Combining dry and reverb outputs

[Erik]

I have a "66" Guild amp the has both dry and reverb outputs. I am considering running both 8 Ohm output to either 1 or 2 8Ohm speakers so that I get the reverb out of the same speaker as the dry sound. Is this no no for the amp or output transformers? Thanks,

[Leo_Gnardo]

Highly unrecommended to combine the outputs of power amps - it looks like that's what you're proposing. In amps of this type, where one speaker handles the dry, and another speaker only reverb, I enjoy the space effect. If you have to mic up for PA or recording, one more mic, geez what a hassle.

[Structo]

Can you post a schematic to that amp?

[Erik]

Really just trying to eliminate equipment, trying to use a 1-12" cab instead is a 2-12" cab. Thanks again for the input.

[Ken Moon]

That is one cool amp.

Here's a pic I found:

http://www.el34world.com/Forum/index.ph ... ttach=9780

[Erik]

Here's what mine looks like now. Pics kind of washed out, Maybe I can find one that is a better color representation.

[Erik]

Here

[Structo]

Wow!

Insane cab for that.

Tell us about your amp and cab!

[Phil_S]

Amateur hour here....it looks to me like point A is where the dry signal is either sent to the reverb or bypasses the reverb. I don't know what happens when you do it, but it looks like if you jumper the reverb switch so it is connected to both poles (both "on") at the same time, you get the wet and dry signal together. It calls for a different type of switch.

Please don't hold me accountable if that causes the amp to blow up or some other undesirable thing happens. Really, I wouldn't try it on an antique like this. You've been warned.

[Leo_Gnardo]

Here

Yow WOW! She's a stunner!

I can think offhand of only one semi-common amp that has the feature of separate power amps & speakers for dry & reverb - the Ampeg Echo Twin. There IS a toggle switch that selects 2 modes, separate, or combined signal going to both speakers, and the switching is done at a preamp level, not mixing the power amp outs. You may want to find an Echo Twin schemo and compare it to your Guild. One thing that may work in your favor, it seems in the 50's-60's Ampeg, Guild and a couple other NJ manufacturers shared a number of ideas and personnel.

Short of making any amp mods, you might consider making a 12 + 8 or 12 + 5 cab and let the smaller speaker handle the reverb. Sano did that in one of their accordion-oriented amps with a 15 and two 8's. Sano was also part of the NJ amp "brain trust."

[Firestorm]

Amateur hour here....it looks to me like point A is where the dry signal is either sent to the reverb or bypasses the reverb. I don't know what happens when you do it, but it looks like if you jumper the reverb switch so it is connected to both poles (both "on") at the same time, you get the wet and dry signal together. It calls for a different type of switch.

Please don't hold me accountable if that causes the amp to blow up or some other undesirable thing happens. Really, I wouldn't try it on an antique like this. You've been warned.

The reverb switch looks like it's labeled crooked. When it's "off" it sends the speaker - driven reverb to the amp for the reverb speaker; when it's "on" it picks up the dry signal at point A and puts that through to the second speaker. Since the reverb is driven by the main speaker, there's no way to eliminate a speaker and still have reverb.

[Erik]

Hey Structo,
As far as I can tell, it's a '66 Guild Thunder 1 w/reverb. Got it from a friend years ago in Va Beach. All that has been done internally is the replacement of a cap or two and the power lamp. I changes the pre-amp tune for one out of a Fisher 800 and think it needs replacing cuz it doesn't sound right anymore, but I have a couple of other projects at the moment so it sits, for now. I built the cabinet using scraps I had lying around the shop, yes scraps. The veneer wasn't long enough to wrap the whole case so I added trim where necessary. I still have to give it a few more coats of finish. It needs the multi-can caps replaced too, I think.
Thanks for all the advice think I will just run a 2-12 cab. to be safe. My main set-up right now is a Silvertone console hi-fi amplifier with a Digitech 2120 pre-amp/effects unit.
Cheers!

[M Fowler]

What a beautiful cabinet.