"An Adjustment-Free Complementary Power Amplifier" by J.Diamond

[jez]

HI lineup, djk,
It does seem a pity that even ancient history articles from 1969 which can surely have no proprietory use by now are still not in the public domain.
I often find that a referenced text from a technical article is either completely unavailable or only from a "closed to non members site" (really must get round to applying for AES membership).
Sometimes a Google search will only comeback with other articles which also reference the same text, most frustrating

I started a thread on here about a couple of years ago about this matter, the jist of which was "why not have a repository of classic technical articles, application notes etc here on diy audio as a WIKI?" There was an overwhelming lack of interest
only a few replies..... mostly along the lines of OK, you do it then!... I have niether the time or the resources.

djk; I tried that again this morning. Same result. "Save target as" just saves "login html"....Oh well, I'll take up Tony's offer to e mail it to me
Jez.

[gbyleveldt]

Tried it first time and it showed "Login.htm", tried it immediately again and then it downloaded properly

[jez]

I have now received the article from Tony via e-mail (thanks) but after trying maybe 30 times to replicate the results that others have got I still just get login.html every time.

[richie00boy]

I just tried about 10 times and only get login.htm. Are you guys having success downloading while at work? Maybe your company has access to IEEE by IP address, no login required. I think my old company did.

[lineup]

richie00boy

see you have several Power Supply, PSU
projects at your website
Very useful .. because any other Diy Audio Project
... will need one supply .. some times more than 1 supply

It is all free (not like IEEE) for non-commercial use!

Projects
All designs will be published in full detail on this website for people to use freely (for non-commercial, personal use).

richie00boy, website:
http://www.readresearch.co.uk/html/projects.htm


thanks!
Lineup

[gbyleveldt]

Originally posted by richie00boy
I just tried about 10 times and only get login.htm. Are you guys having success downloading while at work? Maybe your company has access to IEEE by IP address, no login required. I think my old company did.

Nope, not as far as I know. Just tried it now again at work as I have it on my PC at home. Worked after the 3rd attempt.

I can send it to you if you want.

[richie00boy]

Ha I just tried again and after the 3rd time it worked! Thanks for the offer.

[richie00boy]

Well I'm glad I didn't pay for that. It's just a basic amp with diode bias string and the "revolutionary" thinking of using output device emitter resistors and slightly more bias voltage than the output and driver combined Vbe's, and bonding the diodes to the output devices to stabilise thermal drift. The author was well happy with obtaining 0.2% THD. Well it was 1969 lol.

[gbyleveldt]

Sweet, you came right then

Originally posted by richie00boy
The author was well happy with obtaining 0.2% THD. Well it was 1969 lol.

And that without feedback

[lineup]

AKSA Hugh Aspen Amplifiers
and me, too
have one design criteria of max THD limit ~0.05%

The resoning is that around this very low level = 0.1% THD
human hearing can not perceive any harmonic distortion, by ear.
Is our limit of hearing distortions.
Something like -60 dB.
At least perception beyond this point has never been confirmed & documented.
By any valid listening tests.

So, by using this criteria of a good amplifier
we can rest assure we make pretty good hi-fi amplifiers.

One notice:
Was not long ago even power amplifiers specifications
used: Max Power output at THD=10%
For Car Audio amplifiers, stil many use the 10% distortion level
to tell how powerful one amplifier is

Today many tell Max Power RMS at THD=1.0% level.


For we, the older people. Who was around 1950, 1960, 1970
we have had & listened to good music through several Power Amps
that had more THD than 0.2%.
I can tell we even enjoyed that 60-ies music maybe MORE
than anyone can enjoy music today.

The Beatles, The Rolling Stones,
Bob Dylan, Elvis Presley
Bob Marley, The Queens
... do I need to mention more

Lineup Car Audio Amps

.