"70ies circuit Bludodrive"

[talbany]

100 Watt 70's.. Boing!!

Reminds me of the late great John Candy in Uncle Buck where he's flipping the 20 lb pancake and mumbles.."Yep this is where you seperate the men from the boys"..

Tony

Tony there are a FEW more MEN here than most you guys w/goods are lead ta blv! lol!

jim@Omegaamps

Jim.. Glad to hear that..Plenty of scary talent hangin here you included.. I am well aware!!..Just joking around...Your amps ROCK!!..

Hope you are well!!
Tony

[Max]

Are you implying that by deviating from the given Dumble circuit (let's use #40) by adding or modding with ideas from a different era or circuit is less of a tone generator than a carbon copy build piece for piece?

Hi Ted,

no, it is not "less of an tone generator" IMO, but a different one. Let me try to explain it by using an example: Scott pointed out in the Two Rock Artist thread lately that a usual skyline circuit like #124 is not able to recreate the tone of Robben Ford's "green light, green switches" ODS in its current version because it does not have the special skyline circuit variant of RF's current amp ("the Ojai tweaks"). That is what I am talking about.

So this is my opinion:

If you want to build a "tone replica" of a single Dumble amp - RF's green light, green switches ODS as an example - I would recommend not to build an amp with the #13 PI, mix this with the #124 tone stack, then add the EL34 power amp of #183, the OD entrance of #040, the V1/V2 plate resistors of #123 etc. Instead of this I would recommend to start your build with an exact copy of the single specimen, like the Ojai is obviously an exact copy of Robben's green light amp and the Hi-Plains Drifter an exact copy of EJ's SSS. And then I would start tweaking from there according to your personal taste.

(And BTW: because Brandon has this IMO very reasonable approach, I asked in my opening post, if someone here perhaps knows if his "70ies circuit" amp is perhaps an exact copy, too, and if so, of which amp or generation precisely. And I did not ask himself in an e-mail, because at this moment I don't plan to order such an amp. And I would think it to be not that polite to monkey around with his time, busy as he is building up his business, just out of personal curiosity. And I did not see any reason at all for any "secrecy" concerning these pics I've posted, because these had already been posted before by his customer on "The Gear Page", a site far more frequented than this one - in particular by all his competitors, too.)

And if after your tweaking process you should end up with such a kind of mixture as described above or even with a version of a Hiwatt and this does exactly what you want, then I personally would not care at all if this "personal cocktail" of ingrediences out of say 43 different amps is still "original" or not, as the only thing that matters IMO is, if this mixture pleases you, period.

But indeed I would not recommend to start this "tweaking process" with such a kind of "Dumble cocktail" - just because I personally have my doubts that this would be the most promising starting point.

So if you want to build a "tone replica" of such a 2nd generation ODS, I would recommend not to mix the bright switch value of #02X with the "James configuration" of #03X, the V1 and V2 grid resistor values of #04X, the OD entrance network of #05X etc.

All these specs are IMO parts of the individual tweaking of the individual amp. And IMO the opinion of marcos that the amps Dumble exported to Europe have not been tweaked by him is not correct. If Alexander by whatever reasons should not have wished or been able to tweak them according to his taste, why then all these tiny differences? In this case it would have made far more sense concerning workflow to build all these amps in the very same way and with the very same parts.

And because these "export" amps IMO have been individualy tweaked by Alexander, too, IMO these 2nd generation amps are all "individual tone generators", too - including the exported ones. And because of this I would recommend to start either with a clone of #02X, or with a clone of #03X, or with a clone of #04X, or with a clone of #5X but not with any kind of "2nd generation cocktail". If this should not be possible by whatever reason, then of course some kind of "mixture" would still be a better starting point than no starting point at all.

Cheers,

Max

[Max]

transition generation "classic" ODS pictures

AFAIK all the transition generation amps are originally equipped with:

the "classic" tone stack, 3-position rock/jazz switch with preamp boost activated in the middle position, "ratio" control, internal "trigger" control, preamp out - power amp in and still with a 4 ohm Fender OT.

Some of these amps are originally equipped with a full size presence control (like #075), some with a small size presence control (like #094 and the Henry Kaiser amp), some still with an accent switch (like the "unknown" and #093). #093 has an internal trim pot to preset the amount of negative feedback. AFAIK in order to preadjust the effect of the accent switch.

Most of these are originally equipped with the internal dynamic balance control. #093 the only exception I know of.

#075 is the one of Steve Farris (sold in 2002), #093 is the ODS of Carlos Rios (currently owned by Ben Harper).

[Max]

4th generation "classic" ODS pictures

[Max]

5th generation "skyline" picture

[mojotom]

I was really wondering what tonestack option to use on my 70's, some say 40 got lots of mids and overall tweaking is limited compare to a skyline.

After some talks with Tony and Jelle I settled on a classic stack (250k/100k/250k with a 10k tail) and I'm really happy with the results.

For newbies like me it was a nightmare to choose a stack or the other. Hope to try them all (13 and 40 mostly) and will report back but so far this one is nice with no dead spot or almost non working mid control.

PAB is nice too, very tweedy and more agressive.

Overall a very nice amp, I prefer it to the 124, it's big and open, a bit fuzzy but with some tweaking it's an amazing amp and a loud one, I can't think how loud a 100W might be.

My next one using a CE chassis will have the dual master to balance both channels, PAB and mid boost. Fet is necessary here to push things up a bit and a 5k feedback pot is a nice addition to tweak the "openess" of the amp.

I hope we could build more of them and define what differencies the tonestack brings to the table.


Tom

[talbany]

Tom
Hope you are well.. Just as a suggestion.. If you want to get more gain and sing quality out of the OD (and not use the FET) you can tweak the 1.2 M OD entrance resistor to more like a 510K or even install a trim pot on the back 1M.. (I prefer an Alpha here (believe it or not).. The carbon trace on the pot will take some of the fuzz out and give you the ability to dial in the right amount of gain and sing..Glad the amp worked out .. Good luck on the future builds and yes the 100w is LOUD.. In reference to my Uncle Buck statement!!..

Tony

[Bob-I]

[img:313:400]http://www.cartoonstock.com/lowres/wda0085l.jpg[/img]

[jelle]

Bob,

I understand where you are coming from, but I have to say that I was enjoying this tread and the attempt to dissect the aspects that make these different generations of amps and their tones.

I guess I'll join the ARA meeting tonight and hope to be in the presence of greatness. Have you ever seen how on some Dumble amps, the nuts of the switches are aligned?

Jelle

[Bob-I]

Bob,

I understand where you are coming from, but I have to say that I was enjoying this tread and the attempt to dissect the aspects that make these different generations of amps and their tones.

I guess I'll join the ARA meeting tonight and hope to be in the presence of greatness. Have you ever seen how on some Dumble amps, the nuts of the switches are aligned?

Jelle

It was a joke of course. This thread contains an amazing amount of information, and this attention to detail is what allows guys like Scott to take my amp from bad to amazing in 10 minutes.

[Structo]

Yes check out the jack nuts on the back, all in the same position.

[jelle]

Bob,

I understand where you are coming from, but I have to say that I was enjoying this tread and the attempt to dissect the aspects that make these different generations of amps and their tones.

I guess I'll join the ARA meeting tonight and hope to be in the presence of greatness. Have you ever seen how on some Dumble amps, the nuts of the switches are aligned?

Jelle

It was a joke of course. This thread contains an amazing amount of information, and this attention to detail is what allows guys like Scott to take my amp from bad to amazing in 10 minutes.

Cool!

Sorry, I have been a bit stressed lately. Hope to see you at an ampshow again soon,

Jelle

[dr. who]

I would recommend not to build an amp with the #13 PI, mix this with the #124 tone stack, then add the EL34 power amp of #183, the OD entrance of #040, the V1/V2 plate resistors of #123 etc. Instead of this I would recommend to start your build with an exact copy of the single specimen, like the Ojai is obviously an exact copy of Robben's green light amp and the Hi-Plains Drifter an exact copy of EJ's SSS. And then I would start tweaking from there according to your personal taste...
But indeed I would not recommend to start this "tweaking process" with such a kind of "Dumble cocktail" - just because I personally have my doubts that this would be the most promising starting point.

So if you want to build a "tone replica" of such a 2nd generation ODS, I would recommend not to mix the bright switch value of #02X with the "James configuration" of #03X, the V1 and V2 grid resistor values of #04X, the OD entrance network of #05X etc.

All these specs are IMO parts of the individual tweaking of the individual amp.

Have you ever tried to hodge podge an amp like that. How do you know there is not an amp that might have a very unique sound that is a future generation. Dumble decided at different points in time to look back to previous builds and bring back tweaks from years before.

[Max]

I would recommend not to build an amp with the #13 PI, mix this with the #124 tone stack, then add the EL34 power amp of #183, the OD entrance of #040, the V1/V2 plate resistors of #123 etc. Instead of this I would recommend to start your build with an exact copy of the single specimen, like the Ojai is obviously an exact copy of Robben's green light amp and the Hi-Plains Drifter an exact copy of EJ's SSS. And then I would start tweaking from there according to your personal taste...
But indeed I would not recommend to start this "tweaking process" with such a kind of "Dumble cocktail" - just because I personally have my doubts that this would be the most promising starting point.

So if you want to build a "tone replica" of such a 2nd generation ODS, I would recommend not to mix the bright switch value of #02X with the "James configuration" of #03X, the V1 and V2 grid resistor values of #04X, the OD entrance network of #05X etc.

All these specs are IMO parts of the individual tweaking of the individual amp.

Have you ever tried to hodge podge an amp like that. How do you know there is not an amp that might have a very unique sound that is a future generation. Dumble decided at different points in time to look back to previous builds and bring back tweaks from years before.

Hi dr. who,

your questions probably arose because you've perhaps read over the explanation for my recommendations that you've quoted. I wrote:

If you want to build a "tone replica" of a single Dumble amp - RF's green light, green switches ODS as an example - I would recommend not to build an amp with the #13 PI, mix this with the #124 tone stack, then add the EL34 power amp of #183, the OD entrance of #040, the V1/V2 plate resistors of #123 etc. Instead of this I would recommend to start your build with an exact copy of the single specimen, like the Ojai is obviously an exact copy of Robben's green light amp and the Hi-Plains Drifter an exact copy of EJ's SSS. And then I would start tweaking from there according to your personal taste.

Do you now understand the content of my argument and recommendation? If not, please just ask again.

Have a nice weekend,

Max

[tubedogsmith]

http://ampgarage.com/forum/viewtopic.php?t=398