July 1994

After collecting these in my college days I cheated and bought a Mission Cyrus One instead which I used for 24 years!

[franco61]

Hi jez, I know that this is an old posting but I built a Linsley Hood 75 Watt amp "De Luxe"! in the early '80's. I still have the build manual which is prefaced by some extracts from Hi Fi news articles. Please let me know if this might be of any use to you.
Regards. Frank.

[Andy5112405]

I built the JLH80. The PSU was a bit dissappointing. Far better with CRCRC than with JLHs regulated effort. I have all the parts lists, build manual, the works that came with the Hart Kit.

This dates from about 1994. It's still working today, it's been repaired many times though. Amps were fine it was the PSU and Input Relay boards that seem to be problematic.

JLH has unfortunately passed away R.I.P. he was a great man.