Pass XA60.5
- Thread starter Bruce B
- Start date
I do wonder how well it will control the bass versus the higher models. JA seemed to indicate the bass wasn't so great on a few tunes.
When I had the XA100.5's with my Sashas I found them a little slow and syrupy. I now have XA160.5's on my Alexias and it seems better (hard to say how much as they're still breaking in).
When I had the XA100.5's with my Sashas I found them a little slow and syrupy. I now have XA160.5's on my Alexias and it seems better (hard to say how much as they're still breaking in).
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Audioseduction was specifically asking for Class A power and he owns the Summit's. No way the Pass XA 160.5 can deliver this type of power over a speaker that has a minimum impedance of less than 1 ohm at high frequencies. According to ML the impedance curve drops down to 0.7 Ohms at 20kHz. Happily the XA 160.5 can supply a lot of current in AB mode!
Sorry to say that you suspect, but it will not - Ohm's law does not allow it! Please consider that 300W at 2 ohms means 12A average, 17 peak current. See http://sound.westhost.com/class-a.htm for a more detailed explanation. It is a trade-off, and Pass does not optimize his amplifiers for 2 ohm loads in Class A. But as you say it is an exceptional result!
BTW, the quoted post is #17
Then why would the Alexia reduce the power by a factor of 4?
And the 160.5 will output over 320 watts Class A into 4 ohms; how much will that fall into 2 ohms? Are you assuming the "leaves Class A @ pk power of 320W" means the amp's maximum current output is at 4 ohms?
And the 160.5 will output over 320 watts Class A into 4 ohms; how much will that fall into 2 ohms? Are you assuming the "leaves Class A @ pk power of 320W" means the amp's maximum current output is at 4 ohms?
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No. The maximum class A current is independent of load impedance. It is all explained by Nelson Pass himself here: https://passlabs.com/articles/leaving-class-a
Remember that : Power = Current x Voltage; Voltage = Impedance x Current; Power = current x current x impedance;
As NP clearly says For several years Pass Labs has specified the nominal wattages at which our amplifiers leave push-pull Class A operation into an eight ohm load.
If you use a lower load, class A power scales down proportionally.
For the good of your hears I hope so - the Summits are rated at 91 dB/W and are panel speakers with active subs. Their low impedance zone should be at very high frequencies, where music has lower energy - quite different from the Alexia's. And I think everyone agrees on your second statement!
The XA60.5 review is on the Stereophile web site now.
I use the 60.5 now, driving Magnepan 3.6's, and could not be more pleased.
On 3.6's it beats the ARC Reference 110, ARC D125, and Quicksilver M135's tube amps, and many other SS power amps I have used over the years.
Prior I used a XA30.5 which worked great for my lower SPL requirements, but I wanted more power.
Could be my "end of life" power amp!
I use the 60.5 now, driving Magnepan 3.6's, and could not be more pleased.
On 3.6's it beats the ARC Reference 110, ARC D125, and Quicksilver M135's tube amps, and many other SS power amps I have used over the years.
Prior I used a XA30.5 which worked great for my lower SPL requirements, but I wanted more power.
Could be my "end of life" power amp!
I absolutely love my XA100.5 driving my WP8's! At any volume I care to listen, the meters indicate class A. I don't miss tube amplification with the Pass gear.
You certainly can't go wrong with an upgrade to the 60.5 amps. It would be a substantial improvement that should rid you of your "upgradeitis"
The XA60.5 mono blocks are here! Per Mark at Reno Hi-Fi, I left them powered up for five days for break in. I'm thinking six days is a better time frame. When I started listening to them after five days, they were kind of hit and miss. On day six they started to sing. And now by day seven, I think I might have found a couple of new friends!
Thanks for the advice on the upgrade.
Thanks for the advice on the upgrade.
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