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JLasher22443

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So my local shop got in a set of 15A's and I have a listening session scheduled for this Saturday at noon. They are setting them up so I can listen to my current ARC REF 160S Amp and be able to compare it against the Dan D'Agostino Progression S350 and the Momentum S250 as well as the Boulder 1160 and the 2160 Amps. The Momentum and 2160 are out of my price range by far but it will be cool to hear the 15A's on a much higher end amp. Plus I'll be able to come back and let you know if a Boulder 2160 pushing a crap ton of watts is definitely a great improvement or not.

Boulder 2160 Specs.

1642087462831.png
 

ttocs

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So my local shop got in a set of 15A's and I have a listening session scheduled for this Saturday at noon. They are setting them up so I can listen to my current ARC REF 160S Amp and be able to compare it against the Dan D'Agostino Progression S350 and the Momentum S250 as well as the Boulder 1160 and the 2160 Amps. The Momentum and 2160 are out of my price range by far but it will be cool to hear the 15A's on a much higher end amp. Plus I'll be able to come back and let you know if a Boulder 2160 pushing a crap ton of watts is definitely a great improvement or not.

Boulder 2160 Specs.

View attachment 22256
Now THIS is a audition I'd love to be a party to!!

Please post your detailed review. Love to hear your thoughts!
 

JLasher22443

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Now THIS is a audition I'd love to be a party to!!

Please post your detailed review. Love to hear your thoughts!
Will do. Also they have the Audio Research I50 and some McIntosh Tube amps I can ask for them to drag in and test if anyone is interested? I'm thinking I'll be there for about 4 hours and the guys there are awesome and love to tinker like me. LOL So if Robert or MisterB want me to test out that ARC I50 with the 15A's I can. Its in the $5k range.

Here they are on display in the front showcase area. They are taking them back into the large demo room for Saturday's demo where all of the Wilson, Boulder, Dan D, and dCS Gear is. I believe they are going to be using the following gear for me; the SME 15, Boulder 1108, dCS Bartok, ARC REF 6SE, and demoing AMPS for comparison. I'm excited like a kid going to Disney. LMAO!!

image0-2.jpeg
 

MisterB

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Today my dealer loaned me an MC152 to A/B with my MA352 integrated so that I could get a feel for the difference between the direct coupled amp in the 352 and a Mac amp with autoformers. It is a pretty noticeable difference, with the 152 being very close in sound to what I am striving for. The 152 is more detailed than the 352, with a wider, taller soundstage, smoother mids, and better overall separation of individual instruments. At this point I’m thinking the MA352 is not going to be a keeper.
So after several more days of switching back and forth between the MA352 integrated and the MC152, I am definitely going to replace the MA352 with separates. The question is what. I know I want to stick with McIntosh. It will most likely be the C2700 tube pre, but not sure which amp. At this point I think I'm leaning toward SS with either the MC312 or MC462. I haven't completely ruled out tubes, but since this is a part of a dual duty 2-channel music and multi-channel TV/HT setup, I'm concerned about tube life considering I run my system on average about 8 -10 hours a day between music and TV. Seems like I'd be replacing tubes about every year and a half. Maybe tolerable with the MC275. Not so much with the 1502.

My dealer has a pair of Impressions and the C2700/MC462 pair. I'm going to see if they can set up the combo for me to audition this weekend and go from there. Unfortunately they do not have any McIntosh tube amps on site for me to audition, so a little leery of going tubes without having an opportunity to first hear them paired with my ML's.
 

MisterB

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Will do. Also they have the Audio Research I50 and some McIntosh Tube amps I can ask for them to drag in and test if anyone is interested? I'm thinking I'll be there for about 4 hours and the guys there are awesome and love to tinker like me. LOL So if Robert or MisterB want me to test out that ARC I50 with the 15A's I can. Its in the $5k range.
Wow, would love to be there for that demo. I certainly don't want to make any extra work for anyone, but if you wrap up early with the stuff you're demoing and everybody's bored with nothing better to do, I would love to hear your feedback on the 15A's with either the McIntosh MC275 or 1502, if they have either of those on hand.
 

ttocs

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Will do. Also they have the Audio Research I50 and some McIntosh Tube amps I can ask for them to drag in and test if anyone is interested? I'm thinking I'll be there for about 4 hours and the guys there are awesome and love to tinker like me. LOL So if Robert or MisterB want me to test out that ARC I50 with the 15A's I can. Its in the $5k range.

Here they are on display in the front showcase area. They are taking them back into the large demo room for Saturday's demo where all of the Wilson, Boulder, Dan D, and dCS Gear is. I believe they are going to be using the following gear for me; the SME 15, Boulder 1108, dCS Bartok, ARC REF 6SE, and demoing AMPS for comparison. I'm excited like a kid going to Disney. LMAO!!

View attachment 22257
You may want to watch is this video. It's a comparison of D'Agostino and McIntosh amps, but also the preamps near the end. The entire video is interesting - to me, boring to some, but some good opinions about this equipment. Pay particular attention at 31:13 when one of the reviewers mixed and matched the opposing brands with interesting results.
 

Leporello

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I found that out when moving from 800 wpc SS mono blocks to a 75 wpc stereo amplifier! Now, if I can just find that person who can explain tube watts vs solid state watts to a non-engineer who thought a watt was a watt was a watt. :unsure: This really has my curiosity up and now I'm planning to play around with a pair of even lower powered full Class A (8 wpc) amps...
Without detailed experimentation it's speculation, but my guess would be that a tube amp doesn't clip hard, so can be driven harder without objectionable distortion. And don't forget that watts may be watts, but they're logarithmic as far as the human ear goes. So all other things being equal, a 200 watt amp will sound 3dB louder than a 100 watt amp--just noticeable. For 75 versus 800 it's just a little over 10dB louder--clearly much louder sounding but not what the wattage figures would suggest. And if the 75 watt can be driven all the way to, say, 100 before it starts to sound truly nasty, it's less.
 

Leporello

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When I entered the tube amp arena, I considered that tubes would be expendable items needing replacement.

My KT88 tubes have around 1500 hours on them, so lots of life in them. I went with KT120 tubes just because I like them better. There's probably around 2000 hours on the KT120 now. I'm guessing they'll go 4000-5000 hours, maybe more?

The KT120 set of eight was about $320, which is still the current price. Let's say a set of tubes will go about three years, that's about $100 per year.
My CLS II's did not do well at all with the Latino M-125's. They just sounded rolled off to me. I assume it's because of the sub-2 ohm impedance at the top end. Of course I never tried them (or even heard of) the Zero Autoformers. When I finished the first M-125 build I plugged it into one of my old Ascents, and it sounded fine. But the hybrids are a less nasty load. How does the 13A sound driven directly with the Latinos?

As beautiful as I've heard tube-driven ESL's (most notably Quads) something always bothered me about stepping down the tube volts to 8 or 4 ohms, then stepping them back up for the ESL's Not really an elegant solution. And with the "Zero" you're adding another--an autotransformer isn't really a transformer, but call it half a transformer. People have built direct coupled tube ESL drivers (notably Acoustat, for a while) but as passionate as we are about our hobby, I don't think it's worth risking electrocution.

I think it would be really cool to build a tube amp that steps the voltage up slightly, or maybe even 1:1. It could be more flux efficient than either a step up or step down transformer. But building high quality, wide bandwidth, high power transformers is not in my skill set. I once sent an inquiry to Plitron about a custom tranny, but never heard back, and now they've been acquired by a company with no interest in audio.

If I ever do locate such a tranny, I'd seriously consider shelling out the bucks to re-panel the CLS II's, and use the old ones for experiments.

p.s. Latino isn't pushing the tubes particularly hard. People on the forums report long tube life.
 

JLasher22443

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You may want to watch is this video. It's a comparison of D'Agostino and McIntosh amps, but also the preamps near the end. The entire video is interesting - to me, boring to some, but some good opinions about this equipment. Pay particular attention at 31:13 when one of the reviewers mixed and matched the opposing brands with interesting results.
Yah I subscribe to their channel and watched that video. Another business channel I like is Suncoast Audio on YouTube.

They are both great channels and both do great reviews or demos on pretty great gear. In fact Audio Excellence's video on the comparison between the BHK Preamp and the McIntosh C70 made me go with the BHK for money saving reasons since they compared them as sounding almost identical. However when I found JS Audio which is my now go to store; they proved to me how much the BHK was ruining the soundstage in my system. And I watch all of their videos and other reviewers as well; but I never go off of videos or someone else's reviews now without testing it in my room first. And if the vendor or dealer I am working with is not willing to let me demo I never use them again even if it is the brand I want. And that dude Andrew has the MSB Reference DAC or maybe even the Select now which makes me jealous. LOL

One thing I found about the DanD when I was comparing them to Mac, ARC, and Boulder was it was brighter and fatiguing to me. The test I use to see if a piece of equipment is fatiguing for me is I use Radiohead's Kid A Album with track "The National Anthem" and play it for about 30 seconds to say a minute at about 80db and pause the track. If my ears are ringing the device is fatiguing for me. Now I didn't get that with the ARC and Boulder and only a tad with the Mac. And in the end the cheaper Audio Research won out for me over Boulder 1161. But when testing all of these brands the Boulder just crushed them for stereo amplifiers.
 

ttocs

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My CLS II's did not do well at all with the Latino M-125's. They just sounded rolled off to me. I assume it's because of the sub-2 ohm impedance at the top end. Of course I never tried them (or even heard of) the Zero Autoformers. When I finished the first M-125 build I plugged it into one of my old Ascents, and it sounded fine. But the hybrids are a less nasty load. How does the 13A sound driven directly with the Latinos?

As beautiful as I've heard tube-driven ESL's (most notably Quads) something always bothered me about stepping down the tube volts to 8 or 4 ohms, then stepping them back up for the ESL's Not really an elegant solution. And with the "Zero" you're adding another--an autotransformer isn't really a transformer, but call it half a transformer. People have built direct coupled tube ESL drivers (notably Acoustat, for a while) but as passionate as we are about our hobby, I don't think it's worth risking electrocution.

I think it would be really cool to build a tube amp that steps the voltage up slightly, or maybe even 1:1. It could be more flux efficient than either a step up or step down transformer. But building high quality, wide bandwidth, high power transformers is not in my skill set. I once sent an inquiry to Plitron about a custom tranny, but never heard back, and now they've been acquired by a company with no interest in audio.

If I ever do locate such a tranny, I'd seriously consider shelling out the bucks to re-panel the CLS II's, and use the old ones for experiments.

p.s. Latino isn't pushing the tubes particularly hard. People on the forums report long tube life.
With M-125 connected directly to the 13A the upper frequencies are rolled off a bit early to me. The sound is great, but the top freqs are down too far, about 4dB @ 10kHz, which is too audible for me.

Here are a couple comparisons, the same traces shown two ways, straight up to show the difference in output, and aligned to show the top freqs better.
211007-01-ZERO-M125.jpg


211007-01-ZERO-M125-ALIGNED.jpg


The top image shows the decrease in overall output, about -4dB, and slight increase in top frequency output. In the bottom image the traces are aligned @ 300hz. The sound is quite nice now that the sparkle is not veiled like it was, and the amps run cooler.

Here's the interesting part. I connected my multichannel Krell (which only has two channels operating) with the ZEROs and the sound is smoother than ever, even though the top frequencies are more prevalent, and, like the M-125 amps, the Krell operates so much cooler than it ever has. Because of this, I'm liking the Krell more these days and haven't used the tubes for a while to see what happens when I do go back.

The differences with these amps are that the M-125 amps are unbalanced mono, and the Krell is balanced stereo. Strangely, with the ZEROs the Krell soundstage is somehow closer to what the M-125 amps produce.

My system has been down for almost a month while work is going on in the house, so I'll need to reconnect with my system once it's reconnected.
 

Lightloopy

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My CLS II's did not do well at all with the Latino M-125's. They just sounded rolled off to me. I assume it's because of the sub-2 ohm impedance at the top end. Of course I never tried them (or even heard of) the Zero Autoformers. When I finished the first M-125 build I plugged it into one of my old Ascents, and it sounded fine. But the hybrids are a less nasty load. How does the 13A sound driven directly with the Latinos?

As beautiful as I've heard tube-driven ESL's (most notably Quads) something always bothered me about stepping down the tube volts to 8 or 4 ohms, then stepping them back up for the ESL's Not really an elegant solution. And with the "Zero" you're adding another--an autotransformer isn't really a transformer, but call it half a transformer. People have built direct coupled tube ESL drivers (notably Acoustat, for a while) but as passionate as we are about our hobby, I don't think it's worth risking electrocution.

I think it would be really cool to build a tube amp that steps the voltage up slightly, or maybe even 1:1. It could be more flux efficient than either a step up or step down transformer. But building high quality, wide bandwidth, high power transformers is not in my skill set. I once sent an inquiry to Plitron about a custom tranny, but never heard back, and now they've been acquired by a company with no interest in audio.

If I ever do locate such a tranny, I'd seriously consider shelling out the bucks to re-panel the CLS II's, and use the old ones for experiments.

p.s. Latino isn't pushing the tubes particularly hard. People on the forums report long tube life.
I repaneled a pair of CLS II last year and you are welcome to the old panels. PM if interested
 

BDH55

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Without detailed experimentation it's speculation, but my guess would be that a tube amp doesn't clip hard, so can be driven harder without objectionable distortion. And don't forget that watts may be watts, but they're logarithmic as far as the human ear goes. So all other things being equal, a 200 watt amp will sound 3dB louder than a 100 watt amp--just noticeable. For 75 versus 800 it's just a little over 10dB louder--clearly much louder sounding but not what the wattage figures would suggest. And if the 75 watt can be driven all the way to, say, 100 before it starts to sound truly nasty, it's less.
Good point and it's not the first time I've overlooked that!
 

Robert D

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Will do. Also they have the Audio Research I50 and some McIntosh Tube amps I can ask for them to drag in and test if anyone is interested? I'm thinking I'll be there for about 4 hours and the guys there are awesome and love to tinker like me. LOL So if Robert or MisterB want me to test out that ARC I50 with the 15A's I can. Its in the $5k range.

Here they are on display in the front showcase area. They are taking them back into the large demo room for Saturday's demo where all of the Wilson, Boulder, Dan D, and dCS Gear is. I believe they are going to be using the following gear for me; the SME 15, Boulder 1108, dCS Bartok, ARC REF 6SE, and demoing AMPS for comparison. I'm excited like a kid going to Disney. LMAO!!

View attachment 22257
Id like to know what the ARC 150 amp sounds like on there and compare to the other amps. If it is $5000 or so, thats obtainable for me.

My only worry is that with the Prodigy speakers I have, the woofers arent powered with an internal amp like the 15A is.
 

Len44

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Enough! Enough of this infernal pussy-footin' around. All I want is for you smarter / more knowledgeable folks to tell us what the Three Best Amps are among Tubes and Solid State, and, within Solid-State, Class A, Class AB, Class D (or whatever other classes have recently arrived on the scene).:)
 

ttocs

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We do live in a great time, with of an abundance of fantastic amplifier choices. When we can talk about the nuances of sound from one preamp/amp/speaker combination to another, let alone how great the sound is before discussing the minutia, yes, it's just wonderful with all the choices there are to discover.

Lots to choose from. For solid state there's a brand JLasher22443 mentioned that I was unaware of, Boulder Amplifiers, their flagship mono amp has lots of power and seems like top quality, and it should be for a couple hundred thousand $$$,$$$.
Dan D'Agostino's amps from half a mil down to his budget amps for $38k a pair.
Starke Sound A2.640 which I just read about recently.
Then there's the usual recommendations we hear about around here, like Saunders, McIntosh, Krell, Mark Levinson, etc.

Tube amps are more reasonable by comparison, but some are still as much as a Porsche.
Audio Research, Conrad Johnson, VTL, Linear Tube Audio.

Nobody can really tell us which is best, we all must discover that for ourselves. We can get recommendations based on experience or reading reviews, but until it's connected to our systems in our homes it will remain an unknown as to whether we will like it or not. Every brand I know of that I would consider has a trial period, so that's the safety net for being able to try something for a while. Sure, you might have to pay to ship it back if you don't like it, but you get to hear it in your home.
 

Robert D

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We do live in a great time, with of an abundance of fantastic amplifier choices. When we can talk about the nuances of sound from one preamp/amp/speaker combination to another, let alone how great the sound is before discussing the minutia, yes, it's just wonderful with all the choices there are to discover.

Lots to choose from. For solid state there's a brand JLasher22443 mentioned that I was unaware of, Boulder Amplifiers, their flagship mono amp has lots of power and seems like top quality, and it should be for a couple hundred thousand $$$,$$$.
Dan D'Agostino's amps from half a mil down to his budget amps for $38k a pair.
Starke Sound A2.640 which I just read about recently.
Then there's the usual recommendations we hear about around here, like Saunders, McIntosh, Krell, Mark Levinson, etc.

Tube amps are more reasonable by comparison, but some are still as much as a Porsche.
Audio Research, Conrad Johnson, VTL, Linear Tube Audio.

Nobody can really tell us which is best, we all must discover that for ourselves. We can get recommendations based on experience or reading reviews, but until it's connected to our systems in our homes it will remain an unknown as to whether we will like it or not. Every brand I know of that I would consider has a trial period, so that's the safety net for being able to try something for a while. Sure, you might have to pay to ship it back if you don't like it, but you get to hear it in your home.
I wonder, are those units that are shipped back/returned by customers then sold as used or reconditioned? Could be a good way for another customer to save some $$$.
 

ttocs

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I wonder, are those units that are shipped back/returned by customers then sold as used or reconditioned? Could be a good way for another customer to save some $$$.
Yes, I'm pretty sure they are sold as "Reconditioned". One of the amps I purchased happened to already have been a reconditioned offering. I paid for return shipping, about $50 each. Now shipping would probably be another 70% more.
 
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