amps with spring reverb

[drew_half_empty]

i remember someone on here saying that amps with spring reverb have more gain to em than amps without em

i know this is true of amps with tube reverb, but does anyone care to verify that spring reverb adds gain?

 

[CapoFirstFret]

Re: amps with spring reverb

tube reverb = spring reverb

but...

spring reverb does not = tube reverb

I'd say they mean tube reverb, but typically tube reverb is powering using a spring tank.

 

[ES350]

Re: amps with spring reverb

It depends on the amp---a brown Deluxe (or even the BF non-reverb Deluxe)is a lot 'gainier' than the BF reverb counterpart. Channels with 'verb or tremolo usually suffer some loss from the additional circuitry. I can't think of too many tube amps with reverb that use anything but a spring tank...

 

[ErikH]

Re: amps with spring reverb

And the spring tank doesn't necessarily need to be powered by a tube either. An op-amp will do the job just fine, and be more stable as well. As much as we all love the sound of tubes (myself included), some parts of the amp are best served with op-amps if possible, driving an effects loop and reverb being 2 of those areas.

 

[Rich_S]

Re: amps with spring reverb

I think they were talking about Fender amps - the reverb/vibrato channels often have more gain stages than the normal channels do. This is within a single amp, though - not comparing reverb amps to non-reverb amps.

 

[Farkus]

Re: amps with spring reverb

I think they were talking about Fender amps - the reverb/vibrato channels often have more gain stages than the normal channels do. This is within a single amp, though - not comparing reverb amps to non-reverb amps.

But you would have more tone 'loss' from a reverb or vibrato channel, correct? This would explain why they're less gainy, if that is correct. I've heard that some guys do 'bypass' mods on the vibrato circuit on the vibrato channel on BF's to improve the overall tone. Would just using the normal channel (say on a BF amp) negate the need for such a mod, or are the channels not truly independent?

And, as for tube reverb, maybe I'm just crazy, but I think the tube driven reverb is more 'musically' responsive to signal levels. Just my $0.02 though.

 

[ErikH]

Re: amps with spring reverb

Rich, yes, very well so. But it's very similar, if not the same, no matter the brand, with the same features. Usually in a vibrato or reverb amp, the additional tube is wired with half of it as a buffer to drive the circuit (reverb or vibrato) and then the other half as a recovery stage to bring the signal back up from what is lost after it. Sometimes half would be wired up as an additional gain stage but almost always, half would be a buffer, similar to using half a tube to drive the tone stack.

Coincidentally, it was not uncommon for some to take those vibrato circuits and have that entire tube redone as a full blown additional gain stage (aka, the famous Marshall Stock #39).

 

[Rich_S]

Re: amps with spring reverb

I'm not talking about the reverb driver and recovery. Look at a Super Reverb schematic - not including the 12AT7 reverb driver, nor the 1/2 7025 reverb recovery stage, the vibrato channel has three triode gain stages before the PI, and the normal channel only has two.

 

[ErikH]

Re: amps with spring reverb

I see what you mean, that extra 12AX7 in there in the Vibrato channel. From what I can tell, it looks like it's a small gain stage to help drive the vibrato and keep the signal up. Without it the vibrato would take the signal down too low.

Now that would be a fun amp to mod and put that 12AX7 stage at the tail end of the normal channel, minus the vibrato. Somebody has had to have done that. I'm not much of a Fender amp guy, except the Bassman.

 

[Pink Unicorn Horsey]

Re: amps with spring reverb

Sheesh! This conversation could hardly be more out of my league. I really need to hit the books.

 

[jeremy]

Re: amps with spring reverb

rich is on the right track.

the extra gain stage on the vibrato channel gives that channel more gain than the normal channel. there is extra loss with the extra circuts but the extra 1/2 12ax7 more than makes up for it.

there is a huge loss at the tremolo on fender amps, if you dont use that effect, clip the wire that goes to the controls and Bam! more gain and a wider tone. learned that from gerald webers books