Thanks to all:
This is very interesting.
I've had to interpret as best as possible, but I believe that I have a better, more practical understanding at least.
According to Mr. Whitlock, the number of designs out in the pro audio market that do not work well and or are improperly designed..."The Pin 1 Problem" are many.
At this point, I am no longer surprised by the fact that even though all of my equipment (I think) allows the option to tie-in to either XLR/TRS or RCA/TS, that most of time the single ended I/O just works better.
There are situations, of course, where I need the +4 dB level advantage and the mixer, which can accommodate +4 or -10, so far has not been a problem.
I believe additionally that the studio AC wiring can be improved as well.
I'm going to give all of this additional thought, so I'll reply again shortly.
Thanks.
BTW, here is, perhaps a funny or strange question:
Suppose you have two stereo power amps and one pair of speakers.
If you connect the left/right outs from amp A to the speakers and also the left/right outs of amp B also to same speakers, but never have both amps on at the same time, is this doable?
Why, you may ask?
We are always trying out different equipment here, especially amps.
This is very interesting.
I've had to interpret as best as possible, but I believe that I have a better, more practical understanding at least.
According to Mr. Whitlock, the number of designs out in the pro audio market that do not work well and or are improperly designed..."The Pin 1 Problem" are many.
At this point, I am no longer surprised by the fact that even though all of my equipment (I think) allows the option to tie-in to either XLR/TRS or RCA/TS, that most of time the single ended I/O just works better.
There are situations, of course, where I need the +4 dB level advantage and the mixer, which can accommodate +4 or -10, so far has not been a problem.
I believe additionally that the studio AC wiring can be improved as well.
I'm going to give all of this additional thought, so I'll reply again shortly.
Thanks.
BTW, here is, perhaps a funny or strange question:
Suppose you have two stereo power amps and one pair of speakers.
If you connect the left/right outs from amp A to the speakers and also the left/right outs of amp B also to same speakers, but never have both amps on at the same time, is this doable?
Why, you may ask?
We are always trying out different equipment here, especially amps.
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I thought that the link provided below from RANE Corp.
is interesting, especially towards the end of the article.
Pin 1 Revisited
is interesting, especially towards the end of the article.
Pin 1 Revisited
Yea there was a reason I was ragging on a certain German mic manufacturer....
Actually my experience has been that balanced gear mostly just works with sometimes a trivial fix for something with a pin one problem (connect the cable screen to the case instead of pin one, rare among the good stuff these days and getting rarer), it is the unbalanced stuff that causes fear and loathing around here because when it acts up it can be a right pain to sort out (Compashite video links, looking at you).
Of course it might be that my house stock of balanced line gear is NOT JUNK (tm) where a lot of the unbalanced stuff people bring in I would not have allowed out of the R&D department because it is so flaky (Analogue modular synth designers, looking at you!).
Regards, Dan.
Actually my experience has been that balanced gear mostly just works with sometimes a trivial fix for something with a pin one problem (connect the cable screen to the case instead of pin one, rare among the good stuff these days and getting rarer), it is the unbalanced stuff that causes fear and loathing around here because when it acts up it can be a right pain to sort out (Compashite video links, looking at you).
Of course it might be that my house stock of balanced line gear is NOT JUNK (tm) where a lot of the unbalanced stuff people bring in I would not have allowed out of the R&D department because it is so flaky (Analogue modular synth designers, looking at you!).
Regards, Dan.
Hi Tom,
it was not my intention to say how it should be. If you ask me, when sound has the highest priority it is best to avoid balanced topologies as much as possible.
it was not my intention to say how it should be. If you ask me, when sound has the highest priority it is best to avoid balanced topologies as much as possible.
Disagree,
it is best to use the most appropriate engineering to the situation, sometimes at home that is unbalanced interfaces on phono (spit!, but it is sufficient for the job), but you would not get away with that at say the Albert hall or on any major live event (The lines are way too long, and run through some electrically nasty areas).
In fact as I demonstrated above it only takes a mA of current flowing in the screen if a short phono cable to make an unbalanced interface meaningfully less then ideally behaved, so there is a reasonable argument for going balanced even in a domestic system (And certainly in a multi room setup).
it is best to use the most appropriate engineering to the situation, sometimes at home that is unbalanced interfaces on phono (spit!, but it is sufficient for the job), but you would not get away with that at say the Albert hall or on any major live event (The lines are way too long, and run through some electrically nasty areas).
In fact as I demonstrated above it only takes a mA of current flowing in the screen if a short phono cable to make an unbalanced interface meaningfully less then ideally behaved, so there is a reasonable argument for going balanced even in a domestic system (And certainly in a multi room setup).
I was just taking issue with the what I read as your implication that unbalanced was generally the ideal approach, while it does work (if the system is small enough), it does not scale for either amount of kit or physical distance.
Sure inside the box unbal is generally the way to go most of the time, but external interfaces are generally better off balanced in my view.
Regards, Dan.
Sure inside the box unbal is generally the way to go most of the time, but external interfaces are generally better off balanced in my view.
Regards, Dan.
Dan:
From what I understand, you seem to be pretty much in agreement with Bill Whitlock.
I believe he offered an improved version of an op-amp design which is now offered through the THAT Corp. as the InGenius chip?
Practically speaking balanced intefaces at the I/O and single ended inside, with the claimed superior designed (Bill Whitlock) op-amp/InGenius seems to be a good design objective?
I'm not claiming that Bill's or THAT Corp.'s is the best-I wouldn't know.
As for any issue arising like noise/hum/buzz, etc., would I be over-simplifying by stating that the PIN 1 situation is the main culprit as described in the RANE note that I provided a linked to?
Single-ended interfaces w/single ended internals makes up for about 50% of my setup. When I use only RCA stuff-all the way through the monitors, I never have any issues...dead quiet.
When I have to combine various XLR/RCA, depending on which components, sometimes I do have noise, so I need to better understand my interface wiring because when I lift the ground(s) it goes away.
I also believe that since my studio's AC is such that, I have two different outlets connected to two different panel breakers, that ground differential potentials may be a problem.
I have an electrician coming in to re-wire the whole thing.
His suggestion is that the two outlets be connected in series-cascaded one to the other and connected at one 20 amp breaker.
From what I understand, you seem to be pretty much in agreement with Bill Whitlock.
I believe he offered an improved version of an op-amp design which is now offered through the THAT Corp. as the InGenius chip?
Practically speaking balanced intefaces at the I/O and single ended inside, with the claimed superior designed (Bill Whitlock) op-amp/InGenius seems to be a good design objective?
I'm not claiming that Bill's or THAT Corp.'s is the best-I wouldn't know.
As for any issue arising like noise/hum/buzz, etc., would I be over-simplifying by stating that the PIN 1 situation is the main culprit as described in the RANE note that I provided a linked to?
Single-ended interfaces w/single ended internals makes up for about 50% of my setup. When I use only RCA stuff-all the way through the monitors, I never have any issues...dead quiet.
When I have to combine various XLR/RCA, depending on which components, sometimes I do have noise, so I need to better understand my interface wiring because when I lift the ground(s) it goes away.
I also believe that since my studio's AC is such that, I have two different outlets connected to two different panel breakers, that ground differential potentials may be a problem.
I have an electrician coming in to re-wire the whole thing.
His suggestion is that the two outlets be connected in series-cascaded one to the other and connected at one 20 amp breaker.
Yea, Bill is slightly prone to push his own stuff (Either Jensen iron or the InGenius stuff), but he is basically correct.
Practically speaking I would go for that, with the proviso that there also not be a pin one problem.
'Best' is one of those nasty words that changes depending on context, in this case, there is a difference between lowest noise and best rejection of interference, usually the second is more important at line level, but that is an engineering decision and should be based upon the requirements of the application.
Further doing a 'best' in either sense critically depends on budget and it may well be that a better overall result can be achieved by compromising the interfaces for better components elsewhere in the chain (Perfectly reasonable in a closely coupled hifi system for example, but not going to work right under a quarter MW AM site).
A large part of engineering 'best' is choosing what to compromise to meet cost constraints as well as noise and interference budgets, for some things InGenius or good transformers are the way, for others phono connectors and a cap straight onto the top of the volume pot is a better answer, it all depends on context.
Hum/Buzz, within balanced gear is more often then not a pin one issue, but as soon as you start hooking up unbalanced stuff the fact that most gear with balanced IO is class I (earthed) tends to make for hum/buzz due to the unbalanced connections and IR drops in the screens.
If lifting a screen connection makes it go away you probably have pin one pain in play, you should under NO circumstances lift power ground, there is always another way.
General rule of thumb when interfacing unbalanced kit, Hum = two many ground paths, buzz = not enough ground paths.
Useful lead for connecting unbalanced outputs to balanced inputs, connect the tip to pin 2, sleeve to pin 3 and leave pin one unconnected, the balance will not be perfect but it often pushes the hum down below audible levels.
Regards, Dan.
Practically speaking I would go for that, with the proviso that there also not be a pin one problem.
'Best' is one of those nasty words that changes depending on context, in this case, there is a difference between lowest noise and best rejection of interference, usually the second is more important at line level, but that is an engineering decision and should be based upon the requirements of the application.
Further doing a 'best' in either sense critically depends on budget and it may well be that a better overall result can be achieved by compromising the interfaces for better components elsewhere in the chain (Perfectly reasonable in a closely coupled hifi system for example, but not going to work right under a quarter MW AM site).
A large part of engineering 'best' is choosing what to compromise to meet cost constraints as well as noise and interference budgets, for some things InGenius or good transformers are the way, for others phono connectors and a cap straight onto the top of the volume pot is a better answer, it all depends on context.
Hum/Buzz, within balanced gear is more often then not a pin one issue, but as soon as you start hooking up unbalanced stuff the fact that most gear with balanced IO is class I (earthed) tends to make for hum/buzz due to the unbalanced connections and IR drops in the screens.
If lifting a screen connection makes it go away you probably have pin one pain in play, you should under NO circumstances lift power ground, there is always another way.
General rule of thumb when interfacing unbalanced kit, Hum = two many ground paths, buzz = not enough ground paths.
Useful lead for connecting unbalanced outputs to balanced inputs, connect the tip to pin 2, sleeve to pin 3 and leave pin one unconnected, the balance will not be perfect but it often pushes the hum down below audible levels.
Regards, Dan.
You might find these two interesting:
http://www.passdiy.com/pdf/susy.pdf
Amplifier with gain stages coupled for differential error correction - US Patent 5376899 Abstract
They are descriptions of Nelson Pass' supersymmetric topology, with interesting discussion of various other balanced topologies.
http://www.passdiy.com/pdf/susy.pdf
Amplifier with gain stages coupled for differential error correction - US Patent 5376899 Abstract
They are descriptions of Nelson Pass' supersymmetric topology, with interesting discussion of various other balanced topologies.
Dan:
I only lift ground(s) with the ground lift switch(s) provided, thanks for the good advise anyway!
Yes, I have some custom cables with pin 1 disconnected, as well, some with the screen clipped at the receiving end as per the recommendations from rane corp as I have one of their older Swiss arm knife type patch boxes that was made before syd aud con caused them to re-do some of their interfaces.
What is your opinion regarding the electrician's advice for my new wiring?
The USA has some electrical wiring practises that are very different from Europe/UK (which are themselves a little different), so, due to lack of familiarity with domestic practise over there, I cannot give much advice that I am confident in.
As long as the earth is good (run a ground wire wire, I know NEC allows conduit to be used as a ground path which is crap IMHO) and as long as the loop area enclosed by all three conductors is small, it should be all good.
If there are any sub distribution boards involved it is possibly worth getting the electrician to check to make sure the earth/neutral bond is ONLY present at the main panel (Should be the case anyway, but I have seen this cause absolute chaos on a gig over there).
I am not generally a big believer in the mojo that many in the hifi world associate with power, IME it is just not that big a deal unless it is very, very wrong.
There is a common cry among the less then competent sound system operators, "The hum is because of your power", it almost never is, the hum is because they don't understand how to wire the ******** kit so it works!
RCD/GFCI outlets are a good and happymaking thing however, and I commend there use wherever possible.
Regards, Dan.
As long as the earth is good (run a ground wire wire, I know NEC allows conduit to be used as a ground path which is crap IMHO) and as long as the loop area enclosed by all three conductors is small, it should be all good.
If there are any sub distribution boards involved it is possibly worth getting the electrician to check to make sure the earth/neutral bond is ONLY present at the main panel (Should be the case anyway, but I have seen this cause absolute chaos on a gig over there).
I am not generally a big believer in the mojo that many in the hifi world associate with power, IME it is just not that big a deal unless it is very, very wrong.
There is a common cry among the less then competent sound system operators, "The hum is because of your power", it almost never is, the hum is because they don't understand how to wire the ******** kit so it works!
RCD/GFCI outlets are a good and happymaking thing however, and I commend there use wherever possible.
Regards, Dan.
Dan:
Well said. I agree about the house wiring.
I've learned a lot today, although not as knowledgeable as you and the others here, still, I have a better picture on these matters.
Thank you everyone for an informative discussion.
I want to add that diY is a blessing to me.
Well said. I agree about the house wiring.
I've learned a lot today, although not as knowledgeable as you and the others here, still, I have a better picture on these matters.
Thank you everyone for an informative discussion.
I want to add that diY is a blessing to me.
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