2. amps-preamps
  3. 1313116554

XA 30.5 or mod S/500?

I've been watching the 'Gon fruitlessly for some time to get a Threshold S/500, "late Series II w/Optical Bias" (per Jon Soderberg, this is what he needs in order to do his modification to produce a Class A one-chassis SA/1 "clone" [my word, not his]). I'm beginning to wonder if a Pass XA 30.5 might not be equivalent or better sounding; I know they're easier to find. Unless I get lucky and find an already-Soderberg-ed S/500, the cost of amp and mod might even be approaching the price of a used XA 30.5(?). Either amp will be used with a FET 9 preamp. Speakers are currently Vandersteen 2CEs, but contemplating future purchase of 3A Sigs, or Maggie 3.6s, and a REL sub. Anyone heard SA/1s AND heard XA 30.5? Thanks.
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teajay
1,691 posts
 
Hi Cippoliner,

I use a pair of Threshold SA-1's and Pass Labs XA 60.5's to power my MG-20's. They are both great amps, however Nelson Pass's latest XA.5 series are his best sounding amps of his long great design career.
jebsmith73
167 posts
 
In this case newer is much better, go with the XA-30.5. Has your FET 9 been up dated?
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cippoliner OP
4 posts
 
Thanks for replies; nope, no update.
thesoundhouse
250 posts
 
I have a XA30.5 and a X350.5 and have had two Jon Soderberg moded Threshold amps through out the years. Sonically speaking the Moded Thresholds sound very very good however the PASS sounds significantly better. I can tell you will need more power to drive those Magnepans 3.6 than a XA30.5. My advise is you should buy a used X250.5 or X350.5 if you can. They may not be 100% Class A but they will blow the doors off the Moded Thresholds. I had a pair of heavily moded SA/1 mono blocks with the Optical Biasing and balanced and a new right out of the box X250.5 not broken in killed the The Threshold Mono Blocks and by a huge margin.
unsound
7,329 posts
 
I don't think an XA 30.5 will provide enough power to let any of those speakers demonstrate what they are ultimately capable of.
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