Sound of eggs frying

[Jaclyn Jones]

I have an evil red knob Twin that. Whatever is the instrument is plugged into it has a frying eggs sound in the background that's quite noticeable. If nothing is plugged into the amp isn't dead silent. I tried the tires plugged in it does the same thing every time. I switched cords, cables plugs,everything still make that noise . Any thoughts out there on the cause?

[Lane Gray]

I'd clean the jacks contacts. The frying sound usually comes from dirty contacts intermittently making and breaking. Some of the Caig Deoxit (or similar) and fifteen minutes of yer time (most of it in removing and replacing the chassis: you'll get better results that way than just trying to spray down the hole) and you SHOULD be back in business.

[Dave Grafe]

Frying eggs sound like a failing IC op-amp. Check the overdrive and reverb circuits.

[David Cubbedge]

Yep, the 'frying eggs' sound is what got me out of my red-knob Twin. I bought my first one new in 1990 or so for guitar. Sounded great at high volume, but when I stopped playing there was that sound. As I was a working musician at the time, I just had to deal with it for quite a while. Eventually I got Fender involved, and I must say their warranty and service department impressed me greatly, especially when they 'lent' me a brand new red-knob Twin while they worked on mine. Unfortunately, this one fried eggs too and after about a year of them working on mine, they gave up and told me to keep the 'loaner', which I happily and almost immediately sold. I just don't think that amp was designed as well as others, especially since even they couldn't figure out the problem. I eventually bought a '72 Twin and am seriously happy with it.

I am of an opinion that the amp design is flawed somewhere - I don't think any of these other 'fix' comments is going to help. Cleaning jacks and such...my red knob Twins would fry eggs brand new right out of the box! Good luck!

[Brad Sarno]

Plate resistors can cause this. I think that Fender may have used carbon film types in there, and carbon resistors can do this if they fail on a molecular level. I'd try replacing the preamp tube plate resistors, likely 100k, but I'm not sure. That frying sound is a symptom of these resistors failing.

B

[David Cubbedge]

Brad, would these resistors fail when brand new? (I'm not an electronics whiz, just curious....)

[Jim Newberry]

I've had 100k carbon comp plate resistors be really hissy out of the package. I've switched to using high quality metal film (Vishay Dale) resistors. I hate hiss that gets amplified...

[Scott Appleton]

not the best amp for clean and quiet .. sell sellsell buy the Little walter for sale on the forum ...

[Brad Sarno]

Brad, would these resistors fail when brand new? (I'm not an electronics whiz, just curious....)

Yes, even back in the day, brand new, fresh carbon comp resistors can do this. They may measure fine, but something happens on a molecular level that makes them do this frying sound when voltage is applied to them.

Good quality, non-magnetic, metal film types like the Dale/Vishay sound great for steel, very quiet, very reliable. The RN70 series Dales are military-spec, high grade types that I often use in preamps.

B

[Brad Sarno]

And I will be honest and say that the red-knobbed Evil Twin is historically one of the most despised and loathed amps Fender ever made. I'd fix it and sell it if I were you. I think they're possessed.

B

[Jaclyn Jones]

Oddly, cleaning the input jacks got rid of 90% of the noise. There is still some hiss but not a deal breaker. Thanks for all the info!

[Jaclyn Jones]

It was a preamp tube. 12ax7. Thanks for all the input!