If you used EI KT 90s and a ss rectifier, you could get 100 watts w/ similar sound SS rectification would be less windings on the power tranny ( cheaper) I fpund the Sunns are louder and cleaner w/ ss recti, but the GZ34 has a deeper-warmer sound and if you want to grind a bit, it is the better choice. I swap those socketed diodes in & out from time to time for kix. NOS GZ34s are hard to come by. 6AN8as aren't getting more common either. use a 6SN7 octal to drive KT90s. Old Ampex B15s had a 600 ohm tap off that for studio work. Now it's a 201 S !!!!
KT90 are a little scarce nowdays, probably not the best choice for a production circuit. Ei is gone. EH is the only supplier left ASAIK. I've played with the new Tung Sol KT120, I have a quad in an amp as I type this, and so far they are holding up well. They sound pretty good also, after I get some hours on them I'll know more. I like the reissue Gold Lions, but truthfully can't tell much difference between them and the stock JJ's in my Reeves C225. I think JJ's are real workhorses in the 6550/KT88 class, great sounding, very consistant and reliable. I'm always trying the new phenom tube though, trying to reach that tonal nirvana...
I have a vintage B15N less than 3 ft from me right now. I think it's maybe the best sounding amp I've ever heard, particularly with a passive bass. The huge soundstage on the NOS 6SN7 is so rich and dynamic you can
taste it but; I think a lot of the tone is in the total tube configuration, combined with the circuit itself, not to mention the cabinet. Although my B15 sounds pretty spectacular through my K140 loaded Sunn Sonic I-40 cab also.
Jess Oliver certainly got it right, that's for sure!
As I said I think that the B15 is the cream of the tonal crop, but I'm looking for the
Sunn tone I love, not a hybrid.
Besides, Alessandro already did it;
http://www.alessandro-products.com/amp-basset.htmlNice amp, but then I suppose it ought to be considering it starts at $2600 and with options can cost well over $50,000 (
not a typo).
So, what is the latest EdBass?
Regretfully I don't have much to report; except that the deeper I dig the higher the price seems to go.
To get a saleable amp(s), economy of scale is everything. IMO a 4 x KT88/6550 amp would be more useful for the majority of bass players than a 2 x KT88/6550 would be, but the 200ish watt tube bass amp category is pretty crowded already, both high end hand wired and PCB imports ranging from <$1000 to $3500+.
The 75-100ish watt tube bass amp category is less populated, but mostly because of the perception that you need at least
150 tube watts for a bass amp.
I've played enough gigs with a box stock 200S rig to know that with the right cabinet a 60 watt amp will fill a small to medium venue with strong clean bass without PA support. It's humorous and somewhat entertaining when you see self proclaimed "experts" posting on bass forums about how you need at
least 500 or so watts to play live, but that type of
perception can contribute in making a low powered bass amp a tough sell.
So... I think I would need a 60 watt
and a 150 watt amp to be viable. Actually a rated 100 watts and 200 watts would be more marketable and also easily obtainable without totally bastardizing the Dynaco circuit. IMO the key is to be able to build both amps sharing as many parts as possible (that "economy of scale" thing). Also not a big stretch as the Mark III and the Mark VI are pretty much similar except for the iron and # of tubes. The key would be a universal chassis and head cabinet, 200 chassis/head cabinets are a
lot less per piece than 10 of them are.
Anybody want to donate a 60's era Coliseum PA amp as a "mule"?
Of course all of this effort (and initial outlay $$$) would be a waste of time if I didn't think a target price of <$1500; as close to $1000 as possible, for a hand built amp wasn't important.
That's one of the reasons (besides the truckload of vintage Sunn gear I've accumulated
) I want the vintage Sunn market to jump up to vintage Hiwatt/Marshal/Fender levels. Personally, I think Sunn amps are deserving of the same reverence tonally.
It seems to be
slowly changing, but regretfully Sunn has been adopted for use by an entire genre(s) of non musicians as simply loud, inarticulate noise makers, and I believe it's caused the majority of talented and
influential players and serious collectors to largely ignore them being the tone machines they are. I believe this because I regularly speak with vintage gear pros from all over at shows and showcases. When I bring up Sunn,
some of them acknowledge their tone, but the majority dismiss them as "only good for that xxxxxx, or yyyy garbage."
At $2000 for a 2 tube and $3500 for a 4 tube, on
paper "Sunn clone" building could start tomorrow... And
end in a couple of months when nobody would actually pony up and
buy one for that kind of money.