Where to find 6000uF 50V replacement cap cans??

[Miyagi_83]

What about these two plugs (marked with pink-ish arrows)? Shouldn't they be connected?

[RG100ESROX]

What about these two plugs (marked with pink-ish arrows)? Shouldn't they be connected?

They are. I disconnected that one so I could photograph the board better.

[Miyagi_83]

They are. I disconnected that one so I could photograph the board better.

Ok, next question. While working on the amp, did you loosen any screws, bolts, or nuts on transistors, sockets, or anything? If so, you might have missed one or two when putting it back together and they might rattle from the vibration.

If you're sure it's not mechanical rattle, I suggest you record a sample of the distortion and post it here.

[g1]

If you connect generator to the FX return jack, can you get full power with a clean sine wave into a dummy load?
If so, what signal level is required from the generator to get there?

[RG100ESROX]

If you connect generator to the FX return jack, can you get full power with a clean sine wave into a dummy load?
If so, what signal level is required from the generator to get there?

Do I need to be concerned with anything other than the dummy load getting hot. Or is that even a concern?

Also, should everything be set to zero, with the exception of a minimal setting on the volume and gain of the green channel? Or do you want me to use the red channel?

[Miyagi_83]

Jay, the dummy load will get hot. It soaks power in, so that's the way it is. If you haven't done it yet, put a heatsink on it.

If you plug your signal generator into the FX loop return, the preamp should make no difference. Personally, however, I would turn every knob on the preamp down to zero in case any noise were to bleed through. Maybe I'm paranoid, I don't know.

I don't know what circumstances you are under at the moment, but there are a few questions and requests that you haven't responded to.

From g1
1. If you connect generator to the FX return jack, can you get full power with a clean sine wave into a dummy load?
If so,...
2. what signal level is required from the generator to get there?

From me
3. Are you sure the distortion is not mechanical rattle? You know, from a loose screw, bolt or nut on a transistor, socket, switch, etc.? Or maybe something in the room is vibrating? If it's definitely not mechanical...
4. Could you record a sample of the distortion you're talking about so the more experienced guys can get an idea of what we're dealing with? Even with your phone perhaps?
*I, as an inexperienced guy, would like to learn from that as well.

[RG100ESROX]

Jay, the dummy load will get hot. It soaks power in, so that's the way it is. If you haven't done it yet, put a heatsink on it.

If you plug your signal generator into the FX loop return, the preamp should make no difference. Personally, however, I would turn every knob on the preamp down to zero in case any noise were to bleed through. Maybe I'm paranoid, I don't know.

I don't know what circumstances you are under at the moment, but there are a few questions and requests that you haven't responded to.

From g1
1. If you connect generator to the FX return jack, can you get full power with a clean sine wave into a dummy load?
If so,...
2. what signal level is required from the generator to get there?

From me
3. Are you sure the distortion is not mechanical rattle? You know, from a loose screw, bolt or nut on a transistor, socket, switch, etc.? Or maybe something in the room is vibrating? If it's definitely not mechanical...
4. Could you record a sample of the distortion you're talking about so the more experienced guys can get an idea of what we're dealing with? Even with your phone perhaps?
*I, as an inexperienced guy, would like to learn from that as well.

With initial power up this morning, and with a 8Ω dummy load plugged in. My idle bias current rose extremely fast and way too high to proceed (trim pot set to FCCW.)

Could this be an indication of the issue with the amp?

How to proceed?

[Miyagi_83]

With initial power up this morning, and with a 8Ω dummy load plugged in. My idle bias current rose extremely fast and way too high to proceed (trim pot set to FCCW.)

Could this be an indication of the issue with the amp?

How to proceed?

Did it rise at idle or with signal applied?

[RG100ESROX]

With initial power up this morning, and with a 8Ω dummy load plugged in. My idle bias current rose extremely fast and way too high to proceed (trim pot set to FCCW.)

Could this be an indication of the issue with the amp?

How to proceed?

Did it rise at idle or with signal applied?

With the .1mA 1KHz signal applied...

I checked and this happens with or without a signal applied.

[RG100ESROX]

With initial power up this morning, and with a 8Ω dummy load plugged in. My idle bias current rose extremely fast and way too high to proceed (trim pot set to FCCW.)

Could this be an indication of the issue with the amp?

How to proceed?

Did it rise at idle or with signal applied?

With the .1mA 1KHz signal applied...

I checked and this happens with or without a signal applied.

If I remove the dummy load. The idle current with or without an injected signal is about 5mV.

[Miyagi_83]

What is different from the previous setup when it was more or less functional?

[RG100ESROX]

What is different from the previous setup when it was more or less functional?

Everything is setup exactly as it was at my house, only it's all setup at my folks house, AND...we're injecting the signal in at the FX return instead of at the hi input jack and running it through the preamp. That's the only difference between last time I had everything setup and now.

[Miyagi_83]

AND...we're injecting the signal in at the FX return

This shouldn't make a difference other than the signal being processed (amplified, clipped, shaped etc.) when going through the preamplifier. You can plug your guitar straight into the loop return and play it like that, no problem. Not that you will like the results, but you can. I have done this a number of times.

Did you build that attenuator to control the signal level going into the return jack?

Also, do you have another dummy load resistor to try?

Have you tried playing the amp at your parents' house before you took those alarming measurements?

If I remove the dummy load. The idle current with or without an injected signal is about 5mV.

If I understand it correctly, when you inject a signal, it's no longer idle. Idle is when NO SIGNAL is being applied, so the device is not amplifying anything except noise, it's idle.
When you put a signal in, the output devices will conduct, so the current through the output devices and anything in series with them will rise. Correct me if I'm wrong, anyone.

[g1]

Do not proceed with signal if you have a problem with idle current (no signal).
Get that sorted out first.
Disconnect anything plugged in to input or FX return.
It is critical that the (-) side of the output jack does not get connected to chassis ground (because R63).  Sometimes the test equipment can do this.
Make sure there is no DC at the output.  If so connect the speaker.
With no signal, do you hear much hum?  Does the idle current through the emitter resistors rise?

As Miyagi stated above, when the amp is running properly, delivering power to the load will increase the current through the output transistors.  This is normal, and not idle current, but working current.

[RG100ESROX]

AND...we're injecting the signal in at the FX return

This shouldn't make a difference other than the signal being processed (amplified, clipped, shaped etc.) when going through the preamplifier. You can plug your guitar straight into the loop return and play it like that, no problem. Not that you will like the results, but you can. I have done this a number of times.

Did you build that attenuator to control the signal level going into the return jack?

Also, do you have another dummy load resistor to try?

Have you tried playing the amp at your parents' house before you took those alarming measurements?

If I remove the dummy load. The idle current with or without an injected signal is about 5mV.

If I understand it correctly, when you inject a signal, it's no longer idle. Idle is when NO SIGNAL is being applied, so the device is not amplifying anything except noise, it's idle.
When you put a signal in, the output devices will conduct, so the current through the output devices and anything in series with them will rise. Correct me if I'm wrong, anyone.

Q:Have you tried playing the amp at your parents' house before you took those alarming measurements? YES. I RECORDED A SOUND DEMO OF THE DISTORTION I AM GETTING FROM THE AMP. TRUST ME, SOME MIGHT SAY IT SOUNDS FINE, BUT IT'S NOT. IT'S THE BAD KIND OF DISTORTION SITTING ON TOP OF THE GOOD DISTORTION.


Q:Did you build that attenuator to control the signal level going into the return jack?
I'M SORRY...I COMPLETELY FORGOT ABOUT THIS THING. MY APOLOGIES. I WILL NEED TO BUILD IT. SO, NO, IT WAS NOT USED WHEN INJECTING THE SIGNAL INTO THE FX RETURN. ONCE I HAVE THE POT BUILT, I'LL TRY THIS AGAIN AND GET BACK TO YA. THIS IS WHY THE IDLE BIAS CURRENT WAS SO DAMN HIGH. GEEEEEEEZE....

I AM ASSUMING THAT THIS WILL WORK IN PLACE OF THE 22K POT THAT I WAS SUPPOSED TO BUILD...? I BROUGHT MY RESISTOR SUBSTITUTION BOX WITH ME. I'LL START OUT AT THE 1M, AND ADJUST ACCORDINGLY FOR THE OUTPUT SIGNAL INJECTED AT THE FX RETURN?? AND YES, I AM GOING TO HAVE TO DO SOME CREATIVE WIRING IN ORDER TO USE THE SUBSTITUTION BOX.

Q:Also, do you have another dummy load resistor to try?
I DO NOT. JUST THE ONE (disregard how you see the dummy Load box connected in the photo. it's for the image of the box only.)