Bob Edwards
pfm Member
First off - pardon the length!
With the C19 pandemic ongoing, I had the chance to play with my hifi - both in terms of listening to music and experimenting with some components. I had started with an eye toward upgrading my speakers - I had used a pair of Linn Helix 2s with the ku-stone stands for something like 15 years, and always enjoyed them. They communicate music well, even if I can list out their faults. And they were always good enough to let me hear differences from one component to the next. In their place I now have Monitor Audio Gold GX300s, which were a rather spectacular leap forward (as you'd hope and expect!).
The GX300s did, however, show that my power amp, an Exposure XXVIII (28), might be a bit underpowered (more on that later). So I started thinking about power amplifiers that might work well. Through a set of circumstances I won't bore anyone with, I wound up with a Linn Klout, a pair of PS Audio M700s (PS Audio is based in the town next to mine), and a Belles 350A Reference (with the "soft start" circuit).
Sources were an Exposure 3010S2 CD player, a Naim nDAC (later with a Teddy Pardo TeddyXPS), a Linn Karik III (mainly used as a transport), and, briefly, a Mark Levinson 31.5/30.6 transport/DAC that a good friend has and let me borrow. Preamp was mainly an Exposure 3010S2, I also used a conrad-johnson PF2-L, and, also briefly, an Audio Research LS17SE.
The room is difficult, as it is effectively my entire townhouse - there is no effective separation from the main level to the upstairs, and a thin door is all that separates the main level from the stairs leading to the finished basement. That was part of what led me to look for speakers that could better load the space - the Helix 2s just couldn't do it.
Anyway, on to the amps.
I'll start with the Exposure, as I've owned it for a while now after having the Exposure stack see off (what a fantastic expression - I wish more Americans could understand British English!) a Naim stack. The 28 provides 70 watts per channel into 8 ohms; no 4 ohm rating is provided. It is a dual mono design, with a (fairly large) transformer for each channel, which accounts for much of its 24 lb (11 kg) weight.
Musically, the Exposure is very good. It's easy to follow most instrumental and musical lines, whether on something like Lyle Lovett's cover of "Bears" on "Step Inside This House," or REM's "I Believe" on "Life's Rich Pageant," or Ulrich Schnauss and Mark Peters' "There's Always Tomorrow." The 28 has a balance and inner drive that allows the music to drive itself forward without sounding bright or forward itself. It also does a (surprisingly to me) good job of image placement and depth (particularly obvious with the ARC LS17SE). There is one fly in the ointment, however - the 28 does not seem to have enough power reserve to drive the GX300s to their full potential. It almost literally sounds like it is running out of breath (or 'puff') on notes that have a sustain or long decay. It's particularly noticeable on music like Reiner's Beethoven 5 with the CSO and on different tracks on the Lyle Lovett album mentioned above, to say nothing of more electronic music like the Schnauss/Peters album, or Mickey Hart's Planet Drum. Just another example of the need to system and room match.
Next up was the Linn Klout. One of the classic "oldie but goodie" amps. The Klout, compared to the Exposure, didn't run out of breath, but it also didn't sound as engaging. Relative to the other amps, it sounded a bit dark. I don't want to overstate that, because it was not dull or shut-in sounding, just not as informative with cymbals, triangles, violins, etc. (I should note that the Klout would almost certainly benefit from recapping, as it dates to the mid 90s by serial number). Overall, a reasonably good sounding amp (and solidly built!), but it was not as engaging and interesting (to me) as the 28.
The next amps to arrive were the PS Audio M700s. A rather different approach to amplification, and much newer than any of the other amps, the M700s provide 350 watts per channel and use Class D amplification. Frankly, I don't care what "class" an amplifier is - I've heard amps from different classes sound great and terrible, so I think it's more down to execution than class. Overall, the M700s sounded terrific. They are lively, balanced, and do a good job of letting the music speak for itself. They also recreated the biggest soundstage of the four amps here, and did a solid job of placing performers on the stage (where the music and recording allowed for it). The M700s also initially sounded like they had the best bass extension and grip, although the longer I listened the less I thought that - like the Exposure, but to a much lesser degree, it sounded like the M700s didn't have quite as much sustain as the Klout or the Belles. Out of the four, the M700s provided the best "hifi" and were quite good musically.
Finally, I wound up acquiring a Belles 350A Reference. It's something of a classic American "high end" amp, like the Levinsons, Krells, and Rowlands of yore. Weighing ~65 lbs (or 30 kg), it weighs as much as one of my speakers. Rated at 250 watts per channel into 8 ohms, and 500 into 4 ohms, it's the biggest/heaviest amp I tried. Musically, it does a good job of separating musical and instrumental lines - it's probably the best of the four. It also has excellent extension and grip in the bass, which helps to separate different low-pitch instruments - the Belles makes it easy to hear different drums vs upright bass vs electric bass, etc. It also does a good job of separating instruments in space (again, when the music and recording allow). And the Belles does the best of the four in providing solidity - the character doesn't change as volume increases or decreases, and it does not sound like it ever runs out of breath (or 'puff' - another wonderful example of British English). Another way to put it would be to say that the Belles has the most 'authority' of the four.
I've since sold the Klout and returned the M700s, alternating between the Exposure 28 and the Belles. Yes, it's a pain in the neck switching between them.
After all of that, what I would LOVE to find is an amp that combines the liveliness, drive, and inner balance of the Exposure with the authority of the Belles. I may try a pair of Exposure 3010S2 monos, as Tony Brady has said they'll sound much better than the 28. I also briefly tried a Krell KST100, but was underwhelmed and sent it back. I am open to other suggestions - bring them on!
With the C19 pandemic ongoing, I had the chance to play with my hifi - both in terms of listening to music and experimenting with some components. I had started with an eye toward upgrading my speakers - I had used a pair of Linn Helix 2s with the ku-stone stands for something like 15 years, and always enjoyed them. They communicate music well, even if I can list out their faults. And they were always good enough to let me hear differences from one component to the next. In their place I now have Monitor Audio Gold GX300s, which were a rather spectacular leap forward (as you'd hope and expect!).
The GX300s did, however, show that my power amp, an Exposure XXVIII (28), might be a bit underpowered (more on that later). So I started thinking about power amplifiers that might work well. Through a set of circumstances I won't bore anyone with, I wound up with a Linn Klout, a pair of PS Audio M700s (PS Audio is based in the town next to mine), and a Belles 350A Reference (with the "soft start" circuit).
Sources were an Exposure 3010S2 CD player, a Naim nDAC (later with a Teddy Pardo TeddyXPS), a Linn Karik III (mainly used as a transport), and, briefly, a Mark Levinson 31.5/30.6 transport/DAC that a good friend has and let me borrow. Preamp was mainly an Exposure 3010S2, I also used a conrad-johnson PF2-L, and, also briefly, an Audio Research LS17SE.
The room is difficult, as it is effectively my entire townhouse - there is no effective separation from the main level to the upstairs, and a thin door is all that separates the main level from the stairs leading to the finished basement. That was part of what led me to look for speakers that could better load the space - the Helix 2s just couldn't do it.
Anyway, on to the amps.
I'll start with the Exposure, as I've owned it for a while now after having the Exposure stack see off (what a fantastic expression - I wish more Americans could understand British English!) a Naim stack. The 28 provides 70 watts per channel into 8 ohms; no 4 ohm rating is provided. It is a dual mono design, with a (fairly large) transformer for each channel, which accounts for much of its 24 lb (11 kg) weight.
Musically, the Exposure is very good. It's easy to follow most instrumental and musical lines, whether on something like Lyle Lovett's cover of "Bears" on "Step Inside This House," or REM's "I Believe" on "Life's Rich Pageant," or Ulrich Schnauss and Mark Peters' "There's Always Tomorrow." The 28 has a balance and inner drive that allows the music to drive itself forward without sounding bright or forward itself. It also does a (surprisingly to me) good job of image placement and depth (particularly obvious with the ARC LS17SE). There is one fly in the ointment, however - the 28 does not seem to have enough power reserve to drive the GX300s to their full potential. It almost literally sounds like it is running out of breath (or 'puff') on notes that have a sustain or long decay. It's particularly noticeable on music like Reiner's Beethoven 5 with the CSO and on different tracks on the Lyle Lovett album mentioned above, to say nothing of more electronic music like the Schnauss/Peters album, or Mickey Hart's Planet Drum. Just another example of the need to system and room match.
Next up was the Linn Klout. One of the classic "oldie but goodie" amps. The Klout, compared to the Exposure, didn't run out of breath, but it also didn't sound as engaging. Relative to the other amps, it sounded a bit dark. I don't want to overstate that, because it was not dull or shut-in sounding, just not as informative with cymbals, triangles, violins, etc. (I should note that the Klout would almost certainly benefit from recapping, as it dates to the mid 90s by serial number). Overall, a reasonably good sounding amp (and solidly built!), but it was not as engaging and interesting (to me) as the 28.
The next amps to arrive were the PS Audio M700s. A rather different approach to amplification, and much newer than any of the other amps, the M700s provide 350 watts per channel and use Class D amplification. Frankly, I don't care what "class" an amplifier is - I've heard amps from different classes sound great and terrible, so I think it's more down to execution than class. Overall, the M700s sounded terrific. They are lively, balanced, and do a good job of letting the music speak for itself. They also recreated the biggest soundstage of the four amps here, and did a solid job of placing performers on the stage (where the music and recording allowed for it). The M700s also initially sounded like they had the best bass extension and grip, although the longer I listened the less I thought that - like the Exposure, but to a much lesser degree, it sounded like the M700s didn't have quite as much sustain as the Klout or the Belles. Out of the four, the M700s provided the best "hifi" and were quite good musically.
Finally, I wound up acquiring a Belles 350A Reference. It's something of a classic American "high end" amp, like the Levinsons, Krells, and Rowlands of yore. Weighing ~65 lbs (or 30 kg), it weighs as much as one of my speakers. Rated at 250 watts per channel into 8 ohms, and 500 into 4 ohms, it's the biggest/heaviest amp I tried. Musically, it does a good job of separating musical and instrumental lines - it's probably the best of the four. It also has excellent extension and grip in the bass, which helps to separate different low-pitch instruments - the Belles makes it easy to hear different drums vs upright bass vs electric bass, etc. It also does a good job of separating instruments in space (again, when the music and recording allow). And the Belles does the best of the four in providing solidity - the character doesn't change as volume increases or decreases, and it does not sound like it ever runs out of breath (or 'puff' - another wonderful example of British English). Another way to put it would be to say that the Belles has the most 'authority' of the four.
I've since sold the Klout and returned the M700s, alternating between the Exposure 28 and the Belles. Yes, it's a pain in the neck switching between them.
After all of that, what I would LOVE to find is an amp that combines the liveliness, drive, and inner balance of the Exposure with the authority of the Belles. I may try a pair of Exposure 3010S2 monos, as Tony Brady has said they'll sound much better than the 28. I also briefly tried a Krell KST100, but was underwhelmed and sent it back. I am open to other suggestions - bring them on!
