Adding Reverb to Champ

[Bruce / Mission Amps]

Bruce,

Regarding shutting off the dry signal ........... (if I am not understanding what you are saying, please correct me).

EDIT: Bruce was pointing out an error in how I had drawn the dwell pot and the cap going to it. I have redrawn
the last two schematics and layouts. He was correct that the way I had drawn them would have killed the dry signal.
The Verb O Champ II & Verb O Champ III schematic now show how I have this done on my current amps and it works fine.


I have this reverb circuit with dwell on each of my 3 amps. After reading your post, I plugged in and checked out my memory. I can turn the dwell all one way and then all the other way and it has NO impact on tone or volume at any level that I can tell. Obviously, it does change the amount of reverb and can shut the reverb off but not change the volume or tone.

With respect, Tubenit

Yes you are right, with the wiper on the grid of the 12AT7, turning the pot any direction still holds the 1M resistance on the dry side of the mixer resistor.
Thanks for all the good artwork.

[tubeswell]

Hi Tubenit

Where do you get the software for SCH schematics?

[Tubenit]

SCH files

This is FREE schematic drawing software you can download. AND if you draw up something, there is a program to convert to a PCB board if you like. It is VERY easy to use this program.

http://www.expresspcb.com/

However, you either have to create some of your own symbols like tubes and input jacks .....OR simply click on one of the editable schematics and save what someone else has drawn as a custom component.

Under the Library of components favorites there are typical resistors, caps, electrolytic caps, diodes, transformers, etc.... already drawn.

I like it cause you can share a visual of one's ideas. And it has taught me alot about amp design and reading schematics. It's worthwhile to learn. It's also a great way of keeping a solid record of your tweaks to reference or share with others.

Here are about 80+ editable schematics covering many Fender, Gibson, and other amps...... plus custom designs and concept amps not yet built.

http://www.el34world.com/Forum/index.php?board=12.0

From that list of schematics, I am currently owning and playing:

Carolina Blues Rocket
http://www.el34world.com/Forum/index.php?topic=3947.0

Little Wing Reverb (I have more compliments on this than any of the 14 amps I've built)
http://www.el34world.com/Forum/index.php?topic=3963.0

Texas Raptor
http://www.el34world.com/Forum/index.php?topic=2442.0

(& my closest friend has the Carolina Blues Special which is a fantastic sounding amp and an easy build)
http://www.el34world.com/Forum/index.php?topic=565.0


With respect, Tubenit

[Electron Tornado]

Thanks to everyone for the answers and tips!

[sig]

Fender Musicmaster Bass Amp w/Reverb?

Yeah, I drew them up for this thread. Having said that, I have over 100 editable SCH schematics and layouts so it's pretty easy to do. I usually can find a schematic I have and alter it in about 10-20 minutes into something else.

Some people work crossword puzzles ........ I draw schematics. What's ironic is that 5 yrs ago, I could NOT read a schematic and even tell what was a resistor or capacitor.

Just a hobbyist and have had zero actual training in electronics. Learned by reading the net and experimenting alot.

with respect, Tubenit

I read this post and was wondering since the chassis on my Fender Musicmaster Bass amp is the same size as the Champ, perhaps you could help me with translating a schematic to add reverb to it? I've got two of these amps, I love them. I carry my Silverface Tube Reverb unit on gigs but I'd love to add a real tube spring reverb to these amps. Since I have two, I'd like to give it a try. Thank you in advance! Regards, Paul sigmon@sysmatrix.net

[Tubenit]

I read this post and was wondering since the chassis on my Fender Musicmaster Bass amp is the same size as the Champ, perhaps you could help me with translating a schematic to add reverb to it? I've got two of these amps, I love them. I carry my Silverface Tube Reverb unit on gigs but I'd love to add a real tube spring reverb to these amps. Since I have two, I'd like to give it a try. Thank you in advance! Regards, Paul sigmon@sysmatrix.net

There is quite a bit of information about adding a one tube reverb here:

Adding 1-tube reverb - Hoffman Ampifiers Guitar Tube amp forum

With respect,Tubenit

[bobthebuilder]

Did this amp ever get built?

Layout. Check for errors and consistency with schematic.

Tubenit

This is very interesting!
Has anyone completed this build yet?

[Chuck H]

This is very interesting!
Has anyone completed this build yet?

It's been done many times in many ways. A 12at7 makes for decent drive and recovery. I prefer a 12dw7. Using the au7 side as a driver and the ax7 side for recovery. But it's a less common tube. Doing it with one tube will always mean sacrificing dry signal gain for mixing unless the stock circuit can be modified for an increase in gain.

Ooogle: champ add reverb

Then go to Ooogle images and you'll find some schematics for how guys have done it.

[ThermionicScott]

It's been done many times in many ways. A 12at7 makes for decent drive and recovery. I prefer a 12dw7. Using the au7 side as a driver and the ax7 side for recovery. But it's a less common tube. Doing it with one tube will always mean sacrificing dry signal gain for mixing unless the stock circuit can be modified for an increase in gain.

Ooogle: champ add reverb

Then go to Ooogle images and you'll find some schematics for how guys have done it.

+1. And if you want cool kid points these days, consider building/modding a Vibro-Champ Reverb.

[olddawg]

Honestly... Use a pedal. No overhead in a Champ. Distorted reverb sucks.

[Justin Thomas]

Didn't Gretsch make the Recording Compact, or whatever? My friend got one for $600. Sweet little amp, Verb, Trem, and I think a 12" speaker. 1 6V6 output & 4 AX7s. It's pretty durn clean, too, for a Champ. He uses it in tandem with a Reverberocket II for jazz. The schem is out there.

Justin

[Chuck H]

Honestly... Use a pedal. No overhead in a Champ. Distorted reverb sucks.

Even better... Put a line out on the Champ, Run that to a reverb and into another Champ One for dry and one for reverb.

[Justin Thomas]

"Yeah, just add more amps!"

Said no sound guy, EVER! Hell, screw the sound guy, <I> like it.

Justin

[Chuck H]

"Yeah, just add more amps!"

Said no sound guy, EVER! Hell, screw the sound guy, <I> like it.

Justin

One of my customers has three of my amps (which is 25% of my total product ) I went to one of his bands shows and asked the sound guy "So, which of John's amps do you like best?" And he said "The small one."