Dumble ODS #22

[Dr d]

https://youtu.be/QAq9vnXMumg?feature=shared
Above is a short clip of the amp that was originally owned by Dennis Herring, and now owned by Jason Isbell. I was really taken with the tone, as demoed, of this amp and felt it was as close as one might get to what I perceived as the "Dumble tone". Lovely clean tones and singing, slightly nasal, overdrive tones. Agreed?!!!
So I thought I would start a thread and see what people thought might be going on under the hood.
Dating this amp is tricky. It looks like Dumble used a redundant chassis to put this together. In another video, Herring mentions that he got the amp at a time that he was using a couple of Fender combos and a Rivera modified Boss Chorus.......1977 onwards? Beyond that, these are the few things I have picked up on....
Firstly, the amp has a master volume. How is this implemented? Like a 4th gen amp or HRM?
Second, it has a presence control on the rear of the chassis that can be switched out via the "mid (accent)" switch on the front panel. ("mid" label instead of accent indicates a very early chassis.
Third, it has a "interrupt ' loop.
Fourth, wooden footswitch. When did he stop using wood?
Fifth, in the reverb ad that Jason presumably bought the amp from, it states that it had 3 x 12ax7A preamp valves. Really?

Screen Shot 2024-02-28 at 15.30.14.png

The left hand valve should be a 12AT7. However, though blurry, it does look like it might be a 12AX7.
Sixth, the 1 x 12 cab has no oval baffles and has an EVM 12S (series 2) speaker. Old cab with newer speaker?

Screen Shot 2024-02-28 at 15.28.52.png

So, my feelings are that it was possibly made in the late 70s with a speaker change in the early 90s. What I would really like is for someone who has heard a 2nd/3rd gen amp to tell me if they think what we are hearing in the video is from that era or a more modern design. Tell me what you think!

[Dr d]

More photos....

[dbharris]

I agree this amp sounds fantastic. Regarding the presence pot and mid switch...maybe a similar arrangement to #093 but with the pot mounted externally rather than a trimmer on the board.

srvdumbonetb2.jpg

P.s. I am not sure why the filename for this picture, but afaik it has no connection to SRV.

-Dan

[Charlie Wilson]

The low plate classic was originally owned by Jackson Browne and lent to SRV.
CW

[dbharris]

That's interesting Charlie, thanks for sharing. So it was sold to Carlos Rios after that and then Ben Harper?

[Dr d]

Thank you Dan and Charlie for your replies. The silver face chassis is perhaps a bit misleading. I will would like someone to say whether the amp sounds, say, like a 2nd, 3rd or maybe 4th generation amp. I can get a very similar tone with my recent 70s build, but wonder if there is a bit more to this one. It may, indeed, be similar to a low plate classic. What do we think?

[Dr d]

I agree this amp sounds fantastic. Regarding the presence pot and mid switch...maybe a similar arrangement to #093 but with the pot mounted externally rather than a trimmer on the board.

srvdumbonetb2.jpg
P.s. I am not sure why the filename for this picture, but afaik it has no connection to SRV.

-Dan

Hi Dan, i'm not familiar with #093. My guess with this one is that it is just a standard presence control mounted externally on the back of the chassis. The "MID"(accent) switch just switches the pot/control in and out of circuit.

[dbharris]

I agree this amp sounds fantastic. Regarding the presence pot and mid switch...maybe a similar arrangement to #093 but with the pot mounted externally rather than a trimmer on the board.

srvdumbonetb2.jpg
P.s. I am not sure why the filename for this picture, but afaik it has no connection to SRV.

-Dan

Hi Dan, i'm not familiar with #093. My guess with this one is that it is just a standard presence control mounted externally on the back of the chassis. The "MID"(accent) switch just switches the pot/control in and out of circuit.

I think that is more or less the same arrangement as #093, which is a transition generation chassis and still has the mini toggle Accent switch on the front. I believe the switch makes or breaks the connection between the wiper and the tant cap. Not much difference IMHO if the potentiometer is mounted externally or on the board except for ease of adjustment. Which makes a lot of sense that #022 would have an external control considering it's intended use in the studio of a producer.

Slight derail, but my thoughts on your sound question:

While I recognize all of these amps do sound different, I think they can be dialed in to get relatively similar tones, especially considering digital compression, etc. on our ultimate end of listening. I believe these different circuits will "feel" much more different under the fingers while you play them and that is what draws somebody more to one style circuit or another.

For instance, John Mayer playing a 5th generation EL34 skyline amp on the clean channel does not sound all that different live in concert than him playing the clean channel of a 2nd Gen (this being a personal experience of mine). But I bet he can feel a significant difference between the two. Similarly, I have seen Ben Harper over a dozen times live playing one or more of #093, one of David Lindley's ODS amps(blue pilot light #008), and the green combo ODS that HAD built for him...and he sounds like Ben Harper every time. I most recently saw him at a festival this past September playing a two rock Bloomfield and he sounded fantastic and still like Ben Harper. Sad he is not touring with the Dumbles anymore.

-Dan

[Guy77]

I agree this amp sounds fantastic. Regarding the presence pot and mid switch...maybe a similar arrangement to #093 but with the pot mounted externally rather than a trimmer on the board.

srvdumbonetb2.jpg
P.s. I am not sure why the filename for this picture, but afaik it has no connection to SRV.

-Dan

Hi Dan, i'm not familiar with #093. My guess with this one is that it is just a standard presence control mounted externally on the back of the chassis. The "MID"(accent) switch just switches the pot/control in and out of circuit.

I think that is more or less the same arrangement as #093, which is a transition generation chassis and still has the mini toggle Accent switch on the front. I believe the switch makes or breaks the connection between the wiper and the tant cap. Not much difference IMHO if the potentiometer is mounted externally or on the board except for ease of adjustment. Which makes a lot of sense that #022 would have an external control considering it's intended use in the studio of a producer.

Slight derail, but my thoughts on your sound question:

While I recognize all of these amps do sound different, I think they can be dialed in to get relatively similar tones, especially considering digital compression, etc. on our ultimate end of listening. I believe these different circuits will "feel" much more different under the fingers while you play them and that is what draws somebody more to one style circuit or another.

For instance, John Mayer playing a 5th generation EL34 skyline amp on the clean channel does not sound all that different live in concert than him playing the clean channel of a 2nd Gen (this being a personal experience of mine). But I bet he can feel a significant difference between the two. Similarly, I have seen Ben Harper over a dozen times live playing one or more of #093, one of David Lindley's ODS amps(blue pilot light #008), and the green combo ODS that HAD built for him...and he sounds like Ben Harper every time. I most recently saw him at a festival this past September playing a two rock Bloomfield and he sounded fantastic and still like Ben Harper. Sad he is not touring with the Dumbles anymore.

-Dan

Speaking of Bloomfield amps. We dissected one here and you can see the similarities and differences with an ODS.
I have built several with my own flavorings and they are great amps. Its become my desert island amp.

https://ampgarage.com/forum/viewtopic.php?t=34565

G.

[erwin_ve]

Here's some background info from the original owner; https://www.youtube.com/watch?v=I94Gw4JJyZs

[Dr d]

Slight derail, but my thoughts on your sound question:

While I recognize all of these amps do sound different, I think they can be dialed in to get relatively similar tones, especially considering digital compression, etc. on our ultimate end of listening. I believe these different circuits will "feel" much more different under the fingers while you play them and that is what draws somebody more to one style circuit or another.

For instance, John Mayer playing a 5th generation EL34 skyline amp on the clean channel does not sound all that different live in concert than him playing the clean channel of a 2nd Gen (this being a personal experience of mine). But I bet he can feel a significant difference between the two. Similarly, I have seen Ben Harper over a dozen times live playing one or more of #093, one of David Lindley's ODS amps(blue pilot light #008), and the green combo ODS that HAD built for him...and he sounds like Ben Harper every time. I most recently saw him at a festival this past September playing a two rock Bloomfield and he sounded fantastic and still like Ben Harper. Sad he is not touring with the Dumbles anymore.

-Dan
[/quote]

Hi Dan, fair comment! Theres no doubt than when you hear a Dumble amp in a recording, you think "thats a Dumble" without having any idea what generation it might be. But when you hear a good sounding Dumble, you cant help but ask what it is specifically!

[Dr d]

Here's some background info from the original owner; https://www.youtube.com/watch?v=I94Gw4JJyZs

Some great information on there, Erwin. Thanks for posting it.

[dbharris]

Hi Dan, fair comment! Theres no doubt than when you hear a Dumble amp in a recording, you think "thats a Dumble" without having any idea what generation it might be. But when you hear a good sounding Dumble, you cant help but ask what it is specifically!

I agree completely and wasn't intending to convey that we shouldn't try to figure out all of the details we can for every amp possible that HAD built. More that it can be hard to tell from just a recording what the circuit details might be.

-Dan

[Dr d]

Screen Shot 2024-01-29 at 15.31.48.png

Looking again at the chassis, I've just noticed the single relay mounted under the chassis. very much a feature of the 2nd/3rd gen amps. This confuses me further as to when this amp was built and in turn what design it could be. Perhaps it is a late 70s transitional amp, more akin to a low plate classic?

[dbharris]

You may find this thread interesting:https://ampgarage.com/forum/viewtopic.p ... ey#p122933

You will note the 12AX7 tube in the PI slot of ODS #002. There are also interviews on the interwebs with David Lindley stating that HAD updated #002 from time to time, but he never let him touch #008.

-Dan