Now that Dumble is RIP... I'm curious

Telekarster

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I would be more concerned with someone pilfering the thing while in my possession. hah.

Wow! Good point! Yeah.... I guess it would have to be one of those sorts of things that you'd have to keep a secret, and have insurance paid up etc. I suppose.
 

bcorig

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There is nothing so *special* in there that a good tech shouldn't be able to handle. The reason the goop is applied is because anyone could put the same parts together. There is no way to patent his design, so he would make it difficult to out and out copy what he did.

I would have no issues with having one on my bench. I would be more concerned with someone pilfering the thing while in my possession. hah.
Two excellent points, particularly the second.
 

Telekarster

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I really enjoy threads like this. I learned what a Dumble is, how the different amps work, who he was, what he did and who used his products.
Reading those who know more than I know is always good.
Thanks all!

Right on man. Ditto! I like hearing from folks like @Lowerleftcoast cause for me, not being an amp tech of any stretch of the imagination, and Dumbles being such a mysterious and expensive item, it facinates me to hear from those who are techs and what they might do if ever approached for work on a legit D ;)
 

viking

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Without the internet , most of the hype wouldnt be there
I believe I have read several times that he sold amps for 2500 USD decades ago.
 

David Barnett

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On the amps that were protected by goop, only the input, tone control, and overdrive stages were concealed. So the phase inverter, outputs, and power supply were serviceable by any reasonable tech. And those are the areas where most problems tend to pop up. The layout is not too much different from a Fender, so finding one's way around inside would not be difficult.

If he had to service or modify a part that had been gooped, Mr. Dumble would take a Dremel and cut away the whole blob and rebuild the preamp section.
 

Wally

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Without the internet , most of the hype wouldnt be there
I believe I have read several times that he sold amps for 2500 USD decades ago.

The Dumble reputation existed long before the internet did. I knew about him in the late ‘70s or early ‘80s through Guitar Player magazine. HAD never sold an amp for the exhorbitant prices that some people pay for the used Dumbles that come on the market. Yes, his amps cost more than one would pay for a mass-produced amp. Allessandro put boutique amps out in the market that were priced in the range of a Dumble. I have never seen either a Dumble or an Allessandro which was priced in that range in the flesh around these parts.
I remember being flabbergasted when I read about those Allessandro amps….choice of silver-plated or gold-plated chassis, indeed!
Some amps are simply desirable in the marketplace. A young pro around here brought in his Bludotone ODS for which he had waited two years and paid around $5k USD. Magnificent amp. The overdrive was unlike anything I have ever heard in another amp. When I questioned the cost, the owner noted that he could sell it at any time for more than he paid because there was someone somewhere who did not want to wait 2 years. That happens with high end cars. It used to happen with Harley Davidson motorcycles, too, until sometime after the turn of the century when they started producing masses of bikes and providing extended financing. Yes, a person used to have to order a Harley and wait about a year.
 

GorgeousTones

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I posted this in another thread about Mr. Dumble's passing but then I thought, maybe it's better to have a thread? Anyway, I'm just curious what ya'll amp techs think. If someone were to walk into your shop and say "Hey man, my 1982 ODS has a problem..." I'm curious if it would be something an experienced tech could reasonably repair, or would it be too intimidating to touch given its expensive nature etc.? Likewise, could it even be repaired given Mr. Dumble's propensity to goop over the pre-amp section etc? Since Mr. Dumble was elusive to begin with, I suppose it wasn't easy to get with him for repairs anyway so... I suppose not much has changed but, now that he's gone to the hearafter, obviously that option is 100% moot. Just curious cause if I was the owner of an original Dumble, I'd probably be a bit concerned about this. Have any of you actually worked on a real Dumble before? Thanks for satisfying my curiousity in advance ;)

Hey, I wanted thank you for posting this I hadn’t heard of Mr Dumbles passing. It will certainly be interesting to see how his passing will effect the already obscene prices of his amplifiers. I don’t know how long it’s been since his passing, but I imagine the average value of a typical ODS has already gone up.

Despite all the mystique and legendary genius attributed to him.. Dumble absolutely did NOT reinvent amplifier circuit design or revolutionize the the way valve audio circuits are constructed. Much or nearly all of the fame and reverence attributed to Dumble & his work is due to celebrity clientele (ie J Mayer, Carlos Santana, Robben Ford, and SRV in particular). The other big factor was his reclusive “mad scientist” reputation and secretive eccentric nature. And of course the outrageous prices used models fetch.

I don’t mean disrespect but every amp tech who’s looked over a Dumble schematic will tell you he merely added to and modified what Leo Fender did with 1930’s era technology.. Also despite his “gooping”, Techs have successfully removed it. And pictures of the chassis show that not only were there no special magical parts, but the components were actually pedestrian and oftentimes even cheap low quality. I don’t think any legitimate Tech would refuse repair or maintenance work on a Dumble amp. The only caveat being that most Techs would urge a customer to reconsider making permanent changes or major modifications to the amp which would devalue such an expensive piece of equipment.
 

Telekarster

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Hey, I wanted thank you for posting this I hadn’t heard of Mr Dumbles passing. It will certainly be interesting to see how his passing will effect the already obscene prices of his amplifiers. I don’t know how long it’s been since his passing, but I imagine the average value of a typical ODS has already gone up.

Despite all the mystique and legendary genius attributed to him.. Dumble absolutely did NOT reinvent amplifier circuit design or revolutionize the the way valve audio circuits are constructed. Much or nearly all of the fame and reverence attributed to Dumble & his work is due to celebrity clientele (ie J Mayer, Carlos Santana, Robben Ford, and SRV in particular). The other big factor was his reclusive “mad scientist” reputation and secretive eccentric nature. And of course the outrageous prices used models fetch.

I don’t mean disrespect but every amp tech who’s looked over a Dumble schematic will tell you he merely added to and modified what Leo Fender did with 1930’s era technology.. Also despite his “gooping”, Techs have successfully removed it. And pictures of the chassis show that not only were there no special magical parts, but the components were actually pedestrian and oftentimes even cheap low quality. I don’t think any legitimate Tech would refuse repair or maintenance work on a Dumble amp. The only caveat being that most Techs would urge a customer to reconsider making permanent changes or major modifications to the amp which would devalue such an expensive piece of equipment.

Thanks man, and very interesting take on this you have! BTW - I believe he passed away yesterday, but the word started getting around this morning. It will be interesting to see if anything "new" surfaces from his passing. I've already seen a few photos of him that were taken in the last year or so that I've never seen before... the only known photo prior was about 30 years old, so things like this are coming out of the woodwork already.
 

dogmeat

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I'm curious about what happens to the amps he had under construction. what if you plunked down 20k for him to get started on your build.... what do you get for that???

as for his circuits, there are endless threads over in Amp Garage. there is a dedicated Dumble forum with schematics of at least half a dozen known examples, and plenty of discussion. there are guys that appear to thoroughly understand these circuits. well, at least the known ones, and have a good guess at what is under the goop on others that are not as well diagramed. Dumble did voice every amp to the customer. I've heard that he wanted the guitar to be used by the player for setting the final voice. I've followed discussion over there at A/G about the minutia of his designs where they ponder one little tiny extra filter inserted in an unlikely place. all part of the man's particular genius. you know that in the '60s, fresh out of highschool he was building amps for The Ventures
 

Telekarster

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The Dumble reputation existed long before the internet did. I knew about him in the late ‘70s or early ‘80s through Guitar Player magazine.

Ha! No kidding!??!? That's amazing that GPM was talking about him then... man... had I known I'm sure I would've been in for one, assuming I could've gotten him to build me one that is. Thanks for chiming in BTW Wally!
 

Telekarster

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I'm curious about what happens to the amps he had under construction. what if you plunked down 20k for him to get started on your build.... what do you get for that???
Wow man... that's a very good point! Gosh... and who would know who's what etc.? Hopefully if he did have some outstanding orders, those folks have their receipts and in contact with whomever is handlin' all that business. :oops:
there is a dedicated Dumble forum with schematics of at least half a dozen known examples, and plenty of discussion.

No kidding. That is interesting, man. So, are these schematics such that a reasonable tech could actually build one from scratch if they wanted to?
 

dogmeat

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So, are these schematics such that a reasonable tech could actually build one from scratch if they wanted to?

yes there is... I've had one on the back burner for years (#102 Ford's High Plate Skyline)

there's some very dedicated fans over there... even guys that make PCBs for some of the D circuits

 

Telekarster

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yes there is... I've had one on the back burner for years (#102 Ford's High Plate Skyline)

there's some very dedicated fans over there... even guys that make PCBs for some of the D circuits


That's cool man. Darn.... I wish I knew more about such things cause I'd sure like to try my hand at building one, just to see if I could.
 




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