Old Fender Frontman 25R MIM problem

[Slobrain]

Hello Fellas

I just bought a old fender Frontman 25R that has the black metal grill in the front, made in Mexico. Not the newer one. I noticed it pops real loud when I turn it off. My daughter has the exact same model and hers seem to have a delay turn on and off and does not make that sound when turning on and off.
The circuit looks real simple and the only thing I could think of was the power output chip that might be not doing the delay on and off. The amp works but I wonder how long before poof...

any suggestions?

Thanks

[Enzo]

Many many many amps pop when you turn them off. I don't consider it a problem. ANy pop is no louder than the peak audio it can produce.

Does it make a difference if you turn the reverb all the way down before hitting the power switch?

Perhaps your power switch is a little more arc-y that hers.

These amps don't have delay circuits.

[Slobrain]

Hey Enzo,

Well,

My daughters amp has the TDA1514A output chip 9 pin and suprisingly seems to delay audio on and off for for a brief moment when turning off or on. no pops at all and hers is a 2000 model

The other amp has a 1992 board and a different NEC 12 pin chip that is a uPC1188H in it.

No difference with the reverb on or off. If the amp is in clean channel mode and you turn it off it switches to distortion mode for a brief moment too. My daghters amp does not do that either.


Looks like the circuit in both amps are almost the same accept the output chip.

Thanks

Slo

[JoeM]

Is the pop the only thing your hearing wrong with the amp? My old (about 20years) Fender 85 (SS) amp pops at turn off too, but otherwise it's always worked fine. I dont consider the pop a defect.

[Enzo]

Different circuit, different parts, they perform different. I still don;t see it as needing repair.