SET amp owners thread

[geetee1972]

Hi guys, great thread, glad it's still active. I can post some pictures of my own SET set up but I have a question I've been trying to get an answer to for ages and wondered if someone here can help. I ask more out of idle curiosity than anything else.

I have a pair of Silvercore 833 MKII mono blocs, which i am exceptionally happy with. They are of course single ended triode design but they only have a balanced XLR input. I have almost no knowledge of electrical engineering but I do understand how a balanced/common mode rejection design works and thus know that if an amp is single ended, it cannot also be balanced, so I don't understand why such an amp would have an XLR as the input unless it was simply because the designer chose to use that connection for convenience.

I use adapters on my (long) IC cable runs, which are themselves RCA only, as is my pre-amp. I've asked my dealer who supplied the units a number of times but whilst he's given an explanation, I've never quite understood it. He says there is a transformer immediately behind the input which recombines the signal before passing it through the amplification stages. This makes sense but I still don't understand why you would do that rather than just use an RCA input and lose the transformer (which would simply add cost, unnecessarily it would seem).

 

[SVS]

This is the usual tribute to fashion. Balanced connection is necessary when transmitting weak signals over long distances, for example from a microphone from the stage, or in modern DACs. In this way, the level of noise that occurs in the chip during signal processing in DACs is reduced. A balanced signal can still simplify the design of the PP amplifier. It is not needed at all for the SE amplifier.

 

[Solypsa]

...He says there is a transformer immediately behind the input which recombines the signal before passing it through the amplification stages. This makes sense but I still don't understand why you would do that rather than just use an RCA input and lose the transformer (which would simply add cost, unnecessarily it would seem).

Balanced as a big topic is confused slightly by the fact the term can be used for a variety of related implementations.

What you describe is a balanced line connection, ideally as referenced under AES48 standards.

Traditionally this involved a transformer on preceding equipment output and another on receiving equipment input. If correctly implemented you have a scheme to get high cmrr over the connection, and a specific way to deal with shields and grounds. Most studio gear is this way, albeit with IC often instead of transformers, these days.

Yes line connection can be made without this standard, debates go on over pro/con.

Some gear is differential in circuit, this is a different topic.

 

[norton750]

Transcription Audio 211 monoblocks
G E 211 Valves
Dave Slagle Autoformer preamp

 

[Rensselaer]

As I have said before, mine is the Ayon Spitfire, 30 watts matter-of-fact sound. I play over a pair of Altec A7's that I am always tinkering with (different crossovers, internal reinforcements and wool felt, Markus Klug 1005 exponential horns), latest change is replacing the 902-8B ferrite compression drivers with new 802-8G Series II Alnico drivers from Great Plains Audio. In person, they really improve the "realness" of the music. Piano sounds like a piano in the room now, even with this low power SET amp. I have made another recording of Scheherazade on my iPhone 8 (not great for recreating the sound, but will give anyone with curiosity about the sound of this new compression driver an idea):

 

[morricab]

As I have said before, mine is the Ayon Spitfire, 30 watts matter-of-fact sound. I play over a pair of Altec A7's that I am always tinkering with (different crossovers, internal reinforcements and wool felt, Markus Klug 1005 exponential horns), latest change is replacing the 902-8B ferrite compression drivers with new 802-8G Series II Alnico drivers from Great Plains Audio. In person, they really improve the "realness" of the music. Piano sounds like a piano in the room now, even with this low power SET amp. I have made another recording of Scheherazade on my iPhone 8 (not great for recreating the sound, but will give anyone with curiosity about the sound of this new compression driver an idea):

Spitfire is not a low power SET

 

[Rensselaer]

Spitfire is not a low power SET

Relatively speaking it is, but not flea powered like the best sounding SETs

 

[Rensselaer]

I mean, low powered in-so-far as to play Grand Piano with realistic power and presence

 

[SVS]

Can you give an example of a SE amplifier class other than class A?

 

[morricab]

Relatively speaking it is, but not flea powered like the best sounding SETs

Don’t assume all the best sounding SETs are flea power

 

[bonzo75]

As I have said before, mine is the Ayon Spitfire, 30 watts matter-of-fact sound. I play over a pair of Altec A7's that I am always tinkering with (different crossovers, internal reinforcements and wool felt, Markus Klug 1005 exponential horns), latest change is replacing the 902-8B ferrite compression drivers with new 802-8G Series II Alnico drivers from Great Plains Audio. In person, they really improve the "realness" of the music. Piano sounds like a piano in the room now, even with this low power SET amp. I have made another recording of Scheherazade on my iPhone 8 (not great for recreating the sound, but will give anyone with curiosity about the sound of this new compression driver an idea):

compared the one you had done 4 days ago. This one seems to have more midbass full ness and bloom and more emotional. More sense of ambience too. What is it like in room.

 

[Rensselaer]

compared the one you had done 4 days ago. This one seems to have more midbass full ness and bloom and more emotional. More sense of ambience too. What is it like in room.

Very nice, sounds more real. I have been listening to records ever since the change. I assume it is the Alnico but other aspects may be playing a part. There doesn’t seem to be any other reviews of this new compression driver from Great Plains so I guess I should put more in a video, but I respect and appreciate your opinion on what you heard, thanks.

 

[Argonaut]

There doesn’t seem to be any other reviews of this new compression driver from Great Plains so I guess I should put more in a video, but I respect and appreciate your opinion on what you heard, thanks.

Great Plains have always represented very good value for the quality of sound that they produce imho …

 

[bonzo75]

Great Plains have always represented very good value for the quality of sound that they produce imho …

not really, they were much less cost before and are now charging too much since a private equity firm took over. They are not supposed to be a good as the originals

 

[jeff1225]

Transcription Audio 211 monoblocks
G E 211 Valves
Dave Slagle Autoformer preamp

Sounds like a cool system, post some pics!

 

[Argonaut]

represented very good value for the quality of sound that they produce

not really, they were much less cost before and are now charging too much since a private equity firm took over. They are not supposed to be a good as the originals

What part of the above comment whistled over your head ? Not everyone can afford GOTO

 

[djsina2]

This Otomon Lab PX25 is amazingly good paired with my Luxman AT-3000.

 

[bonzo75]

What part of the above comment whistled over your head ? Not everyone can afford GOTO

ok, clueless, many drivers in horns. Altec was never as high priced as GPA made it to be all of a sudden. And what makes you think Goto is better, have you heard any Goto 2-ways? They are almost always 4 or 5 ways as they are narrow bandwidth and have their own complexity

 

[Kray]

This Otomon Lab PX25 is amazingly good paired with my Luxman AT-3000.

View attachment 107918

Love the simplicity of that amp. was is a custom request or an existing build from them? Still Ken?

 

[Kray]

Here's one of several of my bespoke SET's from Oliver Sayes

6HJ5, 6N7, 5R4WGB
UTC & Lundahl transformers, Duelund caps