Dedicated Reverb Amp/Speaker

[xk49w]

Hammond and Leslie use this arrangement for reverb. The Leslie 122RV for example has two side firing and enclosed 6x9s with a separate amp (2x7189). In the Leslie it is important because it sounds better, I suppose because the reverb would be dopplered by the horn.

Has this approach been used in guitar amplifiers (successfully)?

[benoit]

Hammond and Leslie use this arrangement for reverb. The Leslie 122RV for example has two side firing and enclosed 6x9s with a separate amp (2x7189). In the Leslie it is important because it sounds better, I suppose because the reverb would be dopplered by the horn.

Has this approach been used in guitar amplifiers (successfully)?

Do you mean separate speakers in the same cab or just running a dry/wet rig? IIRC Larry Carlton runs his amp clean, then runs the mic through a mixer to add effects, then runs that out to the PA and to a monitor for him onstage. This is also an approach sometimes used by people playing Trainwrecks for things that would normally go in an effects loop. I've also seen people run their guitar signal to two amps, sometimes set up the same and sometimes not, one effected and one not.

[xk49w]

Do you mean separate speakers in the same cab or just running a dry/wet rig?.

Separate speaker in the same cab. The problem is one of providing reverb to an overdrive channel, where the output stage is distorting. With a master volume amp where the output stage is running clean and distortion provided by an OD channel this may be a non-issue.

[Bob-I]

In fact I've seen this a few times, and tried it myself. At the NY ampfest Andy Fuchs demo'd taking the loop out into a digital reverb, then into another power amp and speakers. HUGE sound from the 2x12 and 2 1x12's with the reverb return.

I've tried taking my loop out into a mixer with digital effects and it sounds great. I've also taken the loop out into a Super Reverb at low volume and high reverb levels. Sounds great to my ears.

I've also tried running the amp dry and miking into an amp with reverb, not quite as effective as the Super config above.

Very cool concept.

[billyz]

Gibson did this quite a lot as well. The RVT79 for one, they even made a separate reverb speaker amp model.

[UR12]

Gibson did this quite a lot as well. The RVT79 for one, they even made a separate reverb speaker amp model.

Billy is right. Valco, (Supro, Gretsch, Wards, etc) all made reverb units back in the 60s that was an amp you ran off of your external speaker out on your dry amp and the unit I own (1961) has a 8"speaker, 5 watt amp and reverb unit. It has one knob to control how loud the rever unit is. You mix the wet and dry from your dry amp and there is a foot pedal to turn the reverb unit off.

[xk49w]

Billy is right. Valco, (Supro, Gretsch, Wards, etc) all made reverb units back in the 60s that was an amp you ran off of your external speaker out on your dry amp and the unit I own (1961) has a 8"speaker, 5 watt amp and reverb unit. It has one knob to control how loud the rever unit is. You mix the wet and dry from your dry amp and there is a foot pedal to turn the reverb unit off.

Did the extension amp produce only the 'verb signal (no dry)? Or was the mix adjustable perhaps.

The Leslie 122RV reverb amp is driven by the regular amp speaker output and has two #19 lightbulbs in series with the reverb tank to provide limiting.

I'm thinking about an 50W ODS 1x12 combo with a separate 'verb channel with its own solid state amp and speaker. The then question becomes how much power and what speaker. Maybe a 4:1 power ratio so 10-15W for the 'verb channel? If so then a National Semi LM1875 might suffice. Possibly a 6 or even 6x9 for the verb channel. Just a notion...

[UR12]

Did the extension amp produce only the 'verb signal (no dry)? Or was the mix adjustable perhaps.

Yes, the extension amp (reverb unit) produced only the verb signal, no dry. I have paired it up with my 5 watt 1962 Magnatone 410 and it sounds awesome. It is a nice way to go but unlike the effects loop setup, if your amp is clipping before the speaker, since the reverb amp is getting it's input from the ext speaker out of your normal amp, you will get distortion coming out both the dry amp and the wet reverb amp.

[xk49w]

Yes, the extension amp (reverb unit) produced only the verb signal, no dry. I have paired it up with my 5 watt 1962 Magnatone 410 and it sounds awesome. It is a nice way to go but unlike the effects loop setup, if your amp is clipping before the speaker, since the reverb amp is getting it's input from the ext speaker out of your normal amp, you will get distortion coming out both the dry amp and the wet reverb amp.

Is it your opinion that it is better to drive the reverb channel with an undistorted signal rather than the output from the OD channel?

[Andy Le Blanc]

ampeg used the feedback loop as a source to drive a reverb tank then used
that signal to input an identical amp ...... echo twin..... there have been a few
external verbs that clip on to the speaker terminals as a source too...
its more up to you and what you like to hear...... my fav. ...... two twins....
with the output of ones verb to the input of the other amp...... big.....
put one against a wall ala. roy buchanan......

[UR12]

Is it your opinion that it is better to drive the reverb channel with an undistorted signal rather than the output from the OD channel?

I'm not sure I have an opinion one way or the other. Most amps with reverb built in usually pick off signal early in the preamp before distortion. I guess you could go either way on that one. I'm with Andy.........it really is a personal preference. It just seems that having a seperate reverb amp with verb from one source and dry from another gives you some ambience or fuller sound that you can't get from a single amp that has a mix of both verb and dry going through the same power amp. Same thing with the effects loop and a seperate amp. if you mike both cabs then you can also do some mixing at a front of house console in live situations or have wet and dry on different channels for recording.

[jjman]

I’m also contemplating this topic these days. I'm currently thinking of adding a parallel effects loop to my head. My Reverb "pedal" works fine until I reach an amp volume setting that significantly clips the signal. At this point the reverb "swells" at the end of a quick note/chord. I think because the clipping is compressing everything, then the end of the note comes and the reverb is still there and not being compressed. I tried placing it in series after the 3rd stage but that's too strong of course. I'm hoping to divi up the signal after the 3rd stage and send only some to the reverb unit (keeping it very wet) and then re-combine it before the PI.

Anyone know of a popular amp with a parallel effect loop that I can find a schematic for?

[CaseyJones]

The simple off the shelf solution: Use an attenuator w/ line out like the Weber MASS. Speaker level to Line level w/ EQ, how cool is that? Then feed yer wet side w/ the Line Out.

I'd have second thoughts about hooking a vintage reverb up the way we're talkin'. 100 watts is more than the limiter circuit was ever supposed to see. Sure it gonna see as lot less than that most of the time but it would suck to have it crap out durin' a soarin' crescendo. Better have a whole pocket full of those stupid little bulbs.

There's still a way to make it work: Stick an L Pad (cheap attenuator to go w/ cheap reverb) in there to help the poor old reverb unit make it through the night. Too much signal is too much signal, it's not gonna sound good w/ the front end gettin' pounded and that's right back where we started.

[FUCHSAUDIO]

Mojo Musical makes this:

http://www.mojomusicalsupply.com/video-mojoverb.asp.

If you have a Fuchs ODS (r), use the effects loop output and use it to drive the reverb. You could also tap the speaker with a Palmer or similar direct box, and produce a feed to the outboard reverb, but that's not really necessary.

The other solution is a wet dry wet like Carlton. You can use the loop output, drive a stereo reverb, a small power amp and two sattelite speakers. I've built some cool stuff in PVC pipe using 4" or 5" full range drivers from MCM. If it's only reverb, it's not too much power nor bandwidth to get a nice tone. Larry's rig sounds great, but it's alot of gear to just get a good stereo reverb.

[iknowjohnny]

the way i do it is to run the DI out to effects set at FULL WET settings and into another small amp. the difference is i don't use the lopp to get the signal from, i use a DI out from the speaker out. that way you get your main amp's entire signal, not just the preamp signal. this works great because you can use most any amp, even something cheezy because all it has to do is provide a reasonably decent clean sound and your main amp give it the full output tone minus any speaker grind. And unless you use a incredible amount of effects to where you sound like your in uther space, only a tiny amp is necassary because it only has to be about 10-20% as loud as your main amp since it's only carrying the wet signal such as only the delayed notes in a delay setting, or only the modulating signal in a chorus, etc etc.

But i've tried both and unless you intend to get a amp thats got a output section equally as good as your main amp, taking a speaker DI out is the way to go IMO. You can use a tiny 15 watt SS amp or such as your effect amps.