VTL ST-85 vs. VTL ST-150 or rather EL34 vs 6550

Evening two: Amp is sounding great, very much to my liking..I will say this though. I have this CD called Superbass which is an excellent mid-bass reference CD I use. I have to admit that this CD sounded ever so slightly better with the 85.

But, the 150 makes human voice sound incredible. Not as lush as the 85, but more forward and real. Piano also sounds incredibly good with this amp as opposed to the 85.

One thing is for sure, I can't take my eyes off it. I love the way it looks. The black shows of the glow of the tubes really well.

Have you listened to it in triode yet?

I prefer Charlize too but seriously, Keep talking about the comparisons between the 150 and the 85, I am particularly interested in this thread because several years ago I was also enthralled with the st-85 and it was also the amp that drove me away from SS into tubes... the EL-34's were very much as you describe, romantic and almost billowy in the midrange. My local dealer had demo'ed the st-85 for me and it was great but just before I handed over the $$$ I noticed a new pair of MB-125's and asked him about those instead. He told me they had a very similar sound to the st-85 but just "more/better/ and more powerful" of everything the 85 did , so I dug deep and bought them instead. I've been in love ever since. A good friend was visiting sometime later and heard them with my [then] Audio Physic Tempo 3's and instantly joined the VTL bandwagon, only he went straight for the MB-450's (6550's) and the deluxe signature transformers and all the other goodies which make it a superior amp, (not to mention the gutsy power). But, as awesome as they drove his Maggie 3.6's I've been quite content with my 125's (and those EL-34's). He told me I'll always have "first rite of refusal" if he ever decides to sell them but that hasn't come up yet (about 6 years so far)and I've always wondered when/if the day ever comes (and my finances permit) if I made the switch would there be anything about the change that wasn't better? I'm sure there's an across the board improvement in probably every important aspect of performance with this substantially superior product, but just like you and the essence of this thread... are the fundamental differences in character between the 2 tube types even in the same brand of amplifier, going to be significant enough to evoke a preference? Keep lissn'n. P.S. The 125's also have a tetrode/triode switch... the tetrode is my "most of the time", triode is for the late night wine/dim lights/atmosphere.

Cyto..Yes I have, am now actually..Not really with much volume though since I am using it when my wife goes to bed.

Bea at VTL said for break in Terode was best since it runs at full power. So for the most part it has been tetrode.

I notice a difference in the two for sure. And triode is definately cool for low level listening.

Couldn't help but chime in here gents.
I just took a leap of faith and went from the ST 150 (going to hang onto for a while) to a new pair of the MB 185 signatures. Both use 6550's, with the 150 having the SED winged, and the 185's having oem's.
Out of the wrapper the 185's present a larger soundstage, to the point of having to reposition my speaks. They sound considerably "leaner" which may be due to tubes not settled in quite yet.
I began with Antique Sound Labs AV-20's, and it was instant tube mania, but they would run out of steam with some volume applied, so it was onto the ST 150.
The ST 150 is a gem, its reliable, sexy, and a brute at only 150-side.
I also noticed a gain change between the 150-185's as the pre's volume doesn't get to far from home before the room is full of sound. Both are very quiet amps, with the 185's having a tad more background hum, but not noticable from the listening area.
I use a lowley VTL LS 2.5 (with Steve Huntley magic) to drive them, and am considering trying a 5.5 to try the balanced i/o.