What's a "Dumble" ??

[Easy]

Hi, y'all. The question is for real. I've listened to Sonny Landreth a bit recently and I like his sound, but how much of it is the amp?

Can the Dumble sound be described?

['67_Plexi]

A Dumble or a well built clone takes on the sound of the player, if that makes sense.

There are multiple evolutions of the Overdrive Special, each has it's own characteristics.

I built a modern HRM based ODS and the clean sounds are BF Fenderish with more mid range punch (on the rock setting anyway). They break up at high volume settings much better than a BF Fender. The overdrive is Marshallesque with more gain on tap than a JCM800, but less than a TSL lead channel. However the overdrive tone is way more focussed, smoother and touch sensitive than any Marshall I've ever played. It doesn't have the compression of a modern high gain amp and will feel difficult to play of you are used to that sort of sound. It emphasizes every nuance of your playing including any mistakes.

There are some sound clips scattered around this site, however I don't believe any of them show the Dumble running at full gain. Most are medium gain settings, but thats what the Dumbles are more known for.

Bottom line is it's a stunning sounding, very verstile amp that can cover many bases.

Alan.

[Easy]

Thank you, Alan. Your reply is very helpful. This sounds like what I'm looking for. I'm gonna take a spin around and try to find some sound clips.

[BobW]

Easy, Listen to Creole Angel vs. Gone Pecan on Sonnys CDs both have a similar tone but the dumble is on Gone Pecan, Creole Angel was recorded with a Demeter. The Demeter is very close to a Dumble tone when put in the right hands and using a compressor and delay. hth

[Easy]

Man, the tone on Gone Pecan is gorgeous! I only have Grant Street so far, so I don't have Creole Angel. I'm gonna call a friend and Sonny freak and see if he has it.

Thing about sonny is that he uses slide most of the time. I don't. Makes me wonder how I'd sound through that rig.

[BobW]

Easy, After listening to Creole Angel (south of I-10 CD) listen again to say 2:10 to 2:20 sec into the tune at 3/4 speed. I am amazed how his dropped D tuning doesn't distort at that volume, and am convinced my Bassman Hybrid REV A is lacking sufficient filtering. Am presently using the 40, 20, 20, 20 filtering.
Anyone wish to comment on additional filtering? Is the best approach to split the plate resistors and add smaller additional filtering at the plates or increase all under the filter pan? Either I'll need to adjust the B+ resistors to keep the same plate voltages.

[Jammin]

I really like the little I've heard from Sonny L. I'm a budding blues guitarist, beginner really so I have lots to learn. I have no blues collection yet, suggestions are welcome, and I guess I'm into the Delta blues, although I also like classic rock as well, which was so often closely associated to the blues.

What is the main differences or characterizations between the Dumble and the TrainWreck? By Plexi's response, it sounded very much like a TW I read a little about.

My rig
50watt Marshall JCM800 modded back toward stock with a pair of greenback clones (Scumbacks M55 & M75) that I enjoy plugging my stock Gib SG Std into.

Do people talk about clones here much, or is that not in vogue? I certainly can not afford the real deal. On second view, seems like you guys are amp builders and as such talk alot about clones...

[Bob-I]

I really like the little I've heard from Sonny L.

Sonny is unique in that he plays a hybrid slide/fretted style, one he developed on his own. He frets BEHIND the slide, pushing the strings down off the slide to fret notes he can't reach with the slide. Amazing to see.

What is the main differences or characterizations between the Dumble and the TrainWreck? By Plexi's response, it sounded very much like a TW I read a little about.

No way. they're completley different animals.

Trainwreck's are power monsters with fairly low gain, getting all their tone from pushing the later stages HARD, at high volumes.

Dumbles are high gain, getting their tone from the cascaded gain stages in the preamp.

TW's are aggressive in your face hard attack.

Dumbles are gentle attack, smooth and singing.

Do people talk about clones here much, or is that not in vogue? I certainly can not afford the real deal.

That's all we talk about. Many folks here have built their own clones, a few build them for sale.

[Bob-I]

Anyone wish to comment on additional filtering?

I'm not sure you're problem is filtering. It sounds like you have too much bass energy. Can you post the schematic? Or at least describe the schematic with regards to....

1) plate load/cathode resistors
2) cathode bypass caps
3) coupling caps
4) tone stack

[Luthierwnc]

Your rig probably won't get you very close to the Delta although it should work great for the English blues styles from a generation ago.

I have "cloned" both types of amps. Wrecks are minimalist in circuit but very demanding in component quality and specs. D amps probably have triple the parts count and they are also very touchy on components -- way more than music store amps. I liked the Express copy but it wasn't versatile enough for my "American" sounds. The D amp is much closer with its 6L6 tubes and flat-response speakers. It also has more ways to adjust the sound -- maybe too many on short notice in the dark.

Both are excellent in their own way and the current state-of-the-art among homebrewers. Those circuits are also finding their way into limited production models from some well-respected commercial builders. Depending on the budget, it would be possible to put a wreck preamp into a D switching chain. Hmmm...

Skip

[Jammin]

Sounds like I'd prefer more of a gentler Dumble rig, or a hybrid might be better. Not in the market now, maybe next year or so. As to
"a D switching chain", (D=Dumble)
I am curious, is there some power options involved perhaps something like a THD UniValve, or what did you mean there about the "switching chain"?

[Luthierwnc]

Dumbles, at least the iterations on the schematics pages, run the signal through one gain stage, a tone stack and another gain stage before it reaches the power amp. When the overdrive is kicked in, it goes through two more gain stages first. After each, the signal is shaped and reduced before going into the next.

The Trainwreck goes through the gain stage and tone stack much like the Dumble. Then it goes through another gain stage, a coupling capacitor and right into another gain stage. This cap and the grid leak resistor are critical to the tone of the amp. Too big and the sound turns to mush. Too small and it wakes dogs. Not the right kind and it grates. Just right and it wails.

Several of the homebrewers here have made both amps and some have also put switchable preamp channels in the D's. You could add a Wreck gain section as one of the options. The problem is that these amps are so sensitive (and the tone standards are so high) that you might not be able to reconcile different components, outputs, speakers, etc to get the best of both. That and the Wreck-pre and overdrive together is probably illegal in most states -- too much of a good thing. I could also make the case that with two heads and an A/B box, you have your back-up with you.

[Jammin]

That you much for the helpful information. I've listened to some of the sound clips of both amps and I'm a bit uncertain that I like the clear articulation factor as much as I thought I might. I like ringing sustain, but I like it ringing with musical overtones whereas most clips I've listened to have so much clarity involved with the singing sustain. Please don't take this wrong, but these amps can sound a bit dry if you will, but if you have musical fingers, they seems to respond quite well and can produce a sort of chorus like chime.

I like touch sensitivity and cleaning up with the guitar's volume control, so I wonder if that is more to do with a great (perhaps simplistic) tube circuit where the function of the tubes spunginess (for lack of a better term) really stands out well. Maybe I'm leaning toward a Gibson Goldtone or perhaps a Vox AC something. I hear class A amps can be really touch sensitive but I don't know if I'd like the compression or not. Unfortunately I have very little experience with class A amps. But I love the distortion overdrive vibe of my Marshall JCM800.

Hmmm, can I have a hybrid of a
- Marshall Super Lead/JMC800
- Vox AC30 (maybe)
- Fender chimey cleans
- Dumble touch sensativity

I'm joking of course. I guess I need more first hand experience with these different kinds of amps. I may be more of a Splawn man. I hear they go from JTM45/Plexi to hot rodded JCM800 to high gain overdrive. I like the Marshall sound but want something flexible with great cleans too.

[BobW]

Bob,
I posted two older layout iterations in the layout post in the files section, but will update and re-post. This is also a good time for me to finally draw a schematic on this amp, better late than never. fwiw, The only changes since those posts were the 150k FET load and dropping resistor between B+4 and B+5 change. I do have the big bassman iron and may have to adjust the tone stack....more on this later. thanks, BobW

[Luthierwnc]

In the sunset of my live playing days, I am glad I can carry the thing and get home by bedtime.

It sounds like you have "loud" covered. As your gear expands, you need to realistically look at the rooms you play. You can't dime a Princeton in most bars. My favorite recent build is a Z-28 copy over a 1X12. 20 watts and it will probably never see "10" live. One amp just can't do it all.

http://www.fulltone.com/qaframe.html

Good luck with your choices and sorry to hijack the thread.

PS An Ampeg Gemini I is a great 20 watter. They have recently been discovered but are still cheap.