NAD, Overdrive Special

Discussion in 'Amp Central Station' started by bullfrogblues, Jun 22, 2019.

  1. rogb

    rogb Tele-Afflicted

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    I'm guessing yours is a Roy M3 type? Looks like these pots have been replaced? Or maybe a later version.
    ezgif-3-8fc2d27a6172.jpg

    The earlier Dumble KittyHawks look like this - very similar to the eyelet boards we know.
    dumblekittyhawk047hk0.jpg


    Also sorry for the hijack:oops:
     
  2. JD0x0

    JD0x0 Poster Extraordinaire

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    Most people don't want direct replacements because they're kind of cruddy plastic shafts that break relatively easily. Most suggest hard wiring in new pots, AFAIK. I have an M1 as well. Gave it a full recap, and socketed the IC chip for the reverb driver. Great amps.
     
    Last edited: Jun 26, 2019
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  3. Wally

    Wally Telefied Ad Free Member

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    Rogb, this amp is an M1, and the pots look nothing like the pots above. The pots in this M1 are PCB mounted. I may Pull this one back apart and see what progress I can achieve......

    FWIW, there is a thread from back in 2018 wherein muscmp had one of these open but decided not to proceed. The schematic is in that thread, and indeed it is a Boogie clone from what I see there.
     
  4. Wally

    Wally Telefied Ad Free Member

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    Yes, JD0x0, there are six or seven broken shafts here. I have been in the mood for working on odd things lately....I got the Premier Super 88 resurrected..fantastic amp. I may bring this one back to the bench.
     
  5. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    I'm not going to spend time belaboring the point with someone who opens a Dumble post addressed to me with "you may not realize, but...' and then fouls too many details to bother with.:lol:

    Kittyhawk NEVER imported Dumble...or Mesa...amps. They bought some from Applied Acoustics, which has been well documented. And each of these early "standard ODS" was NOT the ODS "player specific" amps made (or modified) a few years later - the amps anyone with knowledge thinks of when they hear "Overdrive Special by Dumble".

    If you'd like any more factual information regarding THOSE "Overdrive Specials" please PM me and if I have time I'll explain the realities to you. But it's rude to hijack this Dumble tribute-type owner's thread. I primarily asked him which real Dumble amp the builders based his on if he knew - in a post that was addressed to him. It was not a historical round-table discussion.

    Burt FWIW, I'm still waiting - after 30 years or so - for somebody to post proof of possession of a custom Overdrive Special by Dumble that has been successfully "de-gooped" without parts data destruction. The earlier amps are *irrelevant*. As I previously explained, they are not the "individualized" amps - or, more simply, they are prototypes of the famous/infamous amps made later.

    There are no "clones" of the later, "one-off" amps. There are some really good amps made as attempts to sound like them - but they are not "clones". That shouldn't be very confusing, so I'm baffled why "new entrants" jump into the discussion with incorrect information.
     
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  6. noah330

    noah330 Friend of Leo's

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    This. Now I'm off to make my New Mercedes Day!!!! Complete with photos of a Kia.
     
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  7. L.A. Mike

    L.A. Mike Tele-Holic

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    **Note to the OP. I am sorry your thread got derailed. I won't post in it again. I hope you enjoy your new amp. I have an amp Mark Kane modified and know his work is outstanding.***

    I know about Applied Acoustics and the brothers who started the company. They created the Kitty Hawk guitar amp line. They were the people who owned the Kitty Hawk brand of amps. I didn't feel it was necessary to include all that data in my previous post. Why would it matter?
    As far as the ODS design, it was well established by 1980. Robben Ford was using one by then I believe. The amps Dumble sent to Germany were the same vintage. And some of them were for sale in Hollywood at a couple of music stores I frequented. I saw them, played through them and spoke to Mr. Dumble about ordering one with a 100 watt power section instead of the 50 watts that the music stores had in stock.
    But since you brought Applied Acoustics up, here you go:

    This is from The Blue Book of Guitar Values. The same info is in Wikipedia:

    In the late 1970s, two German brothers, Wolfram and Gundolf Roy, had a company called Applied Acoustics located in Bochum, West Germany. Applied Acoustics was the authorized importer/distributor for Mesa Boogie and Dumble amplifiers for the European market at the time.
    In the early 1980s, the high U.S. Dollar rate and even higher shipping costs created very expensive prices for Mesa Boogie and Dumble amps to be distributed in Europe. Applied Acoustics made an agreement with Howard Dumble that he would ship amplifiers without a cabinet and speaker to save on shipping costs. Then, the combo-cabinets were hand-made in Germany. At that time, a Mesa/Boogie Mark I was even more expensive than a Dumble Overdrive Special! Also, if customers wanted an added reverb or effects loop, Applied Acoustics was authorized by Dumble to make these adjustments. Therefore, a lot of technical details regarding Dumble amps were shared with Applied Acoustics.
    Dumble hand-built each amp himself, and as Dumble amps gained popularity worldwide lead-time for a completed amp increased dramatically. With a lead time of six to nine months, Applied Acoustics decided to build there own amp, the Kitty Hawk Amp. The first Kitty Hawk Amp is an exact copy of a silverface Dumble Overdrive Special, even using the same U.S.-made components.
    When Dumble realized his amps were being copied, he immediately began to cover the preamp circuit with a thick layer of epoxy to protect his circuits so no one could see exactly what components he was using. He also halted distribution to Applied Acoustics, although the damage had already been done.

    Regarding the de-gooping of Dumble amps and clones. There have been amps de-gooped. There are a few that have photos posted on the internet.
    2 things to consider:

    1)Many Dumble amps had the mfg'er ID and the part # sanded off by Mr. Dumble when he built the amp. So, many de-goopers were surprised when they got down to the actual parts. Kind of hard to tell what they are.
    Parts tolerances vary up to 20% on components. Mr. DUmble knew this and would test them individually before putting them in his amps. Each part. They had to be a certain value or he wouldn't use them.

    2) The only way to find out what the value of those parts are, after the amp has been fabricated, is to remove them from the circuit one at a time and measure them with a scope. You can't get a reading from an individual part if it is in the circuit. The other components affect it.
    So if someone REALLY wants to try to make a clone they would have to take the amp apart and measure all the caps, resisters, etc.
    Only a fool would let someone do that to a Dumble.
     
    Last edited: Jun 27, 2019
  8. telemnemonics

    telemnemonics Doctor of Teleocity Ad Free Member

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    Interesting that these historic accounts suggest that Howard sent ungooped Dumbles to a distributor, then started gooping the exact same circuits to prevent anyone from learning the circuit design, that had already been copied.

    I've read endless accounts of guitar industry history, and find lots of it is contradictory, so it can be hard to be certain which account is accurate. Even for example Fender employees who worked side by side have different accounts of their own history.

    I presume that Howard Dumble is highly intelligent, so it seems uncharacteristic for him to have gone to great lengths to keep a secret that was already published and not at all a secret?
    It also seems unlikely that after 1980 he just kept turning out the same product, and stopped developing it?

    Maybe the argument here comes down to semantics.

    Was the ODS after 1980 always the same amp?
    Or was it a series of similar but different amps?
    And are those differences significant?
    Or can we say that after 1980 the ODS was always the ODS?
    Further, if we buy one Dumble ODS clone, did we buy them all?
    Or maybe we didn't buy any of them when we buy a clone of an ever evolving amp?

    So then it's not just semantics but also involves the debate over how a guitar/ amp sounds, which inevitably devolves into "the audience doesn't care", "confirmation bias rules our perception of sound", and "listeners hear the player more than the gear".

    I've poked around inside my D style ODS/ HRM and find it a little hard to imagine a distributor popping a reverb circuit in there after the build was completed. But the above account (also) says that Howard was cool with the distributor modding his amps to add reverb and/ or effects loops?
    A simple FX loop might be an easy addition, but it seems odd that a builder as careful as Dumble would approve a distributor adding reverb to amps he built.

    Maybe KH had a different take on the agreement than did HD?
    And maybe historic accounts are less that totally accurate?

    Thinking of the Marshall Korg agreement.
    Lots of published accounts of Marshall choosing to put 6550s in amps, when it was Korg, who also decided to ban Marshall selling to some of their own customers, hence Park.

    More than wanting accurate history here, it would be nice to not have to fight over historic info.
    But that fighting is probably more certain than any historic info ever will be.

    I do find multiple conflicting accounts of events to be interesting though...
     
    Last edited: Jun 27, 2019
  9. L.A. Mike

    L.A. Mike Tele-Holic

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    I'm only posting again to comment on your question of Dumble protecting his circuits.
    If I had to guess, I would say he never imagined someone would take his amp design, copy it exactly and try to pass it off as a Dumble. He wasn't a businessman turned amp builder, he was an amp builder who had to learn about business on the fly.
    I would guess he innocently thought there was honor among the people in the music business, not thieves. So his reaction to them copying his amp was a kneejerk reaction. "I've been ripped off, what do I do to protect my little business?".
    When I spoke to him he seemed like a real nice guy who loved working on electronics and the electric guitar amplifier. He was just like other amp builders I spoke to around that time, like Paul Rivera, Jim Kelley, etc. No big egos, just regular guys.

    As far as the ODS design, what he told me was it was a basic amp he built and sold but would tweak it for certain customers. If he had the time and if he thought it would make a better amp for them to use. He didn't think I needed anything other than a standard ODS. I had to send him a demo cassette tape my band had made before he'd even consider a special order build.
     
  10. JD0x0

    JD0x0 Poster Extraordinaire

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    How hard are you looking? There's plenty of de-gooped Dumbles. Took me all of 45 seconds to find a pic of #94 degooped. Nothing looks destroyed or unidentifiable in that state. As mentioned earlier, it's not a hard epoxy. It's a pain to remove but not impossible.
     

    Attached Files:

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  11. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    You or I can edit anything we want in Wikipedia. Wikipedia is an interesting collection of reading material, but can't be used as a "factual reference", since anyone can register and edit "facts".

    And NO knowledgable vintage dealer or collector uses the Blue Book, which is a mess of odd pricing mixed with descriptions that turn into reviews - all written by one guy. It's jokingly known in the vintage world as the "Pawn Shop Reference Guide" as they are - except for a small minority of poorly-informed collectors - the only ones who are known to use it. They started out as a price guide for firearms, branched off into guitars and are NOT staffed by vintage guitar and amp experts.

    And you still are missing the fact that those early amps were not the same amps as the personalized models he made soon after the Kitty Hawk fiasco. Regardless, each was a "one off" prototype in essence, and they were not identical "amp models".

    Other than Wikipedia - where DO you get your information? Were you involved in the amp tech business in Southern California in the early 80's, or a Dumble owner, or ever worked on one...or more of amp built by Dumble? Respectfully, it sounds like you've read a collection of stories that have no factual backup information - and perhaps talked to so-called "clone" builders, rather than ever being directly involved with Dumble or his amps. If you respond here to offer some credibility, great, because it's pertinent to the previous posts - but again, I'd prefer responding through PM's and not hijacking this thread.

    Exactly. He wasn't "gooping" amps he was making as prototypes, intended for sales and player feedback.

    No. The whole point. It's not an "amp model" It's a number of amps that have the same name but are...

    ...different enough that each works well for some players and not for others, because they were early test circuits (and later made for specific players) - not "spec" amps made for inventory and sold when orders came in. Dumble never "stocked" amps.

    Have YOU ever removed it? Poked or scraped at it? Soft as compared to what - in your experience? How do you know it's a a pain, soft, but not impossible to remove Or are you just repeated what you heard/read somewhere else? Where?

    And #94 is NOT that easy to find - and it's that's the only de-gooped one with ONE image, and oddly, there's no detail information or analysis as to the circuit or the parts values. And you can't see ANY parts values in the one image posted. Where are the macro shots showing specifics? There aren't any - and there never have of ANY Dumble amp made in the "post prototype""gooped" days that anyone is aware of.

    That picture has floated around for YEARS - and with no specific clones of it being built, details posted, schematic etc. And it's also interesting that the "epoxy residue" is black when the vast majority of ODS have blue epoxy over the preamp.

    Please, post a link to images of a de-gooped, 80's or 90's ODS with parts values in a table and a schematic. If there IS one I've never seen it, and it's not known among Dumble owners, experts or Alexander himself. A legit set of images and technical details would finally be real proof. I'm not holding my breath.

    Last request - if you want to talk about this further please PM me and let's leave the OP's thread alone for discussion of HIS amp. I won't respond to further ....I don't even know what to call it, because there are no facts to debate. But if you or L.A. Mike want to discuss Dumble amps lets do it OFF this thread in respect to the OP. Thanks.
     
  12. 4pickupguy

    4pickupguy Poster Extraordinaire

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    I'd be happy with clean Bandmaster. I cant conceive of a custom built ODS. Video required!!
     
  13. 3-Chord-Genius

    3-Chord-Genius Poster Extraordinaire

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    Enough with this arguing. I'm just glad that the fragile harmonics can survive in a vacuum tube, where are they seem to be eliminated or squashed in a solid state crystal lattice. It comes down to that.
     
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  14. L.A. Mike

    L.A. Mike Tele-Holic

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    First of all, in your first post in this thread, you questioned the validity of the amp the OP had bought. You insinuated that it can't be a true Dumble clone since all the ODS models post 1980 are gooped and can't be degooped. And anything before 1980 isn't a true ODS.
    So, recommending that I continue discussing this with you in a PM, out of respect to the OP, is amusing.
    I have posted in this thread about contacting Mr. Dumble and discussing what I was looking for. He personally told me about the ODS amps. I believe Robben Ford already had his first Dumble when I wanted to get one.
    The ones for sale in music stores in L.A. at that time were 50 watt models and I needed 100 watt minimum because of the venues we played.
    My reason for providing the links was for your convenience. Many people want to "see it themselves" before believing something, so I included the links. I wasn't just repeating things I'd read on the internet. However, some people doubt anything they read in forums unless they agree with it. I don't need to "prove" anything to you. If you doubt my story, fair enough. Doesn't matter to me one way or another.
    You seem to fancy yourself a Dumble history expert. What are your credentials?

    Not all post 1980 Dumbles are gooped. Like Carltons and Fords.
    If you're interested, Carlton discusses Bludotone making some Dumble clones for him by "copying the components". Kind of hard to do if they are gooped.
    The reason you don't see gut shots of these amps owned by famous people posted on the internet is, they signed an agreement with Mr. Dumble to protect his design by not doing that. But Carlton broke his agreement with Dumble, let someone else inside his amps and copy them. I would imagine his relationship with Mr. Dumble is non-existent now.

    https://larrycarlton.com/?p=549
     
    Last edited: Jun 29, 2019
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  15. GuitarsFromMars

    GuitarsFromMars TDPRI Member

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    This has really been badly done up in TDPRI poor taste. The OP (who is a genuinely nice guy) just shared that he got a clone of a Dumble circuit, built by one of the better amp guys in the country. He bought it at my suggestion, and is new to Dumble (poopstorms) amps both as a process and a construct. He did not do a bunch of research before he got it. However, the guy who put it together, has. The guy who built it mos def knows what he's doing. You hard line creatures need to just sit on your hands, if you insist on being smug or overly correct. Just wish him a happy new amp day.

    BTW, OP- Happy new amp day. I hope it brings you years of enjoyment. You make me want another one.
     
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  16. gridlock

    gridlock Friend of Leo's

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    I totally agree with “GuitarsFromMars”, I want one of these Dumble style amps and I live relatively close in Florida.

    Congrats on owning such a great and well built amp. I hope to play one, and possibly own a D-style amp one day soon.
     
    Last edited: Jun 30, 2019
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  17. stevemc

    stevemc Tele-Meister

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    congrats on the new amp op! i am jelly,lol!
     
  18. GuitarsFromMars

    GuitarsFromMars TDPRI Member

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    (sigh) internet experts.

    I love how people follow the rules printed at the bottom of each page around here-

    IMPORTANT: Treat everyone here with respect, no matter how difficult!
    No sex, drug, political, religion or hate discussion permitted here.
     
  19. L.A. Mike

    L.A. Mike Tele-Holic

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    since you posted the rules obviously you think some are not abiding by them
    you do know you can hit the report button so the mods can review the post(s), right?
     
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  20. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    My first post is quoted above. It is nothing like the nasty, "Insinuating", validity-questioning post you try to make it sound like. And I did not go into extensive historical detail, but posted the general information that covers the majority of Dumbles post-Bakersfield output. Are there early exceptions to "gooping"? yes - but, as noted, they are prototype test circuit - a few the same, most not. Remember, he made VERY few amps.`Nobody who has claimed to make a "clone" has shown both the physical amp and schematic worked from - except for very early amps that are basically Fender circuits with minor mods or amps like modded Bassmans (not ODS).

    So I asked a straight forward "clone of what" question and explained - in case he was not aware - the GENERAL situation regarding ODS amps.

    _______________________________________

    As far as "de gooping" - please, show examples with specific details - i.e. de-gooped amps where parts values are noted and schematics drawn up. To date, no tech I know that has worked with Dumble or inspected or serviced his amps is aware of any. There is ONE example on the internet - but no parts values are visible and schematic was drawn up. AND it had unusual black goop, when the vast majority are blue.

    The OP's amp was described as a "clone". I asked a very legitimate question - a clone of "which" amp" What ODS did the builder use as a reference standard?

    If it is a "clone" it is an EXACT copy of something , and the builder should be able to supply that information- I asked i he knew WHAT, exactly, it was a copy of - since ODS amps are not all the same, which you didn't disagree with.` This thread really "turned" when you essentially called me a liar, provided a bunch of irrelevant history, and did NOT post a specific example - with pictures - of a known ODS along with the schematic

    In other words, you have ducked the entire issue of "proof of "clonage"" and spent your time trying to undermine me, degrade my posts, falsely accuse me of insinuating something and (also falsely) accused me of "questioning the validity" of the OP's amp when I actually asked only for info regarding the amp used as a reference (which I have repeated for you now 3...maybe 4...times, since you either aren't getting it or simply think insulting me is a substitute for solid technical information.o_O

    Because of your attitude I preferred that you continue discussion by PM to lower the tension level - which you refused to do.

    For a guy rarely here, a complete unknown and a history equal to a newbie you have a lot of nerve asking ME for credentials. Your claimed chat with Dumble might as well be smoke and mirrors for the amount of credibility you have established over your years here. My "CV" has been posted several times over the years.

    Did you know there's a search function here? Use it. Oh, and I met Dumble in person in the 1990's. Still have his business card. You want to see it you can come over to my house.

    (mic drop)
     
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