I live in a neighbourhood where there aren't many houses around, and the utility transformer is mounted on a pole directly beside my house: http://www.diyaudio.com/forums/showthread.php?postid=899026#post899026
I had a period when I was "impressed" with battery power, but later switched back to AC power as I find it now much more dynamic and "live", especially where low capacitance is used in filtering.
In my comment about "immediacy", I think the better term could be actualy "delicacy". You will always hear another transformer, and although same transformer used in balanced configuration is better sounding than regular isolation, it is still detectable. How much it affects the perceived sound is a very personal matter.
I had a period when I was "impressed" with battery power, but later switched back to AC power as I find it now much more dynamic and "live", especially where low capacitance is used in filtering.
In my comment about "immediacy", I think the better term could be actualy "delicacy". You will always hear another transformer, and although same transformer used in balanced configuration is better sounding than regular isolation, it is still detectable. How much it affects the perceived sound is a very personal matter.
Peter Daniel said:I live in a neighbourhood where there aren't many houses around, and the utility transformer is mounted on a pole directly beside my house
I had a period when I was "impressed" with battery power, but later switched back to AC power as I find it now much more dynamic and "live", especially where low capacitance is used in filtering.
In my comment about "immediacy", I think the better term could be actualy "delicacy". You will always hear another transformer, and although same transformer used in balanced configuration is better sounding than regular isolation, it is still detectable. How much it affects the perceived sound is a very personal matter.
Peter,
I too am very lucky to have a very good power feed to my house, although my experiments and understanding (based on my logic and observations)
place most of the improvements I hear on the secondary side of the transformer through the removal of the dirty neutral as a reference and a common connection between the various components in my system. This coupled with a virtual ground created by the the center tap that is used as a return for the RFI filtering. This effectively keeps the filter return loop from from circulating in the power path.Whether or not a balanced transformer inserted in the supply affects the power transfer and low level dynamics is then determined by the quality of the transformer. Due to the limitations imposed by this form of communications, if you say you hear this and I say I don't, there is no way to make any aspect of this relative and any discussion is pointless.
What I am curious about is your comment about low capacitance in the filtering. Are we discussing the main filter caps or the values of the bypass capacitors. I've had some very interesting experiences using reasonable values of filter capacitance and, from your comment, I was wondering if you had experimented along these lines as well.
Mike.
My current system is pretty simple: it consists of integrated amp, DAC and a transport. While I can run 2 separate dedicated lines (analog and digital) I noticed that if I connect all equipment to the same line, it sounded better (to me).
Another interesting aspect of 2 x 120V AC line is that one side apparently "sounds" better and is generally preferred for audio.
I was recently experimenting with that, and indeed, connecting equipment to a specific tap of 240V gives better results:
http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=1177
My preoccupation with low capacitance in both PS filtering and bypassing started with chip amps, and after achieving great results with very little capacitance there I started to implement that approach in equipment modification as well and generally, whenever the smaller cap value was inserted the sound became "fresher" without loosing any dynamics and bottom end extention (in reasonable value ranges of course).
That approach cannot be used with battery power, as battery seem to act as large capacitors bank, making things slower and less "fresh" (although very smooth).
Another interesting aspect of 2 x 120V AC line is that one side apparently "sounds" better and is generally preferred for audio.
I was recently experimenting with that, and indeed, connecting equipment to a specific tap of 240V gives better results:
http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=1177
My preoccupation with low capacitance in both PS filtering and bypassing started with chip amps, and after achieving great results with very little capacitance there I started to implement that approach in equipment modification as well and generally, whenever the smaller cap value was inserted the sound became "fresher" without loosing any dynamics and bottom end extention (in reasonable value ranges of course).
That approach cannot be used with battery power, as battery seem to act as large capacitors bank, making things slower and less "fresh" (although very smooth).
Just how many batteries would it take to give the same output resistance as your (75kVA, ~2% imp for me) distribution transformer?
I also wonder if any inductive flywheel type effects are coming into play with transformers.
Are your PSUs capacitor input? Less capacitance means wider conduction angle too.
I also wonder if any inductive flywheel type effects are coming into play with transformers.
Are your PSUs capacitor input? Less capacitance means wider conduction angle too.
Peter Daniel said:
I've had the same experience and run a single line with 8ga wire.
Peter Daniel said:
This I have not heard of and will have to give it a try. Luckily it an easy thing to do. I'll let you know how it goes.
With all of the capacitor farms that are the normal approach to any serious highend design, I've thought for years that I was the only one not jumping on the bandwagon. It's funny because these massive capacitor banks got started years ago when Frank Van Alstein added an external bank as a modification to the Dynaco 400; it took off from there... At the time I was experimenting heavily with circuit grounding. I could understand why this mod made such a noticable difference, but it was only because the stock layout was so wrong. There was such a bottle neck for any power trying to get through the supply that any reserves helped.
The same amp, properly laidout (power supply and ground wise) trounced the modified version (and Dynaco's retrofit kit). I performed these changes to a fair number of these amps, but not to many people wanted to hear this in the mid 80's. I've been continuing to refining my understanding of layout and grounding since.
As for reasonable values, I once modified a Sumo 9 and it was reviewed in the the short lived "Sounds Like" audio magazine. The reviewer was estatic about the improvements overall (it's been years since I've read it) but was most blown away by the improvements in the bottom end. He attributed the improvements to the additional filter capacitance of the replacement filters. In reality they where 2000 mfd high frequency capacitors (designed for the then relatively new switching power supplies). I had added a 1 in front of the 2000 mfd with transfer letters.
The real improvements came from a combination of the better filters, and changes to the grounding and supply networks. I thought it best to let the positive comments speak for themselves.
It's interesting after all these years to hear similar feedback, and in a public forum to boot.
I think I hear an angry mob headed towards my house...
Happy listening, Mike.
So that’s it? End of conversation? Gotta love it.
In a room full of people any one of my comments would have elicited a fire storm of arguments or discussion. On the DIY audio discussion forum, nothing. Silly me! I thought a discussion was heading into an interesting direction, so I…
I dissed VanAlstien; been watching his work for years. Although he is an ancient survivor now, which must add credibility? (Maybe capacitor farms do sound good, especially placed a mile away from the output stage.)
I slandered the venerable Dyna 400… Lots to discuss here, but come on, it’s 30+ years old and I doubt it would be built the same today. I hope I don’t upset the fair market value on e-bay.
I alluded to my hard work and God like understanding of grounding and layout techniques. Seems like if there were truly DIY’ers in the audience that I’d be a good subject to dethrone or ask a question of. (Although in my experiences early on, in a thread on amp grounding, it was proven that everything I know is wrong and my amp and preamp can’t possibly work as built. (A bit over the edge there, but it’s that silly sense of humor that made be do it…)
I alluded to being in the audio business (deep thought would have placed it some time in the 80’s) (mid 70’s until late 80’s). I was and it was a fun time. I built a good business based on sound quality and word of mouth. We spent very little on advertising and nothing on snake oil. I was a terrible businessman. I left it to be an equipment engineer for a semiconductor manufacturer (insurance, steady paycheck and no telephone, this was before e-mail).
I defiled a SUMO 9 by putting ¼ the supply capacitance in a Class A amp. This is heresy and not one textbook quote or simulation result was thrown at me. I thought maybe someone might ask how I decided on that value… The thought was probably overshadowed by the fact
I deceived a member of the audio press by purposely mis-marking the capacitance value and not telling him about it to report in the review. Hey, this was the 80’s man. Once capacitor farms became the rage, there would have been no purpose in reviewing the amp with such a glaring design deficiency. In reality I had already rebuilt a Son of Ampzilla for the reviewer and his instruction were to do what ever I wanted to make the amp so I was happy with it. I did, and when I was happy with the amp I struggled with the consequences and the heresy of it all.
Oh I almost forgot, I did imply that the stock SUMO is not perfect… Darn, I did it again which will bring another barrage of insults as to my technical abilities by the venerable Mr.B. Although I won’t be paying attention. The Sumo review says it all. The reviewer was James Jarvis.
Anyway, I’m pretty much done with this site now. I took a pretty broad swipe and there's not much there. Seven months of one way communication is enough for me. From what I read the city fathers here have everything pretty much under control.
Mike.
In a room full of people any one of my comments would have elicited a fire storm of arguments or discussion. On the DIY audio discussion forum, nothing. Silly me! I thought a discussion was heading into an interesting direction, so I…
I dissed VanAlstien; been watching his work for years. Although he is an ancient survivor now, which must add credibility? (Maybe capacitor farms do sound good, especially placed a mile away from the output stage.)
I slandered the venerable Dyna 400… Lots to discuss here, but come on, it’s 30+ years old and I doubt it would be built the same today. I hope I don’t upset the fair market value on e-bay.
I alluded to my hard work and God like understanding of grounding and layout techniques. Seems like if there were truly DIY’ers in the audience that I’d be a good subject to dethrone or ask a question of. (Although in my experiences early on, in a thread on amp grounding, it was proven that everything I know is wrong and my amp and preamp can’t possibly work as built. (A bit over the edge there, but it’s that silly sense of humor that made be do it…)
I alluded to being in the audio business (deep thought would have placed it some time in the 80’s) (mid 70’s until late 80’s). I was and it was a fun time. I built a good business based on sound quality and word of mouth. We spent very little on advertising and nothing on snake oil. I was a terrible businessman. I left it to be an equipment engineer for a semiconductor manufacturer (insurance, steady paycheck and no telephone, this was before e-mail).
I defiled a SUMO 9 by putting ¼ the supply capacitance in a Class A amp. This is heresy and not one textbook quote or simulation result was thrown at me. I thought maybe someone might ask how I decided on that value… The thought was probably overshadowed by the fact
I deceived a member of the audio press by purposely mis-marking the capacitance value and not telling him about it to report in the review. Hey, this was the 80’s man. Once capacitor farms became the rage, there would have been no purpose in reviewing the amp with such a glaring design deficiency. In reality I had already rebuilt a Son of Ampzilla for the reviewer and his instruction were to do what ever I wanted to make the amp so I was happy with it. I did, and when I was happy with the amp I struggled with the consequences and the heresy of it all.
Oh I almost forgot, I did imply that the stock SUMO is not perfect… Darn, I did it again which will bring another barrage of insults as to my technical abilities by the venerable Mr.B. Although I won’t be paying attention. The Sumo review says it all. The reviewer was James Jarvis.
Anyway, I’m pretty much done with this site now. I took a pretty broad swipe and there's not much there. Seven months of one way communication is enough for me. From what I read the city fathers here have everything pretty much under control.
Mike.
Don't get upset, it was just a lul in the storm! If you put your head on the curb, we will step on it for you - if that is what you really want.
Would you like me to say something contrary?
OK.
I have 300,000uf (75kuf per rail) in my Belles 450.
That good enough?
I know you are looking for a minor fricasse, but I'm all outa energy right now, as I was shut down on another forum today. totally different subject, and of the type that has been declared 'off limts' on this one.
Would you like me to say something contrary?
OK.
I have 300,000uf (75kuf per rail) in my Belles 450.
That good enough?
I know you are looking for a minor fricasse, but I'm all outa energy right now, as I was shut down on another forum today. totally different subject, and of the type that has been declared 'off limts' on this one.
Well as you guys want a fracas, I'll point out that no one has distinguished between those benefits offerered by an isolation transformer and those incremental benefits offer by split phase technical (balanced power).
Those features offered by the specific of an isolation are -
Restricted bandwidth,depending on core and winding geometry, etc...
Restricted capacitive noise coupling via a shield or split/multi bobbins
Common mode noise rejection inherent in transformers
The only incremental benefits of balancing I know of are-
'Cancellation' of reactive leakage currents to a grounded chassis.
Transverse/differential mode noise becomes differential (wrt ground) balanced noise at the transformers output and when shunted symmetrically to ground via Y caps, can also potentially 'cancel'.
Its not difficult to evaluate the specific benefits of balancing with a dpdt (center off) switch to evaluate the differences between technical balanced power, floating, and rebonded neutral isolating transformers.
FWIW,
Paul
Those features offered by the specific of an isolation are -
Restricted bandwidth,depending on core and winding geometry, etc...
Restricted capacitive noise coupling via a shield or split/multi bobbins
Common mode noise rejection inherent in transformers
The only incremental benefits of balancing I know of are-
'Cancellation' of reactive leakage currents to a grounded chassis.
Transverse/differential mode noise becomes differential (wrt ground) balanced noise at the transformers output and when shunted symmetrically to ground via Y caps, can also potentially 'cancel'.
Its not difficult to evaluate the specific benefits of balancing with a dpdt (center off) switch to evaluate the differences between technical balanced power, floating, and rebonded neutral isolating transformers.
FWIW,
Paul
pmkap said:
That's what I actually did in the transformer unit I built for Mr. Ebaen: http://www.6moons.com/audioreviews/240_117/240_117.html
With a use of a switch one can go from balanced to isolation mode and compare the effect. When I was evaluating that, the balanced mode was superior.
PS: Regarding reducing capacitance, I described a mod to ML37 here: http://www.diyaudio.com/forums/showthread.php?postid=896134#post896134 were all capacitors have been replaced with much lower values (3 to 20 times less on average). The results have been very satisfying.
Peter Daniel said:
I'd thought it would be understood that balancing is superior to isolation alone when I refered to incremental benefits of balancing .
That switchable between isolation and balancing transformer can be used as a component diagnostic tool, either as a subjective substitue for objective measurement devices or as an adjunct.
Specifically, ground loop issues are often caused by differing voltages induced upon the ground of different components by their reactive leakage to grounded chassis. Simply by listening between 'isolated' and 'balanced' on can position their transformers (and other components) to minimize that leakage. Whether one uses a balancing transformer or not, it pays to optimize layout with regards to reactive current induced hum and noise. Balancing is a great band-aid and can substantially mask the inadequacies of non optimally implemented power suppies, layout and topologies, but I've also found that optimizing the component and then balancing allways yeilds better results. Actually, I been doing this on a Chinese dac, using internal mods to minimize reactive leakage as well as transverse and common mode noise and have found the additional benefits of my balancing conditioner minor, at best, and really not worth the trouble.
pmkap said:
Let me phrase it the other way: I would have never used in my existing setup an isolation transformer as such. Trying same transformer in a balanced mode made me think twice if I liked it or not. As I was pressed on time, I only did quick comparisons and my opinion was based on first impression only. Having it in a system for more prolonged time, might have influence my opinion differently.
Some oif the greatest 'gains' in subjective fidelity I have heard, came from running balanced AC with SMPS powered gear. This was/is contrary, in some ways, to the expected outcome. Meaning, I figgured that the effect would be less noticable than it was/is with split rail AC sourced DC power supplies. Turns out it was just as noticable, if not more. Thought thrown such an outcome begins (tick, tick, tick; therefore-therefore-therefore) to shed light on the results.
What do you think about this choke arangement here http://www.decware.com/cgi-bin/yabb/YaBB.cgi?board=Tubes;action=display;num=1131291437
Here's a good example (in pdf format)
http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US3164766&F=0&QPN=US3164766
http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US3164766&F=0&QPN=US3164766
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