Preamp for Clayton Audio S40?

No personal experience with the S40 or M100 but did an awful lot of research on them as they were #1 on my list to buy when I was searching for power amps. Their un-availabilty in the used market made me look elsewhere.

You might want to read this article:
http://www.soundstage.com/weaver05.htm
Look in the section "Have a Cigar.." where Weaver talks about the various preamps he tried out with the S40.

I have also read that the M100 monos have a 47K Ohm input impedance. Does this mean that the S40 does too? Don't know but it could suggest that Clayton amps have high inp. impedance so mating with a tube amp might not get the best out of them. They might certainly sound very good but you'll never know if you've got the very best out of them.
Here's the other article (on the M100) where some do's & don'ts on preamps is mentioned:
http://www.audaud.com/audaud/APR02/EQUIP/equip3APR02.html

FWIW.

Bombaywalla, For the record,I think you got it backwards - a high imput impedence in an amp is an important criteria for most tube pre amps. 47K or higher should work fine with just about any tube pre amp.

In my current set up, I drive the S40 (up for sale soon) with a Sony T-AP9000es multichannel preamp. I am waiting for my M100 to return back from the factory then the s40 will be available.

One more thing. This amp surprised me when I took it out of the box to use for the first time. I can't believe how nice it is up and down the musical scale.

Newbee,

Yes, I'm quite sure that I know about input impedances & their loading effects on the prior stage.

What I was trying to say in my post was that despite Clayton amps having a reasonably high inp. impedance, it might not be high enough as tube preamps themselves have a high output impedance.
Of course, it might be the case that a tube pre will work just fine with the Clayton but I just wanted to make David aware of the *potential* interplay between the tube pre output imp. & Clayton inp. impedance.

BTW, did you read that 2nd article I pointed David to? The reviewer there also mentions this very same point! Do spend some time to read it.

Bombaywalla - I read the article. Personally, I thought the reviewer was over the top in recommending a SS pre amp just because of a potential, and slight, electrical mismatch might occur if the user wasn't mindful in selecting the pre-amp. IMHO the user should keep an open mind should he have an inclination to a tube pre-amp and not just blindly exclude one because of this reviewers comments.