Carver and Tube Life


I’ve been looking at Bob Carver’s statement tube amps, the Siver Seven 700’s.  These massive tube amps designed by Bob  have been around for years and the latest version of his 700’s can now accommodate KT120 output tubes and his best output transformer design.

EACH mono block uses 20 KT120’s! That’s 40 KT120’s total when it comes time to ‘re-tube.’  However, according to his description these KT120’s should easily last “50 Years”.  Is that truly possible???  Can the output tubes really last that long ?

stickman451
Al, thanks for that analysis.  It’s difficult enough to pay that much coin for a ‘statement’ tube amp, then spend thousands over the next ten years re-tubing it.  But, if I understand your comments the tube replacement rate for this amp would most likely be considerably less than most high powered tube amps.

On that thought.  If you’re driving a power hungry speaker such as the Magnepan 20.7 or the new 30.7, assuming other parameters are equal does it make sense that an amp like the Silver 7 would lead to more sonic joy?  My current mono amps, the Carver Black Beauty 305’s, pump out about 350 watts into the Maggie’s 4ohm load.  A pair of Silver 7’s would more than double that wattage, close to 900 Watts!  Typically does that doubling of watts lead to a more powerful and bigger sound field in your room?   The 305’s don’t strain or struggle with the 20.7’s, but the 30.7’s add a significant amount of area to the speaker membrane, about 25% more bass panel area specifically.  Maybe more power equals better bass overall, a larger and even denser sound field, and a greater ability to push that Huge Power Response into a bigger room.  My room is fairly large at 21 x 29 x 11.

Thoughts?
 
John (Roxy54), thank you kindly :-)

Stickman, I wouldn’t want to speculate on the differences that would result between the two amplifiers with respect to soundstage, dimensionality, bass, or pretty much any other sonic attribute. But given that your 305s don’t seem to strain driving the 20.7 I would think that whatever differences the Silver Seven 700s may make would result mainly from circuit differences and parts differences (including the completely different small signal tubes it uses), rather than from the 3 or 4 db difference in maximum power capability in itself.

And likewise with respect to the 30.7, **if** its sensitivity (for which I couldn’t find a spec or measurement) is similar to that of the 20.7, or higher.

Best regards,
-- Al
Doesn't Bob offer not only a 20 year warranty on the amps themselves, but tubes also?  That would really ease my mind.

KT120/KT150 tubes aren't cheap, especially if you have to replace a bunch.

+1 on Al, (he's our treasure), no you can't have him :-)