ODS #004 For Sale

[crbowman]

Is that starve resistor a 12Meg????

Sure looks like it to me. Wonder if that's supposed to be 1.2M and we're just not seeing the dot.

[Structo]

Yeah, whoever drew that is not the best draftsman.

His 1's look like a ^


The brown coupling caps are most likely Mylar? (polyester)

[glasman]

Is that starve resistor a 12Meg????

Sure looks like it to me. Wonder if that's supposed to be 1.2M and we're just not seeing the dot.

As it was written / drawn in Europe odds on that it would have been noted at 1M2 if it was a 1.2meg resistor.

I have waded thru European schematics for years. (27 years with a Dutch semiconductor equipment maker).

They like to place the multiplier at the decimal point position (which makes total sense!!).

[marcos]

If these schems are accurate, this is indeed one interesting beast.
The PI values are very different from 2nd generation. Maybe 12AX7?
And how 'bout that 8.2K feedback resistor.

AFAIK this amp uses a 12 AX 7 as PI. I was also wondering about the accuracy of the schematic, but it was drawn by a very good tech with
a lot of experience with Dumbles, so I would trust the schematic.
Wish I knew more about the first generation amps, maybe a little more
will surface in this discussion.

Marcos

[FUCHSAUDIO]

Well, I'm going to try this just for fun. I suppose I'll find out why he apparently only did it once !

[marcos]

Well, I'm going to try this just for fun. I suppose I'll find out why he apparently only did it once !

Andy, I believe you are referring to the starve switch.I knew two
owners of the amp, they both said it tended to make the amp sound more
like a Marshall. As I said, I never got to try the amp, so I cannot comment
on the usefulness of this feature. Let us know what you find out

Marcos

[crbowman]

Well, I'm going to try this just for fun. I suppose I'll find out why he apparently only did it once !

Way to go Andy!
As soon as my garage cools down (like, October!) I'm all over it.
Please keep us posted on your progress, impressions and so forth.
This is the generation I'm most interested in, and the one we seem to know the least about.

[ElectronAvalanche]

Hi Marcos,

thanks for sharing the schematics.

This amp is the famous "Karl Ratzer" amp.

I once got the chance to test drive this amp at Mr. A. K. house here in Munich (who owned the famous 150W ODS as well).

The Starve switch gave the amp a Marshallesque quality but dropped the volume of the amp down by 2/3. Maybe that is why HAD dropped the feature?

Again thanks for sharing!

Another great specimen that will see some homebrew reincarnations.

Cheers,

Electron

[talbany]

BTW..Treble Middle and Bass pots are dated 1978

Tony

[glasman]

It sold for a cool $59K

[stevlech]

So could it be safe to say that the clips Max posted a year ago or so were of this amp?

In addition, is that 820k feeding the level pot?

[talbany]

So could it be safe to say that the clips Max posted a year ago or so were of this amp?

004 was owned by both Charley and Harry..AFAIK


https://tubeamparchive.com/viewtopic.ph ... c&start=75

It would also appear that if Lindley's amp had a starve switch he liked it and used it.. both circled in the up position

Tony

[Structo]

Maverick has #009 1978 Dumble Dumbleand Special as well.

http://www.maverick-music.com/vintage-a ... pecial-009

[img::]http://www.maverick-music.com/wp-conten ... %20001.jpg[/img]

[marcos]

[quote="stevlech"]So could it be safe to say that the clips Max posted a year ago or so were of this amp?

I don´t think so, although I am not sure. There was 3rd generation
amp that also belonged to both Charly Bonat and Karl Ratzer at different times, I believe this is the amp on the Karl Ratzer cuts.
The tracks with Charly playing feature his stock 2nd generation amp AFAIK.
This is sometimes confusing because the amps were owned by many players over the years. I know at least five players who owned the 3rd
generation amp in question.

Marcos

[glasman]

It would also appear that if Lindley's amp had a starve switch he liked it and used it.. both circled in the up position

Tony

I talked to David today and was asking about the starve switch. He said the ODS's he owned / owns did not have the starve switch installed. But he knew of the mod and he does have a Dumble modded bassman that has the starve switch.

Ok here is the history on the starve switch according to Mr. Dave. Dumble had a fender bassman on his bench that he was working on, the amp had a problem and did not make enough power, but the tone was "incredible" according to David. Turned out to be a bad tube socket (maybe carbon arc or something along those lines) and that supposedly is where the mod originated.

More Dumble Myth and Lore ............