PV Delta Blues procedure

[firemedic]

Peavey Delta Blues on the bench. 1/2 the output tubes are redplating, cherry red. So some minor surgery is required.

WHY DID THEY BUILD IT LIKE THIS? why is the PCB all folded up like that? WHY?

Anyhow, I know enough folks here have worked on them so, what's the preferred procedure for extricating this PCB? So far it looks like all the pots have to be removed but I was hoping for some easier yet not obvious way.

Also, I suppose I'll have to figure out if it's:

A- leaky coupling cap from the PI, or
B- open/intermittent/failed gridleak resistor on the offending power tubes

I have checked the voltages and the grid voltage on the "normal" sockets is @-16vdc, on the "bad" sockets it's @-11 to -12vdc. This is with no tubes in. I'm leaning towards a bad gridleak or an intermittent gridleak connection.

Anyone have this problem before, with the redplating?

[billcreller]

I did some work on one of those a few years ago.  That PCB arrangement is sure a pain in the ass alright.

[stratele52]

PV Classic 30 same mounting , what a nightmare

With -16 V and -12 V grid voltage you mean you don't have same negative bias on tubes.

With -12 V tube are red plating  I understand.

Socket contact defective/ dirty  ? Tubes defective .

Do you have a bias probe ? If not you need to install 1 ohms resistor on each tube to check their bias. This tell you if tube draw too much , unmatched or defective.

Schematic here ;

www.el34world.com/charts/Schematics/files/peavey/peavey_deltablues.pdf

[plexi50]

Figuring it out is the best way to never forget those amps. There easy to work on once you know how they come out. Real easy actually. Tip!

Remove the speaker output jack board and get it out from inbetween the board. Once you have all the tube socket and pot screws out just push easy down on the tube socket side of the board and get the tube sockets inside of the chassis. The the hole thing will slid out from the EQ pot holes. Dont forget to unplug the white reverb connector

Check R63-R64-C44 bias values. C32 & C35 coupling caps. R43 & R53 screen resistors
Every resistor in the bias grid path

[LooseChange]

Repaired many of these folded pc board gems.... Plan your attack, move very slow and carefully. There is about a 25% chance you'll break one of those jumpers. In fact, they will break on their own. Repair and move on.