SET amp owners thread

Exlibris

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Oct 7, 2015
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I used to own the A-6000. An octet of Emission Labs 300b XLS lasted 9 years, then on to the next owner and still going. They were biased to the lower tick mark and could account for this preservation, but I preferred the sound characteristics. As I grew into different speakers I used only a small fraction of the power needed. If you have the opportunity to listen to any amp designer that implements an interstage (voltage gain) transformer which negates one power tube stage, you may be surprised by this design approach. No phase issues with parallel circuits improve transparency, timbre and delicacy. Zero feedback, ear to the speaker, hearing only silence. This implementation allowed new discoveries in well familiar recordings.

Those who love the 300b need to audition its predecessor, the PX25.
I wonder if the PX25 can be used in the A-6000. It seems to be a drop-in replacement for 300Bs in other units.
 

morricab

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Apr 25, 2014
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I used to own the A-6000. An octet of Emission Labs 300b XLS lasted 9 years, then on to the next owner and still going. They were biased to the lower tick mark and could account for this preservation, but I preferred the sound characteristics. As I grew into different speakers I used only a small fraction of the power needed. If you have the opportunity to listen to any amp designer that implements an interstage (voltage gain) transformer which negates one power tube stage, you may be surprised by this design approach. No phase issues with parallel circuits improve transparency, timbre and delicacy. Zero feedback, ear to the speaker, hearing only silence. This implementation allowed new discoveries in well familiar recordings.

Those who love the 300b need to audition its predecessor, the PX25.

The Aries Cerat Genus is such an amp. It has only two tubes total per channel (E280F in triode and 813 in triode) with an interstage transformer in between. Has a great purity to the sound but can handle complex music as well.
 

Kingrex

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Feb 3, 2019
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I'm starting to understand what the SET gave me, and took away. I am noticing my midrange more. In particular the horn is starting to stand out. mid octave piano, horns, vocal are all great. The lower bass is sounding a little poofey. It doesn't have the guts and umph. Bass drums don't hit. You just hear the fill from the notes. I also miss some of the shimmer from the rivets in a crash cymbal. Maybe that is a horn thing, but I remember them standing out more with my PP KT77 amps. I can see why many people like PP amps. For the bass especially. And maybe the balance. But hey, I was reading the VAC Statement thread and people were saying VAC moved away from linear and more towards a "Sound". Before I get a bunch of, should have bought the Ares Cerat and all would be better. I am playing with $5K or so amps. My $4500 PP KT77 amps had better bass control and I believe top end extension. They do not have the purity in the midrange the Audion has. They are not as realistic with giving the true sound of an instrument in those midrange octaves. I like that part of the SET design. Do they do it all. No, but what amp does.
 

ketcham

Industry Expert
Feb 29, 2016
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Yes. You are correct about the A6000 having the interstage transformer. I was trying to make a broad statement for everyone who is reading this thread.

The PX25 can not be placed into the A6000. The new m2500 and a311m have circuit designs specific for each tube.
 
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Atmasphere

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May 4, 2010
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I'm starting to understand what the SET gave me, and took away. I am noticing my midrange more. In particular the horn is starting to stand out. mid octave piano, horns, vocal are all great. The lower bass is sounding a little poofey. It doesn't have the guts and umph. Bass drums don't hit. You just hear the fill from the notes. I also miss some of the shimmer from the rivets in a crash cymbal. Maybe that is a horn thing, but I remember them standing out more with my PP KT77 amps. I can see why many people like PP amps. For the bass especially. And maybe the balance. But hey, I was reading the VAC Statement thread and people were saying VAC moved away from linear and more towards a "Sound". Before I get a bunch of, should have bought the Ares Cerat and all would be better. I am playing with $5K or so amps. My $4500 PP KT77 amps had better bass control and I believe top end extension. They do not have the purity in the midrange the Audion has. They are not as realistic with giving the true sound of an instrument in those midrange octaves. I like that part of the SET design. Do they do it all. No, but what amp does.

There may be more to it than that. SETs usually do not have feedback and your PP amps do. This allows the latter to deal with impedance variation in your loudspeakers with greater ease. IOW what you are hearing may be due to the match between the amp and speakers, rather than just the amp.

BTW you can get that 'purity' in push-pull amps, but to do it they can't combine push-pull and single-ended operation, as you often tend to get a bit of the 5th harmonic, which makes the amp less smooth. OTOH a full differential amplifier won't have that, it will be mostly the 3rd harmonic (although far less than an SET). The ear treats the 2nd and 3rd the same way.
 

bonzo75

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Feb 26, 2014
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I'm starting to understand what the SET gave me, and took away. I am noticing my midrange more. In particular the horn is starting to stand out. mid octave piano, horns, vocal are all great. The lower bass is sounding a little poofey. It doesn't have the guts and umph. Bass drums don't hit. You just hear the fill from the notes. I also miss some of the shimmer from the rivets in a crash cymbal. Maybe that is a horn thing, but I remember them standing out more with my PP KT77 amps. I can see why many people like PP amps. For the bass especially. And maybe the balance. But hey, I was reading the VAC Statement thread and people were saying VAC moved away from linear and more towards a "Sound". Before I get a bunch of, should have bought the Ares Cerat and all would be better. I am playing with $5K or so amps. My $4500 PP KT77 amps had better bass control and I believe top end extension. They do not have the purity in the midrange the Audion has. They are not as realistic with giving the true sound of an instrument in those midrange octaves. I like that part of the SET design. Do they do it all. No, but what amp does.

If you match SETs to the right speaker they do the bass too
 

thomask

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Dec 9, 2018
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I'm starting to understand what the SET gave me, and took away. I am noticing my midrange more. In particular the horn is starting to stand out. mid octave piano, horns, vocal are all great. The lower bass is sounding a little poofey. It doesn't have the guts and umph. Bass drums don't hit. You just hear the fill from the notes. I also miss some of the shimmer from the rivets in a crash cymbal. Maybe that is a horn thing, but I remember them standing out more with my PP KT77 amps. I can see why many people like PP amps. For the bass especially. And maybe the balance. But hey, I was reading the VAC Statement thread and people were saying VAC moved away from linear and more towards a "Sound". Before I get a bunch of, should have bought the Ares Cerat and all would be better. I am playing with $5K or so amps. My $4500 PP KT77 amps had better bass control and I believe top end extension. They do not have the purity in the midrange the Audion has. They are not as realistic with giving the true sound of an instrument in those midrange octaves. I like that part of the SET design. Do they do it all. No, but what amp does.
I found that LIne Magnetic 508 48 Watts SET has better bass control than Rogue Cronus Magnum II 100 Watts PP with KT120.

It depends on SET amp to choose.
 

Lagonda

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Feb 3, 2014
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I found that LIne Magnetic 508 48 Watts SET has better bass control than Rogue Cronus Magnum II 100 Watts PP with KT120.

It depends on SET amp to choose.
Those LM amps are on my short list for my future 2 system above my garage !
 

the sound of Tao

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Jul 18, 2014
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I found that LIne Magnetic 508 48 Watts SET has better bass control than Rogue Cronus Magnum II 100 Watts PP with KT120.

It depends on SET amp to choose.
+1 The LM805ia has rightness from down low and all the way up. It’s very much an ideal match for Krex’s speakers as well and has great control over the dual 15 inch woofers. One of the best amp speaker marriages I’ve heard.
 

Empirical Audio

Industry Expert
Oct 12, 2017
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Great Pacific Northwest
www.empiricalaudio.com
I'm starting to understand what the SET gave me, and took away. I am noticing my midrange more. In particular the horn is starting to stand out. mid octave piano, horns, vocal are all great. The lower bass is sounding a little poofey. It doesn't have the guts and umph. Bass drums don't hit. You just hear the fill from the notes. I also miss some of the shimmer from the rivets in a crash cymbal. Maybe that is a horn thing, but I remember them standing out more with my PP KT77 amps. I can see why many people like PP amps. For the bass especially. And maybe the balance. But hey, I was reading the VAC Statement thread and people were saying VAC moved away from linear and more towards a "Sound". Before I get a bunch of, should have bought the Ares Cerat and all would be better. I am playing with $5K or so amps. My $4500 PP KT77 amps had better bass control and I believe top end extension. They do not have the purity in the midrange the Audion has. They are not as realistic with giving the true sound of an instrument in those midrange octaves. I like that part of the SET design. Do they do it all. No, but what amp does.

Sounds like you have the wrong amps or bad iron, or maybe an unfortunate amp-speaker matching. Possibly the wrong tubes as well, or a tube type that limits performance no matter which one you get.

I have a superb high-end, killer bass and major slam factor from my SET amps based on the 805A/T output tube. 35W/channel. No deficiencies. My speakers are 93 dB efficient Vapor Nimbus. These have 15 inch woofers. No horns. Compared to my 1000W modded JC-1 monoblocks driving the same speakers, the SET monoblocks beat the SS in every category, highs, bass and slam.
 
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the sound of Tao

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Sounds like you have the wrong amps or bad iron, or maybe an unfortunate amp-speaker matching. Possibly the wrong tubes as well, or a tube type that limits performance no matter which one you get.

I have a superb high-end, killer bass and major slam factor from my SET amps based on the 805A/T output tube. 35W/channel. No deficiencies. My speakers are 93 dB efficient Vapor Nimbus. These have 15 inch woofers. No horns. Compared to my 1000W modded JC-1 monoblocks driving the same speakers, the SET monoblocks beat the SS in every category, highs, bass and slam.
Big iron = bassballs
if a amp doesn’t hurt when you try to pick it up it’s not an amp... it’s uhhhmmm interior design :rolleyes:

The LM’s have proper hernia inducing transformers but are then so lovingly careful and right on the ears. I’ve got two of the big LM SET amps now (one for the horns and one for the Harbeth 40.2s) and they’re not going anywhere... and not just cause I can’t lift them anymore :)
 

Lagonda

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Big iron = bassballs
if a amp doesn’t hurt when you try to pick it up it’s not an amp... it’s uhhhmmm interior design :rolleyes:

The LM’s have proper hernia inducing transformers but are then so lovingly careful and right on the ears. I’ve got two of the big LM SET amps now (one for the horns and one for the Harbeth 40.2s) and they’re not going anywhere... and not just cause I can’t lift them anymore :)
What about those wonderful class D amps they are mostly lightweight , never mind i’m kidding :rolleyes:
 

the sound of Tao

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Jul 18, 2014
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the sound of Tao

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Jul 18, 2014
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What about those wonderful class D amps they are mostly lightweight , never mind i’m kidding :rolleyes:
Hahaa and yes, indeed so light of everything... perhaps because they are just so excellently measurable and yet somehow still so arid and dry :oops: perhaps there’s just no moisture left there to help weigh them down at all.

NB That measured light weightness can also be very handy when you want to remove them suddenly from your system after a brief listen. Just jkin folks :eek:
2D124B9A-00A4-4F65-BB39-1CBE8FFA9AF3.jpeg
 
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morricab

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Apr 25, 2014
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Sounds like you have the wrong amps or bad iron, or maybe an unfortunate amp-speaker matching. Possibly the wrong tubes as well, or a tube type that limits performance no matter which one you get.

I have a superb high-end, killer bass and major slam factor from my SET amps based on the 805A/T output tube. 35W/channel. No deficiencies. My speakers are 93 dB efficient Vapor Nimbus. These have 15 inch woofers. No horns. Compared to my 1000W modded JC-1 monoblocks driving the same speakers, the SET monoblocks beat the SS in every category, highs, bass and slam.
Which amp is that?
 

morricab

Well-Known Member
Apr 25, 2014
9,491
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Big iron = bassballs
if a amp doesn’t hurt when you try to pick it up it’s not an amp... it’s uhhhmmm interior design :rolleyes:

The LM’s have proper hernia inducing transformers but are then so lovingly careful and right on the ears. I’ve got two of the big LM SET amps now (one for the horns and one for the Harbeth 40.2s) and they’re not going anywhere... and not just cause I can’t lift them anymore :)
You should try a back breaking Aries Cerat amp...the baby model weighs over 70kg!
 

morricab

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Apr 25, 2014
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There may be more to it than that. SETs usually do not have feedback and your PP amps do. This allows the latter to deal with impedance variation in your loudspeakers with greater ease. IOW what you are hearing may be due to the match between the amp and speakers, rather than just the amp.

BTW you can get that 'purity' in push-pull amps, but to do it they can't combine push-pull and single-ended operation, as you often tend to get a bit of the 5th harmonic, which makes the amp less smooth. OTOH a full differential amplifier won't have that, it will be mostly the 3rd harmonic (although far less than an SET). The ear treats the 2nd and 3rd the same way.
So, the phase splitter is evil...
 

Empirical Audio

Industry Expert
Oct 12, 2017
1,169
207
150
Great Pacific Northwest
www.empiricalaudio.com
Big iron = bassballs
if a amp doesn’t hurt when you try to pick it up it’s not an amp... it’s uhhhmmm interior design :rolleyes:

The LM’s have proper hernia inducing transformers but are then so lovingly careful and right on the ears. I’ve got two of the big LM SET amps now (one for the horns and one for the Harbeth 40.2s) and they’re not going anywhere... and not just cause I can’t lift them anymore :)

By Iron, I mean the output transformers, not the power supply transformers.
 
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