|
|
Post by leonski on Dec 16, 2019 13:12:27 GMT -5
Big issue will be into huge capacitive loads at such low impedance, too. Some amps simply do NOT like such loading and may go ballistic.
|
|
|
|
Post by donh50 on Dec 16, 2019 16:10:59 GMT -5
Big issue will be into huge capacitive loads at such low impedance, too. Some amps simply do NOT like such loading and may go ballistic. Agreed but it's not as bad as a pure capacitor. The panels themselves are capacitive but ESLs are coupled through a transformer (inductor) which tends to cancel the capacitance... The impedance gets very low but the phase angle is not usually too bad, and power levels are low, so it is mainly just an assurance that the amp won't oscillate with a low-impedance load even at low power levels. |
|
KeithL
Administrator 
Posts: 10,261
|
Post by KeithL on Dec 16, 2019 17:10:55 GMT -5
Different electrostatics offer rather different impedance curves. Therefore, the only way to know how a certain amp will work with a specific model is to try it. (And, if you do, we'd love to have you post the results.)
However, compared to most of our other models, the HC-1 has a more powerful power supply (relative to its output power). And it has performed very well when we've tested it into lower-than-normal loads... So we're quite confident it will work well with pretty much any speaker.
Big issue will be into huge capacitive loads at such low impedance, too. Some amps simply do NOT like such loading and may go ballistic. Agreed but it's not as bad as a pure capacitor. The panels themselves are capacitive but ESLs are coupled through a transformer (inductor) which tends to cancel the capacitance... The impedance gets very low but the phase angle is not usually too bad, and power levels are low, so it is mainly just an assurance that the amp won't oscillate with a low-impedance load even at low power levels. |
|
|
|
Post by leonski on Dec 16, 2019 17:12:40 GMT -5
I think the response (electrical) of 'Stats is sort of design dependent. But tends to follow certain patterns. Here is review of the Soundlab speaker Measurements. Stereophile does a lot of this and can be relied upon. Check out the HF response with HUGE phase angle and VERY low impedance. This is an amplifier wrecking combination with the one exception being that very little power is required at those frequencies. I've seen stuff like this with other 'stats.....All Stereophile data, since nobody else actually bothers. And is IS a PIA, being expensive for just the bench equipment not to mention hiring a person with the expertise needed to do a proper job of it. www.stereophile.com/content/sound-lab-1-electrostatic-loudspeaker-measurementsMy VERY first experience with 'stats was at a friends house where I'd gone to audition a pair of Magnepans MG-1, which I DID purchase. They had some 'Stats and a DIY amp which when hooked up and energized emitted a very loud SuperSonic CHIRP as sit failed altogether. Classic runaway. |
|
|
|
Post by odedia on Dec 22, 2019 13:16:30 GMT -5
I'll just suppose it's a valid comparison. Might be speaker dependent, to some extent. Is one amp to be preferred or does each do something good or better than the other sos it ends up pretty much a 'wash'? I would say the XPA-1L wins every time - warmth, clarity, you name it. It may have something to do with my Goldenear Tritons, they are very easy to drive (they have their own built-in active subs), so the amp probably stays at A-mode most of the time. |
|
|
|
Post by novisnick on Dec 22, 2019 13:28:18 GMT -5
I'll just suppose it's a valid comparison. Might be speaker dependent, to some extent. Is one amp to be preferred or does each do something good or better than the other sos it ends up pretty much a 'wash'? I would say the XPA-1L wins every time - warmth, clarity, you name it. It may have something to do with my Goldenear Tritons, they are very easy to drive (they have their own built-in active subs), so the amp probably stays at A-mode most of the time. I tot, really love what the XPA-1L’s do for the sound ! Definitely a standard to be beat! Good luck world! 😎 |
|
|
|
Post by leonski on Dec 22, 2019 22:10:15 GMT -5
Funny. I've NEVER heard anyone actually admit their speakers were 'very easy to drive'. The Usual beef is that they are 'difficult' or 'hard' to drive. Mostly from people who don't know what constitutes such a condition.
Even the VERY sensitive Klipsch Forte III which I'm going up to LA to look at (after the coming rains!) has a couple spots in the impedance / phase data which tells me to bring a good, 4 ohm rated amp. The sensitivity of those
Klipsch is Rated at 99db but measured somewhat less by Stereophile. Even in a medium sized room, maybe 12.5x20x8 (2000 cubic feet) you'd think maybe 20 or 30 good watts per speaker? No, you'll probably need more....
I think my 125x2 Parasound might be good, but you never know. I WISH the ACA would work, at maybe 8 a side, single ended class 'A' Pass design.
|
|
|
|
Post by songmeesay on Jan 4, 2020 14:30:41 GMT -5
So any real world use opinions on these from users? Thinking about taking advantage of the special pricing to add to my xpa-9 but unsure how much advantage there'd be aside from piece of mind channel separation.
|
|
|
|
Post by ceptorman on Jan 4, 2020 16:58:29 GMT -5
So any real world use opinions on these from users? Thinking about taking advantage of the special pricing to add to my xpa-9 but unsure how much advantage there'd be aside from piece of mind channel separation. I'm considering these also, but not sure how much, if any I would gain from my current XPA-2 G2. I'm have an upgraditus bug for mono blocks! |
|
|
|
Post by RichGuy on Jan 4, 2020 17:19:56 GMT -5
I'm considering these also, but not sure how much, if any I would gain from my current XPA-2 G2. I'm have an upgraditus bug for mono blocks! If these were Gen 2 based instead of Gen 3 based I'd be very interested. An XPA-2 Gen 2 split into separate mono blocks might be too hard to resist  |
|
|
|
Post by ceptorman on Jan 4, 2020 19:05:41 GMT -5
I'm considering these also, but not sure how much, if any I would gain from my current XPA-2 G2. I'm have an upgraditus bug for mono blocks! If these were Gen 2 based instead of Gen 3 based I'd be very interested. An XPA-2 Gen 2 split into separate mono blocks might be too hard to resist That was my original route, but the XPA-2 G2 is 8ohm rated in mono block mode, my speakers are 4ohm. My speakers sound fantastic with the XPA-2. The HC-1s are in my price range, the DR-1s are probably a long shot for me. |
|
|
|
Post by RichGuy on Jan 4, 2020 20:12:03 GMT -5
If these were Gen 2 based instead of Gen 3 based I'd be very interested. An XPA-2 Gen 2 split into separate mono blocks might be too hard to resist That was my original route, but the XPA-2 G2 is 8ohm rated in mono block mode, my speakers are 4ohm. My speakers sound fantastic with the XPA-2. The HC-1s are in my price range, the DR-1s are probably a long shot for me. No I did not mean two XPA-2's bridged, I meant two designed for mono block half XPA-2 Gen2's. Performance like an XPA-2 Gen2 but in two (mono block) halves, so basically an XPA-2 Gen 2 but in XPA HC-1 form separated independent halves. Something which does not exist but would be awesome. It would probably be hard to do in as small a form factor as the XPA HC-1 without losing something in the process though. |
|
ttocs
Global Moderator
I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
Posts: 8,156
|
Post by ttocs on Sept 12, 2021 11:46:41 GMT -5
Different electrostatics offer rather different impedance curves. Therefore, the only way to know how a certain amp will work with a specific model is to try it. (And, if you do, we'd love to have you post the results.) However, compared to most of our other models, the HC-1 has a more powerful power supply (relative to its output power). And it has performed very well when we've tested it into lower-than-normal loads... So we're quite confident it will work well with pretty much any speaker. I can state for the record that the HC-1 amps work very well with Martin Logan Expression 13A speakers! Very impressive. I'm running my 13A speakers totally stock for this, no subwoofers used. So far I'm comparing with a Krell S-1500 amp. This amp has 5 channels, but I've disconnected 3 of the amp blades internally which increases the power to the remaining two channels. In 5 channel configuration the amp is rated at 150/300W @ 8Ω/4Ω, but as a 3 channel or less it's rated at 175/350W, and in either config will power any speaker load. The 13A speaker impedance has a minimum impedance of 0.7Ω. The 13A speaker has dual self-powered woofers with an XO @ 300Hz, so the external amps only power the electrostatic panel. This is a more difficult comparison than I was expecting. I was expecting the amps to fall down in some way distinct way, but so far, they have not. The amps are still too fresh to come to definite conclusions yet, this will take some time. I want to first compare solid state to solid state, which unfortunately is not a straight up comparison because it's comparing a stereo amp to mono amps. So while some aspects will take more time to compare, there is one obvious comparison that the HC-1 amps win vs the Krell in stereo mode: Soundstage. The soundstage is much better with the HC-1 monos, and is surprisingly wide. This will be interesting to see how they fair against the M-125 tube mono amps. I initially made some super short speaker cables so each HC-1 could be placed directly next to each speaker. The sound seemed thin, lacking in bass, but I forced myself to listen for a few hours thinking the amps need some time to run, but then I increased the bass on each 13A using a Bass Control and a Mid Bass Switch. I've never had to do this before, usually the Bass Control is at -2dB when the 13A is running without subwoofers attached (I use a pair of subs for each 13A as extra woofers). The sound still wasn't right. I switched back to the Krell and the sweetness returned along with gobs of bass. Even though the 13A has it's own amps for the woofers, it will take-on the bias of the external amp connected, so some amps will make the speakers have more or less bass. So today I connected the HC-1's to the same longer speaker cables the Krell must use and the sound is much better. Much better. Really, much better! The bass is about the same as what it is with the Krell, so obviously the length of the speaker wire is important here. Where does that leave me then? Well, the soundstage is better with the HC-1, but the Krell still has some sort of "sweetness" to the sound. There's a bit more dynamics with the Krell. The HC-1 is performing extremely well against an amp which cost 5 times more ten years ago than a pair of HC-1's cost today. To answer the question can the HC-1 handle low impedance loads, YES. Does the HC-1 sound great with low impedance loads, YES. Does the HC-1 sound great compared to an amp with a toroidal transformer, yes. Lower case because the dynamics are not quite there, but it's close, which is pretty amazing. Heat? What heat? There's no heat. They don't even get warm, well, maybe barely. And I've been listening at about 92dB for several albums worth today. Conclusion? The HC-1 provides a better soundstage. The Krell has a sweeter sound and more dynamics. More time is needed however. There are other factors to consider which I'll share later. Now, how will the HC-1 sound compared to my tube amps? To be continued . . . . |
|
|
|
Post by JKCashin on Sept 12, 2021 13:10:21 GMT -5
I have the same problem at work. Hence why I would now type it as (1) 300 watt module. and (1) 3kw power supply, if I were discussing this amp. To avoid the same problem my convention is 1 x 300 watt.  It's about time that they have a replacement for the XPA-1L's. Cheers Gary The XPA-1L is fully differential though |
|
|
|
Post by leonski on Sept 13, 2021 0:24:27 GMT -5
Different electrostatics offer rather different impedance curves. Therefore, the only way to know how a certain amp will work with a specific model is to try it. (And, if you do, we'd love to have you post the results.) However, compared to most of our other models, the HC-1 has a more powerful power supply (relative to its output power). And it has performed very well when we've tested it into lower-than-normal loads... So we're quite confident it will work well with pretty much any speaker. I can state for the record that the HC-1 amps work very well with Martin Logan Expression 13A speakers! Very impressive. I'm running my 13A speakers totally stock for this, no subwoofers used. So far I'm comparing with a Krell S-1500 amp. This amp has 5 channels, but I've disconnected 3 of the amp blades internally which increases the power to the remaining two channels. In 5 channel configuration the amp is rated at 150/300W @ 8Ω/4Ω, but as a 3 channel or less it's rated at 175/350W, and in either config will power any speaker load. The 13A speaker impedance has a minimum impedance of 0.7Ω. The 13A speaker has dual self-powered woofers with an XO @ 300Hz, so the external amps only power the electrostatic panel. This is a more difficult comparison than I was expecting. I was expecting the amps to fall down in some way distinct way, but so far, they have not. The amps are still too fresh to come to definite conclusions yet, this will take some time. I want to first compare solid state to solid state, which unfortunately is not a straight up comparison because it's comparing a stereo amp to mono amps. So while some aspects will take more time to compare, there is one obvious comparison that the HC-1 amps win vs the Krell in stereo mode: Soundstage. The soundstage is much better with the HC-1 monos, and is surprisingly wide. This will be interesting to see how they fair against the M-125 tube mono amps. I initially made some super short speaker cables so each HC-1 could be placed directly next to each speaker. The sound seemed thin, lacking in bass, but I forced myself to listen for a few hours thinking the amps need some time to run, but then I increased the bass on each 13A using a Bass Control and a Mid Bass Switch. I've never had to do this before, usually the Bass Control is at -2dB when the 13A is running without subwoofers attached (I use a pair of subs for each 13A as extra woofers). The sound still wasn't right. I switched back to the Krell and the sweetness returned along with gobs of bass. Even though the 13A has it's own amps for the woofers, it will take-on the bias of the external amp connected, so some amps will make the speakers have more or less bass. So today I connected the HC-1's to the same longer speaker cables the Krell must use and the sound is much better. Much better. Really, much better! The bass is about the same as what it is with the Krell, so obviously the length of the speaker wire is important here. Where does that leave me then? Well, the soundstage is better with the HC-1, but the Krell still has some sort of "sweetness" to the sound. There's a bit more dynamics with the Krell. The HC-1 is performing extremely well against an amp which cost 5 times more ten years ago than a pair of HC-1's cost today. To answer the question can the HC-1 handle low impedance loads, YES. Does the HC-1 sound great with low impedance loads, YES. Does the HC-1 sound great compared to an amp with a toroidal transformer, yes. Lower case because the dynamics are not quite there, but it's close, which is pretty amazing. Heat? What heat? There's no heat. They don't even get warm, well, maybe barely. And I've been listening at about 92dB for several albums worth today. Conclusion? The HC-1 provides a better soundstage. The Krell has a sweeter sound and more dynamics. More time is needed however. There are other factors to consider which I'll share later. Now, how will the HC-1 sound compared to my tube amps? To be continued . . . . I'm curious about the longer speaker wire being better. The Only thing which springs to mind is the slightly higher resistance. For a TEST? Wire a 1ohm 10 watt power resistor in series with one leg of the SHORT cable and see if that helps...It might be that the 'stat is right at the lower limit of what your amp finds acceptable. |
|
ttocs
Global Moderator
I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
Posts: 8,156
|
Post by ttocs on Sept 13, 2021 7:54:06 GMT -5
I'm curious about the longer speaker wire being better. The Only thing which springs to mind is the slightly higher resistance. For a TEST? Wire a 1ohm 10 watt power resistor in series with one leg of the SHORT cable and see if that helps...It might be that the 'stat is right at the lower limit of what your amp finds acceptable. I agree that the better result is most likely related to the higher resistance in the longer wires making the system (amp-wire-speaker) a better balance of properties. What perplexes me a little is how the bass is affected being that the external amp has no "direct" effect below the speaker's internal XO of 300Hz. Martin Logan has confirmed that the self-powered woofers can take on the character of the external amp, ie, tube amps are known for "more bass" so that will still be the result, however, the lack of bass with the short speaker wires was not a small difference and the upper ranges were harsh. So could this be because the amps were beyond their capability and just couldn't muster the strength to pass along the bass signal as efficiently? |
|
|
|
Post by leonski on Sept 13, 2021 13:18:24 GMT -5
'Stats CAN be a difficult load in the upper octave or so. Impedance can drop and capacitance rise.......Potentially a bad combo for the partnering amp.
I don't know but SUSPECT the amp is nearing its limits. Not power, but rather stability into a certain load.
Try the resistor 'trick' and see if that helps.....
As for why? HMMMM.
The switcher is fairly high efficiency. But working into a conventional output....meaning A/B where you have a maximum efficiency of maybe 50% or so.......But doesn't sound like you are
stressing the amp, which coupled with the weight of the amp means you just may not feel the rise in temp....
|
|
ttocs
Global Moderator
I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
Posts: 8,156
|
Post by ttocs on Sept 21, 2021 17:55:25 GMT -5
I called today to get RMA #'s to return the HC-1 amps. When I got home I was still wrestling with my decision to return them when I discovered I hadn't exhausted the variables in connection types, namely, XLR vs RCA, Balanced vs Unbalanced.
So I reconnected the amps using XLR to RCA cables and sure enough, things are not so easy anymore. I'll need a few more days . . . .
|
|
|
|
Post by omuracada on Sept 21, 2021 19:45:23 GMT -5
I called today to get RMA #'s to return the HC-1 amps. When I got home I was still wrestling with my decision to return them when I discovered I hadn't exhausted the variables in connection types, namely, XLR vs RCA, Balanced vs Unbalanced. So I reconnected the amps using XLR to RCA cables and sure enough, things are not so easy anymore. I'll need a few more days . . . . As you know I have been running the HC-1 amps and after about a month of running them everyday and then running DIRAC I am in absolute bliss. I ran two dirac filters, one as the L and R set to Large and one where every speaker is at small with a 80 crossover. Thus far I love the filter where the L and R are set to large the base kicks and with my external sub it blends them all exceptionally. I hear lots of detail and yes the soundstage is wide! I am sure at some point I will upgrade (when I run into cash) as I am sure there is better however for what I paid for these I am stoked. |
|
ttocs
Global Moderator
I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
Posts: 8,156
|
Post by ttocs on Sept 21, 2021 20:08:32 GMT -5
I called today to get RMA #'s to return the HC-1 amps. When I got home I was still wrestling with my decision to return them when I discovered I hadn't exhausted the variables in connection types, namely, XLR vs RCA, Balanced vs Unbalanced. So I reconnected the amps using XLR to RCA cables and sure enough, things are not so easy anymore. I'll need a few more days . . . . As you know I have been running the HC-1 amps and after about a month of running them everyday and then running DIRAC I am in absolute bliss. I ran two dirac filters, one as the L and R set to Large and one where every speaker is at small with a 80 crossover. Thus far I love the filter where the L and R are set to large the base kicks and with my external sub it blends them all exceptionally. I hear lots of detail and yes the soundstage is wide! I am sure at some point I will upgrade (when I run into cash) as I am sure there is better however for what I paid for these I am stoked. What is so interesting is that running the unbalanced input seems to be more to the liking of my ears. I agree whole heartedly about the great soundstage! No complaints there. Here's the issue. When I listen to with the HC-1's the sound is now extremely good. I've been listening for about 4 hours straight, and while I'm very happy to continue with the HC-1, it's when I switch to my tube amps - which are not perfect either - that I get a more comfortable feeling. The sound is "rounder" if that makes any sense. It's got just a little more finesse. Neither amp is perfect, nor flawed. They are different flavors of presentation, but the soundstage is pretty equal between the tubes and HC-1, which is saying both are great in that respect. What the tubes lack is the in-your-face sparkle that the HC-1 has above 10kHz. It's not huge, but it's a difference. Case in point. Art Of Noise: Moments In Love, which has very sharp sounding, high frequency bell sounds the highest pitched one is about 11kHz. These are very intense with the HC-1, and frankly a little annoying to me, but with the tube amps it's less loud by a few dB. These are the sparkle sounds I'd like for the tube amps to reproduce better and be more like the HC-1 or Krell when paired with the Martin Logan electrostatics. So the bottom line here is that I'm still getting a better experience overall with my tube amps for music, and if I didn't already have a great solid state amp to use for movies I'd keep the HC-1's, but the HC-1 isn't better than the Krell for movies - and isn't worse - so I guess they're going back, maybe, but I might keep one just for the Center channel, don't know yet. But I gotta say, the HC-1 is a great amp!! Other folks with different ears should try these things out. I'm comparing them to some really great amps and it's been difficult to make a choice, so that's saying a lot. Also, I've had friends bring over some really expensive amps to try with my speakers and they did not do well at all, really fell short of being capable of driving the speakers, so again, the HC-1 really shines. |
|
