I've heard the Frankensteins and the Sophia 845 mono amps on my systems. I cannot reconcile Germanboxer's assessment that Sophia 845 dynamics were inferior to the Frank's, 26w v 8w, with my own experience. I can agree that the Franks yield better "bass weight, bass texture" than the Sophia because, well, the Frankenstein 300B amps are simply higher resolution that the Sophia. There is a key point in my earlier post: equal clarity in a higher power amp yields different impressions than higher power of inferior clarity. The Franks clip gracefully and deliver more information than the Sophia 845. Trying to get the same clarity from the 845 by playing it louder won't do anything other than magnify its deficiencies. But I'll also say that it was easy for me to hear the Franks run out of headroom in an unbounded 2240 cu ft space that feeds into a similar virtual volume as GB. In fact, aside from the Frank having good design and execution, good ratio of power supply to power output, there is nothing else exceptional about it physically. it sounds great, but it doesn't sound any more powerful than a pair of Audion 8w 300B SETamps with physically smaller power supply, I heard at the same time.
But this really isn't about Sophia vs Coincident. You don't have to be listening at levels of aural violence to hear the dynamic limits of an amp on anyone's 101db/w/m speaker. Yes, you can get quite a lot of sound out of 6 watts from a single PX25 tube driving a 101db/w/m speaker but that's in terms of SPL, not the same as achieving dynamic clarity and shove.
There are many things that affect this. One is perceived speed, transparency and the burstiness of one amp vs another on the same speaker -- the apparent instantaneousness that a sound emerges from blackness or silence. Another is how precise or sloppy is this event? Is it slow to start; is the initial defining impulse dulled; does the aftermath linger beyond natural expectations?
Yesterday I listened to a pair of Melody M845 monoblocks and to my Audion Black Shadow 845 amps on Def4s at some length, again. The Melody amps cost less than half the price of the Audions, so there is no criticism in what I am about to say. There is a rated diffence of 2-3w between the two amps, with the Melody having the slightly lower measure of output. In all ways the Melody M845 is remarkable and energetic, and a few good tube upgrades put it in another sonic league from stock. It would be easy for a listener to claim more bass weight from the Melody, but the Audions sound more powerful because they are more resolving and maintain their resolution to higher SPLs. The Audions are "faster." Sounds burst from the Audions with more finesse and projections. Morgan heard this as well, a week ago. But then I put a WWII production 6sn7 input tube Melody and the Shuguang 845C. The 845C is a metal plate variant of the 845 and Shuguang's example has lower plate dissipation, so you give up about 20% of a normal 845's power in a given circuit. That took the M845 down to about 16-17w. However, with the better input tube and the metal plate 845s, the M845 got a lot closer to Audion resolution, blackness and clarity and it wasn't surprising to me that one result was the amp sounds more powerful than it does with the higher output potential of the 845A, though it in fact has less in 845C configuration.
The Sophia 845 monoblocks are built around a more complex circuit than Audion's and somewhat more than Melody's. In my view the new ones carry this too far and I recommend them much less. The older Sophia however is highly sensitive to tube choices and can sound anywhere from just fine to excellent, for their prevailing price on the used market. But it doesn't have the resolution of the very competent Frankenstein.
I don't have to listen at high SPLs to sense an amp's dynamic restrictions. And it's not "strain" we're sensing and what Morgan was referring to. It's the clarity of unbridled transients and the overall sense of ease. In digital filtering there is the phenomenon of pre-ringing, wherein the evidence of a distortion is apparent before the cause. It's like hearing the resonance of a bell before it's struck. It's not really happening that way, but we experience the distortion as though it is. Not directly, but by analogy the dynamic ease of an amp/speaker/room combination is a way of sensing an amp's available headroom before the music exceeds it. The same is true of playing an acoustic guitar. You can play softly and pretty well anticipate how that guitar is going to respond to a massive input. I don't have to thrash an acoustic guitar to reliably know how compressed it will become on hard pick attacks. I can feel and hear its limits before I test them.
The PX25 is also sonically the leanest of modest power triodes. It's very clear but shove isn't among it's assets. Morgan gets 101db from the1st watt. He gets 104db from the 2nd. He gets 107db from the 4th. And then on the way to 110db he instead hears clipping. Now he's not sitting 1m from his speakers and he has a room to load with all kinds of soft and hard stuff in it to swallow acoustic energy. So is it so hard see how he would experience one amp that clips around 109db differently from one that clips around 115db? And even then, the drive and shove of my 845 amps exceeds the "experiential power" of my *same-rated* PSET 300B monoblocks.
I don't listen to "Highway 61" any louder with Zu speakers at 101db/w/m efficiency today than I did with Large Advents in 1974, but I do it with 1/6th the power and more clarity. When I started with Zu on 8w of 300B power I could achieve the same SPL on "Desolation Row" but not the same dynamic ease. Once you hear it, there's no mistaking a dynamically inadequate amp for a sufficient one. There are beautiful sounding 2w 45 amps that produce lovely sound through Zu Definitions. And if that floats you, fine. The common knock on big glass triodes by the SET aficionados is that they lack the finesse of the flea bottles. Well, to a point. But it's a lot less true today than when clumsy big bottle SET amps returned to the market in the 90s. And more to the point, the admirable finesse of flea glass triodes has its own lack: shove and ease. Things start to change when you get into 106db, 114db horns but then you have to deal with their anomalies. 101db/w/m is great in the context of more than two generations of 82db speakers but Zu gave us 101db speakers along with the resolution, speed and clarity to show you why dynamic ease is just as valuable as tone, resolution and finesse.
Phil
But this really isn't about Sophia vs Coincident. You don't have to be listening at levels of aural violence to hear the dynamic limits of an amp on anyone's 101db/w/m speaker. Yes, you can get quite a lot of sound out of 6 watts from a single PX25 tube driving a 101db/w/m speaker but that's in terms of SPL, not the same as achieving dynamic clarity and shove.
There are many things that affect this. One is perceived speed, transparency and the burstiness of one amp vs another on the same speaker -- the apparent instantaneousness that a sound emerges from blackness or silence. Another is how precise or sloppy is this event? Is it slow to start; is the initial defining impulse dulled; does the aftermath linger beyond natural expectations?
Yesterday I listened to a pair of Melody M845 monoblocks and to my Audion Black Shadow 845 amps on Def4s at some length, again. The Melody amps cost less than half the price of the Audions, so there is no criticism in what I am about to say. There is a rated diffence of 2-3w between the two amps, with the Melody having the slightly lower measure of output. In all ways the Melody M845 is remarkable and energetic, and a few good tube upgrades put it in another sonic league from stock. It would be easy for a listener to claim more bass weight from the Melody, but the Audions sound more powerful because they are more resolving and maintain their resolution to higher SPLs. The Audions are "faster." Sounds burst from the Audions with more finesse and projections. Morgan heard this as well, a week ago. But then I put a WWII production 6sn7 input tube Melody and the Shuguang 845C. The 845C is a metal plate variant of the 845 and Shuguang's example has lower plate dissipation, so you give up about 20% of a normal 845's power in a given circuit. That took the M845 down to about 16-17w. However, with the better input tube and the metal plate 845s, the M845 got a lot closer to Audion resolution, blackness and clarity and it wasn't surprising to me that one result was the amp sounds more powerful than it does with the higher output potential of the 845A, though it in fact has less in 845C configuration.
The Sophia 845 monoblocks are built around a more complex circuit than Audion's and somewhat more than Melody's. In my view the new ones carry this too far and I recommend them much less. The older Sophia however is highly sensitive to tube choices and can sound anywhere from just fine to excellent, for their prevailing price on the used market. But it doesn't have the resolution of the very competent Frankenstein.
I don't have to listen at high SPLs to sense an amp's dynamic restrictions. And it's not "strain" we're sensing and what Morgan was referring to. It's the clarity of unbridled transients and the overall sense of ease. In digital filtering there is the phenomenon of pre-ringing, wherein the evidence of a distortion is apparent before the cause. It's like hearing the resonance of a bell before it's struck. It's not really happening that way, but we experience the distortion as though it is. Not directly, but by analogy the dynamic ease of an amp/speaker/room combination is a way of sensing an amp's available headroom before the music exceeds it. The same is true of playing an acoustic guitar. You can play softly and pretty well anticipate how that guitar is going to respond to a massive input. I don't have to thrash an acoustic guitar to reliably know how compressed it will become on hard pick attacks. I can feel and hear its limits before I test them.
The PX25 is also sonically the leanest of modest power triodes. It's very clear but shove isn't among it's assets. Morgan gets 101db from the1st watt. He gets 104db from the 2nd. He gets 107db from the 4th. And then on the way to 110db he instead hears clipping. Now he's not sitting 1m from his speakers and he has a room to load with all kinds of soft and hard stuff in it to swallow acoustic energy. So is it so hard see how he would experience one amp that clips around 109db differently from one that clips around 115db? And even then, the drive and shove of my 845 amps exceeds the "experiential power" of my *same-rated* PSET 300B monoblocks.
I don't listen to "Highway 61" any louder with Zu speakers at 101db/w/m efficiency today than I did with Large Advents in 1974, but I do it with 1/6th the power and more clarity. When I started with Zu on 8w of 300B power I could achieve the same SPL on "Desolation Row" but not the same dynamic ease. Once you hear it, there's no mistaking a dynamically inadequate amp for a sufficient one. There are beautiful sounding 2w 45 amps that produce lovely sound through Zu Definitions. And if that floats you, fine. The common knock on big glass triodes by the SET aficionados is that they lack the finesse of the flea bottles. Well, to a point. But it's a lot less true today than when clumsy big bottle SET amps returned to the market in the 90s. And more to the point, the admirable finesse of flea glass triodes has its own lack: shove and ease. Things start to change when you get into 106db, 114db horns but then you have to deal with their anomalies. 101db/w/m is great in the context of more than two generations of 82db speakers but Zu gave us 101db speakers along with the resolution, speed and clarity to show you why dynamic ease is just as valuable as tone, resolution and finesse.
Phil