Uberschall Tube layout

  • Thread starter Thread starter iamjoe
  • Start date Start date
iamjoe

iamjoe

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BognerUberschallTubeLayout.jpg


Can someone help me identify V1 - V6?
 
Not sure I follow, the diagram you posted shows where they are, with the bottom of the diagram being the front of the amp. Are you looking for what they do? If so, here it is:

V1 = Input stage for both channels
V2 = 2nd and 3rd gain stage for channel 2
V3 = 4th and 5th gain stage for channel 2
V4 = 2nd gain stage for channel 1, single triode only
V5 = FX loop
V6 = Phase inverter **always replace when changing power tubes

V7-V10 = allways replace full set and PI at same time. MUST be re-biased for optimal performance and tube life.

Hope this helps, lemme know if it wasn't what you were asking.

\m/
 
Thanks! My uber is making crackling, swooshing sounds on the clean channel. Going to do some tube swapping.
 
Swooshing can be preamp. Crackling can be powertubes.

How old are your powertubes??
 
I sometimes get crackling with new tubes as they burn in. It should go away after a few uses.
 
If there is a sound on one channel over the other, it could very well be the preamp tubes for that particular channel. When you put in the new power tubes, did you bias it up? Did you change the V6 PI tube and put in a new balanced one? Like Leib10 said, the powertubes do need some burn in, so that may likely resolve itself. Keep us posted!
 
Thanks guys.

New power tubes, biased per Charley's recommendations, new Ruby 12ax7 in V6, new tungsol reissue in V1. Clean channel is not usable, the noise is too much.
Charley suggested that I swap out all preamps to Chinese 12ax7b so I am going to order a few.
 
Weird, I wonder if there is an issue with V4? You bought this one from Adlene, correct?
 
JPH-214":2jdmj4w1 said:
Weird, I wonder if there is an issue with V4? You bought this one from Adlene, correct?
Click to expand...


Yes sir, Funny thing, now the noise has made it over to channel two.
Tubes are on order.Will know shortly if it needs to go to a tech.
 
All good now, I replaced all pre-amps with Chinese 12AX7B (per Charley) and we are back in business. Found the culprit tube too, V1.
Back in business!
 
Great info in the beginning and diagrams. Just bought a twin jet and about to put some badass vintage tubes through it!
 
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