Wavac PR-T1 thoughts?

So 600ohms may be too high of a resistance to the Gryphon amps you think? Ie too high of an output resistance coupled with too high of an input resistance means not enough signal gets through?

too high of an output resistance coupled with too high of an input resistance means not enough signal gets through?

No, the main problem is that neither impedance, especially the preamp output impedance, is likely to be perfectly constant with frequency. The amount of signal that is seen by the power amp input is dependent on the ratio of power amp input impedance to the total of the two impedances. Therefore if the two impedances do not vary with frequency in an identical manner, the overall frequency response will become non-flat.

Higher power amp input impedance and/or lower preamp output impedance will reduce the significance of whatever variations may be present in the impedance vs. frequency characteristics.

Tube preamps usually have an output impedance that rises considerably at deep bass frequencies (approaching 20Hz), due to the coupling capacitor at their output. That will result in reduced deep bass response if the power amp input impedance is not high enough. I see, however, that the PR-T1 is transformer coupled, apparently with no capacitors in the signal path at all, so that should not be a concern in this case.

Another effect that can occur, although it is usually much less of a concern, is that if the output impedance of the preamp is high at HIGH frequencies, and the capacitance of the interconnect cable is high (due to the cable being very long and/or having high capacitance per unit length), the preamp's output impedance and the cable capacitance will act together as a low pass filter, producing a slight dulling of the upper treble, and also resulting in transient response that may be perceived as sluggish.

Regards,
-- Al

Al - great information & very much appreciated. I know a few owners that uses the PR T1 + Gryphons and swear there's no impedence issue. It's a risk so I do need to think it over. The safest is using the Gryphon Mirage which I have actually heard and seems to be quite good (whatever that means).

Hi Enzo,
Only just found your blog , about the wavac prt1 this is superb , better tan the kndo m77 and all the other stuff out there, I know i have one and the lrx2 phono stage to go with it .
I have heard this in other systems with boulder power amp and with solution 710, I am a valve man myself , also for the power amps . however wavac power amps are expensive , only the 833 amps the rest are not that good . unless you have very eficient speakers. make sure that you are getting the 3 box
set up as I think wavac are changing to a 2 box set up .
the prt1 and lrx2 6 boxes in total is virtually unbeatable .
Steve

Hello Steve,

I have a Wavac PRT1 on trial and noticed that it is brilliant in every microdynamic respect regarding midbass to midrange to treble, however having lived with CAT preamp for 12yrs, it is lacking the visceral physical slam that one feels with big orchestral wacks like TItanic soundtrack, and though it has low bass it just does not seem as a solid underpinning of rhythm and pace demonstrated by CAT preamp on pieces from Sarah K, Holly Cole and Leonard Cohen. This is in my system and every system is different. But I will tell you that my system which consists of 2 powered subs per channel with CAT preamp has reproduced realistic orchestral impacts that are startling. Not so yet with the PRT1. Can PRT1 attain this type of character or is this the trade off: microdynamics for macrdynamics?