Pass Labs INT-25 Integrated Amplifier measurements (John Atkinson)

[direstraitsfan98]

I apologize for the gorilla style pictures. When my digital copy from Zinio arrives I will upload better pictures. My print version arrived before my digital (???)



Seems like they'd be a very fine match with my JBL 4367 which stay around 6-8ohms in the mid and upper treble frequencies.

 

[NTomokawa]

What amp are you running right now?

 

[pma]

Power amp XA25 is here
https://www.stereophile.com/content/pass-laboratories-xa25-power-amplifier-measurements

Looks like similarly very high distortion rising sharply above 1kHz.

 

[direstraitsfan98]

What amp are you running right now?

I'm running an Akitika GT-102 and PR-101 preamp. Total cost less than $600. I sold my Pass Labs XA30.5 and XP-10 preamplifier for them. Those were over 10 times more expensive. No regrets! But I do have experience with Pass Labs and it's a very nice luxrious piece of kit to own and I wouldn't mind owning it again at some point. These 5 figure amps with 1 inch thick steel face plates and VU meters are audio jewellery so you just pick what you think looks best and if it will be compatiblie with your speakers and you get it and enjoy.

 

[direstraitsfan98]

Power amp XA25 is here
https://www.stereophile.com/content/pass-laboratories-xa25-power-amplifier-measurements

Looks like similarly very high distortion rising sharply above 1kHz.

Yes, it's the INT-25, I modified the thread title to be correct.

 

[NTomokawa]

you just pick what you think looks best

When independent measurements are absent, that may as well be the best way to choose amps.

I myself am a fan of how Atma-Sphere's "lamp boards" look...

 

[ousi]

I had the XA25 new for around a month before I sold it off. Lost around 600USD in the process.
I don't think the XA25 is dynamic enough for most stuff, even with my relatively efficient Paradigm Premier 800F. I tried it with the Omega 3XRS single-driver and it worked out okay but sounds very flat rolled off at both ends (which the single-driver doesn't help at all). It does make mediocre sounding songs sound smoother in my opinion. Before reading this I thought the high end was quite rolled-off and sounds different to a lot of different amps I had (Parasound HCA-3500/2200II/A21/A23, Red Dragon Audio Pascal Class D amps, Bryston 7B3 to name a few) and I found it annoying when I play songs/recording with tons of cymbals even with the high-end roll off. But compared to a tube amp it sounds cleaner and actually sounded like a Prima Luna, and a bit more dynamic than the CJ Premier 11A I had. Now I understand why from the measurement.. Replaced with a pair of DIY NC500MP mono (ghentaudio case and NC500MP module from eBay) and it sounds so much better... while waiting for my pair of Apollon Purifi monoblock to arrive.

So, I don't recommend buying it even though it holds value quite okay (like McIntosh stuff). Like my father told me who's a big fan of Class A amp - 25W is just not enough. You need at least 100W/ch, and needless to say he was a great fan of Krell KSA series.

 

[Sal1950]

I apologize for the gorilla style pictures. When my digital copy from Zinio arrives I will upload better pictures. My print version arrived before my digital (???)

Hows this,

Sidebar 3: Measurements
Prior to measuring the Pass Labs INT-25 using my Audio Precision SYS2722 system, I preconditioned it for an hour at one-third power into 8 ohms. At the end of that time, the heatsinks on the amplifier's sides were hot, at 122°F (50°C), as was the top panel, at 116.6°F (47.8°C). Owners should make sure this amplifier is well-ventilated. The amplifier's maximum voltage gain into 8 ohms was 25.4dB, and the amplifier preserved absolute polarity (ie, was noninverting).
https://www.stereophile.com/content/pass-labs-int-25-integrated-amplifier-measurements

 

[Sal1950]

Seems like they'd be a very fine match with my JBL 4367 which stay around 6-8ohms in the mid and upper treble frequencies.

If I were you and looking to spend that kind of money I'd be looking at Anthem STR with ARC room correction or NAD M10 with Dirac Live. Room correction will make a much bigger improvement than any change to gear without it..
https://www.stereophile.com/content...d-amplifier-trying-dirac-live-room-correction
https://www.stereophile.com/content/anthem-electronics-str-da-integrated-amplifier-arc-measurements

 

[anmpr1]

Seven and a half large? For this? Sometimes I have to wonder just what designers are thinking. Atkinson really must have little shame when he can write, "There is much to admire in the Pass Labs INT-25's measured performance." Or maybe he just throws back another beer and chuckles to himself, "Sucker..."

 

[Sal1950]

Seven and a half large? For this? Sometimes I have to wonder just what designers are thinking. Atkinson really must have little shame when he can write, "There is much to admire in the Pass Labs INT-25's measured performance." Or maybe he just throws back another beer and chuckles to himself, "Sucker..."

Yep, pretty nuts when 1/10th of the money would get you an Asian integrated with a hell of alot more power and just as good SQ.

 

[Omar Cumming]

A $7K 25 watt distortion machine.

Phooey!

 

[pkane]

A $7K 25 watt distortion machine.

Phooey!

At least you get a lot of distortion for your money!

 

[Spocko]

If I were you and looking to spend that kind of money I'd be looking at Anthem STR with ARC room correction or NAD M10 with Dirac Live. Room correction will make a much bigger improvement than any change to gear without it..
https://www.stereophile.com/content...d-amplifier-trying-dirac-live-room-correction
https://www.stereophile.com/content/anthem-electronics-str-da-integrated-amplifier-arc-measurements

Or the new NAD M33 streaming MQA/DAC/Dirac integrated with Purifi amplifier section coming this spring! This looks solid
https://nadelectronics.com/nad-mast...purifis-ultra-quiet-amplification-technology/

 

[Spocko]

A $7K 25 watt distortion machine.
Phooey!

To be fair, you'll be surprised how many people prefer the sound of 2nd order harmonic distortion aka "analog warmth", and are willing to pay a pretty penny for just the right amount of it. Nelson Pass knows full well what he's doing - it's no accident that the distortion is there. Pass could EASILY eliminate the distortion, but he knows what his customer base is looking for. The "art" is in adding just enough distortion so it's audibly enjoyable and that's what you're seeing.

 

[Jmudrick]

To be fair, you'll be surprised how many people prefer the sound of 2nd order harmonic distortion aka "analog warmth", and are willing to pay a pretty penny for just the right amount of it. Nelson Pass knows full well what he's doing - it's no accident that the distortion is there. Pass could EASILY eliminate the distortion, but he knows what his customer base is looking for. The "art" is in adding just enough distortion so it's audibly enjoyable and that's what you're seeing.

To be clear, he acknowledges this, no hidden agenda on his part.

 

[Spocko]

To be clear, he acknowledges this, no hidden agenda on his part.

Absolutely, IIRC Nelson Pass has explained his design objectives in a few interviews posted online and YouTube.

 

[mhardy6647]

Absolutely, IIRC Nelson Pass has explained his design objectives in a few interviews posted online and YouTube.

Plenty of 'design exercises' and/or white papers on his websites -- he's pretty transparent (pun partially intended) on his art.

https://www.passdiy.com/project
http://www.firstwatt.com/articles.html

 

[ta240]

To be fair, you'll be surprised how many people prefer the sound of 2nd order harmonic distortion aka "analog warmth", and are willing to pay a pretty penny for just the right amount of it. Nelson Pass knows full well what he's doing - it's no accident that the distortion is there. Pass could EASILY eliminate the distortion, but he knows what his customer base is looking for. The "art" is in adding just enough distortion so it's audibly enjoyable and that's what you're seeing.

I can't figure out why this angers some people.
He makes no claims of veils lifted or secret parts of the music being revealed.
He is simply putting spices on the steak because some prefer it that way and it drives others up the wall because "It should taste like steak and nothing else!!!!"

Think of how much better the world would be if we could all sit back and go "that isn't my preference but I'm happy that you enjoy it" with everything.

 

[Spocko]

I can't figure out why this angers some people.
He makes no claims of veils lifted or secret parts of the music being revealed.
He is simply putting spices on the steak because some prefer it that way and it drives others up the wall because "It should taste like steak and nothing else!!!!"

Think of how much better the world would be if we could all sit back and go "that isn't my preference but I'm happy that you enjoy it" with everything.

Agreed. "High Resolution" for the sake of resolution is no different than saying,"I want to eat my salad without any dressing because I want to taste every lettuce and tomato." There's nothing wrong with that, but it's also not wrong that people drown their salad in ranch dressing.