Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => EZ Board postings => Topic started by: Geezer on June 18, 2005, 05:42:17 am
-
Hoffman Amplifiers
> Tube Amp Building - Tweaks - Repairs
> Simple reverb circut
<< Prev Topic | Next Topic >>
Author Comment
Funkalicousgroove
Junior tube assistant
Posts: 29
(3/23/04 12:43 pm)
Simple reverb circut
--------------------------------------------------------------------------------
Does anyone know of a more simple reverb circut than fender's? I'm trying to free up at least one triode to use for another gain stage, or, does anyone have a simple mod to the fender reverb circut that would use 1 triode on the input stage of the reverb instead of two? I am using a 12ax7 instead of a 12at7 in my reverb driver stage.
Casey4s
Senior tube assistant
Posts: 150
(3/23/04 2:46 pm)
Re: Simple reverb circut
--------------------------------------------------------------------------------
If you take 1/2 of the 12AT7, you'll change the impedance and power going to the reverb pan. I don't think I'd do that.
A 12AX7 is NOT intended for high freq. utility applications, this is what a 12AT7 does best, and was never intended as an audio tube.
What kind of amp are you talking about? A fender reverb is about as simple as it gets IMHO.
Funkalicousgroove
Junior tube assistant
Posts: 30
(3/23/04 4:16 pm)
Re: Simple reverb circut
--------------------------------------------------------------------------------
It's kind of a blackface, the reverb circut is 100% fender, with a dwell, mix, and tone control. I modified the driver stage to use a 12ax7 because I can't find any decent 12at7's. The amp started it's life as an Allen TONESavor, but it's FAR from that now. I want to add a high gain stage to it, and was hoping to do so without another hole in the chassis. I've heard of people "borrowing" 1/2 of one of the reverb tubes to add a 3rd stage. Maybe I'm nuts
Casey4s
Senior tube assistant
Posts: 152
(3/24/04 8:45 am)
Re: Simple reverb circut
--------------------------------------------------------------------------------
OK, that's a little more information.
I know David Allen is real easy to communicate with. Give him an email nd see what he thinks.
If it were me (and it isn't) I would just add another 12**7 tube. I have never seen one of Daids schematics, but if it Fender Similar, chances are that if you add another gain stage you may also need a Cathode follower.
Just my 2 cents worth....
Casey4s
Funkalicousgroove
Junior tube assistant
Posts: 32
(3/24/04 10:24 am)
Re: Simple reverb circut
--------------------------------------------------------------------------------
Thanks, It's a blackface type circut so I should be fine with an extra gain stage after the tone recovery stage sans cathode follower, I was hoping to avoid the dreaded chassis punch though. Ampeg reverbrockets have a more simple reverb circut that as I understand it, has no transformer-know anything about those?
tubenit
Junior tube assistant
Posts: 49
(3/26/04 6:09 am)
Re: Simple reverb circut
--------------------------------------------------------------------------------
You might look at the schematic for a Gibson Scout GA-17RVT. It uses a 12AX7 tube for the reverb. (The schematic shows 6EU7 but the layout on the same schematic shows 12AX7 which is actually correct) As I understand the schematic, the tube functions as both the reverb driver and recovery. I recently rebuilt a Scout and it has a great sounding spring reverb but a step down from a Princeton Reverb quality IMO.
Casey4s
Senior tube assistant
Posts: 153
(3/26/04 10:48 am)
Re: Simple reverb circut
--------------------------------------------------------------------------------
"Deleated" post
Edited by: Casey4s at: 3/26/04 10:52 am
<< Prev Topic | Next Topic >>
Topic Commands
Click to receive email notification of replies
jump to: Tube Amp Building - Tweaks - Repairs (New)New Product Suggestions (New)Praises - Complaints - Suggestions (New)Buy - Sell- Trade (New)Archives (New)
- Hoffman Amplifiers - Tube Amp Building - Tweaks - Repairs - Hoffman Amplifiers -
Powered By ezboard® Ver. 7.32
Copyright ©1999-2005 ezboard, Inc.