SF Assemblage ST-40 tube amp?

I was thinking of looking for a used ST-40 amplifier to try, for a foray into affordable tube amps. Problem is, nobody seems to be selling theirs, so there must be something good happening with them, maybe? I have several different speakers, and am interested in finding out how well this amp would drive them on my own, but wonder if this amp is worth trying.................What I would like is to hear from those who either own one, or have compared one directly to another tube amp of similar price.........OR..........The Rogue Model 88 looks intrigueing too, but is a little more than I want to spend on a tube amp. (I'm an ss guy, my current amp is a Krell KAV-250a, and it's not going anywhere...) And please, NO CHEAPSHOTS from the peanut gallery (you know who you are). I get riled easily, and am not responsible for what you'll unleash...heh heh. And as everyone says, "thanks in advance".......Carl
On the cheaper, and low powered side, the Dynaco Stereo 70's are great amplifiers. www.echohifi.com has one for $400 (updated and refurbished). I've bought from their retail store and they're good guys. I have heard old, refurbished fisher receivers sound very good too. I have the Big Big brother version of the ST-40, the SFM-160's. Their sound is very warm and tubey. They don't have the detail or quietness of my AR vt100m2, but do have a larger soundstage, and arguably better midrange. See www.soundstage.com for a review of the st-40.
Hey Carl, have you checked out bottlehead.com ? The have a DIY brand called Electronic Tonalities. The sell a tube preamp kit called the Foreplay for $99 and have many amp kits as well. The also have a good discussion board. Good luck and keep us informed on how it goes.
Thanks to both of you. I'm interested in buying something that's already depreciated, so I can sell it again if I don't like it (seems like I already said that, but oh well). Not interested in any preamps of any sort right now, don't need them. Neither one of you has heard or owned either the Rogue 88, or the ST-40, have you?
I have not, just throwing out some ideas.
I can vouch for the Dyna St-70. Excellent highs and midrange. But needs work on the bass end...especially if you have some difficult to tame speakers. I've heard the ST-70 II, the revamped model by the Japanese, is much better in that department. But the old Dynas are so cheap its obscene. I like my first so much, that I'm shopping for a second to running dually on my Vandys. If I were you, I'd get one for $200 or so and see how you like it...it will be a great intro to that "tube sound" that everyone talks about.
Sorry. I thought the question was open-ended. :)
Thanks anyway, Osclib. I checked out the bottlehead.com, and their amps aren't powerful enough for me (although Sam Tellig thinks the 2A3 tube is the "tube of the 21st century", heh heh). They'd be interesting if I had really effecient speakers (one of my speaker projects will be, but I've got to build it first).........................No problem at all, John. John and Issabre, I may just have to try a Dynaco ST-70, then. I don't know, we'll see. The whole reason I was thinking the Sonic Frontiers Assemblage was because it was supposed to be very good in the bass (as ANY tube amps go, besides affordable ones...has a high claimed damping factor for a tube amp), and not do anything seriously wrong in the rest of the range. It even supposedly has a terrific midrange. It's possible that the Dynaco is a better amp, other than the bass, though. I have no idea...........I HAVE HEARD A TERRIBLE SOUNDING TUBE AMP BEFORE. It was a Luxman, not sure the model number. Very inaccurate and blurry sounding, with bass and lower mids having the most coloration I've ever heard from a hi-fi component. Perhaps the tubes were long past going bad, I don't know. That was with Dynaudio Contour 1.8 Mk 2 speakers..........I would have been discouraged about tube amps if I hadn't since heard a 125 watt VTL amp that sounded less tubelike and more analytical on Soundlab speakers, than did my Krell amplifier on my Paragons!.......I own various speakers, and am building several more. The primary commercially bought ones I have right now are: Alesis Monitor Ones, Paragon Acoustics Radiants, and Magneplanar MMG's. I have high hopes for my project speakers...but need to spend more time working on them, than talking about them, heh heh.
You will probably write me off as "the lunatic fringe", but I have a few words of advice for you if this is your first tube amp. To get the real MAGIC that the vacuum tube has to offer, you need to look for the following types of circuit: Point to point wired-no printed circuit boards; only two output tubes per channel, regardless of the power output (this is assuming that you are interested in push-pull amps as opposed to single ended); simple circuit, using minimal number of parts; and, tube rectification. True, you can get good sound from some designs that do not incorporate these features, but, most all vintage products are built this way and can be obtained for minimum dollars. Do not listen to people that claim all old tube amps sound "warm, veiled, or murky" Some of these designs have a clarity and transparency (true transparancy) that will blow away many modern multi killobuck products. Do not be afraid to slightly modify the input circuit. Remember that everything that happens before the input tube is sacred. this means that you should add good input jacks and eliminate any pots. or input caps if possible. I find that true tube magic comes from lower powered amps, assuming that you have a compatible speaker.
Harv, thanks for your input. Um, I'm afraid we're ALL on the lunatic fringe, being in this hobby in the first place (whether tube-heads, solid state-heads, digi-heads, styli-heads, whatever). So, I'm not dismissing you! I agree that a simpler circuit can usually be better (and point-to-point, rather than circuit boards). But, I'm really looking for something in at least the 30 to 40 wpc area, since I'm used to 500 wpc (use most of it only on the Maggies, though). I'm hoping to churn out a quick DIY speaker on the cheap that uses a bunch of low cost series-parallel cones, that should be easy to drive, and very efficient. If it turns out to be more efficient than I'm thinking, then I can consider the "few watts per channel" types................However, it will feature 2 Vifa dome tweeters in parallel, so the impedance will be dropping to like 2.5 ohms in the low treble (unless I can somehow compensate for it in the crossover). WILL THIS KILL A LOW POWERED TUBE AMP? The impedance below the treble will be nominally around 6 ohms, so that should be ideal for all but maybe extraordinarily weak and unstable amplifiers.
Carl, you are right about the severe impedence dip being inappropriate for a low powered tube amp. Speaking of Maggies, here is an interesting story about my first tube amp: For years I enjoyed the sound of my MGIIIA's with a pair of Adcom 565 300 watt per channel mono amps. One day I answered a newspaper ad for a reel to reel tape recorder. The tape deck was junk, but the guy had something else that caught my eye. This was a set of Fisher components that he had cannibalized from a huge console stereo. I bought the tuner, preamp, and two mono amps for $100.00! So, I get home and try the amps out first on some old Boston A60 spkrs. that I use in my Video/TV system. The sound was quite good, and it surprised me how loud these little amps would play. They use a pair of 6BQ5 output tubes and probably put out only 15-20 watts. I couldn't resist the temptation to try them on the Maggies, thinking that I could always turn them off quickly if there were any signs of strain, or FIRE! But, you know what? These little amps were just blowing away the big solid state Adcoms! The timbre, the clarity, the sense that the musicians were in the room, even the bass was more natural. All of a sudden the music just made sense. I walked around for weeks with a secret inner smile like I had had some born again religeous experience. I don't know how or why these amps work so well, but I can tell you that I have since spent thousands to try and find something better only to come back to the Fishers again and again.
Interesting story, Harv.
I found this too with the Fishers. One of my friends has a set of Soundlab electrostatics driven by a refurbished Fisher tube receiver. Excellent sound. Not powerful, but very detailed and airy.
OK, does anyone know someone, who knows someone, who has heard this amp?
CARL !!! DYNACO ST-70 !!!! MANY audiophiles have one or two they use now and then.Albert has one.They sound very good.The bass isnt as bad as you might think.They are so cheap,BUT you gotta get Svetlana EL-34 for it.They put my Dyna in a new level I didnt think possible.They are SO CHEAP you can easily re-sell and maybe make a couple bucks if you decide to get a better tube amp.You would have to pay alot more though for better sound. I have a stock Dyna I paid $150 for.I bought 2 NOS RCA 7199 @ $25 each and 4 Svetlana EL-34 @ $17 each. (Audio Advisor) For under $300 I have great sound.My speakers are 92db and I get more volumn then I need and I like my music quite loud.Dont miss out on a chance to own a real American classic amp!! There is a very good reason so many people own them and never sell them.The only down side is the RCA inputs are in the front and poorly spaced.I had to take the locking barrels off my H.T. Pro-silways for them to fit.I knew that before hand but bought the H.T. anyway.The Kimber plugs fit just fine and Im sure many others.There are many upgrades for Dynas that you could do a little at a time.Im keeping mine stock and plan on getting a Pass sometime in the future,but NEVER will I sell my beloved Dyna!!!!! E-mail me if you want more specifics. DAVE
David!!!! Thanks, but I just couldn't live with the weak bass. Apparently ST-40 owners are every bit as rabid about them as Dynaco ST-70 owners are (if not more so), but I'm thinking the ST-40 has more of what I want.