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Tube Amp lower power vs higher power and cruising volume

After having Solid State my entire life thus far, I bought a PrimaLuna EVO 300 integrated and absolutely love it. I am currently driving 20 year old B&W CDM9NT's and it does a wonderful job, I never heard my B&W's have that much bass before, even at lower listening volumes. The EVO 300 is rated at 42W. Since I recently purchased it I have the option for a brief time without losing money to possibly move up to the EVO 400 integrated which adds 4 more output tubes and gives you 70W. I believe the 300 and 400 both use the same transformer because they both weigh the same 68 lbs. So my only reason for possibly doing this would be for future speaker upgradability having a little more power. I know my B&W's are not the most efficient and the 300 seems to be driving them very well, volume rarely goes past 9:30/10. So my question, if I get a higher power model, since I listen most of the time at comfortable listening levels, with a higher power tube amp will you have to turn it up higher to hit that cruising speed where it starts to open up? The 300 seems to hit that early and I listen at comfortable levels and good extended bass without having to crank it which is nice when I am listening at night and my wife and daughter are sleeping. Overall I am very happy with the 300 but while I have the option I am trying to decide if the extra for a 400 is worth it. Thanks
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barts's avatar
barts
720 posts
 
To the OP.
Much good advice given already.  Seems like you're in a sweet spot, where you have an integrated that is designed to handle double the tube complement. 

But as you say " volume rarely goes past 9:30/10 " I sort of cringe. Aside from being meaningless, you really don't know if the amp craps out at
"11:00 or 12:00" or wherever.  You may be playing at 4 watts, in that case a 3db increase (double the perceived volume) would cause the amp to output 40 watts, ten fold increase.  Seems to me I would want to know where the amp STARTS to sound overdriven. 

This is anathema to many audiophiles, but I like a lot of headroom.  Give me 500 watt mono-blocks to play at 75 watts and bounce up to who knows where.

After all that if your rig thrills you everyday, you've hit the grand slam.
Don't change a thing!

Regards,
barts   
sandthemall
544 posts
 
I own the Evo 400 power amp. I also auditioned Evo 300 power amp.

I say go for the Evo 400.

It won't sound any better but what you will notice is that the switch to triode mode makes almost no difference in volume. The Evo 300 will drop in volume quite a bit more.

The Evo 400 does make changing out tubes a bit more expensive, however, after swapping tubes out with the dialogue premium during my audition period...El34s won that contest for me.




jjss49's avatar
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jjss49
6,612 posts
 
@sandthemall 

just so we don't unnecessarily muddy the waters, on the primaluna's amps (and others with the switch), when the triode mode is activated (from base mode ultralinear) the power tubes screens are tied to their grids with a small value resistor (usually 200 ohms) and the ultralinear tap on the transformer winding is bypassed... this results in a 3 db reduction (half power) in output from the power tubes....

this happens whether we are dealing with 2 or 4 power tubes per channel...
audition__audio
1,500 posts
 
The David Berning stuff is wonderful. I am not sure if these designs are as adverse to lower impedance speakers as other OTL designs seem.
atmasphere's avatar
atmasphere
11,844 posts
 
The David Berning stuff is wonderful. I am not sure if these designs are as adverse to lower impedance speakers as other OTL designs seem.
The Berning ZOTL amps are not OTLs by any stretch (read the patent), although a brilliant design nontheless. They have no worries with low impedances.
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