OD Reverb #13 (1976)
Moderators: pompeiisneaks, Colossal
OD Reverb #13 (1976)
OD Reverb #13 partial schematic, as traced by me from HAD's original layout drawing.
Interesting things to note:
-Values of tonestack
-Method of reverb (tapped off right before V1B -> reverb send -> tank -> reverb recover -> mixed with clean signal from output of attenuation network after V2B)
-NFB loop in reverb recovery/mixer
-Clean/reverberated mix gets sent to the OD stage
NOTE: I don't know if I should put up Dumble's actual hand-drawn layout. I think there might be some copyright violation issues. One of these days, I'll get around to redrawing this.
Interesting things to note:
-Values of tonestack
-Method of reverb (tapped off right before V1B -> reverb send -> tank -> reverb recover -> mixed with clean signal from output of attenuation network after V2B)
-NFB loop in reverb recovery/mixer
-Clean/reverberated mix gets sent to the OD stage
NOTE: I don't know if I should put up Dumble's actual hand-drawn layout. I think there might be some copyright violation issues. One of these days, I'll get around to redrawing this.
You do not have the required permissions to view the files attached to this post.
- Funkalicousgroove
- Posts: 2232
- Joined: Mon Jul 25, 2005 8:04 pm
- Location: Denver, CO
- Contact:
Re: OD Reverb #13 (1976)
Would you be willing to share it privately?
Owner/Solder Jockey Bludotone Amp Works
Re: OD Reverb #13 (1976)
Sure.
Shoot me an email at bhs3 (AT) duke.edu
Shoot me an email at bhs3 (AT) duke.edu
Correct #13 Schematic???
oldmanmac
Someone, (maybe you) gave me an electronic copy of this 2-3 years ago. Unfortunately I lost the email after a Windows crash and retained only a copy I had printed, but it is illegible in some areas.
I have made a schematic from it, but some of the values are more guess than anything. If I email this to you, do you think you can correct it? If so, we could post it for all to see!!!!
David Hicks
Someone, (maybe you) gave me an electronic copy of this 2-3 years ago. Unfortunately I lost the email after a Windows crash and retained only a copy I had printed, but it is illegible in some areas.
I have made a schematic from it, but some of the values are more guess than anything. If I email this to you, do you think you can correct it? If so, we could post it for all to see!!!!
David Hicks
Re: OD Reverb #13 (1976)
Actually, you sent me the blurry layout on a CD, which is where I got this from!
If you send me a schematic, I'd be glad to take a look over it. I've built an OD Reverb based on this, so I have a pretty good idea of what the values should be, or at least the values that I like in there.
Ben
If you send me a schematic, I'd be glad to take a look over it. I've built an OD Reverb based on this, so I have a pretty good idea of what the values should be, or at least the values that I like in there.
Ben
Re: OD Reverb #13 (1976)
Hey Ben,...
I've got my layout on AutoCad at work. I've got a busy week, but I'll port it to .bmp or something early next week. Damn!!!! I wish I could figure out who sent me that drawing. I'm sure another generation closer to the original would be much easier to read.
DEH
I've got my layout on AutoCad at work. I've got a busy week, but I'll port it to .bmp or something early next week. Damn!!!! I wish I could figure out who sent me that drawing. I'm sure another generation closer to the original would be much easier to read.
DEH
Re: OD Reverb #13 (1976)
Consider installing the free CutePDF writer to "print" to a PDF.
e-mail me?
Oldmacman, can you e-mail me? tommy.dale@c2i.net
I have some questions about the reverb schematics..
Tommy
I have some questions about the reverb schematics..
Tommy
Re: OD Reverb #13 (1976)
Does this reverb circuit require 2 or 3 pots?
There is of course a send and return pot in the actual reverb circuit.
But there is also a pot after V1B before the dry signal goes to the mixer. Is it a trim pot?
Tommy
There is of course a send and return pot in the actual reverb circuit.
But there is also a pot after V1B before the dry signal goes to the mixer. Is it a trim pot?
Tommy
Re: OD Reverb #13 (1976)
It's a trim pot. Only 2 reverb controls on the front panel.
Don't know how it's done on later models. I've seen a couple where there's a Reverb control for the OD channel on the back panel.
Don't know how it's done on later models. I've seen a couple where there's a Reverb control for the OD channel on the back panel.
Re: OD Reverb #13 (1976)
I managed to find it on the original, although it's a bit unclear scanning.
How do you set that trim? I'd imagine it shouldn't have too much resistance, since that would lower the signal level, and act like a clean-master pot, making the preamp deliver less clean signal than it would without it..?
Tommy
How do you set that trim? I'd imagine it shouldn't have too much resistance, since that would lower the signal level, and act like a clean-master pot, making the preamp deliver less clean signal than it would without it..?
Tommy
Re: OD Reverb #13 (1976)
Some of the resistor values has a ? after them. Have you used the values that are printed, and does it work with them?
Tommy
Tommy
Re: OD Reverb #13 (1976)
I haven't looked at that layout in a while, but I've changed a couple of things. The values should work, but no guarantees.
On the reverb return stage, try using 220K/3K3 plate/cathode resistors, and try 220K plate resistors and a 1K5 cathode resistor on the mixer stage. You get a bit more headroom.
The 820K resistor on the NFB loop on the reverb return stage is adjustable. I think I have 2M2 in there now, but I'd have to open it up to be sure.
If you're new to building Dumbles, start with a straight ODS using a layout like the one Gil Ayan and ElectronAvalanche posted recently - Dumble used that one starting in the early '80s. Start with something like a Hybrid-A (be sure to use 220K/100Kpot into the overdrive), use the right parts, and build it right, and you'll be happy.
Ben
On the reverb return stage, try using 220K/3K3 plate/cathode resistors, and try 220K plate resistors and a 1K5 cathode resistor on the mixer stage. You get a bit more headroom.
The 820K resistor on the NFB loop on the reverb return stage is adjustable. I think I have 2M2 in there now, but I'd have to open it up to be sure.
If you're new to building Dumbles, start with a straight ODS using a layout like the one Gil Ayan and ElectronAvalanche posted recently - Dumble used that one starting in the early '80s. Start with something like a Hybrid-A (be sure to use 220K/100Kpot into the overdrive), use the right parts, and build it right, and you'll be happy.
Ben
-
- Posts: 1
- Joined: Sun Mar 26, 2006 4:01 pm
- Location: ITALY
Layout Question.
hi, i'm from italy.
does anyone that give me a complete working layout?
I can use only 4 12ax7 and 2 el34 'cause my trasformer currnt is 120mA.
Oldmacman can you give me a hand made layout privatelly?
Question for relè: what type of relè i can use?
Thanks....(i want..i can...i thank...you....)
OOps...My EMAIL is: faxfux@email.it
Fabio.
does anyone that give me a complete working layout?
I can use only 4 12ax7 and 2 el34 'cause my trasformer currnt is 120mA.
Oldmacman can you give me a hand made layout privatelly?
Question for relè: what type of relè i can use?
Thanks....(i want..i can...i thank...you....)
OOps...My EMAIL is: faxfux@email.it
Fabio.
-
- Posts: 208
- Joined: Fri Feb 24, 2006 11:29 am
- Location: Vleuten, The Netherlands
- Contact:
Re: OD Reverb #13 (1976)
Hi Ben
Can you email me that one too?
(work: info AT cmwamps DOT com)
Many tia!
Chris
Can you email me that one too?
(work: info AT cmwamps DOT com)
Many tia!
Chris