For anyone who moved from tubes to solid state — a question

Just to demonstrate the reality that while there are generalities that are generally true, there are also instances where the generality isn't true:

The xenoliths have B&W Matrix 801 Series 2 speakers with North Creek crossovers.  These speakers are nominal 6 ohm and 87 dB sensitivity.  They are among the speakers that have most been referred to as needing big solid state amplification to best perform.

We've driven them with a Jon Soderberg modified Threshold Stasis 2 with about 225 watts/channel on tap for the last 17 years.  Jon described this amp as comparable to a Pass X250.  For completeness, the preamp over that time period has been first an Audio Electronics Supply AE-3 DJH Super preamp and then a Dodd battery powered preamp.  Based on the quality of sound we heard, bass included, mrs. xenolith and I have always thought that we were providing plenty of healthy power to our speakers. 

A couple of months ago we purchased a pair of custom built (they took about 6 months to build) 4 x KT-77 based monoblock amplifiers.  These amps weigh approximately 70 lbs. each and produce about 120 watts in ultralinear mode.  The bass from our big B&Ws is completely unrecognizable relative to what we'd become familiar with over the last 17 years.  Extension seems like a FULL octave lower...we're "hearing" bass notes that are so low that they are more felt than heard.  Never heard anything remotely approaching that with our Threshold.  Additionally, bass tonality is far more textured and nuanced; makes the bass through the Threshold seem one-note by comparison.  Lastly, dynamics, across the frequency spectrum, but in particular with respect to bass, are explosive compared to the sluggish "dynamics" produced by the Threshold.  The big 12" woofers of the 801s have always had great "growl", now they also have great "bite".

Anyhoo, FWIW.   

The key issue with big tube amps that compete with big SS amps is how much do they cost and how much time and money to maintain them over time.

Nominal 6 ohm speakers would seem like fair game for a good quality tube amp depending on the details though some might assert any amp, but more so most tube amps, will do better the easier the load.

Also have to consider that many good 17 year old+ amps could be challenged to compete with similar good modern ones, especially if some maintenance might be needed.


Modern Class D amps have done an effective job of keeping me off the tube amp boat to-date. I’m glad I tried them first. I love tube gear but not the overhead that goes along with it, especially for larger amps with many tubes.

I'm hoping for folks to compare:

well matched amplification and speaker -- with TUBES
vs.
well matched amplification and speaker -- with SOLID STATE

If other factors are responsible for a sonic difference, then I do not have an answer to my question.

This is always tricky! The problem is that many speakers these days are low impedance, a big difference from how it was when tubes were king.

But transistor amps make more distortion into low impedances than they do into higher impedances, and in high end audio the idea is (usually) all about getting the system to sound as real as possible; to that end low impedance speakers really don't have a place in high end audio.


But quite often people compare tubes to transistors on low impedance speakers. Its not an even playing field- if you really want to know what the differences are all about, an 8 ohm speaker (and one that is not 4 ohms in the bass) is how you would do that comparison. My speakers are 16 ohms and I've yet to hear a solid state amp that can play bass as well; if you are playing Sound Labs or Quads you'll probably find the same on them as well (even though a lot of people use solid state on those speakers).


The reason tube amps are still around all these decades on is that they make less audible distortion than transistor amps- the brightness of solid state is caused by distortion (and is as much a coloration as anything tubes do); this is why a solid state amp and a tube amp can measure flat on the test bench but the solid state amp will sound bright and the tube amp will not.

I tried tubes but never liked them I grew up with SS, perhaps that's why. I've moved to active speakers no longer worry about amp matching and whatnot.

My 4 tube (including rectifier) Dennis Had SEP needs efficient speakers unless you’re listening very near-field...plenty of clear and snappy bass (12 or 17 or something ground shaking watts depending on tube type), but supplemented with a couple of REL subs (no tube subs for me!)...the amp runs full range so it gets no relief, but doesn’t seem to need it...tubes seem to last a long time and hey, there’s only 4 of ’em. For my brain, it simply sounds better than any solid state amp or push-pull tube amp I’ve heard over the years...many years...so many years...*sigh*...