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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
128x128jmphotography
atmasphere's avatar
atmasphere
11,588 posts
 
Usually in tube amps (with output transformers) the smaller amps are the better sounding, usually on account of the output transformer, but also in how the power tubes are driven by the driver circuit (by far the lessor variable).


If you don't overload the amp I would see no reason to go for more power! It will just be wasted as heat, and highly unlikely that it would sound better. BTW the KT88s were likely more bright due to distortion rather than the tweeter (which is the same tweeter you were using with the EL34s). This is the same distortion that makes solid state amps bright- higher ordered harmonic distortion. A tiny amount more is audible as the ear uses them to sense sound pressure, so its very sensitive to their presence.
charles1dad's avatar
charles1dad
10,230 posts
 
@jmphotography,
In regard to the volume control setting (Plenty loud at only 9 30-10 o’clock). this has more to do with the amount of gain rather than amplifier power.
1 Your source may have a high voltage output.
2 The amplifier may have a low input voltage (High sensitivity).
3 The amplifier (Integrated) may simply be a high gain design.
Charles
decooney
1,905 posts
 
@jmphotography
FYI, give your amp, tubes, caps inside time to settle in if it’s all brand new. Break-in / burn-in is a real thing, and it will smooth out some more once you get 200+hrs on it. Let this occur before changing more output or small input tubes or cables. Patience will pay off, as many learn later... If it’s brand new, more smoothing out is yet to occur.

If you can manage to stick with the 300, you might be saving yourself a future step-back-down step later on. More tubes is more heat, more maint, cost,and does not always sound better. I’d prefer to have less tubes, less noise, with the same transformers, fwiw.
hilde45's avatar
hilde45
4,792 posts
 
@jmphotography 
+1 on the comments above.

I had a bit of brightness and thanks to advice from @decooney I got some nice KT77's for my outputs and they were a happy change from some rather harsh JJ KT88s. A change of signal tube in the preamp also made a difference.

I am very new to all this, but I am learning (as a general rule) that once one has good gear, the best place to educate myself about changes are with tubes and cables. Input tubes first, then other tubes and perhaps cables. It's very system dependent, and I'm just repeating what (I think) I've learned.

Also, for me, The Room is a big unaddressed area to consider. I have REW software and a microphone, and I'm learning how to deal with that issue. (The elephant in the room IS the room, I think the saying is.)
tuberist's avatar
tuberist
951 posts
 
JMP,
congrats on your purchase. I’ve owned a PL Dialogue integrated a couple of years and am very happy and impressed. The thought that went into the design is superlative and so is the sound. I agree with recommendations not to switch amps as you can always install stronger power tubes like the KT150. I use KT120s.
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