Well, I've built a few amps - not a lot like most of you guys but I know my way around enough to source one and put it together. So now I think it's time to try my hand at a Dumble design. I won't be building it for awhile (putting in a living room floor & new furniture) but I like to research a project as much as I can. Plus, I've got the amp building bug bad and studying a next build keeps me going.
So, any recommendations on which design? I don't know how many amps I'll be able to build in the future but I want one to be the best Dumble I can manage. I've looked at the schematics . . . a lot. And I know the sound I like when I hear it - Ford, some of Carlton's, things I've heard here and there, youtube, etc. I play mostly blues but leaning towards jazz (rock back in the day - ZZ, Rush, Travers, etc). But that sweet smoothness that Dumbles get is, well . . I want to build one of those.
I know they're a bit more than what I've done before but I think just taking my time will get it done right. I'll get a chassis and build a cab then start collecting parts and so on.
So again, 124? 102? Skyliner? I don't think an HRM is really what I'm after, from what I've read.
If you mainly play humbucker guitars go for a skyliner, high plate design (like #102 or #183) for the Ford for sounds. Works for Tele's as well.
If you're a singlecoil/strat player go for one of the low plate classic designs (either ODS or SSS) (alternatively a 2nd gen., 3rd gen.)
I think you will have more succes with a humbucker guitar into a lowplate/ classic than with a strat/single coil guitar into a skyliner. However, this is just my experience, (having tried most of the designs, exept the 1st gen).
Well, I play a Strat and I'm used to single coils but I just got this one and it's an HSS. Actually, from the reading I've done I am inclined to agree - a low plate classic sounds like what I'm after.
What exactly do you mean by 2nd or 3rd generation?
It depends on what amps you already have. If you already have a Fender, you may as well go for a high plate skyliner, to have something different. The impression I get from most members here is that low plate classics have better cleans but that the overdrive is not quite as good. I like these amps mainly for their overdrive channel, so the choice was easy for me.
Remember that you can always modify the amp afterwards to some extent, if you change your mind.
sepulchre wrote:Well, I play a Strat and I'm used to single coils but I just got this one and it's an HSS. Actually, from the reading I've done I am inclined to agree - a low plate classic sounds like what I'm after.
What exactly do you mean by 2nd or 3rd generation?
You will find these designs in the files section. Those (2nd and 3rd) are amps prior to the classic, which is the 4th gen. of the Dumble amps.
Check out postings by forum member 'Max'. He knows all about the various amps, serial numbers etc.
Okay, looks like the #124 Low Plate Classic is what I'm after. So what size chassis will I need? And what iron works well in one? I'm not going for the top of the line but I do want as good a sound as I can get.
sepulchre wrote:Okay, looks like the #124 Low Plate Classic is what I'm after. So what size chassis will I need? And what iron works well in one? I'm not going for the top of the line but I do want as good a sound as I can get.
Check out the BOM (Bill of Materials) in the files section.
Regarding iron anything made for a fender twin (100w) or Bassman/Super (50w) will work. I have tried Mercury Magnetics, but IME its not worth the extra $. The right capacitors, resistors and, not least, Lead Dress are more important factors.
You can adjust the feedback resistor to tune the amp for various iron. Also you might want to consider putting a loop on board while your're at it.
Two seemingly opposite ideas: one is that the BOM is pretty specific on the type and brand of the small components. Orange Drops, RN resistors for the plates and another type of metal films for the cathodes -- that sort of thing. Two is that after that, I don't think you'll find a lot of cost difference in the more expensive parts. I got custom wound Heyboer transformers at a hundred buck each (100 watter) which wasn't that much different than finding something off the shelf. The path on speaker selection gives you some wiggle room but you stray at your peril.
I would add that you should consider a few extra resistors and caps close to the ones sped-ed because these are a tweaker's amp. Get the high plate and low plate values (and don't do elaborate wraps underneath the component board if you think you might mix and match). For an extra fifteen bucks or so you can significantly change the first tone you get dialed.
Then I would agree with Mr. Hankey that it also depends on what you have. If you rethink it and go for one of the 2nd or 3rd generation amps (I have a #2 and love it), you don't really need a Dumbleator. If you go with one of the Skyline or later preamps I think you do. It is a cool project itself and I feel a necessary component of the modern versions. Auxiliary or on-board, figure that into your parts list and budget.
I built my first #102 with NOS components (electro mf for plates and cathodes, pihers in the signal path, old Twin OT / Choke, CTS pots out of an old Twin, etc...) and it turned out great. I built my second one with all off the shelf parts (KOA speer CF resistors in the signal path, KOA Speer MF on the plates and cathodes, custom wound Heyboer PT, MM High Powered Tweed Twin OT and MM Twin choke, etc...) and the new one actually turned out to be better sounding. I think a lot of it is just HOW you build it to be honest. For the new one I think I had a better handle on the nuances of the build process - wrapping and double checking all the connections were strong before soldering, putting dummy tubes in the sockets before soldering them, using silicone under the caps, orienting the caps for outside foil, etc... Anyway, I'm happy enough with the #102 circuit not to want to try anything else (as long as there's a D'Lator in there too). BTW: I use a Strat.
sepulchre wrote:Pardon my ignorance but what do you mean by "wrapping"?
I have a broken tube. Maybe I can smooth it with a torch and use it for a dummy.
Soldering 101. When a lead is terminated at a solder lug, it should be bent back on itself 180 degrees. If a lead passes through one lug and is terminated on an adjacent lug, it should have two points of contact with the lug that it passes through. If this technique is followed on the tube socket lugs, and solder is applied sparingly, filling a socket with solder is a non-issue.
sepulchre wrote:Pardon my ignorance but what do you mean by "wrapping"?
I have a broken tube. Maybe I can smooth it with a torch and use it for a dummy.
Soldering 101. When a lead is terminated at a solder lug, it should be bent back on itself 180 degrees. If a lead passes through one lug and is terminated on an adjacent lug, it should have two points of contact with the lug that it passes through. If this technique is followed on the tube socket lugs, and solder is applied sparingly, filling a socket with solder is a non-issue.
Yes. What Martin said!
I actually did most of my build on my dining room table away from the soldering iron. I'd go section by section, getting all the components and wires connected to their eyelets / lugs / pads in such a way as they were completely immobile and solid. Then I'd bring it down in the basement and solder it up. Getting the connections solid took about 10 times as long as doing the actual soldering, but I'm starting to get better at it. The forceps helped a lot. This is probably obvious stuff to someone who's been trained to solder formally and most how-to's online describe something similar, but actually doing it consistently was something I had to consciously think about.
Bluesman - Okay, I must have been really tired not to find the 2nd & 3rd gen plans. Sorry.
Martin & aflynt - When I built pipeline inspection equipment back in the 70s before I was a tech we had to take yearly courses on soldering, but there were no tube sockets. I do know to make a strong physical connection before soldering. But on my first amp I was a little over zealous with the solder and plugged a socket. If a tube had been in it I'm afraid the tube would have been there for good. So my technique has improved, hopefully, and I won't have to use a tube base. Thanks guys.
aflynt - It takes me far longer to wire things up than the soldering takes, too. I'm a bit OCD about going over the layout and schematic comparing them to what I'm doing several times before putting solder to anything. Yes, forceps are probably my most used tool and I have a few different kinds.
So, does "wrapping" mean making the physical connection with the wire/lead to the lug or other connection before soldering? When I read "wrap" I had visions of lacing, which I have also done a lot of. Looks nicer than tie-wraps, IMHO. And speaking of wrapping, I think this time I'll use turrets rather than eyelets. Looks like they would be easier to make strong connections.
BTW: I use a Strat.
