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Old 12th June 2007, 06:47 PM   #11
Tweeker is offline Tweeker  United States
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Triode is least sensitive as to OPT load.

If your using full wave rectification, you can drop voltage with a zener on the center tap.

Quote:
Just connect G2 to the anode with 100 ohm and g3 to the cathode?
Pretty much. Some sources recommend 200 ohm screen stoppers on these, but I dont know that thats necessary.
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Old 12th June 2007, 06:50 PM   #12
beamnet is offline beamnet  Netherlands
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Thanks tweaker! that helped a lot.

I have no center tap, but elsewise a good idea!
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Old 16th June 2007, 06:00 PM   #13
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Could you please send the PP GU50 Ampli? I've been interesting this.

Thank you very much

Happy D.I.Y
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Old 16th June 2007, 07:00 PM   #14
beamnet is offline beamnet  Netherlands
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This is what works well for me, but must be seen as a prototype!
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File Type: gif gu50pp.gif (13.3 KB, 476 views)
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Old 16th June 2007, 07:03 PM   #15
beamnet is offline beamnet  Netherlands
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The 7193 is 1/2 6sn7

I would recommend e1148 tubes there. These are wonderfull if you can get the non microphonic ones...

CV6 work a champ too with beefier music.
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Old 16th June 2007, 08:29 PM   #16
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Quote:
Originally posted by beamnet
The 7193 is 1/2 6sn7

I would recommend e1148 tubes there. These are wonderfull if you can get the non microphonic ones...

CV6 work a champ too with beefier music.

Dear Sir,

Thank you very much for your soon support. I'm very high appreciation.

I'll try to do it by myself follow your schematics.

I did make a Single End GU 50 Ampli, using 6H8C for pre tube, D.I.Y PSU & OPT, it sounds very good.

I'am very sorry with my English

Thank you very much

Best regards,
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Old 16th June 2007, 08:35 PM   #17
beamnet is offline beamnet  Netherlands
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I use 6n6p instead of the ecc99. I think it sounds better....

You ARE using the GU50's with the steel sockets are you? I can't see why people think they are ugly!

Bas
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Old 18th June 2007, 04:01 PM   #18
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I also like 6H6P instead of ECC99 tube.
So far, I've been made the chassi and PSU for PP GU50. The next is OPT and choke.

I think, the steel sockets are not ugly, they make me feel safe and easy to determine heater, cathode, anode and grid point.

Thank you very much for your advice me use 6H6P

Best regards,

thomas-NGU
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Old 18th June 2007, 07:49 PM   #19
igormak is offline igormak  Russian Federation
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Bas, I made amp in 1986 with close schematic, shortly:
1/2ecc82(pre)-1/2(phase) - 6n6p(driver)-gu50, PP, UL,
Ua 560V, FB 10db, Diods bridge rect. Bias fixed smth near -50V as i remember. It was my first amp with self made toroids opts. I was very happy with it 5 years, later i present it to my friend. So, i think u will like gu50's. They have a bit sharpy sound, but that for taste.

imho UL mode the best, but need careful approach. OPT the most important thing. Better to listen all variants. Avoid using resistors in cathodes they spoils a lot. Put 1 ohm to measure current and finally remove.
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Old 18th June 2007, 08:15 PM   #20
beamnet is offline beamnet  Netherlands
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The ecc82 is known to be sounding a bit sharp. I have no Fb and bandcore OPT's. It sounds good in penthode mode.

Currently too busy to try the mods, a shame...

The use of the E1148 was a "golden choice" in this amp. It's like 400% better than any 6sn7 i tried there.

The ecc99 are good sounding tubes, but i actually put in the 6n6p to clear up the highs...

Bas
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