Looking for info on an extremely rare tube amp

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Ibanez666
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Looking for info on an extremely rare tube amp

Post by Ibanez666 » Tue May 21, 2013 12:05 pm

Hummel Electronics `The Studio Guitar`English front text. German parts, GE 7355 power tubes and 3 12ax7 and a ECC808

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Re: Looking for info on an extremely rare tube amp

Post by Ex Lion Tamer » Tue May 21, 2013 12:16 pm

Ooooh, I totally love those knobs!

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Ibanez666
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Re: Looking for info on an extremely rare tube amp

Post by Ibanez666 » Tue May 21, 2013 12:30 pm

Hehehe ok :)

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StevenO
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Re: Looking for info on an extremely rare tube amp

Post by StevenO » Tue May 21, 2013 2:14 pm

Ex Lion Tamer wrote:Ooooh, I totally love those knobs!
There's a joke here... :shifty:

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Re: Looking for info on an extremely rare tube amp

Post by eggwheat » Tue May 21, 2013 2:55 pm

Well it is sitting on a koch..

No idea but I did have a Klein & Hummel EQ if thats the same company.

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Re: Looking for info on an extremely rare tube amp

Post by Ex Lion Tamer » Tue May 21, 2013 4:31 pm

StevenO wrote:
Ex Lion Tamer wrote:Ooooh, I totally love those knobs!
There's a joke here...
 Honi soit qui mal y pense.

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Re: Looking for info on an extremely rare tube amp

Post by sookwinder » Tue May 21, 2013 7:52 pm

this is a dumb question....

are those yellowy caps what people call "mustard caps"

reason I ask is that i have discovered my dad's workshop some caps that look like those and I am trying to work out what they are...
relaxing alternative to doing actual work ...

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Re: Looking for info on an extremely rare tube amp

Post by timbo_93631 » Tue May 21, 2013 8:11 pm

sookwinder wrote: ...are those yellowy caps what people call "mustard caps"...
Yep, Philips mustard caps

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Re: Looking for info on an extremely rare tube amp

Post by øøøøøøø » Tue May 21, 2013 8:17 pm

Well that's a first.

U-I core transformers on a guitar amp.

Oxidized laminations with the corners cut off, to me that's reminiscent of East German or maybe Czechoslovakian or Yugoslavian or Polish origin.

U-I transformers are more often seen in microphones, etc. It's a cool design... there are a lot of advantages (the biggest disadvantage being time/labor cost... dual bobbins!).

I'm used to seeing that type of transformer in microphones, etc., but never in a guitar amp.

Wild.

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Re: Looking for info on an extremely rare tube amp

Post by Ibanez666 » Tue May 21, 2013 9:32 pm

So, what are the advantages then? :)

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Re: Looking for info on an extremely rare tube amp

Post by øøøøøøø » Wed May 22, 2013 4:03 am

Ibanez666 wrote:So, what are the advantages then?
less metal used in the core, for one thing. This is probably a big part of why you often see them used in Eastern Europe during the communist era... labor was probably easier to come by than materials/alloys used in transformer laminations. It's also why they would cut the corners off the laminations... an extra labor step, but saved material.

But in audio terms, they have higher efficiency, lower capacitive coupling, and they can also be wired as humbucking, unlike an E/I core transformer!

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Re: Looking for info on an extremely rare tube amp

Post by Ibanez666 » Wed May 22, 2013 4:40 am

øøøøøøø wrote:
Ibanez666 wrote:So, what are the advantages then?
less metal used in the core, for one thing. This is probably a big part of why you often see them used in Eastern Europe during the communist era... labor was probably easier to come by than materials/alloys used in transformer laminations. It's also why they would cut the corners off the laminations... an extra labor step, but saved material.

But in audio terms, they have higher efficiency, lower capacitive coupling, and they can also be wired as humbucking, unlike an E/I core transformer!

Ok, thanks for the Info! One of the transformers says "Bayern" I believe

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Re: Looking for info on an extremely rare tube amp

Post by Ibanez666 » Wed May 22, 2013 4:42 am

The tremolo unfortunately doesnt work. But the sound is warm and a bit Fenderish. No reverb either. I will try it with some distortion and drive pedals soon :)

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Re: Looking for info on an extremely rare tube amp

Post by øøøøøøø » Wed May 22, 2013 4:54 am

tremolo is an optical design-- the optoisolator "roach" is clearly visible in your pics, and is of the same type used in black/silver Fender amps.

It's about a $10 fix, four solder joints.

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Re: Looking for info on an extremely rare tube amp

Post by øøøøøøø » Wed May 22, 2013 4:55 am

the almost home-made look of it also hints at eastern european heritage, perhaps.

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