My 66 Fender bassman tube guitar amp is cutting out intermittently and is making a bl

[signalpaths]

My 66 Fender bassman tube guitar amp is cutting out intermittently and is making a blip blip blip noise after notes are struck?? Has anyone ever had a similar problem? If so any guidance would be greatly appreciated.


Thanks guys

Eric

 

[DaveMcLain]

blip blip blip sounds like some sort of power supply problem, it's trying to "motorboat". I would bet that the problem is elsewhere and some other portion of the amp is drawing too much current. Look for a bad coupling cap first. It seems like I've had a resistor in the power supply cause that problem before too but it also was caused by some other problem which caused it to see too much current.

 

[signalpaths]

I read somewhere that if a cap has a resistance over 350k that it is leaky is there any truth to this? And if not is there any bulletproof way to test for leakage. BTW I've also heard that if you put AC or DC current through I can't remember what kind or even how much if there is current going through the cap it is leaky. Any help getting to the bottom of this would be appreciated.

Thanks
Eric

 

[audiotuber]

Solder joint, bad connection. Take a chopstick and poke around the board and wires.

 

[audiotuber]

If you want to test for a leaky coupling cap. Put your meter to DC and measure after the coupling cap. There should be very little DC voltage.

 

[signalpaths]

Thank you audiotuber!

 

[signalpaths]

Found it BAD PHASE INVERTER TUBE!!

thanks guys


eric