Need Info: From scratch build for a high headroom clean amp

[Geoff J]

I am NOT a tech, but have a friend that does builds all the time, so he will do the build.

Ideally, i'd like to do an SSS circuit, but I have already posted that in the Dumble forum (pretty scarce info thus far)

PLAN B:
I was thinking of getting a Weber Head of the 80 W high power tweed twin.

The problem is that I like the tone, but those amps break up way too soon for my tastes. (i use low impedance buckers 7-8.8k range, and 200W EVM 12L w/THD CAB)

SO . . . could it be feasible to get the Tweed Twin head kit, but go for 4 6550's ?

What Transformers could I get that can handle those tubes ?

What other considerations would there be for the parts ?

I want to get overdrive out of another head & A/B to the clean amp

Looking for high headroom jazz cleans w/no break up

Not really big on getting a 2 channel dumble design because of the cascading gain thing, not really my cup of tea.

[benoit]

If 80ish W is enough, why not build a clean only ODS? Of course the name Overdrive Special no longer fits... But it'd be a great clean amp with a passive series effects loop. Reverb and/or a buffer for the effects loop could be very easily added to the amp as well. It's a very nice clean to be sure. What sort of sound are you going for?

[jaysg]

I'm personally puzzled by the recent (last year or so) interest in clean amps. 15 years ago, you could hardly give away a Hiwatt 200. Anyway, what's the purpose & venue of this hypothetical high-headoom amp? Will it be driven into distortion a little/lot or only used clean. Can I assume it will be used for guitar only?

[benoit]

I'm personally puzzled by the recent (last year or so) interest in clean amps. 15 years ago, you could hardly give away a Hiwatt 200. Anyway, what's the purpose of this hypothetical high-headoom amp? Will it be driven into distortion a little/lot or only used clean.

I think at least in part that SRV/SSS put ideas in people's heads, but I know plenty of guys, from traditional jazz to indie rock to country to blues that like a clean amp either because they don't use distortion at all or because they prefer to get dirt from a pedal. I don't really get it myself (I love clean as much as the next guy but I also love amp dirt way more than any pedal I've heard). I also have a buddy who likes the sound of two different amps into two different 4x12s. For his dirty tone he uses a JMP50 and his wants me to build him a clean only amp because that's literally all he'd use it for.

[Geoff J]

If 80ish W is enough, why not build a clean only ODS? Of course the name Overdrive Special no longer fits... But it'd be a great clean amp with a passive series effects loop. Reverb and/or a buffer for the effects loop could be very easily added to the amp as well. It's a very nice clean to be sure. What sort of sound are you going for?

Sounds cool, but I actually would want to go for 150 watts w/ 4 6550's and a trannie that can handle it

I am going for a high headroom jazz tone on a big stage, and sometimes outdoors. Don't want to have to be 100% on the soundman properly mic'ing me

For OD, i prefer the 50W v-plex for that to A/B to

, what's the purpose & venue of this hypothetical high-headoom amp? Will it be driven into distortion a little/lot or only used clean. Can I assume it will be used for guitar only?

The venue i in a 7000 sq foot theater, and outdoor festivals.

I prefer to only use it for clean for guitar only and hit w/pedals

I personally don't like the 2-channel cascading gain thing prevalent in Dumbles, not really my thing

How feasible is it to build a 1 channel clean ODS, but with 4 6550's instead w/the right trannies that can handle it?

I was thinking the SRV SSS circuit would be more appropriate since it was designed for cleans

Is there info for the SSS circuit available or not ?

[jaysg]

It's going to weigh a bit. If you have friendly bass players about, you might see if you can concoct a rig built of a tube preamp, a 1000W power amp, and your favorite speaker cab. Don't run it at more than 100 to the cab and see what you think. The Alembic F2-B is really just the preamp from a blackface amp.

[selloutrr]

hiwatts are regared as a high volume clean amp easy to clone kit costs under $1k

[Geoff J]

hiwatts are regared as a high volume clean amp easy to clone kit costs under $1k

Hmmmm, combine that w/the F2-B , and go Gilmour ?

[FUCHSAUDIO]

Go Ampeg style: cathode coupled driver, 600 or so on the plates of the 6550's and regulated screens at about 450 V.

Solid 150-W from a set of 4 6550's, tight low end, sparkle on the high end. Buy a good OD pedal, and be done with it...

[Geoff J]

Andy, thanks mucho !

Is there a particular Ampeg amp model you are referring to ?

Would it be safe to say that we are talking about a 1/2 power SVT ?

I'd also be concerned about what type of PT to get to handle a heavy load like 4 6550's !

Go Ampeg style: cathode coupled driver, 600 or so on the plates of the 6550's and regulated screens at about 450 V.

Solid 150-W from a set of 4 6550's, tight low end, sparkle on the high end. Buy a good OD pedal, and be done with it...

[tonestack]

If one wants a totally clean amp that holds together at high volume levels, solid-state is the only way to go.

[tonestack]

Go Ampeg style: cathode coupled driver, 600 or so on the plates of the 6550's and regulated screens at about 450 V.

Solid 150-W from a set of 4 6550's, tight low end, sparkle on the high end. Buy a good OD pedal, and be done with it...

Just remember to purchase a roadie or two to go along with the build!

[skeezbo]

Why not try something like the old familiar Twin Reverb? You can get a master volume silver panel twin for way less dough than you would pay to build something similar, then copy the skyliner tone stack from one of the Dumble schematics. It would be more fun to build it, of course. This should get you close to SSS territory.

Then, get some real efficient speakers (if you are lucky your twin will already have JBLs in it), maybe the Emminence Commonwealth or one of Weber's high end speakers.

Would you ever need more clean power than that?

Skeezbo

[Geoff J]

Owned Non-MV silver twins - tried everything from BF-ing to speaker swaps - not my sound - too flat for my tastes, and I still think they broke too fast, but I didn't try JBLS. BUT, i will keep an open mind to your suggestions

1. Maybe build a BF TWIN head w/the skyliner EQ ???

2.Where is the specs for that EQ circuit ?

3.Which JBL's ?

4.What other circuit tweaks, local NFB ?

I'm a head cab guy - just like the piecemeal loading better than 1 big awkward piece


Okay thinking this out, not necesarrly in the right order yet:)

1. make a HW 103 the circuit the base
http://www.ceriatone.com/productSubPage ... 03Kits.htm

2. get it w/o the PT, OT, or TUbes

3.Contact heyboer, and get a DR 201 replica PT/OT, which can handle the 6550's

QUESTIONS:

1. Can I fuse Andy's Ampeg ideas in with this build idea ?

2.What value bias resistor would be needed ?

3.Other factors ?

[Firestorm]

I don't know if this helps, but I built essentially this amp about a year ago for a noted jazz guy who had the same needs. Based it on the Fender 135 amps (ultralinear). I used KT88s instead of 6550s (the current manufacture 6550s can be fussy in my experience). Used the stock 12AT7-based PI instead of Andy's Ampeg driver idea (I needed all of the tubes so I couldn't, but Andy's idea would work great). Made one channel "tweed" (right down to the 12AY7), and made the other one James/Baxandall/Ampeg. Channels are in phase so they can be bridged; both have reverb, and I rigged the reverb mix stage so it works sort of like a master volume as well. I think it worked out to about 180-watts (high voltage in these guys), but you never get anywhere close to that in actual use. He's been running it into a 2x12JBL and a 1x15 Eminence Commonwealth and it sounds very cool. It doesn't break up, per se, but is clearly a tube amp rather than SS. The Baxandall makes a huge difference because you can have mids that are totally lost in the FMV tonestack.