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What is the Single Ended Triode thing?

Indeed, owning a valve amplifier is a little like owning a high performance sports car, in that the running costs are going to be higher, but then everything "high performance" comes at a price. Hopefully more Porsche and Mercedes than Ferrari or McLaren..
Thats a fair point if your buying gear, but the single ended / high efficiency lends itself to those with diy skills
The last single ended amp I've built used a mosfet output stage and one valve driving that, all for less than the cost of a decent output transformers, and in my case exceeded the performance of every set amp I've built or heard to date.
I run an audio meet in Doncaster every year, there's one next month where we compare all sorts of kit, mostly diyers but we have a few traders amongst us, Brook audio and nick gorham (longdog etc.) will be there as enthusiast's.
There will be a few set amps and high efficiency speakers, some of which where very low cost as hifi goes. Details are on the audio talk forum if anyone is interested.
 
Thats a fair point if your buying gear, but the single ended / high efficiency lends itself to those with diy skills
The last single ended amp I've built used a mosfet output stage and one valve driving that, all for less than the cost of a decent output transformers, and in my case exceeded the performance of every set amp I've built or heard to date.
I run an audio meet in Doncaster every year, there's one next month where we compare all sorts of kit, mostly diyers but we have a few traders amongst us, Brook audio and nick gorham (longdog etc.) will be there as enthusiast's.
There will be a few set amps and high efficiency speakers, some of which where very low cost as hifi goes. Details are on the audio talk forum if anyone is interested.

This audio meet sounds interesting - do you have to bring something along or can you just attend and learn a thing or two ?
 
This audio meet sounds interesting - do you have to bring something along or can you just attend and learn a thing or two ?
I've sent you a reply to your pm,but its entirely up to you if you bring anything. What you will do is learn alot about how different topologies and kit sounds, and chat among like minded people.
 
A very valid point and one of the reasons I'm reluctant to move back to valve poweamps, especially SET designs, the expense of the amps to start with, the expense of replacement Valves, seemingly good quality valves are an arm and a leg, combined with the necessary 98db Horn loudspeakers (according to GT, and I'm inclined to take his word) which generally tend to be expensive and large.

Coda II has been exposed to those, all be it for a limited period of time, but I am sure if you ask him he will tell you what he heard...

Indeed, owning a valve amplifier is a little like owning a high performance sports car, in that the running costs are going to be higher, but then everything "high performance" comes at a price. Hopefully more Porsche and Mercedes than Ferrari or McLaren... :)

@Darren L : To me a stable and high impedance is more important than a very high sensitivity, especially with SET designs.
The thing is, many, if not most, manufacturers are lying with their specs. Especially with the sensitivity and the nominal impedance.
There are so many claimed 8 ohm speakers which in reality have only 4 or 5 ohm in reality.

The Tannoy Legacy Arden that I use are rate at 93 dB and from memory it was an independent test I saw that showed they don’t dip below 6 ohm. As the Atlantic amp is built to order this was factored in to the build. Given my listening distance of 2 or 3 metres I have never been aware of distortion due to volume or indeed that my choice of music was being dictated by the limits of the system. (With the usual caveat that I tend not to listen to much in the ‘loud’ genres of music).
Yes, I did indeed have the pleasure of hearing the reference system assembled by @G T Audio and it really is a revelatory experience, unlike anything I have heard anywhere before. The speakers are very, very big and have a price tag to match. So on the one hand hearing Tron amplification in this context is revealing of what it is ultimately capable of, it is also necessary to hear it with more modest speakers such as Tannoy or the Klipsch that Graham carries.
It is in fact an ongoing conversation as to the place of a SET amp as a real-world, every day amplifier as opposed to a keep it for best, track day special, component.
One last point which I am also curious about: in designing for very efficient horns it is necessary/desirable to have the amp as electrically quiet as possible, because the horn will amplify any noise as well. With an amplifier intended for less efficient speakers this aspect may still be desirable but the point of ‘good enough’ is arrived at sooner. Should this also be taken as part of the SET package? ie. that an amp that isn’t sufficiently quiet into a high efficiency speaker isn’t a good match in the first place?
 
an amp that isn’t sufficiently quiet into a high efficiency speaker isn’t a good match in the first place?

There is not a direct link between noise and quality when you listen, but distortion tests will show it does as the hum will be measured as distortion.
But a 'little' hum does not stop a revealing amplifier from sounding like a revealing amp !
Some of my amps are dead quiet, but a few have a just little hum, it doesn't bother to be honest
I went through a horn phase about 15 years ago, I ended up hearing horn colouration after a while,
My speakers are still 100db each without horns
 
One last point which I am also curious about: in designing for very efficient horns it is necessary/desirable to have the amp as electrically quiet as possible, because the horn will amplify any noise as well. With an amplifier intended for less efficient speakers this aspect may still be desirable but the point of ‘good enough’ is arrived at sooner. Should this also be taken as part of the SET package? ie. that an amp that isn’t sufficiently quiet into a high efficiency speaker isn’t a good match in the first place?
I have gone from 86dB Quad 2805s to 92dB Tannoys. And I now run my Icon Audio MB90 IIs from the 4 ohm tap. Partly to increase the damping, but also to reduce the hum, which is clearly audible with the Tannoys on the 8 ohm tap. It's still there on the 4 ohm tap, but only really noticeable if you get close. However past experience has shown that even that sort of level affects the perception of dynamics, and if you listen quietly late at night as I regularly do, it has an even bigger effect. In a similar vein, when I first went from an active pre to a TVC, the background silence was striking. YMMV of course.
 
There is absolutely no excuse for any valve amplifier to hum or produce noise. Especially if it is a push-pull design. If it does, then it is a poor design, or poor implementation, simple as that. Reference was made earlier to Audionote UK in that they make a wide range of SE amplifiers, but they are designed to drive their own loudspeakers (which is fine), not high efficiency speakers like horns, as in 98dB efficiency and above. Their amplifiers have more gain and in reality produce noise when used with horns above 98dB. It's the same for Kondo designs too. As I have said for the last 25 years. You have to design for high efficiency which really requires different design criteria.

Actually, in a high resolving system it is easy to hear how much an amplifier's performance improves when hum is removed. Remember the hum at 50Hz, 100Hz etc, plus their harmonics, modulates and distorts the music at those frequencies up the audio spectrum, so it is absolutely critical that all unwanted noise is removed.
 
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Yes, I did indeed have the pleasure of hearing the reference system assembled by @G T Audio and it really is a revelatory experience, unlike anything I have heard anywhere before. The speakers are very, very big and have a price tag to match. So on the one hand hearing Tron amplification in this context is revealing of what it is ultimately capable of, it is also necessary to hear it with more modest speakers such as Tannoy or the Klipsch that Graham carries.

You get a very similar experience to the one you heard when using the Klipsch Cornwalls in my system. Which is quite amazing when you consider the price difference...
 
@Darren L : To me a stable and high impedance is more important than a very high sensitivity, especially with SET designs.
The thing is, many, if not most, manufacturers are lying with their specs. Especially with the sensitivity and the nominal impedance.
There are so many claimed 8 ohm speakers which in reality have only 4 or 5 ohm in reality.
Which real world speakers ( for me that is £1500 max :)) will give me the stable and high impedance you speak of?
I have 30 watts of SET amplification. My current speakers have a nominal impedance of 8 ohm, a minimum of 4.7
 
Which real world speakers ( for me that is £1500 max :)) will give me the stable and high impedance you speak of?
I have 30 watts of SET amplification. My current speakers have a nominal impedance of 8 ohm, a minimum of 4.7

If your amplifier does output 30 watts, then as long as the speaker has a nominal impedance of 8 ohms and is 89dB and above efficient, you should be OK for normal domestic listening levels.
 
@kneecap : Your speaker is a perfect example for what I have written about manufactures claiming wrong specs.

If the impedance minimum is 4.7 ohm your speaker has a nominal impedance of 6 ohm (5,88 ohm).

The minimal impedance is not allowed to drop to a value under 80% of the nominal impedance, so a 8 ohm speaker is only allowed to have an impedance minimum of 6,4 ohm.

Real high impedance speakers are very rare these days. BBC designs like Spendors Classic line, Graham, Harbeth, etc. and the Tannoy Legacy range are staying above 5 ohm, full range speakers can have a higher impedance. DeVore has interesting speakers for SET amplifiers and maybe some high end companies like Avantgarde Acoustic or Cessaro. Most other companies I know have speakers that drop down to around 4 ohm or deeper.

So I'm afraid to say that I can't recommend anything in your budget. The advice of @G T Audio is a good starting point.

BTW: The Unison S6 is a PSE = Parallel Single Ended not an SET = Single Ended Triode.
The power of the Unison drops very much from 8 ohm to 4 ohm.
 
The last single ended amp I've built used a mosfet output stage and one valve driving that, all for less than the cost of a decent output transformers, and in my case exceeded the performance of every set amp I've built or heard to date.
I run an audio meet in Doncaster every year, there's one next month.

Your hybrid single ended amplifier build has got my interest, I’d like to hear that. Are you planning to bring it your Doncaster meet? I could be tempted to make a trip north. I could bring my single ended parafeed 2A3 amplifier that I’ve just stripped and rebuilt into a two stage amp with bifilar wound interstage transformers, it’s the amp we played on your open baffles at the last Eggfest in 2006, or was it 2007?
 
@kneecap : Your speaker is a perfect example for what I have written about manufactures claiming wrong specs.

If the impedance minimum is 4.7 ohm your speaker has a nominal impedance of 6 ohm (5,88 ohm).

The minimal impedance is not allowed to drop to a value under 80% of the nominal impedance, so a 8 ohm speaker is only allowed to have an impedance minimum of 6,4 ohm.

Real high impedance speakers are very rare these days. BBC designs like Spendors Classic line, Graham, Harbeth, etc. and the Tannoy Legacy range are staying above 5 ohm, full range speakers can have a higher impedance. DeVore has interesting speakers for SET amplifiers and maybe some high end companies like Avantgarde Acoustic or Cessaro. Most other companies I know have speakers that drop down to around 4 ohm or deeper.

So I'm afraid to say that I can't recommend anything in your budget. The advice of @G T Audio is a good starting point.

BTW: The Unison S6 is a SEP = Single Ended Parallel not an SET = Single Ended Triode.
The power of the Unison drops very much from 8 ohm to 4 ohm.

I see Proac quote 10 ohms for the Tablette 10?

SEP? :(
 
@kneecap As long as you are happy with the sound of your system it doesn't matter if it is a PSE or a SET and if the impedance is 10 ohm or 6 ohm.
 
@kneecap : Your speaker is a perfect example for what I have written about manufactures claiming wrong specs.

If the impedance minimum is 4.7 ohm your speaker has a nominal impedance of 6 ohm (5,88 ohm).

The minimal impedance is not allowed to drop to a value under 80% of the nominal impedance, so a 8 ohm speaker is only allowed to have an impedance minimum of 6,4 ohm.

Real high impedance speakers are very rare these days. BBC designs like Spendors Classic line, Graham, Harbeth, etc. and the Tannoy Legacy range are staying above 5 ohm, full range speakers can have a higher impedance. DeVore has interesting speakers for SET amplifiers and maybe some high end companies like Avantgarde Acoustic or Cessaro. Most other companies I know have speakers that drop down to around 4 ohm or deeper.

So I'm afraid to say that I can't recommend anything in your budget. The advice of @G T Audio is a good starting point.

BTW: The Unison S6 is a PSE = Parallel Single Ended not an SET = Single Ended Triode.
The power of the Unison drops very much from 8 ohm to 4 ohm.

Also, I very much doubt the S6 delivers 30 watts with 3 x EL34s per channel. I did some investigation work on behalf of the Unison Research UK distributor around 2000, because they were having so many EL34 failure in Simply 2 & 4 amplifiers. On investigation I measured 4 watts per channel from the Simply 2 and even then the output valves was running 20% over its anode dissipation. Unless they have radically changed their designs I estimate your S6 probably outputs about half of what is quoted.
 
Your hybrid single ended amplifier build has got my interest, I’d like to hear that. Are you planning to bring it your Doncaster meet? I could be tempted to make a trip north. I could bring my single ended parafeed 2A3 amplifier that I’ve just stripped and rebuilt into a two stage amp with bifilar wound interstage transformers, it’s the amp we played on your open baffles at the last Eggfest in 2006, or was it 2007?
That must have been some of my early baffles.. lowthers and goodmans bass drivers ? Or was it the perspex baffles that James brought?
I don't remember your amp at the moment, but there's alot of people and kit been to our meets over the years, we had 2 meets a year for the first 10 years or so.
My amps and loudspeakers have improved considerably since then. I think it would be worth a trip up, the mosfet amp is really that good. Mind you its driven by late 1920s shortpath valves with tribute interstages.
If you do come please bring your amp to compare if you can. Let me know your name it may jog my memory..
 
@G T Audio: The Unison S6MKII was measured by Australian Hifi

13 watt @ 8ohm @ 20Hz driving 2 channels
36 watt @ 8ohm @ 1kHz driving 2 channels
28 watt @ 8ohm @ 20kHz driving 2 channels

12 watt @ 4ohm @ 20Hz driving 2 channels
18 watt @ 4ohm @ 1kHz driving 2 channels
18 watt @ 4ohm @ 20kHz driving 2 channels

other reviews with measurements:

https://www.tad-audiovertrieb.de/sites/default/files/stereoplay_04-2013_s-6_mk-2_0.pdf
https://www.tad-audiovertrieb.de/sites/default/files/unison_lp411_s.62-65screen.pdf
 
In the mid 90s I ran yammy ns1000s on a 4 watt el84 amp that I had rebuilt from a quality radiogram
Before that I'd used various solid state amps by audio analoge, audiolab and more, there was no going back to them.
That little amp made me realise what was special about single ended operation.
My next amp was a pye mozart that got my treatment, the extra volume was just enough for the yams, 3-4 watts didn't really cut it on 91db speakers for me, but I was hooked on the single ended sound.
 


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