adding a new verb to a champ 12 ??

[themaidsroom]

has anyone ever
swapped out the reverb on the champ 12
i am living in the uk for a spell
in nyc i am spoiled and i live in a studio
with custom tube amps and a custom tube driven
full sized plate.........

here, i have a little room and a used champ 12.....
any suggestions to mod this amp are welcome

thanks

be well

- jack

[themaidsroom]

anyone ?

[tubeswell]

Have you tried googling "Champ 12 mods"?

(There wasn't much I could see.)

The Champ 12 relies on the OT to drive the reverb pan, and as a consequence the reverb in it is quite sucky. I don't think it'd be very easy to mod if you're looking for an easy way out. You'd probably need to rewire the verb to a BF twin style, which means changing the location of the reverb 'send' and 'return' inside the amp, sticking an extra tube and reverb tranny to drive the pan, and a different pan. With all the stuffing around, its probably cheaper to flick the amp and get a better amp with decent 'verbiage.

[themaidsroom]

i feel like i need to just do this.
i bought the amp used for £150
i am going to order a weber speaker and the torres mods
and i like the idea of something compact. another pan and those electronics
will fit in this case if someone is kind enough to give me a tip as to
how to go about it......
there is nothing else that will sound as good for small money.....
i am in the midst of moving from nyc where i have several custom emery
tube amps and a custom tube driven full sized plate.......
i am ok with the challenge as i don't think the perfect champ is going
to simply show up......i don't know of a great combo amp with reverb.....
i keep telling my friend curt emery to build one

anyone with thoughts on this, please let me know, i love the idea of one
cable or maybe two if i need a tuner......i have the electro-harmonix - it is
ok, but digital.......

thanks

be well


- jack

[tubeswell]

Well then check out some of the blackface schematics and layouts, and see how they do the 'verb.

Your PT will need to be rated enough for the xtra dual triode (an additional 300mA on the heater winding) - don't know what the PT in there is like. if you get it all hooked up and the B+ goes down by more than 20V its probably no good.

Besides that you will need a reverb transformer and a new pan, a noval tube socket and 12AT7 or similar and some chassis-hole making tools and other amp-making tools (multimeter, soldering iron etc), the necessary range of resistors and caps and other hardware (extra turret board and mounts etc) for the new reverb circuitry etc. So as I said before its quite a mish and quite a few bucks to spend for the aggravation, especially if you're new to this.

Also high voltages inside tubes amps are potentially lethal, and they can give you a nasty kick or kill you even after they've been turned off and unplugged (which they should always be when you're working on them BTW)

[themaidsroom]

i built and own a beautiful analog studio
in new york
i built an extensive tube mic patchbay
i have never done something like this.
i wish my friend curt emery would simply build
this amp i am trying to patch together.....alas
also i am now living in london, running the studio
in new york, and money is scarce....
when you say pt - you mean power transformer ?
it may not be large enough to handle the additional
tube.
maybe i should get an outboard tube reverb like the
63 reverb........
i would love to just make it in that one box......
perhaps in reaction to my studio in nyc where
more than 96,000 wires join in the central patchbay
to be the brain of the studio.......

i want the champ 12 to be a small lightweight mini twin....
anyway
thank you mr. swell
any ideas about how to implement this would be welcome

thanks

be well

- jack

[tubeswell]

Yep 'PT' is power transformer.

You want help to learn? - I suggest that you try more simple mods (like the Torres mods) first and see if you can make them work without hassle before you try complicated mods, but that is up to you.

If you want to attempt more ambitious mods like re-doing the reverb circuit, then like I already said - one place to start is looking at the blackface schematics (the mid '60s twin reverb, deluxe reverb, princeton reverb, etc). There (if you have looked already) you will see that the reverb is taken after the tone stack recovery stage and goes to the reverb driver, reverb tranny, pan, reverb recovery, and then it goes back to the PI. But this means substantially changing the amp circuit from what is in your '70s Champ. For a start you will have to find an extra tube and reverb transformer to drive the pan (assuming the PT has enough juice to drive the extra tube without hassle), plus the hardware you need to mount the tube, tranny and the other caps, resistors etc that you will need to use.

Then (having got your schematic idea from somewhere) you will have to figure out the best way (including materials etc) to lay it out. What is the best way? I don't know without trying it, and I haven't got a Champ 12 to experiment on at my place. Look at the guts of other amps to get ideas. There's all sorts of things that could need troubleshooting - new wires could pick up unwanted stray coupling, oscillations that drive you crazy, hum from several possible sources, bad grounding, mis-wiring etc.

Welcome to the forum.

[themaidsroom]

thank you
do you know anything about the
weber addverb ?

i will do the torres mods first.
the reverb on the champ 12 is a real
drag......

be well

- jack

i love dave dobbyn 's 1995 record "twist"

[tubeswell]

What can I say? Dave Dobbyn is a kiwi legend. Th' Dudes were an excellent band too. All those songs are classic.

Don't know about the addverb - I suspect it is like a stand alone reverb unit going by the description. (Send a PM Ted Weber on this forum. He will be able to tell you about it)

[themaidsroom]

it is a verb that can live inside
an amp......
i don't know where it gets its power ??
i love that
"twist" record
beautifully recorded 15 ips
by tchad blake
produced by neil finn


be well

- jack

[tubeswell]

I suspect it is a mutation/version of a stand-alone (6G15) reverb type unit, that probably attaches inside the amp skin somewhere, and uses the same power chord. Not sue how he tackles the grounding issues. (Let me know when you find out)

[themaidsroom]

i think you are right.
i have heard those weber
reverbs can sound quite good

[tubeswell]

If its anything like a stand alone reverb, it should sound pretty good. I built one at the end of last year to go with my tweed clones, and its outta this world in terms of every other 'verb (if I say so myself).

[themaidsroom]

you should hear my plate in nyc..........
it wouldn't fit in a champ 12....
thanks for the info..
maybe i should just build the
stand alone kit .....