It is a well known and measureable fact that a SE tube amplifier adds a healthy dose of 2H. It is also known that the added 2H (and others) vary with the level and frequency of the signal. It is also widely known that the output impedance of a triode based SE amplifier is mich higher than a similar powered SS amplifier. There are other known measurable quantities that I am not including. My point is that a skilled team of DSP experts should be able to measure a particular tube amplifier with all the known measurement criteria, develop a mathematical model for that amp based on those measurements. It then should be possible to develop an algorithm based on that model to replicate that sound in a reference amplifier which has also been suitably characterized. This has not yet been achieved.
The high end audio market is too small and fragmented for this to occur. The electric guitar market is not, and DSP effects boxes and amplifiers are available that tout models of certain guitars played through certain amplifiers. These devices are far more convincing than the stomp boxes of the past, but they are not causing serious players to trade in their Marshall stacks. I believe that we still have a lot to learn about the dynamics of human hearing, and sound generation / amplification. As we learn more we will be able to measure more. Eventually we will understand enough to make a better mathematical model.
We still improve the models of electrical elements that we use every day. Tons of money have been thrown at IC developmental models in the past 10 years. We wouldn't have todays personal computers or cell phones without it. That kind of cash is simply not spent on audio, or we would have "45 triode SE" chips and "Stratocaster through a Marshall stack" chips already.
tubelab.com said:
Why try to 'develop' an algorith for something when you have the real thing?
Sorry, Tubelab - That was too inviting to let pass!
Seriously - yes, I cannot see why that should not be possible. But as you say (agree with all of it), hi-fi and even sound equipment in general, even perhaps including the guitar/band scene (and here I am speaking in ignorance), is too small a field (and perhaps too diverse in what is regarded as important!) to get the attention of major bucks. One can only say that in the field of hearing generally some research has been going on for such duration that the 'normal' ear can at least be categorised reasonably well. By that I mean that increasingly more of what I read confirms past results and increasingly less contradicts it. (This done mainly in the interest of hearing wellness, not hi-fi.)
Again agreeing as per above. One must just remember that development is aimed at need, which rather excludes audio products per se. Yes, some improvement in op-amp performance etc. has been achieved - I am no longer on the edge of this, but such development seems to have the purpose of miniaturisation, use of improved materials and such for use in cell-phones and digital control electronics etc. It would appear to me that audio development per se has reached a zenith as far as consumer audio is concerned (again, not really up to scratch with the latest developments). One did get digital output stages, but then as I see it, more in the interest of mass-production and miniarisation etc. than improved hi-fi.
I forgot that you are a guitar player. Yes, in that field 'special' sound is part of the excercise - instrument and electronics are part of the same music-producing thing, often with a complex 'definition' of what is desirable. Electronics in service of the musician there.
But now I am quite off-subject. Back to Kuroguy and anything more on power cords?
PaleRider said:
Well, you could use BX housewire for that. It comes with a spiral armor conductive shield, and a twisted pair of solid conductors. You'd need to use special cable clamps (electricians call these "connectors") on the amplifier chassis. And a metal cased 3 prong power plug. It is rather stiff, and not designed for "portable" power cord use, though. And the clamps will work loose after a while because of flexing when you move the amp around. This doesn't happen with house wiring installed inside the walls, once it's installed, it never moves.
Hi Johan , Hi Tubelab , Hi all ,
IMHO , this thread was very useful ( Congratulations to Dognut ) ,
mainly to dismantle a lot of myths and the voodooism about the
real importance of power cords .
But not less important for all of us is a summary (a condensation )
of all that was said here . This is very important for the newborns
in tubes and / or electronics , too .
I ‘ll try to do that , using all the posts on this thread and mixing with MY OWN experience for over 30 years as an engineer , and handling with tubes and SS devices .
I am not going to talk about :
1) Speaker cables
2) Interconnect cables ( RCA or XLR )
3) Internal assembly / interconnect cables
Because they UNDOUBTEDLY do A LOT of difference in the
sound quality . I think that , this is a convergence point of agreement .
( I hope that I’m not wrong !!!! , if so , please someone starts
a new thread , not here )
Regarding the power cords , a lot of things was said here , and once again , Tubelab hits the target , when he said :
“ It all depends on the amplifier and how well its power supply was designed. In the perfect world every amplifier would have a well filtered and regulated power supply that wouldn't care if it was fed with two strands of coat hanger. But in the real world every amp must meet cost and size constraints that force a non zero output impedance from the power supply. “
... and I excuse to complete the text and write :
“ ... may be even that it is a mistaken design !!!! “
This is the absolute truth !!! The vast majority of you will
not believe me when I say that there is A LOT , of VERY
EXPENSIVE pre / amplifiers ( I’m talking about prices over the
USD$ 5,000 ) that DO NOT HAVE a well built power supply .
PLEASE , do not get me wrong , I’m not talking about that massive
transistor amplifiers that can draw about 20 , 25 or even 30 Ampéres during a deep bass . In this case is obvious that not only the power cord but all the home electrical facilities , need to be able to supply this massive instantaneous current .
Nor I am saying that YOUR amplifier was not well built . But what I said above is the truth , you can be sure .
I am talking about normal ( BUT EXPENSIVE ) amplifiers .
In these cases , NO DOUBT , is obvious that a better power cord
will turn the sound better , due to the no-zero impedance as explained above . So the power cord become a relevant actor of the scene reducing the path resistance and other beneficial effects , out of this thread’s subject , working togheter ( or matching ) with the house wiring .
Please do not ask me about brands or trade marks , this would not be ethical from me , to mention names on the Internet .
But PLEASE , do not go too far , using a USD$ 700 power cord ,
this is a total INSANITY . You can get the best , spending around , USD$ 60 or even USD$ 100 ( at maximum ) , or even less if you do the stuff by yourself .
In other hand , if your preamp or amp has a VERY WELL designed
and built power supply , definitely DOES NOT MATTER what is
going on before the IEC connector ( AC input ) , since you are
feeding the set from a good source of noise free 120 Volts / 60 Hz ( or 220 V / 50 Hz in some countries ) , you can use even a
USD$ 1 PC power cord , and the sound will be the same .
Exactly the same !!!
I will give an example . The best power supply I could ever saw
was the one of COUNTERPOINT SA -11 preamplifier ( around
only 50 or 60 of them were built ) . The set has a total of 17
( seventeen tubes ) where only 4 ( four ) of them are in the
audio signal path . The rest , 13 tubes are in the power supply
stage and more ( around 8 ) three pins integrated regulators ,
mos-fet’s working as constant voltage source , etc , etc.
All of you can be sure , DOES not matter the power cord you
are using , the sound will be ALWAYS the same . I made
all the tests .
This is an extreme example , but illustrate the other side .
I think that is all , and the purpose was to clarify and justify
both sides of the debate .
What I am doing is a “ blend “ among the truth , my own experience , other people experience , the physical principles , the electronics principles , the testimony of my clients and the common sense , to explain and justify all arguments.
But I accept that , the most important , is YOU and YOUR EARS ,
because they are the judge .
Regards ,
Carlos
IMHO , this thread was very useful ( Congratulations to Dognut ) ,
mainly to dismantle a lot of myths and the voodooism about the
real importance of power cords .
But not less important for all of us is a summary (a condensation )
of all that was said here . This is very important for the newborns
in tubes and / or electronics , too .
I ‘ll try to do that , using all the posts on this thread and mixing with MY OWN experience for over 30 years as an engineer , and handling with tubes and SS devices .
I am not going to talk about :
1) Speaker cables
2) Interconnect cables ( RCA or XLR )
3) Internal assembly / interconnect cables
Because they UNDOUBTEDLY do A LOT of difference in the
sound quality . I think that , this is a convergence point of agreement .
( I hope that I’m not wrong !!!! , if so , please someone starts
a new thread , not here )
Regarding the power cords , a lot of things was said here , and once again , Tubelab hits the target , when he said :
“ It all depends on the amplifier and how well its power supply was designed. In the perfect world every amplifier would have a well filtered and regulated power supply that wouldn't care if it was fed with two strands of coat hanger. But in the real world every amp must meet cost and size constraints that force a non zero output impedance from the power supply. “
... and I excuse to complete the text and write :
“ ... may be even that it is a mistaken design !!!! “
This is the absolute truth !!! The vast majority of you will
not believe me when I say that there is A LOT , of VERY
EXPENSIVE pre / amplifiers ( I’m talking about prices over the
USD$ 5,000 ) that DO NOT HAVE a well built power supply .
PLEASE , do not get me wrong , I’m not talking about that massive
transistor amplifiers that can draw about 20 , 25 or even 30 Ampéres during a deep bass . In this case is obvious that not only the power cord but all the home electrical facilities , need to be able to supply this massive instantaneous current .
Nor I am saying that YOUR amplifier was not well built . But what I said above is the truth , you can be sure .
I am talking about normal ( BUT EXPENSIVE ) amplifiers .
In these cases , NO DOUBT , is obvious that a better power cord
will turn the sound better , due to the no-zero impedance as explained above . So the power cord become a relevant actor of the scene reducing the path resistance and other beneficial effects , out of this thread’s subject , working togheter ( or matching ) with the house wiring .
Please do not ask me about brands or trade marks , this would not be ethical from me , to mention names on the Internet .
But PLEASE , do not go too far , using a USD$ 700 power cord ,
this is a total INSANITY . You can get the best , spending around , USD$ 60 or even USD$ 100 ( at maximum ) , or even less if you do the stuff by yourself .
In other hand , if your preamp or amp has a VERY WELL designed
and built power supply , definitely DOES NOT MATTER what is
going on before the IEC connector ( AC input ) , since you are
feeding the set from a good source of noise free 120 Volts / 60 Hz ( or 220 V / 50 Hz in some countries ) , you can use even a
USD$ 1 PC power cord , and the sound will be the same .
Exactly the same !!!
I will give an example . The best power supply I could ever saw
was the one of COUNTERPOINT SA -11 preamplifier ( around
only 50 or 60 of them were built ) . The set has a total of 17
( seventeen tubes ) where only 4 ( four ) of them are in the
audio signal path . The rest , 13 tubes are in the power supply
stage and more ( around 8 ) three pins integrated regulators ,
mos-fet’s working as constant voltage source , etc , etc.
All of you can be sure , DOES not matter the power cord you
are using , the sound will be ALWAYS the same . I made
all the tests .
This is an extreme example , but illustrate the other side .
I think that is all , and the purpose was to clarify and justify
both sides of the debate .
What I am doing is a “ blend “ among the truth , my own experience , other people experience , the physical principles , the electronics principles , the testimony of my clients and the common sense , to explain and justify all arguments.
But I accept that , the most important , is YOU and YOUR EARS ,
because they are the judge .
Regards ,
Carlos
Sorry, but there is a lot of doubt that they make ANY difference beyond resistance in high current applications.refference said:
I've seen plenty of expensive gear too that surprised me how poorly it was engineered and built.refference said:
Please explain, exactly how a modest engineering textbook designed PSU will benefit from a different power cord (assuming the original was up to the task).
I don't get that myself. And I was also assured that a line filter (like a Corcom) would absolutely ruin my sound; this is in the context of a normal analog power supply. I dunno, if keeping RF and hash out of the power supply is anathema to good sound, maybe the crazies are right and I'm actually deaf.
Keep in mind through this, then, that the ideal cord provides 60Hz (or 50Hz). Period. Hash or RF is undesirable and can/should trivially be filtered out. The impedance of any power cord at 50/60Hz and lower order harmonics is just the DCR no matter what the construction.
The power transformer reflects the cord resistance in series with the primary resistance. This total resistance is multiplied by the stepup ratio and then is in series with the secondary resistance. Let's say that two power cords have a half an ohm difference (and that's a LOT; in most cases it will be a fraction of that). To make this worst case and use a power amp transformer. You've got a primary resistance of (typically) 15 ohms and a stepup ratio of 3. So now, with cord A, the reflected impedance is 45R, with cord B its 46R5.
Secondary impedance will be something like 50R. So the impedance to the rectifier/filter will be 95R vs 96R5. At 200mA draw, that's 0.3V difference on the B+ rail. If you can hear that, you should be in a museum. And you should be rewiring the circuit between power station and you house, which also appears in series.
With PSUD, you can simulate the effect of that difference on ripple and regulation for your favorite filter. When you're done that sim, please tell me that you can hear the difference between 0.02% and 0.021% ripple.
Any amp (and presumably we're building, not buying) with a modest input filter and even moderately competent power supply and grounding will be totally immune to the difference between power cords of sufficient capacity, except in flights of audiophile delusion.
Since very expensive power cable replacements are sold, it is to be expected that the merits are argued.
I work on the premise as expressed by Evenharmonics in post # 9.
So when I wired my house power I installed a dedicated line that supplies ONLY my audio system, and a separate dedicated line for my PC and it's peripherals.
I work on the premise as expressed by Evenharmonics in post # 9.
So when I wired my house power I installed a dedicated line that supplies ONLY my audio system, and a separate dedicated line for my PC and it's peripherals.
Homer nods. The transformation should be as the square of the primary impedance. Doesn't really change the scale issue- a meter here-and-back of 16 gauge copper wire is about 24 milliohms. So my estimate of a 500 milliohm difference is far too gross.
Sorry, this stuff makes no sense. Show me either real measurements or a controlled listening test.
Sorry, this stuff makes no sense. Show me either real measurements or a controlled listening test.
Next week,I hope to be able to post our findings here on power cables,and in our case,one of the tests will be the power cable on a turntables power supply.The second one will be on a tube integrated amplifier.We will be three people,and we will all pass from the listener's chair,while the other two will switch the cables and keep notes.After all three finish the "round",only then we will compare our scores.Two of the three are engineeres,one of them used to work at a British UK Tube amp manufacturer,and the other one has just started production of his 120W/ch Tube integrated amp and phono stage with a radical power supply.More details will be posted.With his permision I might be able to post a couple of pictures of the amplifier.
kuroguy said:
If any one of us wishes to be blindfolded,then he will be.Sure thing is that no one will have any visual contact with the cables.The idea is for everyone to feel as confortable as possible at the time of listening,so to consentrate on his listening as carefully as possible.
One thing I can assure all is that the results we will post to the forum will be 100% true,no matter what these will be.
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