Actually you do
There's ALWAYS another Steve Williams BUT there's only "oneobgyn"
Industry Affiliation........Lamm Dealer
With my Ultimate One Sound-Lab speakers I got the best overall performance and absolutely the best bass (ever) with a single pair of VTL 750s.
The Tube Research GT 400 was best midrange, probably close second on bass, maybe even tied with my Atma-Sphere MA2 which worked wonderfully on older Sound-Lab speakers that had the rising impedance curve (about 30 ohms at 35 Hz and 3 ohms at 20K +).
The Tube Research sounded best in Triode with NOS Tung Sol 5881 or Mullard EL34 XF2 but it would blow to hell about every 1.5 to 2 weeks with that set up.
Changing Tube Research outputs to SED Wing C 6550 resolved all reliability issues but then it was about as exciting as cold pizza. When I discovered the VTL 750 it worked perfect (and sounded wonderful) with the same 6550 tubes and proved to be a very stable amp with a nice blend of the best traits of all the previous.
The CAT Sig. is Triode and a great amp but you can buy VTL 750s used for about $9500.00 a pair at Audiogon. I can't think of another product with this performance at anywhere near that price.
Add to that, I've had my two pair for 8 years and 6.5 years and only one repair and that was due to a screw up from a guy I hired to work on them. Last thing, a reviewer friend of mine had the VTL 750, the new Siegfried and the Wotan 1250 in his home long term. His rating was VTL Wotan 1250 first place, VTL 750 second place and the new VTL Siegfried last place. The Siegfried is (maybe) 50 watts more power but a lot more electronic sounding in the high frequencies than the two older versions. Perhaps due to auto bias system?
Last point, when a VTL 750 blows, it's a single KTK-3 fuse, even if it's multiple dead shorted output tubes. I've seen some famous similarly rated amps "explode" circuit boards when outputs failed and often required a trip to the factory for repair.
If they were better, my friend could save a chunk of change!
Everything you say is true, I only changed a single KTK-3 and a 6550C in two and an half years.
I think that the main sonic difference between MB750s and the Siegfried is due to the regulated power supplies for the input and driver stages. The auto bias is a static system once the amplifier settles, and should not affect sound quality. I have considered building a panel with 12 meters for each mono-block, but the bias is so stable that I forgot about it.
I have not heard the new 450 but a female friend of mine bought a pair of the old version for her Wilson Sophia and although they sounded good she had several problems with reliability in the first two months. More problems than I've had in several years. I don't know what to make of that, just passing along the experience.
As for your question, the 750 would be better than the new 450 I would think, even if only for power reserve and dynamics. If too much power the VTL 750 can always be run in Triode which is incredibly rich sounding and cuts power in half.
Last point, unless your friend has access to special pricing his investment will be lost as soon as the new 450s are installed in his home. Used 750s will probably not drop for a long time. I was lucky and bought my last pair for $7500.00 which is an insane deal considering the performance. Then again it "came to me" by word of mouth from a manufacturer, it never made it to Audiogon or I would have missed it.
Your statement about the bias being stable is dead on. When I bought my first 750s I checked every tube at start up and after 20 minutes to confirm bias. My previous amp failed so often I was checking my VTL every month, evolving into every three or four months and now new tubes get second bias check after about thirty hours burn and then I forget about them until time to re tube.
You mentioning custom meters brought something to mind. A few years ago a close friend in my audio group purchased some beautiful 600 watt mono bloc tube amps. These were easy to bias, meters and adjustments right on the faceplate, but these amps had a lot of reliability issues.
On more than one visit to his home i heard what sounded like a shotgun being fired which was large portions of his amp (literally) exploding it's circuit boards and traces followed by fire licking through the vents holes on the top cover.
I was there when a repair person turned absolutely pale after he had repaired one of these and the "other" amp failed while waiting to see if the fist would run after start up. I half expected a wet spot on the floor where he was sitting.
After five such massive failures and two trips to the factory which totaled thousands of dollars in repairs he sold them off for VTL 750s.
Since then he moved to Lamm, sold them and bought the new CAT JL3 Sigs. All these were absolutely excellent and any one could be called "the best" depending on which trait you focused on to be enamored with.
For the record, I've had but two issues with cj tube amps in 30 years of owning them. The first was in my old MV75A1 where after 8 years of use, it blew a resistor (hell Krells have been known to blow something after 8 years too-but Dan and Lew and Bill usually stand behind their products -even if it is eight years old and will in many cases repair the issues for free.). The second turned out to be a fault in the winding of the power transformer and that was replaced free of charge.
When a tube goes, it takes out a $12 fuse and that's it. I hear so many horror stories where when an output tube goes (and this is an enevitability with tube amps -but some like VTL will "tell" you when a tube is about to go, it takes out a circuit board. Why this happens I don't know; possibly the manufacturer is trying to eke a little better performance (?) and sacrificing reliabilty. After all, there's nothing more disheartening than being without one's favorite amp for any extended period of time
Anyone know how many pairs of 750's were built by VTL? Is it over 200?
Does anyone have any sense why VTL is playing second fiddle to ARC in TAS? I got the impression that both Heilbrunn and HP like the VTL amps. JV, however, is an ARC fanatic. And he has had a pair of 610Ts since they were released (and will have them until the next model is released, and ultimately until he can no longer hear or get up to turn the amp on/off). The 610T is the "best" and "product of the year" according to the TAS editors. Is it all political or is it an honest difference in opinion?
Also, interestingly, David Wilson runs his Alexandias driven by an ARC pre and VTL Siegdrieds in his home. I wonder if this is political also.
Of course, Microstrip, you are running a similar combo, and I imagine you have no affiliation with either ARC or VTL.