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Old 12th April 2005, 09:45 AM   #1
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Default 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

and

GEC 912+

Help appreciated,
thanks,
FrankieS
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Old 12th April 2005, 01:28 PM   #2
EC8010 is offline EC8010  United Kingdom
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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.
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Old 13th April 2005, 03:31 PM   #3
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Hi,
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,
FrankieS
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Old 13th April 2005, 04:21 PM   #4
EC8010 is offline EC8010  United Kingdom
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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).
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Old 13th April 2005, 05:04 PM   #5
Yvesm is offline Yvesm  France
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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

Yves.
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Old 13th April 2005, 05:15 PM   #6
EC8010 is offline EC8010  United Kingdom
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As you say, there's nothing earth-shattering about the design
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Old 13th April 2005, 06:01 PM   #7
Yvesm is offline Yvesm  France
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Quote:
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%"

Yves.
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Old 13th April 2005, 06:36 PM   #8
EC8010 is offline EC8010  United Kingdom
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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...
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Old 13th April 2005, 06:52 PM   #9
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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 ???

bye,
FrankieS
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Old 7th January 2007, 09:08 PM   #10
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Thumbs up 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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