Dumble Bass Amp

[JammyDodger]

Hey All,

I went to jam at a buddys house last night a played through a Dumble amp called a Small Special 100. The guy told me that he took his bass amp in to HAD in the mid 70's and was told it was dead. Mr. Duble said that he had an amp that might work for for bass and the guy wound up buying it.

It was in a short head cabinet with a gold anodized front plate and leather above that. There was a volume control on the left followed by three switches, bright, deep and guitar/bass, then the Treble, Bass and Level controls. Finally there was a switch that said 'Accent'. I had a quick look in the back and there were two 12AX7's and 4 Power Tubes. There was a lable that said Dumble Amplifiers.

Nice sounding amp although I would not be my first choice for bass. Really loud!!!

Anyone ever hear of a Dumble Bass amp?

Cheers, Mike

[JimiB]

sure! is there any way he would let you open it up and take pictures?

[tomrasdf]

Found this pictuer floating out on the interweb. Look like this?:

[jelle]

The schem is on the Schematicheaven....

[Pete]

The schem is on the Schematicheaven....

Can't find Schematicheaven (schematicheaven.com) is that site still up??

[JammyDodger]

To All,

Yes - just like that picture except there was no logo on the front.

I don't know the guy well enough to ask him to show me the innards. He was kind enough to let me play through his amp and I'm sure I'll be seeing him again.

Cheers, Mike

[heisthl]

If anyone has that Schematic - I'd like to see it for the possibility of Bass use.

[jelle]

Hee guys, we have it right here:

https://tubeamparchive.com/viewtopic.php?t=419

It is the 60 OD amp. Glad to able to return a favour ,

Jelle

[dr. who]

thanks jelle...been looking for this

[skeezbo]

Has anyone built this preamp? The tone stack looks strange to me: The .1 and .01 are familiar Skyliner values, but on closer inspection the .01 seems to be taking the place of the .001 that goes around the bass pot on the standard Dumble tonestack. No mid pot, so no mid cap? Maybe I am I just expecting to see something Fender-like.
I have channel one dormant on a Bassman 100 that I use for bass (Skylinerish second channel). If the schematic is correct I would love to have HAD's bass preamp, too. If the tone stack in the schematic makes sense to you guys, I'll wire it up and report back.
One other question: some of the values in the PI are different from the stock Bassman 100 schematic. I'm going for a clean sound (for bass). How important is it to swap those values? When I modded the lead channel I just changed the tonestack values and the way the mid pot was wired. I'll change everything else, too, if you think it'll make a difference!
Thanks,
Skeezbo

[jelle]

Yeah, the preamp is a little hotter and the pi a little more linear.

Sounds nice btw.

Jelle