Dumble & Mark II

[zebpedersen]

Here's my new D***** amplifier. I've had it for a good few weeks now and wanted to discuss with my fellow amp aficionados.

Does anyone else have experience with this type of amp? I'm particularly interested in what people think about it in relation to the Mark II - I believe this is the amp that Randy says the ODS circuit is similar to, and I tonally I can see where he's coming from.

Dumble fans?

 

[Boogiebabies]

I think Dumble used a few techniques in the ODS that Smith did not have the idea for yet.
Specifically, the ODS has a feedback loop in the preamp that adds overtones and harmonics that the Mark's
never had. Every amp we know has circuits borrowed from designs from the 50's. Similarities are bound to happen
when both designers are dipping into the Fender pool. To my eyes and ears the Boogie design is no where near the
Dumble. Two totally different designs and philosophies.

 

[zebpedersen]

Interesting that you say that about the feedback loop, would that increase the gain on tap as well as adding harmonic content? The Dumble puts off just as much drive as the Mark, but has fewer preamp tubes (3) and only one active stage in the EQ. (Please, correct me if I'm wrong, but presumably in a cascading gain preamp design more stages means more gain? And the Marks have active Bass/Treb/Mid and the graphic is active also? Whereas the D* has passive EQ with 2 active boost switches and a voicing switch.)

I must confess, I bought it for the 'Larry Carlton sound', however I've since discovered that's akin to buying a Mark II for the 'Petrucci sound' when there's so much more on offer.

 

[Boogiebabies]

Both tone stacks are passive. The GEQ is active on Boogie's as it can cut or boost.

The overdrive characteristics to me are very different. The Dumble uses a more modern high value coupling capacitor
to assist in turning treble frequencies into gain. The Boogie uses more plate voltage and higher cathode voltages to achieve the
overdrive. Boogie also uses what may be considered a duller sounding Tantalum type for all cathodes whereas Dumble's use electrolytics.
To my ears, good electrolytics have a sharper high end frequency, less rolled off than Tantalum. The Dumble's have a bight that Boogie's don't.

 

[zebpedersen]

See, I always learn something by asking questions!

Cheers man, a nice slice of info.

 

[Boogiebabies]

I've been slowly Dumble-izing a Fender Hot Rod. :wink:

 

[zebpedersen]

I've seen so many online communities completely dedicated to that amp, loads of weird customised gear stuffed mainly into old Fender heads - never in a Hot Rod before, though!

The US built clones by Bludotone etc... are just so overpriced, no wonder people build their own.

 

[dodger916]

I've been slowly Dumble-izing a Fender Hot Rod. :wink:

I'd love to hear that, Ed.