Dumble Really Lite

[mootej]

Hope this isn't to far off topic. I built a couple of Dumble #102's with the info here and what great amps! It took about three years (oh well) but very pleased with the result...except...wow, I'm getting too old to haul around all this heavy stuff. My buddy who got one of the Dumbles for the price of two empty cabs from Sourmash and two sets of tubes bet that I couldn't get a pair of six inch speakers to get that 12" speaker sound. He suggested the bass end would just be, well, lacking. Enter this...

I built this with some Beyma 6B30/P's:
[img:480:640]http://i855.photobucket.com/albums/ab11 ... 1c2bc0.jpg[/img]
[img:480:640]http://i855.photobucket.com/albums/ab11 ... 673fd6.jpg[/img]

from here:
http://www.talkbass.com/forum/f15/nano- ... ld-978212/

The Beyma's should get to about 60Hz, maybe a little higher with the cab, maybe 70Hz, and the 4mm max should be able to push about as much air as a Jensen 12", or that was the thought. On paper, it should work.

WOW! Great sound and less than 20 lbs to carry. We'll see how it holds out at practice but definite full range tone and great OD sound with the Dumble. Pretty loud too and nothing shredded yet. A little tweaking to version B but I am very happy with the sound and the volume.

Next project, a pencil tube version of the Dumble that weighs a lot less, maybe 2 to 20 watts, maybe four 5902's push-pull in place of the 6L6's and 6112's in place of the 12AX7's. Anybody got any ideas on a nano-Dumble design that an old man can carry to practice or small venues? 125V supply, maybe one of the opt's from Musical Power Supply, like an OT2PP or OT5PP with extra henries to keep the low end?

[LeftyStrat]

I couple of guys who hang out here and at the Hoffman board have come up with some sweet sounding amps using the ECL82/6DX8/6F4P and a Dumble inspired topology. It puts out I think around 7-9 watts, but the bottom end is much better than any other 10 watt amp I have heard.

There's also the Tweed BluezMeister, which has cathode biased 6L6's for about fifteen watts that sounds really fat. I think the ECL82 amps were also based on this.

http://el34world.com/Forum/index.php?topic=9498.0

Have any more details on that cab? I've always thought two speakers sounded better than a single. That cab looks like something I wouldn't mind lugging around.

[mootej]

I couple of guys who hang out here and at the Hoffman board have come up with some sweet sounding amps using the ECL82/6DX8/6F4P and a Dumble inspired topology. It puts out I think around 7-9 watts, but the bottom end is much better than any other 10 watt amp I have heard.

There's also the Tweed BluezMeister, which has cathode biased 6L6's for about fifteen watts that sounds really fat. I think the ECL82 amps were also based on this.

http://el34world.com/Forum/index.php?topic=9498.0

Have any more details on that cab? I've always thought two speakers sounded better than a single. That cab looks like something I wouldn't mind lugging around.

Try the link for all the details on the cab. I used the Beyma 6B30/P speakers (~$58/ea):

http://www.beyma.com/uploads/ftp/Fichas ... 002436.pdf

The only things I would change, make the cab just a little wider and taller, maybe 1/2" or 3/4". That way, you can fit a 1/2" post in on either side of the speakers for the grill frame. I had to carve mine out and it made the frame too weak. I also mounted the back on with screws instead of glue. This required 1/2" stock on the inside to screw the back screws in. Really, the hard part was the speaker holes which my buddy did with a router.

THX for the links...I really need this to match up with a nano-Dumble because it sounds sooooo good in overdrive with these speakers.

[10thTx]

I've built a Tweed BluezMeister (D-inspired amp). I've tried it with 6K6's and with 6BM8's. Both of those had about 7 watts and sounded very good to me.

The 6BM8's gave it more of a Marshallish tone/feel, IMO. (I even built the SoLow Watt with 3-4watts using ECL84's. It has very surprising bass to it)

I also built the D'Mars ODS with 6K6 also. I think this sounds fantastic. This is used regularly by a church that I gave it to. I think it sounds excellent in the mix & cuts thru great (which typically has piano also).

Do they sound like Dumbles? No they don't.

I don't think you can get an ideal Dumble tone with anything less than a 50w to 100w amp. I think you can get a great but somewhat less than ideal tone using 6V6's.

Part of the problem is you need lower voltages on the smaller power tubes & yet still need higher voltages on the preamp and OD section. One could use a VVR set in a position that allowed higher preamp/OD and lower power tube voltages.

Having said that, I've gotten incredibly nice "oh wow!" comments from other players who have plugged into my Tweed BluezMeister and the D'Mars. And I personally like the tone I'm getting about as well as what I hear on many of the Dumble clone sound clips. But again, it's simply a personal preference & I am NOT saying that the TBM or D'Mars sound better. .

The lower wattage amps can still get great clean and OD. They can get fantastic sustain also. I am very happy with them. They relay switch and have midboost, PAB, etc.......

Using no other effects than a delay pedal and some added delay and compression in the mix, I recorded this using 6K6's for 7-8 watts using a Tweed Overdrive Special (also sort of a D-inspired amp).

http://www.soundclick.com/player/single ... i&newref=1

With respect, 10thtx

[10thTx]

Anybody got any ideas on a nano-Dumble design that an old man can carry to practice or small venues?

IF you wanted to truly go "nano", I'll offer this idea for a consideration. It's something I drew up some time ago but have NOT built. I am very curious as to how it would actually sound?

I realize there are some unusual values in the preamp and OD. However, I have an amp using 6V6's and 6K6's with those values and like the tone I am getting. I did build it with the Musical Power Supply 20w PT and OT.

So essentially, everything up to the LTPI is a "proven" design which means I like how it sounds. The LTPI to the 6SN7's , you will have to figure out. I have no idea whether the PPIMV would be needed?

IF I were attempting this, I'd probably use the Musical Power Supply PT of
275-0-275 with 120ma and then the Hammond 125C listed.

So, strictly for consideration .............

With respect, 10thtx