Do All New '68 DRRI Have Reverb Hum?

[T Prior]

I would think that's because it's just a fact of audio life, not a fault in the circuit. I always wonder in what settings people are playing where "noise" actually creates problems.

Audio life, really ?

I have two Fender amps, a 95 Blues Deluxe and late 90's Hot Rod Deville, there is no reverb hum unless you literally have it set at MAX. Same with the Carvin Nomad. My early Bandmaster reverb didn't exhibit annoying reverb hum at a high setting. Neither did my Twin Reverbs .

The Blues Jr however, early 2000 build requires that the R tank be turned around, the hum is better but not gone. The hum is audible even if I place the R tank several feet away.

It's an annoyance , we shouldn't buy an amp, bring it home then complain about hum.

Having to replace a reverb tank on an amp that is near new is a quality issue, many of us used the same Fender amp for 3 or more decades and never had a reverb tank issue. If we are buying a $300 made in China amp, ok, we suck it up, maybe even expect it, but not on a $1000 brand new amp.

No bigger Fender fan than me, but there are a couple of amps they RI'd which to me is all about profit and bottom line.

 

[Silverface]

Unless there is something specifically wrong with the amp - usually one or more bad tubes - reverb hum is inaudible at usable levels when playing. But reverb springs are also a type of antenna and pick up stray electrical and magnetic fields. Fender raised the height of Bandmaster Reverb and Showman Reverb heads specifically to reduce reverb hum.

I don't know of a combo amp that won't hum when the reverb is dimed and nobody is playing.

As I recall Duane Eddy used studio "plate reverb" - a concrete chamber underground with a huge steel plate that created the reverb. Dick Dale also used studio reverb - the Fender Reverb unit was for live use.

Very few players in real studios have ever used amp reverb. Studio reverb effects like plate chambers, recording amps in specifically reflective rooms and such sound far better than any spring reverb. And nowadays the norm is to record guitar signals "dry", adding reverb later - that way it can be controlled. If you record "wet" that's it - can't take it away. Same with compression.

 

[SoK66]

There's a bogey in the way Fender wires V3 on the reissues and custom reissue amps that contributes to the hum, and it's easily corrected. On the vintage amps fender wired the grids of V3 with a lead jumper directly across the tube socket from pin 7 to pin 2. There's also a jumper across the cathodes, pins 8 to pin 3, though Fender would often just bend the pin tabs down flat across the socket and solder them together so the grid jumper couldn't short against it. Then for the plates of V3 they ran a jumper wire around the socket from pin 1 to pin 6 and soldered the blue wire from the reverb transformer to pin 6.

On the reissues Fender boo-boos and jumpers the plate wire across the socket and runs a jumper wire around the socket for the grid. The grid picks up interference that causes hum and sends it right through the circuit. Just reverse the wiring vintage style and virtually all the reverb hum will be killed off.

Thanks to Lyle Caldwell of Psionic Audio for the tip.

 

[corliss1]

I think the real question here is "are you not getting enough reverb on lower settings?" Fender amps are known to be crazy intense with the reverb much higher than 5-6, and I can't imagine using it at the max setting. If you're not getting enough verb, there's something else going on with the amp.

Yes, the pop when shutting off the amp normal and expected.