[jimdgoulding]

I don't suppose it's possible Melody gave you max impedance instead of average on the RCA's?  I believe that's how the original question to us was phrased.  30kohms does seem high, but we've paired it with a bunch of different amps and never found it to be finicky.  Also, when Ron Nagle reviewed it for Enjoy The Music he paired it with a Roger Sanders ESL power amp, which according to their website has an input impedance of only 50kohms, and he gushed about the sound.

I read that review for my own information, if you could call it that.  Hardly wrote anything on the subjective side, as I recall, altho he did say anyone in the market should or must hear it.  Something like that. 

[GT Audio Works]

UPDATE....
 Well I gave up on the Mystere Ca21..I don't know for sure what the delay was, but I believe it has something to do with a factory part out of supply and waiting for a replacement.
At Kevin Deals suggestion I purchased a PrimaLuna Dialogue Premium preamp..a little more money but it comes from the same designer.
It should be at my door next week. Anyone have any experience with it ??
 here is the link     http://primaluna-usa.com/product-main/dl-prem-series/dl-prempre
                                      Greg

[jimdgoulding]

No personal experience here, but I've followed this unit in the press.  Bet you're going to be happy.   Enjoy.

[GT Audio Works]

No personal experience here, but I've followed this unit in the press.  Bet you're going to be happy.   Enjoy.

I like the tube selection better 12au7 vs 6sn7.. also has alps remote volume the Mystere  has a 24 step attenuator.which could be an issue with my speakers finding a  volume level.
But sound is the ultimate criteria..will compare against a friends Mystere and see.

[Steve]

I don't think the "20x input impedance rule" is a correct guideline. Impedance matching is relatively new to audio but is a reference connection in a few of the ultra high end company's. Krell, PBN and Dartzeel all use impedance matched connections from pre to amp with matching cables.

You are correct, Nick, 20x is out of line. The RCA Radiotron Designers Handbook, written by 26 engineers, states 5 times
is enough. I am conservative so I often state 10x.

I am with you. I would have to actually see the spec to believe the
output impedance (Z) is 30K is accurate. Anything below 3k ohms or so is fine.

I have a "White Paper" explaining output Z/capacitance and frequency response, midpage, at:

http://www.sasaudiolabs.com/sasaudio.htm

Cheers.

[GT Audio Works]

UPDATE....
 Well I gave up on the Mystere Ca21..I don't know for sure what the delay was, but I believe it has something to do with a factory part out of supply and waiting for a replacement.
At Kevin Deals suggestion I purchased a PrimaLuna Dialogue Premium preamp..a little more money but it comes from the same designer.
It should be at my door next week. Anyone have any experience with it ??
 here is the link     http://primaluna-usa.com/product-main/dl-prem-series/dl-prempre
                                      Greg

 

Well it arrived yesterday and in good condition. The packaging was heroic...triple boxed foam lined,, able to withstand UPS's best efforts to ruin my day.
Handsome and heavy.. looks better with the tube cage off,,IMO.
Black face plate and a nice paint job on the metal work..a kinda metallic gun metal blue grey.
Excellent fit and finish.


50 plus lbs. six 12AU7's two 5AR4's, big transformer iron.
Cold and not broken in I heard good things.
After burning in all night and a good part of today, I must say I am very happy.
Big, well placed sound stage, effortless dynamic ability, well extended and smooth top end, wonderful low end heft, just the right amount of sweet but still very resolving.
Noises in the audience , coughs etc. at a live event have the proper solidity and ambience of the venue , without an etched or hyped leading edge that has no body that draws your ear then leaves you wanting for the decay.
I think a few hundred hours from now it will be even better.
No reviews out on this unit yet, but I imagine at $3,200 retail people will be talking.
I guess it's quite new, they didn't have an owners manual for it yet.
Kevin Deal says he has plenty of tubes available for the roller..not my thing..I would hope I get a long life out of the stock units,
10,000 hrs are claimed.
                                         Greg