Clean Power

[stefanobilliani]

By the way I did try transformer to "center" the ground , but didn't find that worth it , if yes audible .

Hi Stefano. Audible in a good way or bad? The main criticism of transformers is that they can sometimes seem to compress dynamics and make the sound a bit dull/lifeless. Did you find this?

Mani.

Hi Mani ,

the time I did try that it was with a big non feedback amp in depletion mode Mosfets (that amp itself has a big Power Supply with double full waves rails) . So the "balanced" transformer was at the source , for the CD player so to speak .
The sound was very "big" and dynamic . That is what "typical" (?not so typical)  single ended amps without feedback do lol.
So no , I would not say it was like the dynamics were compressed .... it was all more equilibrate and precise .
It was really a good listening . Considering that the amp was connected the Earth ( and I do not play music without ) , I didn't really investigate on the " center " of the transformer .But if I remember well , it was not at the same potential of the Earth , but imo it was safe to connect like that .
It was a nice setup anyway .These  days I listen to 3 lovely amps ( feedback , non feedback various topologies , but all single ended which I love ), and all have different PS arrangements . So saying a definitive word about the transformer would be a bit  too much this side , but it was "different" somehow .

[PeterSt]

Stefano, just curious ... With SE you mean that your amps can take RCA input only ?
(by now we can go a couple of directions with SE vs. "Differential")

[stefanobilliani]

Stefano, just curious ... With SE you mean that your amps can take RCA input only ?
(by now we can go a couple of directions with SE vs. "Differential")

Hi Peter ,

yes indeed , RCA only . For years I have been a fan of the balanced operation with amps and dacs , but now I am more SE oriented ...but I know , there are some balanced configuration that "sounds" like being in paradise 

s

[PeterSt]

I hope it is not too much off topic (okay, it is), but why exactly do you feel SE is better (soundwise, technical ideas about it) ?
Keep in mind, I am NOT suggesting at all that differential is better !

Curious ...
Peter

[stefanobilliani]

I hope it is not too much off topic (okay, it is), but why exactly do you feel SE is better (soundwise, technical ideas about it) ?
Keep in mind, I am NOT suggesting at all that differential is better !

Curious ...
Peter

It's is a matter of effects probably , and since I can play with amplifiers with non clinical stages and feedeback ,usually one stage or max 2 stages, and  low distorsion ( between second and third harmonics mainly ) ...I think this has come into a choice of tastes , but also pratical .Pratical becouse single ended is sometimes simpler 
I also used to be a musician playing the accordeon ... the difference between second and third harmonics is still an interesting phenomena...
Of course , balanced operation permits other fantastic permutations and topologies , for example the Supersymmetry (tm) which indeed deserve to be explored and listened ...
So let's say its not an "exact" thing ; some analogies are tremendously close however .
But remember , multistage and waste of gain for the feedback are out of the way for me , and don't even think to amplify with BJT's .

s

[juanpmar]

Hi,

Mick Maloney owner of Supratek amplifiers, the ones I used some time ago, has this opinions about Balance/Unbalanced operation:

Balanced operation

I often get asked about the advantages of balanced operation-my reply is based on the following:
 
-Balanced/unbalanced is a conentious subject. It comes from the pro audio world where they need it to balance out the noise pickup from very long cables.

-True balance involves either using balancing transfomers or turning a Single Ended cicuit (as most preamps are) into a push pull circuit with double the components, circuitry etc- this is the only way to achieve "true" balanced throughout the preamp.

-There's a lot of hype about it, with a lot of so called balanced operation being psuedo balanced, which is basically having an XLR socket wired to accept a balanced signal and turning it back to unbalanced.
Personally I prefer Single Ended operation every time- there's an ease and effortlesss about it, wheras true balanced sounds more electronic to me, especially the push pull types of operation.

-One area where it is useful is in helping with RF noise in the big cities- it is not an isue for me in my country town isolation, but places like NY benefit from it and in my mind the best way to use balanced is to take it off the output transformer of a preamp, which fortunately we can do with the Supratek pres- it is true and perfect balanced with the minimum of circuitry to degrade the sound. (there's virtually no circuitry!)

-One balancing point in a preamp is all that is necessary- the output transformer turns the single ended circuit into a balanced circuit with two phases and the noise common to both channels (hum, RF etc) is greatly reduced.

-Going for balanced throughout is sonic overkill that does more harm than good IMO- it has been a successful marketing campaign by some companies, but it is marketed to sell amps.

I personnaly use XLR in my Spectron amps. I live in downtown Madrid sorrounded by offices and computers. My interconnection cables are also quite long. At the end I like more the sound with XLR than with RCA.


Best regards,
Juan

[stefanobilliani]

Hi,

Mick Maloney owner of Supratek amplifiers, the ones I used some time ago, has this opinions about Balance/Unbalanced operation:

Balanced operation

I often get asked about the advantages of balanced operation-my reply is based on the following:
 
-Balanced/unbalanced is a conentious subject. It comes from the pro audio world where they need it to balance out the noise pickup from very long cables.

-True balance involves either using balancing transfomers or turning a Single Ended cicuit (as most preamps are) into a push pull circuit with double the components, circuitry etc- this is the only way to achieve "true" balanced throughout the preamp.

-There's a lot of hype about it, with a lot of so called balanced operation being psuedo balanced, which is basically having an XLR socket wired to accept a balanced signal and turning it back to unbalanced.
Personally I prefer Single Ended operation every time- there's an ease and effortlesss about it, wheras true balanced sounds more electronic to me, especially the push pull types of operation.

-One area where it is useful is in helping with RF noise in the big cities- it is not an isue for me in my country town isolation, but places like NY benefit from it and in my mind the best way to use balanced is to take it off the output transformer of a preamp, which fortunately we can do with the Supratek pres- it is true and perfect balanced with the minimum of circuitry to degrade the sound. (there's virtually no circuitry!)

-One balancing point in a preamp is all that is necessary- the output transformer turns the single ended circuit into a balanced circuit with two phases and the noise common to both channels (hum, RF etc) is greatly reduced.

-Going for balanced throughout is sonic overkill that does more harm than good IMO- it has been a successful marketing campaign by some companies, but it is marketed to sell amps.

I personnaly use XLR in my Spectron amps. I live in downtown Madrid sorrounded by offices and computers. My interconnection cables are also quite long. At the I like more the sound with XLR than with RCA.


Best regards,
Juan

Personally I refer to Balanced Amps ( or preamps or dacs ) or Single Ended amps . Knowing that by topology . There are push pull designs which are not balanced , no matter if there is or not XLR connections at the imput or transformers somewhere .
OTHO , there are Balanced Single Ended amps , they accept both RCA and XLR inputs ( no transformer ), and their output are balanced , and they act in push pull also .
An example : the differential pair . The exploitation of a differential pair with local feedbak is called supersymmetry .
Another example : running 2 monoblocks with balanced signals . In this case , -no connection- is taking place between the two amps , if not the speaker itlself .

 

[manisandher]

OTHO , there are Balanced Single Ended amps , they accept both RCA and XLR inputs ( no transformer ), and their output are balanced ,and they act in push pull also .

The highlight is mine.

And there are single-ended amps (i.e. not push/pull) that are true balanced designs. My old Pass Labs Aleph4 was one. A very nice-sounding amp indeed. But a bit 'too polite' for XX/NOS1 duties.

Mani.

[stefanobilliani]

OTHO , there are Balanced Single Ended amps , they accept both RCA and XLR inputs ( no transformer ), and their output are balanced ,and they act in push pull also .

The highlight is mine.

And there are single-ended amps (i.e. not push/pull) that are true balanced designs. My old Pass Labs Aleph4 was one. A very nice-sounding amp indeed. But a bit 'too polite' for XX/NOS1 duties.

Mani.

I know the Aleph 4 . It has the differential pair at the input ( XLR and RCA ) , but the rest is single-ended , infact the speaker referes to ground by design scheme . The Aleph current source is still a modern invention imo .
Very nice piece indeed .

s

[manisandher]

Ah, I didn't know this. I sold it a couple of years ago and the guy who came to pick it up just couldn't understand why I would sell such a sweet sounding amp.

But one question: Is possible to have a truly balanced single-ended poweramp? I mean, my Pass X1 preamp is such a design, and if it's possible in a preamp surely it must be possible in a poweramp also, no?

Mani.

[stefanobilliani]

Ah, I didn't know this. I sold it a couple of years ago and the guy who came to pick it up just couldn't understand why I would sell such a sweet sounding amp.

But one question: Is possible to have a truly balanced single-ended poweramp? I mean, my Pass X1 preamp is such a design, and if it's possible in a preamp surely it must be possible in a poweramp also, no?

Mani.

Yes , sure .

s

[manisandher]

Is possible to have a truly balanced single-ended poweramp? I mean, my Pass X1 preamp is such a design, and if it's possible in a preamp surely it must be possible in a poweramp also, no?

Yes , sure .

This seems to contradict something that Juan quoted earlier:

Mick Maloney owner of Supratek amplifiers, the ones I used some time ago, has this opinions about Balance/Unbalanced operation:

Balanced operation

-True balance involves either using balancing transfomers or turning a Single Ended cicuit (as most preamps are) into a push pull circuit with double the components, circuitry etc- this is the only way to achieve "true" balanced throughout the preamp.

Doesn't it?

Mani.

[manisandher]

I'm gonna try the following:

electricity meter -> dedicated consumer unit -> PurePower2000 regenerator -> 5KVA balanced transformer (house PE on input, dedicated PE on output) -> 8-way distribution block

Spent until the early hours of the morning doing this. (The input ground of the transformer is connected to the house PE and the output ground to my dedicated PE.) I think it was a worthwhile redistribution. I'm getting the same beautiful balance between micro-detail and smoothness as I did when I initially reinstated the PurePower2000 last week, but strangely I'm getting what sounds like a deeper (and more satisfying) low-end. The only thing I'd like more of is a hint more 'sparkle'. But I haven't yet optimised 'Le Monster' (liquid cooler still needs to go in, all fans need to come out and I need to look at BIOS settings)... and of course there's still 0.9z-7 to come!


There's a very interesting review of the top-of-the-line Equi=tech product here: http://www.6moons.com/audioreviews/equitech/1.html. It makes a very strong case for balanced power and even mentions what Peter was talking about (in his long post earlier in this thread). My main concern now is that my Airlink balanced transformers may not be of the quality really required for a truly low-noise balanced system - I doubt they go to the same lengths as Equi=tech. Also a friend of mine who has a great sytem (centred around the dCS Scarlatti) once mentioned that he heard one of the most profound changes to the sound of a system when an Equi=tech was introduced.

Don't think I really need the 15KVA isolation transformer. Anyone want one? It's 120Kg though!

I may need to sell a few things in order to scr*pe enough pennies for an Equi=tech.

On a final note, my 'noise sniffer' doesn't seem to like my current AC setup. It shows quite a high noise reading even with zero load. Anyone have any idea why this might be?

Mani.

EDIT: What's wrong with the word 'scr_a_pe'? It just means 'to rub away'...

[PeterSt]

Anyone have any idea why this might be?

Hey Mani - most stupid answer : because it is so ?
Maybe not stupid when you think it is a false alarm of the meter, but after the sentence about your description of the sound, my immediate idea was : so, thus noisy.

If you meant to ask how that noise can be there, then I for sure don't have an answer to that. Pickup ?


PS:

It makes a very strong case for balanced power and even mentions what Peter was talking about

Is it allowed to know what this was ? I mean, maybe I am going to read that article, but reading my own posts ?

[stefanobilliani]

Is possible to have a truly balanced single-ended poweramp? I mean, my Pass X1 preamp is such a design, and if it's possible in a preamp surely it must be possible in a poweramp also, no?

Yes , sure .

This seems to contradict something that Juan quoted earlier:

Mick Maloney owner of Supratek amplifiers, the ones I used some time ago, has this opinions about Balance/Unbalanced operation:

Balanced operation

-True balance involves either using balancing transfomers or turning a Single Ended cicuit (as most preamps are) into a push pull circuit with double the components, circuitry etc- this is the only way to achieve "true" balanced throughout the preamp.

Doesn't it?

Mani.

Single Ended Balanced is what we could call a "scaled up" X1 design . Or take a look at the " son of zen " . A differential pair is something "more" than doubling 2 single ended designs . And remember it is a matter of effects how the balanced amp acts with the speaker.... and it is typically another story with respect to a real single ended amp .
Once I did build 2 pairs of Zen V2 ( with the Aleph current source ) for having a balanced design , in that case there wasn't connection between the 2 halves of the amp , but the sound was like paradise , also for the effect of the 2 Aleph arrangement -around- the speaker .
Again , the big circuital differences are when there is the exploitation of the balanced ciruit .It happens when a connection takes place between the halves ( differential pair ).

s