harp amp build speaker questions - opinions wanted

[Wrongdog]

I would like some opinions on a 5f2H amp I am building. I want to use one 10 inch Weber signiture series 8 ohm and two eminence 8 inch neo speakers (4 ohm) that I aquired on ebay. These are the same speakers Fender used in their discontinued Accoustinator amp. They are 125 watt RMS and roll off at about 3500hz. The amp will have the Weber OT and Choke so I hope it will sound LARGE. Those pieces of iron are SerIoUsly HeaVy!!

SO it is a 2x8 plus 1x10 set up. Do I want to put two eights up high above the 10 or vice versa? Make any dif?

Whats the opinions on using 16 ohm full winds of Teds big SE iron rather than making it run at 4 ohm tap??? Really any big dif???

Also thoughts on doping speaker?? I have always lightly doped my speakers and I use mostly for guitar - thus light dope. For harp is a heavier doping better?? I use custom made beam blockers on my harp amps so is the heavier dope needed with the blockers? I do have good luck with blockers controling feedback with the harp. How about largr dustcaps?? Felt?

I will mess with pre amp tubes - 5751 or lower gain ones so I can dime it and get power tube distortion. I have a homebrew Champ tweed BF hybrid (BF tone stack, no negative feedback big iron and others mods) that works real well for me but this new build is the next step for my uber harp rig I hope!!

Thanks for any help!! Lots of Q's!!!

[Bruce / Mission Amps]

My original 5F2H amp was based around a 10 watt 2x8' amp and a single KT66.
The OT was a Hammond 125ESE... if I were to do it over again I'd try using a Hammond 125GSE and big 6L6GC or 6550.
The big SE OT weber was selling, was a Chinese copy of my Marvel/Mag Comp copy of the... guess what?... the Hammond 125ESE. I didn't care for the Chinese copy of the American made copy of the Canadian made Hammond, and subsequently never built another one using any weber transformers.
Also, I quickly found that unless you had the killer 8" speakers from the West side of Chicago, just about any decent 10" speaker pair sounded better.
Two 8" and a single 10" is something I had not really tried... but I did try four 8"s with limited success, fondly called my Bassboy 10... followed by a superior sound with only the two 10" speakers.
I have also tried those same Eminence neo speakers, that of which you mentioned.... they sounded better with an electric guitar, in a guitar tuned amp and a small boost pedal.
However, all in all, they were actually a decent speaker.
Personally, I think I'd put the two 8" on the bottom and the 10" in the middle above them.
I haven't heard many (maybe none) Weber speakers that won't cone cry, edge yowl or ghost note with a good, hot harp mic and guy who can push hard with closed cupping.

[MWJB]

Harp amps usually prefer amps at the speaker (guitars aren't as fussed regarding efficiency, it's more of a tonal issue with them as they feedback less), rather than volts. So I'd wire the speakers for 4ohm total load (2x8"s in series for 8ohms, then the pair of 8"s wired in parallel with the 10")...unless you can wangle a 2ohm output and have the lot in parallel.

No experience with the 8"s you mention, but if it were me, I'd be looking at 2x10" for a "big" sound (max projection), 8"s tend to round things off.

[Bruce Saunders]

Just to add to what Bruce Collins and MWJB have written: I built a 2x8 and 1x10 combo cab in the past, wired exactly as MWJB suggested. It had a nice sound but found I could get more volume and better projection from a 2x10 configuration despite going down in overall speaker surface area. In contrast to Bruce Collins suggestion I went for the 2x8" up top and 10" on the bottom, like the Meteor Amps "Mini Meat". As you have the speakers, give it a try and see if you like it, but I'd cut a spare baffle so that you can go for 2x10 if you want.
Larger dustcaps can help: I installed Weber's H caps on some cheap 8's I had, and got a significant improvement in the tone and the volume available before feedback.

[Wrongdog]

Thanks Bruce's and MWJB! Yeah, I have those wierd 8 inch Eminence/Fender speakers laying around so I will try them and also make a 2x10 baffle to have for the future. I am going to put the 8's on top. It will work better that way for my grill I am designing - think the general grill shape of a late 1950's Studebaker Hawk. I will dope the Weber with rubber cement that I have used successfully in the past.
The larger dust cap mod is still in debate. I am hoping someone else will chime in on that.

My projects never stay the same as built so the 2x10 will be done at some point. I also may change it to 2 6v6's in series sometime. I have the unused octal rectifier socket since I used a SS rectifier. It is all fun!

[Wrongdog]

may change it to 2 6v6's in series sometime

Ummm - that would be in PARALLEL....