SET amp owners thread

[bonzo75]

You mention above a 2A3 PSE or 300B, both are around 8-10W.
IMO, not enough to drive the O/96 to level I want to listen at (and I used to own an O/96).

I mentioned specifically the NAF2a3 multiple times as the best heard on these and have put the link up and which amps it bettered.

Airtight 300b has great drive, much better than AN300b of the same wattage. This doesn’t mean it is better, except where the drive is required.

I haven’t heard my favoured GM70 with yet but am sure it will work. That is SE no feedback 14w

 

[iaxel]

I mentioned specifically the NAF2a3 multiple times for these and have put the link up

The link you put up is for their "Legend" integrated, which is a KT66 PP amplifier: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-legend-mkii/
While their 2A3 integrated is, probably, a PSE based on 2A3: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-e-stereo-performance-2a3-mkii/

The 2A3 will not be enough. The KT66 may be, but I'm less of a KT66 fan.

 

[bonzo75]

The link you put up is for their "Legend" integrated, which is a KT66 PP amplifier: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-legend-mkii/
While their 2A3 integrated is, probably, a PSE based on 2A3: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-e-stereo-performance-2a3-mkii/

The 2A3 will not be enough. The KT66 may be, but I'm less of a KT66 fan.

Oh sorry cut paste error. But the link correctly says 12w. Not 8

 

[morricab]

Who said 8? It's not 18 as claimed either, more like 12 or so I think. They are not SE either.

Also, you are confusing loudness, drive, gain, even in this post. No one is allowing me to play Beethoven 9th late night not even in my own home.

New Audio Frontiers Legend MKII Integrated Amplifier | Audio Emotion

The integrated amplifier Legend MKII arises as a reply to New Audio Frontiers desire of bringing to a new life a legend that of

www.audioemotion.co.uk

The NAF amp you linked is a PP amp, not a SET…

 

[morricab]

The link you put up is for their "Legend" integrated, which is a KT66 PP amplifier: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-legend-mkii/
While their 2A3 integrated is, probably, a PSE based on 2A3: https://www.newaudiofrontiers.com/portfolio/amplificatore-integrato-e-stereo-performance-2a3-mkii/

The 2A3 will not be enough. The KT66 may be, but I'm less of a KT66 fan.

No, the 2A3 amp and their 300b amp are also PP. Only their 845 and 211 amps are SET.

 

[morricab]

I mentioned specifically the NAF2a3 multiple times as the best heard on these and have put the link up and which amps it bettered.

Airtight 300b has great drive, much better than AN300b of the same wattage. This doesn’t mean it is better, except where the drive is required.

I haven’t heard my favoured GM70 with yet but am sure it will work. That is SE no feedback 14w

Depends which ANUK amp. The higher 300b models have interstage transformer coupling I think, which makes a huge difference in drive for a given rated power.

 

[morricab]

That just refers to loudness and is not a problem at all because they are easy to drive iirc 10 ohm impedance. Tannoy are 100db and much more difficult to get their driver to move. A 95 db multi driver speaker that will have impedance swings to 2 ohm or so and requiring grip for the woofer will also be much harder.

What about Sigma MAAT (one with white midrange)? Original Wilson X1 was true 95dB and I think impedance never went below 5 or 6 ohms. A SET with 15 or more watts should work fine with it. I know 30 watt SET from KR Audio did.

 

[morricab]

Paul Miller's O96 review says a couple of things I have been saying on this forum for years:

1. You need a lot of space around it from the walls.

Paul: "The O/96s are less inclined to favour a corner or near-wall siting, delivering their most open and transparent sound when positioned clear of boundaries and toed-in towards the listening position. "

2. They are very transparent to recordings

Paul: "Transparency is a term all too readily bandied about in reviews, but the O/96s truly exhibit this quality. The instant you hear these boxes in action then 99% of other 'boxes' sound, well, like they need a kick up the pants to get them going. The O/96s simply do not reveal themselves as a 'sound source' – their 'touch' is so light that the faintest of notes and sounds seem to slip unhindered into the room. "

Given the British mentality towards speaker design, I can imagine the O96 was lively but I doubt Paul ‘measurements’ Miller has a lot of experience with other easy to drive speakers that don’t need a ‘kick up th pants’ to sound alive.

 

[bonzo75]

Given the British mentality towards speaker design, I can imagine the O96 was lively but I doubt Paul ‘measurements’ Miller has a lot of experience with other easy to drive speakers that don’t need a ‘kick up th pants’ to sound alive.

Not so much modern, unless you go all the way back to vintage, vitavox, Tannoy, etc. British speakers for the last few decades are Naim, Linn, B&W

 

[perart1]

Not so much modern, unless you go all the way back to vintage, vitavox, Tannoy, etc. British speakers for the last few decades are Naim, Linn, B&W

Errr What about Living Voice....British and modern....Gosh who would have thought it

 

[Atmasphere]

This went from a thread celebrating SET amplification to some warped lecture series meant to disabuse us of our own pleasures.

If you read my posts then you know my response to that:

I'm not saying don't use an SET. I am saying if you're going to use one, its best to know what it can do and what it can't. Its pretty obvious from this thread most people here know what they can do. Its also apparent that the limitations are less well-known. So if you know that bass is a problem, simply don't let the amp get exposed to it. That is a simple matter; one capacitor of the right value in series with the input, plus a subwoofer or separately powered woofer is how you do it.

As I've pointed out before, the most successful SET systems I've heard and the people I know who are most ardent about them all did their homework and don't allow bass into the amps.

Instead of try to shoot the messenger, how about give it a shot and report back? If I'm wrong that would come out soon enough...

You could look at this another way: if you know there's a speed limit and you break it all the time you should expect a speeding ticket. Or you could simply drive the posted limits. If you are educated about the limitations of your audio equipment you're far more likely to get the most out of it.

 

[perart1]

If you read my posts then you know my response to that:

I'm not saying don't use an SET. I am saying if you're going to use one, its best to know what it can do and what it can't. Its pretty obvious from this thread most people here know what they can do. Its also apparent that the limitations are less well-known. So if you know that bass is a problem, simply don't let the amp get exposed to it. That is a simple matter; one capacitor of the right value in series with the input, plus a subwoofer or separately powered woofer is how you do it.

As I've pointed out before, the most successful SET systems I've heard and the people I know who are most ardent about them all did their homework and don't allow bass into the amps.

Instead of try to shoot the messenger, how about give it a shot and report back? If I'm wrong that would come out soon enough...

You could look at this another way: if you know there's a speed limit and you break it all the time you should expect a speeding ticket. Or you could simply drive the posted limits. If you are educated about the limitations of your audio equipment you're far more likely to get the most out of it.

There are moments on WTBF when it is like the parable of the blind men and the elephant. This seems to be one of them

 

[Argonaut]

If you read my posts then you know my response to that:

I'm not saying don't use an SET. I am saying if you're going to use one, its best to know what it can do and what it can't. Its pretty obvious from this thread most people here know what they can do. Its also apparent that the limitations are less well-known. So if you know that bass is a problem, simply don't let the amp get exposed to it. That is a simple matter; one capacitor of the right value in series with the input, plus a subwoofer or separately powered woofer is how you do it.

As I've pointed out before, the most successful SET systems I've heard and the people I know who are most ardent about them all did their homework and don't allow bass into the amps.

Instead of try to shoot the messenger, how about give it a shot and report back? If I'm wrong that would come out soon enough...

You could look at this another way: if you know there's a speed limit and you break it all the time you should expect a speeding ticket. Or you could simply drive the posted limits. If you are educated about the limitations of your audio equipment you're far more likely to get the most out of it.

Why would a Trafomatic Audio Elysium or Wavac 833 or Lamm ML 2.2 , etcetera , cause such pearl clutching vapours over a reasonable load , reasonable impedance curve , transducer woofer ?

 

[Atmasphere]

Why would a Trafomatic Audio Elysium or Wavac 833 or Lamm ML 2.2 , etcetera , cause such pearl clutching vapours over a reasonable load , reasonable impedance curve , transducer woofer ?

I did answer this question before. It has nothing to do with the speaker for starters. If you had a non-inductive 8 or 16 Ohm resistor the amp would have the same problem at low frequencies.

The output transformers in these amps have a gap in their cores to prevent DC saturation of the core. This is because the tube draws current through the transformer; when you draw DC current through a wire that is wound around a bunch of steel, that is a recipe for creating a DC magnetic field. The DC magnetic field thus generated can saturate the core of the transformer so it can't do any more work (such as pass an audio signal). In case you don't get the saturation bit, what that means is when the core is saturated, it can't make a magnetic response to the audio signal properly. It will make distortion instead. To prevent this, the output transformer has the aforementioned gap in the core, which breaks most of the DC magnetic circuit. This vastly reduces distortion in the transformer.

But that comes at a price. The inductance of the transformer (which is the MO for the way the transformer works, as I've mentioned in prior posts), goes down with frequency. What that means is the easy load the tube had at 1KHz is no longer an easy load at 50Hz. For one thing the load impedance has gone down quite a lot (even though the speaker load is benign). The other issue is the load line, which is a mathematical concept used to define the tube's operating point, is no longer a line. Its become elliptical so distortion skyrockets in addition to the low impedance causing the tube to run hotter.

Power goes down because more of the power made by the tube is dissipated in the tube rather than in the speaker on account of the load impedance the tube sees has gone south. This is why I say no SET can make full power at 20Hz.

That's no way to treat an expensive power tube!!

But the solution is simple. Just don't let the amp see bass frequencies. The result is a lot like a breath of fresh air in the same way that getting bass off of a Quad ESL allows that speaker, like an SET, to be immediately more coherent and transparent. Its an inexpensive way to get the system to sound better in a way that is immediately noticeable.

 

[adamaley]

There are moments on WTBF when it is like the parable of the blind men and the elephant. This seems to be one of them

I'll be sure to send in my tuition check

 

[PeterA]

Power goes down because more of the power made by the tube is dissipated in the tube rather than in the speaker on account of the load impedance the tube sees has gone south. This is why I say no SET can make full power at 20Hz.

Ralph, when you say no SET can make full power of 20 Hz, does it matter if you’re only getting 35 Hz in room and you only need 10% of the power of the SET to get you to the volume you need?

In other words, are you describing a condition that is not often met under normal use?

 

[acg]

This is why I say no SET can make full power at 20Hz.

This is more a marketing issue than a SET issue. The amplifier should be rated by the maximum power it can make in all the audio frequency range, so if it is limited to less power at 20Hz then that lower rating should be the power rating of the unit, not what it makes at say 1kHz.

There are three simple answers to the "problem" of fullrange SET amps and bass frequencies: don't use full power, use only a fraction of it say one-third; or better yet use multi-channel SET amps; or best of all do both. A set amp can be designed and transformers wound to make 20Hz at full power. The lowest channel in my multi-channel SET amps makes full power at 6Hz (a whopping 9w) and is specifically designed to push a 0.9ohm speaker load (not a typo - eight paralleled 10" woofers). That amplifiers frequency response according to the measurements is good past 20kHz but I certainly would never use it that high: the transformer is intended for 10Hz-500Hz and is massive with large gauge wire used in its construction, so not suited to high frequencies. My SET channels cover 35Hz-40kHz. Below that A/B amps manage 10Hz-20Hz. Sure, if my lowest SET channel was 900w rather than 9w I would probably not need the infra-bass channels, but there is plenty of texture in the sound at 40Hz and my SET's sound so much better there than the A/B amps.

So it can be done, but it is easier if you are not buying amplification or loudspeakers off-the-shelf.

 

[morricab]

I did answer this question before. It has nothing to do with the speaker for starters. If you had a non-inductive 8 or 16 Ohm resistor the amp would have the same problem at low frequencies.

The output transformers in these amps have a gap in their cores to prevent DC saturation of the core. This is because the tube draws current through the transformer; when you draw DC current through a wire that is wound around a bunch of steel, that is a recipe for creating a DC magnetic field. The DC magnetic field thus generated can saturate the core of the transformer so it can't do any more work (such as pass an audio signal). In case you don't get the saturation bit, what that means is when the core is saturated, it can't make a magnetic response to the audio signal properly. It will make distortion instead. To prevent this, the output transformer has the aforementioned gap in the core, which breaks most of the DC magnetic circuit. This vastly reduces distortion in the transformer.

But that comes at a price. The inductance of the transformer (which is the MO for the way the transformer works, as I've mentioned in prior posts), goes down with frequency. What that means is the easy load the tube had at 1KHz is no longer an easy load at 50Hz. For one thing the load impedance has gone down quite a lot (even though the speaker load is benign). The other issue is the load line, which is a mathematical concept used to define the tube's operating point, is no longer a line. Its become elliptical so distortion skyrockets in addition to the low impedance causing the tube to run hotter.

Power goes down because more of the power made by the tube is dissipated in the tube rather than in the speaker on account of the load impedance the tube sees has gone south. This is why I say no SET can make full power at 20Hz.

That's no way to treat an expensive power tube!!

But the solution is simple. Just don't let the amp see bass frequencies. The result is a lot like a breath of fresh air in the same way that getting bass off of a Quad ESL allows that speaker, like an SET, to be immediately more coherent and transparent. Its an inexpensive way to get the system to sound better in a way that is immediately noticeable.

This amp can do 65 watts SET with 80% max power from 8Hz - 110Khz.

Concero 65 Reference Product Page – Aries Cerat

As can this one:

Exsequor Reference Product Page – Aries Cerat

You are limited by what you think you know about design but not what is actually been done out there.

 

[morricab]

Ralph, when you say no SET can make full power of 20 Hz, does it matter if you’re only getting 35 Hz in room and you only need 10% of the power of the SET to get you to the volume you need?

In other words, are you describing a condition that is not often met under normal use?

There are SETs that can do it but they are big with huge output transformers. They can be wound in such a way to get the extended response. Just because it isn't easy or cheap to do doesn't mean it's not possible. When Ralph says "impossible" he might mean either for him or that it is merely difficult or impractical.

 

[acg]

In other words, are you describing a condition that is not often met under normal use?

He is, up to a point (it depends). But I've heard enough sub-par SET installations to realise that if some people have paid for 5 watts that they fully intend to use every last one of them.