Egnater Tweaker 15 Problem

  • Thread starter Thread starter xnanx
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xnanx

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I have another problem. When i turn the Amp on, everything's ok. But when Amp is on, the first sound reduces by 20% and buss and mids disappears whenever i take it in Ac mode or brit then in ac again
However, without making any changes, if i use it in ac mode, the sound reduces again after 30 minıtes and bass and mids disappear as well. It sounds as if it was plugged a 1x8 speaker from 4X12
Whenever that happens, i reopen the ampli, and then it runs normally.
The only thing i have altered in Amp is r29 470 ohm
I'd like to know what may cause that problem.
 
Hi
According to schematics the US/AC/Brit switch only changes some component (resistor/capacitor) values in the tone control part.
My guess is therefore that it could be bad solder joint between the "switch" and the board.
If one of the pins on the switch is disconnected from the board, it will affect tone and volume.
I would check the switch and its solder joints and maybe re-solder the pins to the board.
/Kalle
 
When the mids and bass disappears, what happens when you switch it to Standby? Does the amp crackle and pop?

I'm having the same trouble as you. After a while the volume drops out and mids and bass is reduced. When I switch the amp to standby it crackles. When I switch it back on it's fine again for a little bit...

I've had it at a tech before who claimed a zener diode had gone bad and was allowing current through in the wrong direction or something like that. It was fixed for a while, but started acting up again. I've not been able to take it back to him yet.

I'm no amp tech, so I can't vouch for whether the above is correct or not, but it might help you pinpoint the problem.
 
Vetseun
You can find the Tweaker 15 schematic here.
http://el34world.com/charts/Schematics/ ... matics.htm
The only zenerdiode (D1) in the amp is a part of the input gain stage ( Cascode design with two FET transistors). If the zenerdiode or other other parts of the input gain stage goes wrong, it can affect both volume and tone. But it would affect in same way at all positions of the US/AC/Brit switch.
If the Master volume and/or Gain volume is turned down, can you still hear the crackle & pop when you swith off standby ? If the crackle comes from a faulty input stage, the Gain and Master volume (zero) would block the crackle. If the crackle is not blocked by Gain volume but by Master volume, the fault is located somewhere between the Gain volume and Master volume. It could be tubes V1 or V1 (12AX7).
But if the Master volume can´t block the crackle, the fault is located after master volume control.
Maybe in the V3 (12AX7) or V2/V4 (6V6)
/Kalle
 
Kalle_in_Sweden":1miys1zk said:
Vetseun
You can find the Tweaker 15 schematic here.
http://el34world.com/charts/Schematics/ ... matics.htm
The only zenerdiode (D1) in the amp is a part of the input gain stage ( Cascode design with two FET transistors). If the zenerdiode or other other parts of the input gain stage goes wrong, it can affect both volume and tone. But it would affect in same way at all positions of the US/AC/Brit switch.
If the Master volume and/or Gain volume is turned down, can you still hear the crackle & pop when you swith off standby ? If the crackle comes from a faulty input stage, the Gain and Master volume (zero) would block the crackle. If the crackle is not blocked by Gain volume but by Master volume, the fault is located somewhere between the Gain volume and Master volume. It could be tubes V1 or V1 (12AX7).
But if the Master volume can´t block the crackle, the fault is located after master volume control.
Maybe in the V3 (12AX7) or V2/V4 (6V6)
/Kalle
Click to expand...

Thanks!! That's really great info. I'll definitely troubleshoot some more with the above in mind. :thumbsup:
 
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