SS Pre-Amp / Tube Amp

One of my very favorite combinations was as SS pre (Musical Fidelity A3cr) with tube amps (Audio Valve ppp45). Although, I agree, the conventional wisdom is the opposite, it worked very well for me.

I'm not sure what criteria (input/output impedance, etc) you should look for, but my experience demonstrates that it can, indeed, be done and sound terrific.

Michael

There is something backwards about using a solid state preamp with a tube power amp. Why? If there are any disadvantages to vacuum tubes, they are related to the difficulty of driving speaker loads and low impedances as well as the need (in most cases) for output transformers. Those problems do not exist in the preamp where the tubes get to drive a delightfully high input impedance in a power amp. So it would seem that there is no downside to tubes in the preamp whatsoever.

Another thing to consider is that preamps are more about finese, fine detail, and microdynamics while power amps are more about brute force and macrodynamics. This argues for tubes in the preamp and solid state in the power amp rather than the reverse.

From a practical standpoint tubes in the preamp are also much more maintenence free and therefore easier to live with than power tubes, which also cost much more, last less long, make more heat and draw more power from your electrical service.

This is, of course, a generalization and there are surely examples where what I call backwards will work quite nicely, but still the generalization makes more sense.

In my opinion, the speakers enter into the picture.

In many if not most systems, the most important component pairing is speaker and amplifier. If the speaker works best with a tube amp, then that's the place to have tubes in your system. From there, the preamp can either be tube or solid state. On the other hand if the speaker works best with a solid state amp, go with solid state amplification and then choose whichever kind of preamp you like best.

Duke
dealer/manufacturer

This is what I do with my system - although I ended up resorting to horizontal biamplification to get the most of it. So Duke is right on - if your speakers are efficienct enough, there is no problem. But as I find out with my JM Lab Electra 926s, tube amps will sound completely different with a nice load (like the top end of my speakers) compared to giving them a large 3-way with double woofers (full-range operation).

Arthur

I use a solid-state preamp with my vacuum tube amps in the reference system for my audio company. I chose this particular solid-state preamp because, other than a slight leanness, it is extremely neutral, as a reference should be (I was able to eliminate that leanness later, to my delight). Solid-state amps usually have high damping factors, and tend to offer overdamped bass--dry and unnatural-sounding, IMO. An extreme example of this was a friend who had Klipsch Cornwalls and drove them with a Crown DC-300A ss amp (known in the 70s for its high damping factor). We thought the speakers had no bass, but the problem was that the Crown amp was telling the 15" woofer to stop before it could overcome inertia and get all that mass to move! He bought a used ARC tube amp, and, voila! Low frequencies!

It's an unfortunate dilemma of life and physics that a low output impedance is necessary to eliminate frequency response variations, but that it strangles the bass via overdamping. You have to accept the compromise that works best for you in this regard. As for me, I'll take slightly underdamped over slightly overdamped anytime (until perfect bass becomes an option). Obviously, some tube amps are waaayy underdamped, and I find this as unacceptable as solid-state bass. As a learning example all you need to do is go to a live concert, pay careful attention to the bass, go home, listen to a live recording of similar music on your soid-state-amp stereo, and cry. BTW, once you become aware of the overdamped-bass problem, you realize it's not just a problem in the bass, but in all frequency ranges.

This is a perfect example of why you need a good dealer or trusted, experienced adviser for building a system; the answer to these types of questions is the "it depends".

Dave, I disagree with your assertion that a SS pre and tube amp is "backwards". It was one of my best combinations. I went from a tube pre + tube amp to SS pre + SS amp. I couldn't believe the difference! (And the SS pre cost a lot less than the tube pre, to boot.) The bass was MUCH better, and so were the dynamics. That doesn't support your theory that the preamp is all about microdynamics and the poweramp is all about macrodynamics. In fact, I've learned just how tremendously preamps can influence the sound; indeed, in my system, the preamp is the most volatile part of the system, as I've gone through a number of preamps in the past few years.

Don't be afraid to try the "backwards" method; it has the potential to work very well.

Michael

I ran a klyne 6lx3p preamp with my Cary slam 100's driving my dunlavy sc3's and there was good synergy between them; I am a believer that a solid state preamp can work very well with tube power.

I agree with Audiokinesis. First you pick a speaker you love, then find a great sounding amp that is compatible with your speaker choice. That amp may be a solid state amp if higher power or ability to drive a difficult load becomes an important consideration (I personally don't like most high-powered tube amps, so if my speaker choice were different, I might prefer solid state amplification).

I've run my system, which has a single-ended triode tube amp, with a solid state preamplifier (Levinson No. 32). The sound was pretty good. However, I got a much better sound from a tube linestage (Emotive Audio Epifania) and tube phono (Viva Fono) combination. Does this mean tube preamplification is inherently better? I don't know. It just happens to be the case that this combination works better in my system. Perhaps there is a solid state component that would work even better.

The point is, the Levinson certainly worked well, but a tube alternative worked even better (albeit at a much higher price point).