My soldano SLO highgain channel preamp info and clips.

Billy Batz · Post by **Billy Batz** » Wed Mar 16, 2005 9:48 am

There is no single correct Dumble ODS schematic since every Dumble is different and not just a little different ya know? But similar. I have quite a few and pages and pages of notes from people whove checked out the chassis etc... Theres a few late 90s ODSs that was reverse engineered and schemed and a few 70s and 60s but that 80s Carlton/Ford ODS was missing but the VersionA2 and Hybrid use values reported from people whove looked inside some from that era. Ill send you all the info I have on them if you want. If your serious about it PM me. I really enjoyed mine. Sounded just like the Carlton/Ford tone. Ill tell you one thing. A lota people say a lota amps are detailed and dont let you get away with sloppy playing. This is the only amp Ive ever played that was really like that. Your lagato has to be perfectly snapped and hammered, your picking in perfect time with your fretting and your mutting solid. So much snap and clarity to the note. Like its an immediate envelope after you pick compared to other amps.

Flames1950 · Post by **Flames1950** » Wed Mar 16, 2005 12:57 pm

If you could e-mail me whatever info you have I'd love it. I don't think I'll do it to my current Bandmaster or '66 Bassman, and like I said I'm tired of tearing apart my '68, but 70's Bassman 50's turn up all the time on eBay and might be fun to do an ODS project on. I don't feel as bad hacking those up.

Ill tell you one thing. A lota people say a lota amps are detailed and dont let you get away with sloppy playing. This is the only amp Ive ever played that was really like that. Your lagato has to be perfectly snapped and hammered, your picking in perfect time with your fretting and your mutting solid. So much snap and clarity to the note. Like its an immediate envelope after you pick compared to other amps.

That's why I won't play with reverb, you get used to it, and then you go without it and realize how freakin' sloppy it's made you. I'm a sloppy-enough blues based player without adding to the slop by choice.

Billy Batz · Post by **Billy Batz** » Wed Mar 16, 2005 1:12 pm

Ill send you everything I have but its a lotta stuff.

The schems that are most accurate to that Carlton/Ford era Dumble which everyone loves are somewhere in the 1992versionA2 and the Hybrid schems. The other ones are too early or too modern. The most current ones sound really thin. He's doin lots of weird things these days. One thing youll notice is some schems have a second tone stack in the OD section. Thats called the Skyliner EQ and almost everyone hates the amps with the skyliner. Its very thin and bright. VersionA2 has all the right switches but the hybrid includes the Deep switch which I think is a waste and doesnt do anything for me. Theres lots of values to play around with and some make a huge difference like a resister after the coupler in the OD second stage. Ill send all the stuff to you and if you ever decide to do it lemme know. I spent a long time on mine and its pretty intense tweakin one of those amps. Oh and theres also a lot of junk about building a relay board. If you dont build your own already webbers relay board kits are awesome.

Its a lot of files so gimme some time to send it to you later.

Flames1950 · Post by **Flames1950** » Wed Mar 16, 2005 2:03 pm

Lemme see.......one input jack, nine knobs, and two switches........guess I'd better plan on a Bandmaster chassis for sure instead of a Bassman......too bad, Bassmans are a dime a dozen, Bandmasters aren't quite as easy or cheap to come across. C'est la vie, I couldn't remember what the controls on one were. It's not like they turn up in Des Moines Iowa to check out!!
Thanks for the goodies though. A couple of the schems (the hybrid) are almost dead ringers for the one I've got, but it's on a different computer so I can't be sure until I'm at home.

Flames1950 · Post by **Flames1950** » Fri Mar 18, 2005 8:47 am

Well, I just BIN'd a Bassman 100 off the 'Bay for $299, so I'll probably be working up a 100 watt version of the Dumble. The Bassman 100 already has 7 pots and two switches, I can add two smaller pots in the Normal input holes and use some push-pull pots for the rest of the switching. Should be mucho fun. I just can't bring myself to tear up my '68 Bassman again. I think I'll eBay it to help cover the price of this project; I took some pics of the McIntyre turret board I made inside the amp last night (I'll post them here too for fun), got her biased up and played it a while. It's a cool amp with monstrous midrange capabilities and lots of thick distortion when you want it, but it's just not that radically different from a Marshall otherwise. Someone can get good use out of it.
I'll probably try to work up a turret board layout from your Bandmaster layout drawing, and get the materials from George to wire it up.

Billy Batz · Post by **Billy Batz** » Fri Mar 18, 2005 9:08 am

I still have some board layouts from when I did mine. Ill send them to you. I put all the grid resistors directly on the tube sockets and used sheilded cable on the first 2 grids. I also used those 3 terminal strips for the local FB loop when I used it and the RC high pass filter on the second stage grid. You can probably still use the Bassman power supply board just adding the last filter on the board next to the first 2 gain stages.

That layout isnt mine BTW. Also the trim control is a trimmer pot inside the chassis in Dumbos. I put it as a control on the front panel. I think its usefull there. Some people do some dont.

Billy Batz · Post by **Billy Batz** » Fri Mar 18, 2005 9:37 am

We've totally hijacked this thread. Sorry Stan.

Lets get some follow up reviews on the SLO. You still completely happy with it?

Guest · Post by **Guest** » Sat Mar 19, 2005 3:24 pm

yes,i love it!!!havent had much time for it.its been a crazy week!!!

bmf5150 · Post by **bmf5150** » Mon May 23, 2005 9:50 am

took a few minutes and played the slo preamp over the weekend(.im selling my house so i havent had much time to play)i think it sounded a tad bit muddy.i think im going to get rid of the vishay dale resistors and try the carbon film.i know the vishay are a darker resistor that can get muddy.probably to much for a high gain amp.
stan

Brentsp · Post by **Brentsp** » Wed May 25, 2005 1:34 pm

bmf5150 wrote:i know the vishay are a darker resistor that can get muddy.probably to much for a high gain amp.
stan

Hmmm didn't know that

My XTC has a number of Vishays.

myker · Post by **myker** » Wed May 25, 2005 3:04 pm

i never found them to be much darker either, sound like regular metal films to me...just cost three times as much.
mike

Brentsp · Post by **Brentsp** » Wed May 25, 2005 3:07 pm

myker wrote:i never found them to be much darker either, sound like regular metal films to me...just cost three times as much.
mike

Holy crap 3x's as much? At .35 each I thought that was good. .12 each like you say sounds better.

myker · Post by **myker** » Wed May 25, 2005 6:00 pm

the difference resistors make is the last thing i would worry about. its much more likely to be brightened up by changing the capacitor values.
mike

Billy Batz · Post by **Billy Batz** » Wed May 25, 2005 7:00 pm

Yeah I agree. While I do take resistors into consideration their actual effect is something in the 5%'er world. Those people who are always trying to get that last 5% to perfect tone like the Dumble and TWreck builders who obsess over the tone of colors of wire and layouts. I somehow think that resistors make a larger difference then those though

I just havent gotten the motivation to do what gnugear did and try everything in every position in the same amp.

bmf5150 · Post by **bmf5150** » Sun Jul 31, 2005 12:34 am

im going to try some 6550s in my power amp to take the el34s place.i think that should give me some more note definition!
stan