I would like to your input (pun intended) as to what may be causing a problem that I am having with one of my amps, and what I could do to possibly rectify the situation. I have a 65' (vintage) Fender Super Reverb that squeal's like a pig when the reverb knob is turned-up past 3 on the dial. I have switched out the reverb driver tube (V4) several times, and even taken it out altogether, and the problem persists. Amy I ideas, and or opinions, would be greatly appreciated.
Attention Amp Gurus and Bench Warriors!
- Thread starter KJRH
- Start date
NegativeEase
New member
Re: Attention Amp Gurus and Bench Warriors!
It's the Rotary Girder for sure.....
Get a replacement on StewMac.com
It's the Rotary Girder for sure.....
Get a replacement on StewMac.com
Re: Attention Amp Gurus and Bench Warriors!
Greetings NegativeEase! What's a "Rotary Girder"? I suppose I should be able to "google it" and find out, but a bit more info. on the subject may be helpful. Thanks for the reply, and for the suggestion - I greatly appreciate.
Greetings NegativeEase! What's a "Rotary Girder"? I suppose I should be able to "google it" and find out, but a bit more info. on the subject may be helpful. Thanks for the reply, and for the suggestion - I greatly appreciate.
ehdwuld
A Ficus
Re: Attention Amp Gurus and Bench Warriors!
My reverb on my Belair did exactly that
The tube socket has a cracked solder joint
Remove the tube
Remove the pan to access the solder joints of the tube socket
Touch the solder joints until the the solder reflows
Reassemble your amp, pat your self on the back, and let me know how great it sounds now
My reverb on my Belair did exactly that
The tube socket has a cracked solder joint
Remove the tube
Remove the pan to access the solder joints of the tube socket
Touch the solder joints until the the solder reflows
Reassemble your amp, pat your self on the back, and let me know how great it sounds now
NegativeEase
New member
Re: Attention Amp Gurus and Bench Warriors!
Sorry man, I was just being funny
It's probably your tube for the reverb section. easy to swap -no bias required
Sorry man, I was just being funny
It's probably your tube for the reverb section. easy to swap -no bias required
Re: Attention Amp Gurus and Bench Warriors!
It's good to have a sense of humor, but most of the time it's best to keep it to yourself.
However, there is such a thing called a 'rotary girder', although it has nothing to do with
my amp or the reverb control pot causing it to squeal. And it's not the tube - try that. I
did receive one possible cause of the problem from Ehdwuld, although I haven't had the
time to check into it yet.
It's good to have a sense of humor, but most of the time it's best to keep it to yourself.
However, there is such a thing called a 'rotary girder', although it has nothing to do with
my amp or the reverb control pot causing it to squeal. And it's not the tube - try that. I
did receive one possible cause of the problem from Ehdwuld, although I haven't had the
time to check into it yet.
ehdwuld
A Ficus
Re: Attention Amp Gurus and Bench Warriors!
The howl is the arc across the crack of the solder joint
It gets louder as it heats up, am I right?
You will spend more time taking everything apart
And waiting on the iron to get hot
I would touch off on all the tube socket joints whilst in there and the iron is hot
You won't need any solder
Just a hot iron
Be careful it's still hot when you finish
Unplug it over night
Let the caps discharge
Take all the tubes out
Numer them so you can put them back in the correct spots
I laid my amp on its face
And set the pan up across the open back
The howl is the arc across the crack of the solder joint
It gets louder as it heats up, am I right?
You will spend more time taking everything apart
And waiting on the iron to get hot
I would touch off on all the tube socket joints whilst in there and the iron is hot
You won't need any solder
Just a hot iron
Be careful it's still hot when you finish
Unplug it over night
Let the caps discharge
Take all the tubes out
Numer them so you can put them back in the correct spots
I laid my amp on its face
And set the pan up across the open back
Last edited:
NegativeEase
New member
Re: Attention Amp Gurus and Bench Warriors!
Yeah, sorry Rotary Girder is a common joke in the US meaning I have no idea what I am talking about. -its from the movie Tommy Boy.
Cracked Solder joint is very plausible, also -inspect the board for burned resistors and caps.
Yeah, sorry Rotary Girder is a common joke in the US meaning I have no idea what I am talking about. -its from the movie Tommy Boy.
Cracked Solder joint is very plausible, also -inspect the board for burned resistors and caps.
NegativeEase
New member
Re: Attention Amp Gurus and Bench Warriors!
This is great feedback for TS, but not being sure of TS experience inside an amp -It's worth mentioning that there are deadly voltages stored in an Amp after they are powered off. Need to be careful in there and watching a video online of safely discharge current from the caps before poking around too much in there
Here's a list of basics -sorry if you already know this stuff
http://www.aikenamps.com/index.php/safety-tips-for-working-on-tube-amplifiers
This is great feedback for TS, but not being sure of TS experience inside an amp -It's worth mentioning that there are deadly voltages stored in an Amp after they are powered off. Need to be careful in there and watching a video online of safely discharge current from the caps before poking around too much in there
Here's a list of basics -sorry if you already know this stuff
http://www.aikenamps.com/index.php/safety-tips-for-working-on-tube-amplifiers
Last edited:
Tone Meister
New member
Re: Attention Amp Gurus and Bench Warriors!
It sounds to me like either 1) the RCA cables to the reverb tank are reversed, or 2) one of those cables is damaged, most likely the shield.
Try reversing those cables first
It sounds to me like either 1) the RCA cables to the reverb tank are reversed, or 2) one of those cables is damaged, most likely the shield.
Try reversing those cables first
NegativeEase
New member
Re: Attention Amp Gurus and Bench Warriors!
God, this is such an obvious critical first troubleshooting step -that nobody mentioned.
Great point Mr Tone Meister.
God, this is such an obvious critical first troubleshooting step -that nobody mentioned.
Great point Mr Tone Meister.
Chickenwings
Alnico 6/8
Re: Attention Amp Gurus and Bench Warriors!
But it wont hurt once youve done that to replace all the tubes. It is probably past due anyway.
If that doesn't sort it, then it is time to go deeper into the amp
Plus 1
But it wont hurt once youve done that to replace all the tubes. It is probably past due anyway.
If that doesn't sort it, then it is time to go deeper into the amp
Tone Meister
New member
Re: Attention Amp Gurus and Bench Warriors!
Once you have finished changing ALL the tubes, please check the RCA cables to the reverb tank for reversal or damage. The male RCA cable ends must fit tight on the female connectors, and the females must be clean and free of rust and tarnish. Try buffing those with steel wool if tarnished. If the males don't fit tightly or the cables are damaged, just replace them.
Another thing to try is this: with a 1/2" nut driver, loosen the female RCA connectors for the reverb send/return on the rear chassis, then tighten them both snugly. This will allow the star washers underneath to "grab another bite" into the chassis, which will restore any lost grounding in the reverb circuit.
Once you have finished changing ALL the tubes, please check the RCA cables to the reverb tank for reversal or damage. The male RCA cable ends must fit tight on the female connectors, and the females must be clean and free of rust and tarnish. Try buffing those with steel wool if tarnished. If the males don't fit tightly or the cables are damaged, just replace them.
Another thing to try is this: with a 1/2" nut driver, loosen the female RCA connectors for the reverb send/return on the rear chassis, then tighten them both snugly. This will allow the star washers underneath to "grab another bite" into the chassis, which will restore any lost grounding in the reverb circuit.
Re: Attention Amp Gurus and Bench Warriors!
Now that's a thought, and could very well be the solution. At any rate, it's something that I can try without having to take the time to remove the chassis. The you very kindly Tome Meister, and the rest of you amp gurus for your input and support. I think I have enough suggestions to help me solve the problem with paying one of you a king's ransom, and I would if I thought it was something seriously wrong with the amp. I'll post the results of what I make of the suggestions sometime this weekend.
Cheers!
Now that's a thought, and could very well be the solution. At any rate, it's something that I can try without having to take the time to remove the chassis. The you very kindly Tome Meister, and the rest of you amp gurus for your input and support. I think I have enough suggestions to help me solve the problem with paying one of you a king's ransom, and I would if I thought it was something seriously wrong with the amp. I'll post the results of what I make of the suggestions sometime this weekend.
Cheers!
Tone Meister
New member
Re: Attention Amp Gurus and Bench Warriors!
For the record, I was being facetious about changing ALL the tubes. The only 2 tubes you should be concerned with are V3 (12AT7) and V4 (12AX7).
In a worst case scenario, the reverb tank itself could have internal problems such as a broken spring or bad transformer. Sometimes the small wire connections to the RCA connectors inside the reverb tank will come apart and those can cause the noises you describe. The replacement tank is 4AB3C1B
For the record, I was being facetious about changing ALL the tubes. The only 2 tubes you should be concerned with are V3 (12AT7) and V4 (12AX7).
In a worst case scenario, the reverb tank itself could have internal problems such as a broken spring or bad transformer. Sometimes the small wire connections to the RCA connectors inside the reverb tank will come apart and those can cause the noises you describe. The replacement tank is 4AB3C1B
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