Ampeg V4BH Problem

[Dr. Gonzo82]

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That should be the amp the op has problems with.
A friend of mine bought one brand new in the early 2000s, worked fine for about a year, then started blowing tubes. After three visits to the amp doctor, he sold it.

 

[agedhorse]

Thank God for your superb knowledge.

I have ordered 13-pin connectors both female and male that I'm gonna solder in when they arrive. When I looked closer into the picture of the board I noticed that pin 4-6 looking burned. I have zoomed in on the picture here.

The females do NOT solder on, that’s a good way to end up with a mess.

The male headers solder to the PCB, those are double sided IIRC. If you are not VERY careful, you can damage the board and end up with a bigger problem.

Rarely is the male header bad, my recommendation is to leave it alone. You will need the correct tool and the matching female housing for the repair (or a replacement harness from Ampeg). Note that the housings have a matching tool, different brands do not interchange with tooling.

 

[olahak]

Hello everyone!

I forgot to write back to you after I got the new inline connectors and soldered them in place.

I soldered the pins one at a time and on different connectors so it had time to cool off.

Now it works like a charm, not a problem since!

Thanks so much a all of you for the advice!

Best Regards, Ola

 

[Patrice B]

Glad you got it sorted! The V4 is a wonderful amp!

 

[beans-on-toast]

Hello everyone!

I forgot to write back to you after I got the new inline connectors and soldered them in place.

I soldered the pins one at a time and on different connectors so it had time to cool off.

Now it works like a charm, not a problem since!

Thanks so much a all of you for the advice!

Best Regards, Ola

Good to see that you figured it out.

Heater problems when the pathway is through connectors like you've encountered is not uncommon. Ampeg used two connector pins for each heater to share the current through the connector.

The reissue Fender amps use spade connectors for connecting the transformer heater wires to the main board. The spade plugs often have carbon buildup from arcing due to initial currect surges. It's a design flaw that makes the amp easier to assemble. It looks much like the image with the burnt connector that was posted above. A common fix is to bypass the spade connectors and not use the PCB for that pathway. Transformer heater wires are run directly to the first power tube socket, then use twisted pairs of wires flown overhead to the other tubes. Maybe a better connector should be used! There are other flaws in the Fender designs that I won't go into.

 

[agedhorse]

Properly designed and executed, this is not an issue.

 

[beans-on-toast]

Yes, and when not properly executed, it often comes down to cost cutting not engineering.