Dumble Land/300SL Schematic Starting Here

[Max]

They are placed as small trim pots on the preamp board as a part of the phase inverter circuit.

I know what is inside an ODS Max ;O)

If I am guessing .... it is a rather educated guess imo.

let's look at the facts.
None other than the 6550 based amps have the "Balance Phase Inverter" on the rear.

Hi ampdork,

facts?

- In the ungooped DL 300SL I had a chance to look into, the dynamic balance control was on the PI board inside the amp and not at the back panel.

- If you find the time to look at the pictures on Bill Morgans (before:Yukihiro's) site, you will notice, that on both 300 SL's the hole for the "Balance" control is closed.

But I understand that, as ic-racer wrote, this project was ment by him just for the fun of discussing guesses anyway (btw: nothing wrong with such a kind of hobby IMHO)

But if "Dumble small talk" is the goal of this thread anyway, of course I understand, that my reminders, that to end up with a fine 300SL clone, some kind of precision would be of some advantage, have missed the whole point. No problem, sorry for my misinterpretation.

BTW: In regard of entertaining and amusing small talk topics, the question if Alexander is a "genius" or not, is for my own taste one of the most boring topics I can imagine. But of course: tastes are different.

Cheers and have fun

Max

[dr. who]

Over at fliptops.net they have V9 pt's for $255 and the ot's for $265. Does anyone kow the chassis dimensions for the 300sl? Did any of them have a PAB? Does anyone know the value ranges used for the caps and resistors for the filter switches?

If we don't have known values lets offer some directions for different voicings-
What values would y'all use in the tonestack for let's say a funk player who uses alembic bass p'ups? What values for fender j and p basses? How about a blues/rock bassist with those three different basse?

[ic-racer]

We can decide on where to put the PI balance control when it comes time to work on a layout

I have uploaded an updated schematic. Still pretty bare.

Next problem areas to work on; incorporate the SVT PT into the power supply and come up with a reverb schematic. (I also see some that I missed some grid resistors on the output tubes).

I am also thinking that, until correct documentation is available, suitable component values for the filters could be obtained by trial and error in a real-life circuit.

[ic-racer]

But I understand that, as ic-racer wrote, this project was ment by him just for the fun of discussing guesses anyway
Cheers and have fun

Max

Actually, the creation of the schematic or clone is the FUN part. The discussion of guesses is part collective intelligence theory. (Did you see the link I posted earlier?)

[RJ Guitars]

We have an ongoing project in somewhat of a kindred spirit with you...

http://ampgarage.com/forum/viewtopic.php?t=7972

I suspect we have a great deal in common between the these amps... and has been mentioned, each of these amps in either individual series is a beast unto itself.

rj

[Guitarman18]

With the absence of an original specimen to explore I believe the next best thing is to speculate, hypothesize and experiment as to the innards of the DL 300SL. As we all agree, Mr D would not have built two amps identically but quite clearly, having spoken to a prospective customer he would have used one of his existing platforms to refine, rather than re-inventing the wheel every time someone called. So if all that can be ascertained from such an archaeological 'dig' is ''what was the general base line platform toplogy and the appropriate tweak points'', I believe this project can be taken a long way forward.
I personally have never seen one up close, have no real desire to attempt a build and have no information that would be of any use to this discussion but there are people who, having seen original specimens have a great deal of information that would truly be a great benefit to this project.

While #124 was a revelation to AG, on it's own as an original specimen, it doesn't tell you much more than what it is, which is a fine example of an amp, a snapshot view of the design life of HAD. It's only when information about other ODS's was discovered that the context of the platform design can be compared and contrasted and appreciated. The benefits of collective knowledge!

Reading the early posts from the legendary pioneers of AG, you get a real sense that something truly spectacular and exciting was unfolding throughout the threads. This could be the next great thing to happen. Ask yourself, not what AG can do for me but what you can do for AG. We need more AG legends.

Well done ic-racer for getting this started. Good luck!

[ic-racer]

We have an ongoing project in somewhat of a kindred spirit with you...

http://ampgarage.com/forum/viewtopic.php?t=7972

I suspect we have a great deal in common between the these amps... and has been mentioned, each of these amps in either individual series is a beast unto itself.

rj

I actually started my research with the intent on trying a SSS schematic to fill your chassis. But it seemed like there was more info on the 300SL and that it might be more likely to be completed. It was kind of an arbitrary decision on my part.

I'm also fascinated by amps with six output tubes, after doing my Fender Super Twin ODS conversion.

[dr. who]

Well the pre and the reverb are supposed to be roughly the same topography in the SSS and 300sl. I think that Big-D used what he could get his hands on for the power section, and thats why the power section of the SSS' have different trannies. Do any of the 300sl amps have anything other than v9/svt trannies?

[groovtubin]

I'll post an updated schematic tomorrow.

Remember, this is just for fun. No one is going to loose their job or be castrated if the guesses are wrong or if the schematic has some deviations from the real thing.

SInce this IS a amp building forum, and not he &^% gear page, thank you for going for it! ALot of people KNOW whats goin on, some don`t, who cares, have fun......i look at it like this, NO one is or can be the original creator, take it FURTHER, that IS the intended point of all this right??
jim@omegaamps,

[dr. who]

Are the chassis dimensions the same as a svt?

[dr. who]

I found this on the net talking about Ultra Linear power and thought it would help to clarify some stuff about the power section.

[nickm57]

Sorry more questions than answers.
Looking at the SVT it's 300 watts... DL 300... wouldn't this be the basis of a build?
It includes a mid switch but from the board here The SVT uses an inductor while the dumble design does not?

And from Articles ...here say.. The SSS was created because of the dumbleland in Jackson Browne's studio.

So what would be the differences between an amp like a ampeg V7 and the dumbleland. Or is barking up the wrong tree for these amps.

Nick

[Max]

I found this on the net talking about Ultra Linear power and thought it would help to clarify some stuff about the power section.

Hi Dr. Who,

I have never heard of a Dumble Amp that uses UL circuits.

Cheers

Max

[Max]

Were they all for bass guitar?

Don't think so (FET, PB, Reverb). And as far as I know Mr. Cross plays guitar.

But at least one of them has been used by Tommy Shannon (SRV-Double Trouble / bass guitar)

Max