Using a tube amp with a Solid State preamp

You guys are great, thanks for all the responses. There is not a question that this community can't answer. Thanks again to all. Danny

It is the rarer way to go, but it is done. I myself am running an InnerSound SS preamp into my VTL MB-185 Sig's. I just got tired of trying to find quiet tubes for the high-gain sections in the preamp. In my experience, the tubes make the most difference to the sound when they are driving the speakers anyway. I think many folks do the reverse, with tube preamplification and SS power amplification, because they actually do not want a real 'tube' sound (or tube heat, or replacement costs), but would like to have a bit of tubularity in the mix somewhere, if just to feel they are being a true audiophile by running some tubes.

Replacing an all-tube Conrad-Johnson PV-8 in my system, the SS preamp has given me better transparency and definition. The old pre had a slightly less clear soundstage, with image outlines that were not as sharp, and a less-neutral warmish tonal coloration. Dynamics are now more unfettered, and the bass has gained control and speed. I do not hear increased grain, but maybe just a little hardness, since the tube pre was comparitively softer. I think the new preamp is more accurate, and passes the cleaner signal. I loved my C-J when I used it before, but when I drop it back in the system now, I am aware of losing some clarity, bandwidth, impact, and immediacy.

But to be fair, the InnerSound is 10 years newer than the C-J, and twice the price. Aspects such as the attenuation control system are completely differently implemented. And when the C-J originally replaced an even older SS preamp several years ago, I heard many of the same improvements then that I'm talking about now, so it's all a matter of the individual pieces in question. I have no doubt that newer, more premium tube preamp designs would've also improved on my PV-8 in many of the same ways, but there still would have been the matter of finding good tubes.

I have done the same thing for my phono preamplification as well, hearing a lot of the same improvements and more, moving from the C-J's built-in phonostage to a SS Camelot Tech Lancelot unit. Here the benefits from not having to find quiet tubes are even more profound, and the sound only got better. But again, the C-J was the only tubed unit I have owned in preamplification, and better surely exists. One thing, though - if I ever go back to tubes in these stages, it will be with designs that employ lower gain, so the tubes won't drive me batty. For the time being, however, I remain firmly tubed in power amplification.

These are only generalizations, but in my system I have found solid state preamps to be quieter with better dynamic capabilities than tube preamps. Tube preamps tended to be a little sweeter and more delicate on the top end, sometimes with better spatial characteristics. These are the tradeoffs as I experienced them, but they will vary from model to model and system to system -- again, these findings are generalizations to be used as guidelines only, and you should really try at least a couple models of both types in your system to get a good feel for what works best for you in your system.

My preference, for what it's worth, is to use a high quality solid state preamp(for its silence and dynamics) that does a nice job with the highs, tonality, and soundstage(many of them don't). I'd suggest trying a Pass Labs preamp, or if that's out of your price range you might also try the Marsh P2000, which sounds great and is an incredible bargain at about $1000 new(for a few hundred dollars more they also make a tubed version, which may make for a nice comparison if you have a dealer nearby). Best of luck and happy hunting.

I use a Pass Labs Aleph P with a Berning ZH270; I think it sounds great. I tried my friend's BAT VK5i with the Berning and me and a couple of other guys thought it didn't work so well. Now the BAT is an EXCELLENT piece; so my point is that there can be strange interactions with any given combo.

Marakanetz and Newbee--you're right, I had it backwards. Thanks for the correction.

In all logical sence there will be no problem whatsoever as to mating amps(not the speakers) More impedance match to consern when you're using tube preamp with SS amp but SS pre with tube amp will never cause the problem since input impedance of tube amps are usually infinitely large compared to output impedance of SS pre(no matter if direct or transformer coupled)

Rcprince, in ideal case(something like ss-pre and tube amp)you would definitely want an output impedance to be approaching to zero and input impedance to be approaching infinity like Newbee mentioned above.

These are two cases in mixing amplification that can be argued between each other:
In case if you're using tube preamp and SS amp you have some tube signature, very often a tube midrange presence along with punchy and fast drive, sufficient current delivery onto the voice coil.
In case if you' running SS preamp with Tube amp there is certainly tube sound but more on the analytical side with more details and often better stage and imaging.

If to drow the budget vs. performance curve there are I bet the points where you rather get SS or passive preamp having a tube amp.

To my experience all tube preamps significantly colour the signal unless you go for the level of AudioNote M5 where you feel the dynamics of an active preamp and transperency of a passive at the same time.
In all other cases SS preamps in general are more transperent than tube.

What you want to look for is an amp with a high input impedance(say, 35k ohms or higher). You will want as low
an output impedance on your pre-amp as possible. The reason for this has to do with transferring power, buffering, etc.

If you mix, most people I know will use a tube preamp and solid state power amp.

As far as what you might gain or lose with this setup, not much.

you won't have a problem with impedences using a ss pre amp. you want the pre-amp output impedence to be no greater than 1/10th of the imput impedence of the amp. most ss preamps have output impedences of l ohm or less (whereas tube preamps typically have high output impedences anywhere from 500 to 3500 ohm, more or less, which require high imput impedence in the amp. tube amps typically have high impedences and will match well with eith ss or tube preamps. the same cannot be said for matching tube preamps with ss amps - thats where the trouble can be. Relax about the electrical match. However it would seem to me, sonically speaking, that you would have a much better realization of the benefits of a tube amp by using a tube preamp to go with it.

I prefer a tube preamp with solid state amp if I am not going all tube.

I'm reaching back into my memory here, and I may have this wrong, perhaps an engineer can help, but many solid state preamps have comparatively low output impedances, while tube amps have very high input impedances. Normally you would want the output impedance to be higher than the input impedance. This may not make a difference with short cable runs, but with longer ones I recall reading you could lose some of the high frequencies. I like Sugarbrie's suggestion to ask Bill Thalmann.

I know of one person who does this successfully. Bill Thalmann at Music Technology uses a Conrad Johnson Motif MC-10 solid state preamp with a Conrad Johnson Premier tube amp. The MC-10 is similar to the Conrad Johnson PFR. Bill is a former engineer at Conrad Johnson. You may be able to ask Bill yourself. He can be found at www.musictechnology.com

It depends on what kind of speakers you are going to use. If you have some kind of speaker that is not going to be tube friendly, like dropping under 4 ohms, then you will gain better stability, bass damping, and slam with the SS amp. If your speakers present a tube friendly impedance, then I think you can do better with a good tube amp.