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scherffi 12th April 2005 09:45 AM

Gec 912+
Hi all !

Does anybody have a schematic (+ maybe more, f.ex.
description of function etc.) of the following
tube amps, and willing to email me a scan ???

GEC 912


GEC 912+

Help appreciated,

EC8010 12th April 2005 01:28 PM

I have the original GEC booklet, but there's quite a bit of it and it's likely to generate very large files when scanned.

scherffi 13th April 2005 03:31 PM

scan size
thanks for the reply.

What do you think how big the files would be
and how many pages of text/description?

Would a photography with a digital camera be
an option?

If there is text it would suffice if it is just legible.
But it would be nice if the the schematic has
an acceptable quality.

I'm still interested...

But maybe somebody else has a schematic-jpg-
on his hard disk???

Thanks again,

EC8010 13th April 2005 04:21 PM

If you would like to temporarily enable emails (in your user profile), I can email you and send you a scan of the drawing (695k).

Yvesm 13th April 2005 05:04 PM

Hey guys !

By the way, it's nothing more than an PPUL with EL84 / 6BQ5 driven by a concertina with an ECC81 / 12AT7 (or ECC85 in later versions)

A simple and good design. All is in the OPT :D


EC8010 13th April 2005 05:15 PM

As you say, there's nothing earth-shattering about the design

Yvesm 13th April 2005 06:01 PM


Originally posted by EC8010
As you say, there's nothing earth-shattering about the design
But this doesn't mean it's bad !

From the paper I have, the OPT was quite poor according to today standards, and probably, the feedback loop could be simplified as well as the caps at the primary greatly reduced :)

Oh, and link caps increased a bit ;)

Interrsting too, GEC departs from the "sacro saint" 43% taps, they just state "20 to 50%" :cool:


EC8010 13th April 2005 06:36 PM

Yes, the output transformer was terrible. Many years ago I acquired a 912 plus the booklet of instructions. The amplifier was let down by its output transformer...

scherffi 13th April 2005 06:52 PM

email enabled
Hi EC8010 !

Have enabled email function.
Thanks in advance for sending
the schematic.

Any more suggestions (f.ex. EICO ...) for a nice
EL84 push pull amp ???


John King 7th January 2007 09:08 PM

the 912 & 912+
I have a great respect for the GEC 912 and built several
the amplifies lends itself to several build configurations
Mono blocks separated preamp & power supply.
DC heaters in the front end make it exceptionally quiet
amplifier. I remember at the time I bought the New Quad
3-0-3 Transistor amplifier, didn't see any appreciable
improvement over the 912, Precision Windings at Bognor
make a superb audio output transformer for the 912,

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