I'm totally at a loss right now....
The amp came to me blown up. I replaced all of the blown/charred components and leads to and from them....
I've replaced all of the caps, I've replaced many ground wires....reflowed solder joints, replaced the power resistors....new tubes....
My amp is still motorboating and humming. The bass signal that passes through is very quiet and distorted......
I just don't know what else to do. I don't wanna give up....Any ideas???
Thanks....
stumped by my b15....
Moderators: pompeiisneaks, Colossal
Re: stumped by my b15....
Have you checked out the output transformer?
That wouldn't explain the motorboating, but it would the other symptoms.
That wouldn't explain the motorboating, but it would the other symptoms.
Life is a tale told by an idiot -- full of sound and fury, signifying nothing.
...in other words: rock and roll!
...in other words: rock and roll!
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stompjunkie
- Posts: 75
- Joined: Mon Jun 05, 2006 4:13 pm
Re: stumped by my b15....
I didn't do that yet ....I was kinda afraid of that.... I'll have to do that tonight.
oh fwiw... the volume of hum and motoring aren't affected by any changes on the volume pot....
oh fwiw... the volume of hum and motoring aren't affected by any changes on the volume pot....
Re: stumped by my b15....
To test the OT, I'd hook it up to a 24 volt AC adaptor or some such thing with a dummy load on the secondary and work out the voltage ratios you see on either side of it.stompjunkie wrote:I didn't do that yet ....I was kinda afraid of that.... I'll have to do that tonight.
oh fwiw... the volume of hum and motoring aren't affected by any changes on the volume pot....
The motorboating being independent of the preamp settings suggests it's further upstream in the power supply. I'd double check the ground connections and the resistor values in the power rail ...?
Life is a tale told by an idiot -- full of sound and fury, signifying nothing.
...in other words: rock and roll!
...in other words: rock and roll!