Amp makes no sound. Help me troubleshoot please.

[Archer250]

I have a master volume Plexi clone. Today I plugged it and it had no sound.

I switched the leads and the holes. No sound.
I cranked the volume. There was sound, but it's rather quiet. (50-watt plexi, ALL VOLUMES ON TEN)
I bypassed the effects loop. Didn't help... but there WAS a pop, so I guess that means the speakers are not to blame.

Amp turns on fine otherwise...

Anything else I can check without having to look at its guts?

 

[Powerstrokedr]

Re: Amp makes no sound. Help me troubleshoot please.

Sounds like gut check time to me.

 

[Vasshu the humanoid typhoon]

Re: Amp makes no sound. Help me troubleshoot please.

Fuse...
But why did it blow if so?

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Fuse...
But why did it blow if so?

I thought that it wouldn't turn on at all if that happens. Thanks. I'll check. They're the opaque ceramic type, though.

 

[Kamanda~SD]

Re: Amp makes no sound. Help me troubleshoot please.

There was a pop when....when you bypassed the FX loop? Try putting just a single cable from send to return, and spray in the jacks, could be shorting out there.

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

There was a pop when....when you bypassed the FX loop? Try putting just a single cable from send to return, and spray in the jacks, could be shorting out there.

Oh. Correction. There was a pop when I jumped the loop and switched between bypassed and non-bypassed

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[dystrust]

Re: Amp makes no sound. Help me troubleshoot please.

Does the amp produce sound if you plug your guitar into the effects return? That would indicate an issue in the preamp such as a dead 12AX7.

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Will try tommorow

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[Chickenwings]

Re: Amp makes no sound. Help me troubleshoot please.

Have you replaced the tubes and eliminated them as the source of your problem?

 

[Nostalgic Distortion]

Re: Amp makes no sound. Help me troubleshoot please.

Have you replaced the tubes and eliminated them as the source of your problem?

I was thinking the same thing. It seems like the most obvious place to start & just because they are hot or glowing it doesn't necessarily mean that they are good???

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Have you replaced the tubes and eliminated them as the source of your problem?

Don't have the money for a full set that sells retail (****ing retailers)... and if that's the case, I could send the amp to the builder and have him replace and maybe re-bias the tubes. He buys direct in large quantities, so it's probably cheaper that way too.

 

[Chickenwings]

Re: Amp makes no sound. Help me troubleshoot please.

replace one at a time cos it might only be one tube. A single preamp tube doesnt cost much.
If you are gigging, you should always have a spare set on hand anyway.

 

[chadd]

Re: Amp makes no sound. Help me troubleshoot please.

I have a master volume Plexi clone. Today I plugged it and it had no sound.

I switched the leads and the holes. No sound.
I cranked the volume. There was sound, but it's rather quiet. (50-watt plexi, ALL VOLUMES ON TEN)
I bypassed the effects loop. Didn't help... but there WAS a pop, so I guess that means the speakers are not to blame.

Amp turns on fine otherwise...

Anything else I can check without having to look at its guts?

When you got the pop was it loud? If sou, it sounds like a preamp problem.Testing by plugging into the return should help narrow it down.

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

When you got the pop was it loud? If sou, it sounds like a preamp problem.Testing by plugging into the return should help narrow it down.

Loud enough to give me a mini heart attack.

Will try.

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[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Just plugged into the return. Yeah. It works.

HOPEFULLY it's just the tubes and nothing else.

 

[Kamanda~SD]

Re: Amp makes no sound. Help me troubleshoot please.

Yup sounds like preamp issue or your loop still could be shorting out, your just breaking that when you plug into return.

Loud enough pop to give you a heart attack? Go thank your stars your speakers didn't blow.

Also...I get not being able to have a bunch of tubes at your disposal, but one should always have 1 or two preamp tubes handy and even an old pair of working power tubes (or pres) for situations exactly like this.

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Yup sounds like preamp issue or your loop still could be shorting out, your just breaking that when you plug into return.

Loud enough pop to give you a heart attack? Go thank your stars your speakers didn't blow.

Also...I get not being able to have a bunch of tubes at your disposal, but one should always have 1 or two preamp tubes handy and even an old pair of working power tubes (or pres) for situations exactly like this.

It's not really that loud a loop, but I didn't expect it, so I jumped a bit.

I don't *think* it's shorting out because: a) I've jumped the loop and plugged into the front; didn't work. b) I bypassed the loop completely with a switch and it didn't work either...

but I could be wrong.

 

[dystrust]

Re: Amp makes no sound. Help me troubleshoot please.

With the effects return working and the amp nearly silent when plugged into the input, my first guess would be V1.

 

[chadd]

Re: Amp makes no sound. Help me troubleshoot please.

Yup sounds like preamp issue or your loop still could be shorting out, your just breaking that when you plug into return.

Also...I get not being able to have a bunch of tubes at your disposal, but one should always have 1 or two preamp tubes handy and even an old pair of working power tubes (or pres) for situations exactly like this.

This is the time to solve the tube supply issue. Buy a full set of replacements for the amp. Replace the preamp tubes one by one until you find the bad one. Then, toss the bad one and keep the rest as spares.

 

[Archer250]

Re: Amp makes no sound. Help me troubleshoot please.

Yeah. It's the preamp tubes... V1 specifically. Had v1 and 2 replaced with Sinos and the amp modded further a bit.

I'm getting it back tomorrow

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