A 70's ODS

[crbowman]

Great work Tony, and thank you!
I'm about 3/4 of the way through a 70's style 40's ish build. Took a lot of browsing and parsing through different posts to compile what you have basically confirmed here.
I do notice that you've added some snubbers on the preamp grids that I'm not seeing on the pics of #40. Is this a 'season to taste' kind of thing?
You've done us a great service sir!

[Funkalicousgroove]

2n4416A is an equivallent to an NTE 452, I have used the 452 and find it almost identical to the 2n4416a.

[Funkalicousgroove]

v1B coupler should be .01.

[crbowman]

I put a socket in the FET circuit on mine so I can try a couple of different FET's. Also put in a 10k trim pot in place of the 8.8K resistor so I can adjust the bias. I plan on trying a 2n4416, a 2n5457, and maybe others. I'll let you know what I find as soon as I complete the build and fire her up.

[talbany]

I thought I remembered reading somewhere about the 270 snubbers.. Going back over the info couldn't find any evidence of them being there.. This is not to say he never used them however for historical accuracy I've omitted them...FYI.. the ODSR in 76 used 250K mid..1M Bass.. 1M treble....100k Overdrive 1M level.. This would be a better suited stack if you want to squeeze more gain out of the stack..I want to try this stack first..I also want to try a 250k Overdrive pot to thicken things a bit...

I put a socket in the FET circuit on mine so I can try a couple of different FET's. Also put in a 10k trim pot in place of the 8.8K resistor so I can adjust the bias. I plan on trying a 2n4416, a 2n5457, and maybe others. I'll let you know what I find as soon as I complete the build and fire her up.

Keep me posted.. Thanks

Thanks Funk.. Changed..




Tony

[Funkalicousgroove]

I've also seen 500/250/500 on the pots with an 05 mid in the 70's amps, as well as the traditional skyline setup(500Bass, 250 Mid, 250 Treble) .

[Max]

There isn 't a such thing as a 70's classic

A classic has .05 mid, 100K slope, 250/100/250, the 220K/100K trim OD entrance and standard overdrive.

70's amps are unique and mutually exclusive from classics. Let's not further the confusion.

Thanks

Everything correct.

Max

[Max]

I've also seen 500/250/500 on the pots with an 05 mid in the 70's amps, as well as the traditional skyline setup(500Bass, 250 Mid, 250 Treble) .

Yep.

Max

[Max]

I thought I remembered reading somewhere about the 270 snubbers.. Going back over the info couldn't find any evidence of them being there.. This is not to say he never used them however for historical accuracy I've omitted them...FYI.. the ODSR in 76 used 250K mid..1M Bass.. 1M treble....100k Overdrive 1M level.. This would be a better suited stack if you want to squeeze more gain out of the stack..I want to try this stack first..I also want to try a 250k Overdrive pot to thicken things a bit...

I put a socket in the FET circuit on mine so I can try a couple of different FET's. Also put in a 10k trim pot in place of the 8.8K resistor so I can adjust the bias. I plan on trying a 2n4416, a 2n5457, and maybe others. I'll let you know what I find as soon as I complete the build and fire her up.

Keep me posted.. Thanks
Thanks Funk.. Changed..




Tony

Never found snubbers before around #70. There are "transition" amps between last generation "silverface" and first generation "blackface" that are (more or less!) identical with first generation "blackface". The Farris amp (#075) is an example of these "transition" amps. In these "transition" amps I saw the first snubbers. But one should keep in mind of course, that his "westcoast" amps have often been worked on, like Jackson Browne's ODSR or Steve Farris' ODS etc.

Cheers

Max

[talbany]

I thought I remembered reading somewhere about the 270 snubbers.. Going back over the info couldn't find any evidence of them being there.. This is not to say he never used them however for historical accuracy I've omitted them...FYI.. the ODSR in 76 used 250K mid..1M Bass.. 1M treble....100k Overdrive 1M level.. This would be a better suited stack if you want to squeeze more gain out of the stack..I want to try this stack first..I also want to try a 250k Overdrive pot to thicken things a bit...

I put a socket in the FET circuit on mine so I can try a couple of different FET's. Also put in a 10k trim pot in place of the 8.8K resistor so I can adjust the bias. I plan on trying a 2n4416, a 2n5457, and maybe others. I'll let you know what I find as soon as I complete the build and fire her up.

Keep me posted.. Thanks
Thanks Funk.. Changed..




Tony

Never found snubbers before around #70. There are "transition" amps between last generation "silverface" and first generation "blackface" that are (more or less!) identical with first generation "blackface". The Farris amp (#075) is an example of these "transition" amps. In these "transition" amps I saw the first snubbers. But one should keep in mind of course, that his "westcoast" amps have often been worked on, like Jackson Browne's ODSR or Steve Farris' ODS etc.

Cheers

Max

Max
Thanks for the input.. It would certainly stand to reason that the first 50 or so amps varied more so than the later Blackface ones. This for several reasons... In the world of amp making you might as well consider the first 25 or so as prototypes...( Even Lindley got a prototype)...At that point he was more than likely still searching for trademark tone he wanted associated with the amp.... With that being said he was more opt to very the design's based on the customers needs all the while still searching the cracks.....Most of his high profile players at that point were the first to be offered upgrades and tweaks since the ODS was still young he used what these guy's were telling them to no doubt help finalize the design...At some point you finally say that's it it's perfect at that point you usually work on getting the amps look modified and finalized which he then changed to the Blackface look..To me this is the natural course of events that has to take place..This takes TIME!!. Just how it works

[Max]

Max
Thanks for the input.. It would certainly stand to reason that the first 50 or so amps varied more so than the later Blackface ones. This for several reasons... In the world of amp making you might as well consider the first 25 or so as prototypes...( Even Lindley got a prototype)...At that point he was more than likely still searching for trademark tone he wanted associated with the amp.... With that being said he was more opt to very the design's based on the customers needs all the while still searching the cracks.....Most of his high profile players at that point were the first to be offered upgrades and tweaks since the ODS was still young he used what these guy's were telling them to no doubt help finalize the design...At some point you finally say that's it it's perfect at that point you usually work on getting the amps look modified and finalized which he then changed to the Blackface look..To me this is the natural course of events that has to take place... Just how it works

Yes, you are right. All this is an ongoing process. And as many of his customers have been great players, he got constantly valuable feedback. But I don't think all this stopped at one point, but went on until today.

If you only think of all those variants like the Mid-Switch and the Skyliner EQ, the Bluesmaster concept, introduction of the EL 34 power amps, higher plate voltages (pwr-amp) and different transformers and so on and on, you see that there are not less "generations" in the eighties and nineties then in the seventies.

That's one of the reasons, why I am not that sure (but I am not a tech of course) that these sort of "hybrid" style schems make much sense as they mingle structures and parts that perhaps never existed in this mixture in a real Dumble amp. I never tried it of course, but I would not be surprised if the same amp would sound different with the second generation "Columbia flexfoam" and later "Tandy" wire e. g.. He really thinks of every single amp as a "prototype" of a special kind of guitar amp suited for mass production of a great guitar amp for a special kind of taste and musical approach.

That's why I would always recommend, if someone want's to built a clone, to start with a 100% exact copy of an original amp, as far as you still find the original parts or such kind of parts that have been made like those from similar materials and with similar production techniques (production techniques are very different 2009) and then go into an A/B playing and listening process.

While this A/B process lasts, IMHO it's important for the "cloner" to have constant access to the original. With some luck perhaps at some point you end up with an amp, that reacts and sounds identical or very very similar to the original.

If you have done such a kind of clone, I would recommend to put it on a shelf and never touch it again.

Then you can do a second one and start to go away from the original and try different things and compare the results with the original and with clone #01.

Our hearing is no measuring device but mostly a mental process. That's why we will love an amp and hate it one day later and think it's unplayable.

That's why I never would touch an amp again, that I really liked a lot at some point, even if I think it is really a bad one at some other day. Otherwise this will only lead to more and more confusion, because the amp of course is still the same as yesterday, but w e often are in a different state of mind and focus.

If you don't have access to an original, I would recommend to start with a schem that has been often "rechecked" with the original on the bench. Make an experiment: Draw a schem and lay it away. Draw a schem of the same amp a week later and you will find mistakes. After one week more you will find more mistakes and so on. I would never trust a schem, that has been made in the context of a "one shot" situation. And two or three small mistakes may have a great impact on how the clone behaves and sounds.

For cloning these seventies amps have an advantage, because they don't have the goop (Many of the "big amps" btw too, even if they are from the eighties!). Many of the collectors (musicians often don't mind) I know would not buy de- and regooped amps and if you degoop one, the market value may be affected. You know this from the "vintage guitar" market.

What was most interesting for me (I am a curious guy) in meeting that many of his amps has never been the question "good or not so good?" but always the question "what did he have in mind, when building this special one, what kind of music has it been made for, what kind of guitar player will be happy with it". Very interesting. Can't wait to meet the next one.

Have fun

Max

[M Fowler]

Great information gentlemen and very much appreciated.

Colassal and I were just having this discussion last week about how we love an amp one day and dislike it the next time we play through it.

Was I playing the same way with the same pick attack for those harmonics or was I lazy and unenthused that day?

I just keep builting them.

Mark

[Max]

At that point he was more than likely still searching for trademark tone

Very important point.

It is my strong believe that Alexander did never have in mind to create something like a "Dumble" tone. What he had in mind is to create a "David Lindley tone", a "Larry Carlton tone", a "Steve Farris tone", a "SRV-tone", a "Robben Ford tone" and so on and on.

It is u s who took the Larry Carlton or Robben Ford sound and declared this to be "the Dumble tone". Complete nonsense btw, if you consider, that Larry Carlton mostly does not even play with "Overdrive" engaged.

I spoke about this at length with Jimmy D'Aquisto, who was always called a "Jazz-Guitar builder". He did not think this about himself but thought of himself just as a "guitar-builder" that, as being in the same shop for the first time as his teacher, got mostly Jazz-guitarists as clients, something he was not that happy about btw.

Cheers

Max

[crbowman]

In the OD input, you've got 220K - 3.3K junction to ground. I think this should be 220K - 33K no?

[talbany]

Max

As a manufacturer your always pull and tug with what it is you want to do.... and what you have to do to stay in business and sell amps..

I would have to think that Dumble had to contend with the ever changing times/ sound's put before him before he became known as the brand we relate to today.. In dealing or talking about most of the very early designs as it relates.. Most sucessfull builders start off with the vision of a completely new sound not really interested in copying or wanting to sound like say your Fender Marshall whatever.. They approach it from a totally different mind setl.. This is where I said the first 25 are literally prototypes..or as you state custom builds for these players.
However and this is a big however building customs for high profile players and the general public is 2 TOTALLY different animals.. Most of the pro's are more open to experimental designs and welcome the uniqueness.. However the general public is not so kind to radical departures from the norm.. If it doesnt feel like a fender or Marshall what ever they shy away never really interested in exploring the possibilities.. Play 3 chords Nah don't like it!!.. I am sure he heard quite a bit of that from even the pro players.. Take Lowell George saying it's a Fender built right or Stevie saying it's an overgrown Fender.. This has got to erk ya!!!LOL.
.This is most likely why at some point he started asking for auditions before he build one for you...Ridiculous as it sounds..It all makes sense to me..You have to figure over time all this really wears on you.... you begin to give in and start to make the full circle back to the comfort factor of the benchmark amps everyone grew up playing..All these builders today have the luxury of building off a brand name or sound whether that sound actually exists or is just a figment of someone wanting to sound like a Bla Bla, is really irrelevant sense we know only they can sound like that..All you have to say is the word Dumble and they can't wait to play it... I am not saying some here don't sound great playing through them I am talking about those that want to sound like tha.....t it's in the guitar players chip..If you don't believe me try marketing an amp advertised as a totally new design...Sorry for the rant here but my point is Dumble didn't have that luxury.. I'll bet he had to make compromises along the way..Whether it's going to the 34's HRM / Bulesmaster Marshall, as I think these were design changes to cut build times minimize the tweaking and wine factor as well as keep up with the sound of the times vs the earlier designs when all that other stuff didn't exist.. The natural evolution of a business..

Tony