Powerful Tube Amp for SF Strads?

Hi Tuboo,

I have now spent 12+ hours listenin carefully. Answers to questions I have been asked:

1. Biasing. I tried low volume at 50%...on pre-amp that goes to 99 and where 71 will deliver volume to punch thru 2 floors of concrete cynderblock to disturb my neighbor, once I past 19, I found 75% was necessary to feel like I had full class A.

Once I got to 30...the level most audiophiles would 'start' their true auditioning, you really want 100%. The technical differences are almost non-existent in the sound...but 100% really does have a sense of naturalness that you 'feel/sense' rather than articulate just by hearing differences in decay or added detail, etc. But you definitely feel it intuitively.
The nice thing is that you can almost gauge how much class A you are using by the heat dissipation. When the amp starts to steam, the volume is low and the amp is burning off 'excess Class' via heat. But when volume is cranked up enuf, the unit starts steaming less and becomes like any tube amp. For me, I find 38 on my pre-amp is where I find the unit heat very normal and therefore enuf class is cranking music as opposed to dissapating heat.
2. I was shocked to find that the Strads were not getting nearly as much help now from the Velodyne DD-18 as I thought. Wow...the 2 10" cones on each speaker are really pumping now, and if I mute the Velodyne, it shocking how little I miss it. Maybe 5% extra for most House tracks! On the other hand, because I am a bass freak, I find that on certain tracks, that extra bass really adds a quality, visceral touch that is indescribably satisfying. Plus, on movies, it's killer.
That's all for now. Hope that helps. Thanks!!

Tuboo,

To try to give you a (slightly) more 'objective' sense of the biasing options, I would say that once the volume requirement surpasses the ability to stay in Class A, it sounds like very high quality solid state. There is a slight hardening of the treble...and because this is an extremely wide bandwidth amp, you really feel the treble harden when the volume breaches class A in the lower 2 biases. That said, it is still very good SS...much purer to my ear than a top level krell...but for a tube lover (who is expecting absolute purity of tone and a natural sound), I do feel this difference. As I said above, the technicals (decay, accuracy, space) will be nearly indistinguishable between biases...but I definitely "feel" the difference. Because I play at 38-50 on all music, I leave it on at full bias. According to Gryphon, the amp draws 800 watts from the wall...a lot but not horrible in the context of a home. Hope between the posts above and this one that you get some idea of the differences in biases.

Hi Lloyd

IMO, just leave the Gryphon in full class A.
Sounds better that way and living in the UK, you always need a heater :-)

cheers

thanks for sharing experiences.
800 watts is a lot, i used to own Atma MA2 which eat up 800 watts each channel..
but a reasonable household vacuumcleaner will eat up 1.5kW and sounds very bad too.
very clever thinking of Mr Rasmussen to implement the various Class A bias range.
i had just the same experience with the Pass XA30 amp here. at lower volumes it sounded sweet, but the moment i really crancked it, it turned to a nasty SS.
btw Pass has a great article on 'Class A' at his website. a must read.
this http://www.tubedepot.com/whisbipo.html is a must read too and a great way of showing how class A works.

keep em spinning :-)

Thanks Tuboo. I will say on full Class A, the sound does not harden at full volumes. But it will on the lower biases when class B starts to get introduced...just slightly. Of course, once you get to a certain point, it is these very slight changes which are important in the never-ending search for 'true sound". I am doing some reading on the Less Loss. Thanks for the advice!