Peavey Bravo 25 watt 1990's

[sealeg]

Does anyone have any idea of the value of the burnt out resistor (brown/buff one) in picture. Thanks for any help. Please.

[Jazz P Bass]

That looks like R62 400 ohms. 5 Watts.
That is your B+ rail.
Something killed the resistor by drawing alot more than 5 watts through it.
You just might also find a bad power tube.

[sealeg]

Thank YOU for your extremely quick reply Old timer.
One of the power tubes was glowing a bit bright with a strange noise(high pitched squeal) coming from the amp. It fused.
I took the amp apart, replaced the fuse and watched. One valve flashed a kind of purple and I noticed the resistor glow, very brightly.
It had been doing that for a wee while(squealing) occasionally.
On your advise I'll replace the valves.
Thanks again, your a scholar and a gentleman.
I'll reply as soon as.
sealeg.

[Jazz P Bass]

Uhmm.
You need a new resistor too.
It may function for a while, but I do believe it has been stressed to the point of being unreliable.

[sealeg]

I intend to replace the resistor at the same time as the valves.I've removed the resistor. Will get them in the am. Thanks a ton again.
Will let you know the outcome.

[Enzo]

Just a note, Peavey used that 400 ohm resistor in many models. However 400 ohms is not a standard value. If your source doesn't have 400 ohm resistors, use a 390 ohm resistor, which IS a standard value. In fact, when Peavey runs out of 400 ohm ones in production, they install 390 ohm ones instead. That resistor burnt almost always means a power tube failed.

[sealeg]

Just awaiting new valves. Replaced the resistor with a 390 ohm, that's all they had. Had a few old mullard el 84's. Tried those and it powers up and plays fine, no bright glowing as before. The only problem now is when I turn up the reverb there's a loud hum. The more you turn it up the louder the hum gets. I'll try the new valves when they arrive. It's a great sounding amp.
Thank you for your advise guys, much appreciated.

[Enzo]

OK, is the reverb hum there instantly when you turn up the reverb? Or does it take a couple seconds to build up once the control is turned up? The first thing is real hum, the second thing is acoustic feedback in the reverb pan. Hum is the sound of touching the tip of your guitar cord. The reverb feedback is a low WOOOOOO sort of note. Like a boat foghorn.

[sealeg]

The hum is there instanly you turn up the reverb.
Kind of like the touching your guitar cable, mixed with white noise. Getting louder with the more reverb you add. The reverb is working though??

[Enzo]

OK, so not feedback.

Several common possibilities:
Broken wire inside the reverb pan. Look inside the pan, and there should be two tiny wires for each jack. See if one or more tiny wire is broken off in there.

Broken conection in the cable up to the amp from the OUTPUT end of the pan.

Bad reverb IC on the board.

Of course there are other posssiblities, but these things are way more likely than anything else.

[sealeg]

Replaced the IC, rc4558p, Sounds as good as new, if not better with the mullards. Breaks up much earlier on the clean channel. It did have the PV original valves in, 21 years quite awhile eh. Only just acquired the amp and was seriously miffed.

A very very big THANK YOU for all your help, it's been much appreciated. Thanks guys.

[sealeg]

The new JJ el84's just arrived, even better than the old mullards(they were old) fantastic sound. I replaced the original speaker with a Celestion g12 greenback. What a great little amp, big sound small amp. Head over heels.
Thanks again fellows. If I knew you all I'd be getting a good few beers in.Cheers and good health.

[Enzo]

The little Bravo is a cool amp. There is a whole "Cult of Bravo" following for the amp over at the Peavey boards.