New 100 watt ODS Build from New Member

[badtweed]

I just came across this Amp Garage community a few days ago. I thought I'd post a few shots of my recent build/version of a 100 watt ODS that I built per a client's request.
I built two of these and will they will likely be the last as I'd prefer to continue building my own designs.
I used my own spec'd trannies that Schumacher Elect. Corp. built for me along with my own etched panels and garage shop created chassis and cabinetry.
The layout is my own and is all point to point terminal strip layout, no turret board.
I incorporated some mild circuit deviations from the basic Dumble circuits that I've seen on the web.

Sorry for the poorly lit photos, I'll try to post some better shots once I get a sun break

[img806]http://home.comcast.net/~Badtweed/Amp_01.jpg[/img]

[img960]http://home.comcast.net/~Badtweed/Amp_02.jpg[/img]

[M Fowler]

Very nice and I hope that sun brings us chassis gut shots

[Chad]

Nice!! Point to point huh,Would like to see that unless that would be inappropriate to ask Great looking cab.

[David Root]

Looks verrry nice! Let me guess, two KT88s showing, the two others pulled, custom Twin type iron?

[JD0x0]

Looks verrry nice! Let me guess, two KT88s showing, the two others pulled, custom Twin type iron?

Post soundclips if you can i'm in the middle of a KT88 ODS build and i'd like to hear what they sound like

[badtweed]

Those are Groove Tubes KT66's in there at the moment and are just for use during sound shaping and general testing.
The Schumacher built trannies are basically beefed up twin style and I also use an independent tranny for the 9 pin tubes' heater supply.
I'll try to post some interior shots and perhaps some sound clips once I
settle on a specific output tube type.

[talbany]

IMHO...KT66's or even KT88's go really well in these amps.. The big round bottom end and added headroom...The .02 PI entrance cap and .1 PI couplers lets quite a bit of low end into the output section.. causing in some cases and in my experience a farty low end (especially w/smaller iron) in a 2 6L or 6V amp when you really get it cranked.. If you lower the value of that cap to an .01 it's just not the same to me.. The .02 is a big part of the tone of these amps....The 66's and 88's seem to handle the larger .02 a bit better..I like slightly higher voltages say 480-66's 500 for 88's or 6550's and bias no hotter than 60%..a tad colder..Bias is of coarse totally subjective..KT's Kinkless Tetrode transition into grind is not as smooth given the larger plate structure vrs 6L's unless you have a pair of Mo Valve's....I never really cared for the GT 66's..The smoother sounding to me were Gold Lions or Shuguang's...JJ KT-88 not a bad tube either..Cathode Bias w/big iron say Hammond 1650 KT88 in a Dumble style can be a beautiful thing..

Just so you know I heard that the RI Tung Sols 66's ground pin 1 to the metal base of the tube...


Tony

[JD0x0]

IMHO...KT66's or even KT88's go really well in these amps.. The big round bottom end and added headroom...The .02 PI entrance cap lets quite a bit of low end into the output section.. causing in some cases and in my experience a farty low end (especially w/smaller iron) in a 2 6L or 6V amp when you really get it cranked.. If you lower the value of that cap to an .01 it's just not the same to me.. The .02 is a big part of the tone of these amps....The 66's and 88's seem to handle the larger .02 a bit better..I like slightly higher voltages say 480-66's 500 for 88's or 6550's and bias no hotter than 60%..a tad colder..Bias is of coarse totally subjective..KT's Kinkless Tetrode transition into grind is not as smooth given the larger plate structure vrs 6L's unless you have a pair of Mo Valve's....I never really cared for the GT 66's..The smoother sounding to me were Gold Lions or Shuguang's...JJ KT-88 not a bad tube either..Cathode Bias w/big iron say Hammond 1650 KT88 in a Dumble style can be a beautiful thing..

Just so you know I heard that the RI Tung Sols 66's ground pin 1 to the metal base of the tube...

Tony

My current build will be using shuguang KT88 with Hammond Iron. I cant wait to see how it sounds

[badtweed]

Here's a shot of the guts during tone shaping chores and prior to finishing up the wire routing cleanup.
It's a bit of a rat's nest but the layout is purpose driven for the most part.
The green pcb for the relays is from Weber.
I plan to replace it with my own Omron populated board after
I play with this enough to feel confident that it's been tweaked sufficiently to float me to marsh-mellow ville.


[img806]http://home.comcast.net/~Badtweed/Amp_03.jpg[/img]

[Bob-I]

Wow, a true PTP Dumble

[heisthl]

Not to harsh your mellow, and I truly admire all your hard work and the beautiful appearance of the amp - you know there's a but coming - but the worst sounding clone I've ever made was point to point and I did a lot of tweaking to make it not so, and was never successful. You need parts of the layout and wire routing to get the smoothness and "Dumbly" character. I sincerely hope you prove me wrong.

[bluesfendermanblues]

Not to harsh your mellow, and I admire all your hard work and the beautiful appearance of the amp - you know theres a but coming - but the worst sounding clone I've ever made was point to point and I did a lot of tweaking to make it not so, and was never successful. You need parts of the layout and wire routing to get the smoothness and "Dumbly" character. I sincerely hope you prove me wrong.

In some of the later TwoRock, they (Joe and Bill) seem to put emphasis on the fact that they use a minimum of wire and even go as far a soldering components directly to the tube sockets to 'save' wiring. I guess one example of this philosophy would be their new 10th anniversary model.

[tubedogsmith]

Not to harsh your mellow, and I admire all your hard work and the beautiful appearance of the amp - you know theres a but coming - but the worst sounding clone I've ever made was point to point and I did a lot of tweaking to make it not so, and was never successful. You need parts of the layout and wire routing to get the smoothness and "Dumbly" character. I sincerely hope you prove me wrong.

In some of the later TwoRock, they (Joe and Bill) seem to put emphasis on the fact that they use a minimum of wire and even go as far a soldering components directly to the tube sockets to 'save' wiring. I guess one example of this philosophy would be their new 10th anniversary model.

the only parts on the tube sockets in one of those that's different from a non hrm dumble are a couple caps and resistors for the loop based on the one I've seen. They made an amp a few years ago, the Opal I think that was wired point to point in a fashion. Whoever they have wiring the amps now is doing a much neater job though than in the past.

[paulster]

In some of the later TwoRock, they (Joe and Bill) seem to put emphasis on the fact that they use a minimum of wire and even go as far a soldering components directly to the tube sockets to 'save' wiring.

Sounds like the usual marketing hype they come up with every time they want to flog a new range of amps to all their existing customers. Next thing they'll be telling us they don't clone Dumbles.

[badtweed]

Not to harsh your mellow, and I truly admire all your hard work and the beautiful appearance of the amp - you know there's a but coming - but the worst sounding clone I've ever made was point to point and I did a lot of tweaking to make it not so, and was never successful. You need parts of the layout and wire routing to get the smoothness and "Dumbly" character. I sincerely hope you prove me wrong.

Appreciate the comments regarding your experience with the p2p approach and your compliments.
Since I have never had a Dumble in hand to test out directly I can't say with any certainty that my amp exhibits the same smoothness and character of a real Dumble.
I do hope to post some sound clips eventually so you can have a listen though.
While this build is new and not without a few issues that were taken care of in the typical tweaking process,
I'm very happy with the performance and tone of the amps as is the client. I like the range and versatility.
I just prefer p2p construction for my builds and have been doing it this way for the most part since my first tube amp build (a fender dual showman) in 1964.
If I were to be building more of these I'd probably go for the standardized turret board layout that is popular just to save time and
have a nicer under the hood appearance.
But as I mentioned I have no plans to build any more of these Dumble circuit based heads other than the two I just completed.
I do plan to couple the cosmetics and chassis form factor of this build with my own circuit designs.

Thanks for your observations. btw, I had a listen to your amps and they sound terrific! Priced nice also.