New amp day bummer

[AutomationBias]

I just got a used 50 watt Metropoulos in the mail today and something is definitely not right with it. It doesn't start breaking up until around 8, and then it sounds like a kazoo. It feels like every note is choked off. It was sold as a 12,000 series, but I'm skeptical that's what it is as there's no 3-way switch or pull knob. I've got an email into George to ask if he can identify it for me by the serial. I'm afraid I'm going to have to send it back. I know some of you guys build amps - any clue about might what be wrong? I'm hoping it's something simple.

 

[Mongillo19]

Oh my! Yes a kazoo is very accurate

Such a bummer.....I hope it gets sorted!

 

[gearJunkie]

Something definitely sounds amiss with the amp, but your playing .

Hope you get it sorted.

 

[SKU]

Sounds pretty good to me. Vintage Marshall..

 

[AutomationBias]

Here's a better clip that illustrates what's happening:



It behaves pretty normally at lower volumes, but totally falls apart once the amp starts to break up.

 

[spawnofthesith]

Damn

 

[AutomationBias]

The store I bought it from (online) says I can either ship it back or take it to someone local for repairs, so I'm going to put some feelers out and see if I can get someone to take a look at it.

 

[James Freeman]

Do you have spare tubes?
Replace the preamp tubes one at a time, test each time.
Next replace both power tubes, biasing doesn't matter for a quick test.
That's about all you can do without opening the amp.

The cause can be many things, I don't think guessing will be of any help, a tech has to open the amp and check literally everything.

 

[AutomationBias]

Do you have spare tubes?
Replace the preamp tubes one at a time, test each time.
Next replace both power tubes, biasing doesn't matter for a quick test.
That's about all you can do without opening the amp.

The cause can be many things, I don't think guessing will be of any help, a tech has to open the amp and check literally everything.

Yeah, I swapped out the preamp tubes and it didn't make a difference. I don't have any spare EL34s, unfortunately. I figured it was destined for the bench, but I figured it was worth asking on the off chance there was something I hadn't thought of.

 

[Life Eats Life]

My guess,
new power tubes and a good bias up.

 

[Life Eats Life]

My guess,
new power tubes and a good bias up.

And a quad of solid 34’s is far north of the cheap.

 

[Life Eats Life]

DIG the f’n playing man.
Thst Hill Street Blues type stuff can be real tear jerker’s man

 

[Jambi]

Idk man, I felt like I was jamming to Canned Heat for those 15 seconds.

 

[AutomationBias]

My guess,
new power tubes and a good bias up.

Probably. The seller is going to cover the cost of repairs, so I'm going to find someone local to get it sorted out. Will post clips once it's fixed.

 

[Sascha Franck]

But you *do* know that Kazoos are highly sought after items, don't you?

 

[miggelblast]

Yeah well I don't know, I could totally gig with that amp. Sounds like a boutique Maestro style fuzz played with a Jazzmaster.

 

[AutomationBias]

But you *do* know that Kazoos are highly sought after items, don't you?

I guess if Jive has the trumpet, I could have the kazoo

 

[AutomationBias]

The Metro is fixed! There was a bad solder joint in the phase inverter which caused the push-pull between the power tubes to be "way asymmetrical", in the words of my tech. There was a short in one of the power tubes as well. Sounds like a proper plexi now.



I sent an email to George Metropoulos to find out what the deal was on the amp, and he said this was the last 50 watt replica he built.

 

[gearJunkie]

That's great news. Sounds fantastic.

 

[la szum]

I love Happy Endings that are actual Happy Endings.