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Need some Tube and Class A SS Suggestions

I recently purchased a pair of Spendor D7s and am just loving these speakers. I have them paired with a musical fidelity KW 500 integrated. The combo is super fast, tight, and dynamic. However, the Spendors can be a bit too revealing in the high frequencies given a harsh or bright recording. This has me headed down the rabbit hole of tube amplification and possibly Class A SS. If the lowest bass is not as tightly defined I'm ok with. It actually may be too tight and defined at the moment. Added warmth in the upper bass would be fine as well. And if I'm going to upgrade then maybe it's time for separates too!

Here are the power amps I'm considering:
  • Primaluna EVO 400
  • Pass Labs XA25
  • Line Magnetic 805IA
  • Schiit Aegir Monoblocks - the price is just too good.
And on to the preamps:
  • Rogue Audio RP-5 and RP-7
  • PS Audio BHK Preamp
Ideally I would find at least one of the two Pre/Power used. I can probably get about $2200 for the musical fidelity so budget would be about $6k or so assuming I can somehow get both items used.

I'm curious to hear if any thoughts on what I've picked out already and if there are other units worth looking.

Thanks!
shahram
shahram OP
116 posts
 
Hi @georgehifi 

Thanks for the suggestion here. The impedence of that stereophile graph really doesn't rise until 10khz. A 10khz tone is VERY high pitched. Not much music above 10Khz so that impedence graph doesn't really bother me.

Definitely considering a Primaluna or Rogue Audio preamp with a class A SS power amp. I think if I went class A SS the pass labs XA25 would be my top choice. But part of me really wants to hear what this speaker can do with a Tube power amp...the dilemma continues!
photomax
174 posts
 
I just ordered a Pass Labs XA30.8 to go with my Spendor D9s. Will be selling my Bryston 4BSST-2 amp...
georgehifi's avatar
georgehifi
10,312 posts
 
shahram OP


https://www.stereophile.com/images/1214PLDPIfig01.jpg
Here is a behavior graph of the Prima Luna’s output transformer, as you can see it goes into stability ringing from 10khz up and the harmonics of that can effect even further down the line.
This combined with the high impedance of the speakers in the same area can be put to question.
Because the higher the impedance of the speakers, and if you look the output transformer ringing is worse at high impedance put the two together and you have something nasty going on.

Cheers George
three_easy_payments's avatar
three_easy_payments
2,097 posts
 
@shahram   

But part of me really wants to hear what this speaker can do with a Tube power amp...the dilemma continues!

You likely won't come close to getting the low-end grip (both weight and speed) of SS with a tube amp and you will almost definitely get more noise.  I moved from a tube amp to SS with my D7's and knew the second I turned on my Pass XA30.8 that I had made a transformational improvement even moving to amp with half the watts as my prior tube amp. 
shahram OP
116 posts
 
@three_easy_payments

Yes, i realize that low end grip might be compromised some with a tube amp. But I've read that newer tube amps from Primaluna and Rogue do not sound like the tube amps of yore...maybe I can find a dealer nearby that will let me borrow an amp for a fee to test it out.

What tube amp did you use previously? 

When you are listening at what you consider a loud volume, how far do you push the volume knob? Or where do you never go past on the dial?



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