push pull using an output transformer?
push pull using an output transformer?
-- Real Programmers Do things like this. http://webpages.charter.net/jamie_5
can anyone send a circuit diagram for self build power amps using valves.Thankyou George Black.
There are many web servers out there which can provide you with valve amplifier circuits in response to a request from your web browser.
Did you have any particular specification or configuration in mind?
Ed
>
How about a transformerless output?
Philips/Mullard produced one in the late 1950 or early 60s. I think it needed a 120-ohm speaker.
I don't believe it was ever published as a project in any of their amplifier designs books, but an outline of it was given in one of their training manuals. It looked as though the circuit was taken from one of their contemporary commercial hi-fi amplifiers.
I can't remember the name of the book but I'm pretty certain the authors were Nijsen, Schobemma and Slot.
-- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
Hello Robert,
Is "valve" rightpondian for "tube"? (hold the tomatoes...)
We did one when I was a kid and had less respect for what 900VDC could do. Rewound a speaker coil on one of those monster speakers and that was no fun at all. Then we placed large labels onto the wires, warning everyone to never ever mess with these. The first twang on that E-guitar was phenomenal. We thought the rafters would come crashing down.
Oh, and since a transformer was way over budget we opted for a "transformerless power supply". Three cascades from 230V and huge capacitors so we had enough oomph. In fact so much oomph that we could trip a 230V/16A circuit breaker.
Regards, Joerg
What i meant was no capacitor coupling to the speaker, and use of a stadard 8 ohm speaker. The directly related patents are: C.T. Hall Mar 1955 #2,705,265 (filed June 1951) J. Futterman Dec 1956 #2,773,136 (filed July 1953) R. Karsten Jan 1988 #4,719,431 (filed Apr 1986) R. Karsten Jun 2001 #6,242,977 B1 (filed May 1999) And it is fun using the new design, touching the plates and ground - and feel zilch. And a gas, unplugging a tube or three while operating - and having zero problems. The "classic" Futterman design was a bitch to operate and caused a lot of bad ingrained ideas as how bad OTL "is". Modern OTL is very stable and robust.
No tomatoes, but just a clarification:
The word 'tube' is used in the UK to mean a CRT, the picture tube of a TV or a computer monitor. 'Valve' is a thermionic device for rectification or amplification (remember when they didn't used to be tubular?).
I'm sure you all knew that anyway.
-- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
Try the book by the late John Linsley-Hood:
fred.
Hello Adrian,
I remember that from my days in Scotland. Turn on the tube or "telee". After that, hoover the carpet. Then off to pub (pronounced something like "poub") for a few pints of McEwan's Heavy. Ah, the good times.
My first tube looked the shape of a Russion Babuschka. The others were actually all tubular, including the steel ones.
Regards, Joerg
Hello Fred,
Thanks. Interesting. But I was more into RF gear in my tube days. Big tubes. I grew up with tubes because they were available for free when I was a teenager. Discarded transistorized TVs showed up much later and then I could lay my hands on hotrods like the AF126.
Audio tube amps presented in the electronic magazines were often a disappointment. To me 10 or 20 watts wasn't anything to write home about, we could build that with a few 2N3055 in those days. The monster tube amps that some of us built had to be calculated from scratch. The only reason the kilowatt range could hardly be cracked was that the typical circuit in Europe had "only" about 15 amps. One chord on the guitar and the lights went out.
Regards, Joerg
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