Allied Knight conversion issue

[mattnorthrop]

Hello all,

I'm in the process of converting an old 50s Allied Knight amp (with 6v6s power section and 5y3) into a 5E3 circuit, but with a few exceptions: One, its only one channel (only 1/2 of the 12ay7 is being used); two, i opted for a treble/bass tone stack instead of the more typical tweed deluxe setup. Besides this, everything else is wired as a 5E3.

My question is this: When its turned on with a guitar plugged in, the volume is adjustable, but relatively low and a really ugly distortion comes out at all volumes. I figured I wired something wrong, but I can't seem to find the problem.

Any idea of what's going on?

Many thanks for any help you all would be able to provide!

[bnwitt]

Matt,
do you have a layout as wired that you can share?
Barry

[mattnorthrop]

yes, although I will have to wait until next weekend to post it.

Many thanks for your help!

-Matt

[mattnorthrop]

Well, I figured the problem out: loose solder joint.

However, now I have another question:

When the amp is turned on (with standby switch off) it warms up just like any tube amp should. When the standby switch is turned on, the amp plays and sounds as expected. However, if the amp is on and the standby switch is then turned off (with the amp on), there is a buzzing noise that gradually decreases, but doesn't completely go away. If the standby switch is then turned back on, the amp sounds completely normal with no buzz.

I installed the standby before the filter caps, just as it is usually done. Any ideas as to what this is?

Thanks for your help!

[Dave Curtis, dB AudioTech]

Well, I figured the problem out: loose solder joint.

However, now I have another question:

When the amp is turned on (with standby switch off) it warms up just like any tube amp should. When the standby switch is turned on, the amp plays and sounds as expected. However, if the amp is on and the standby switch is then turned off (with the amp on), there is a buzzing noise that gradually decreases, but doesn't completely go away. If the standby switch is then turned back on, the amp sounds completely normal with no buzz.

I installed the standby before the filter caps, just as it is usually done. Any ideas as to what this is?

Thanks for your help!

It's your amp's way of telling you that it's already warmed up. That's really the only time it's needed, and IMO, the only time it should be used.

If it's warmed up and you power off, then power up in standby, does it buzz?

What frequency is the buzz; 60 or 120hz? I'd recheck and confirm the wiring/switch/rectifier.

[baddog]

However, now I have another question:

Quote:
When the amp is turned on (with standby switch off) it warms up just like any tube amp should. When the standby switch is turned on, the amp plays and sounds as expected. However, if the amp is on and the standby switch is then turned off (with the amp on), there is a buzzing noise that gradually decreases, but doesn't completely go away. If the standby switch is then turned back on, the amp sounds completely normal with no buzz.



Where do you have the center tap for the ouput transformer connected. If it is at the rectifier move so it is after the switch. I had the same problem that dissapeared after i moved the center tap. Let us know if it works

Baddog