In the seventies american cars had theire positive battery pole hooked on the chassis of the carbody.JBL had woofers in that time the red speaker connection as negative and the black connection as positive.When you hook those driver on a todays amp and don't turn the connection the cone will move inverse.I think that's why it is important how you wind your coil.
I'm not sure to get it completely, but is it only relevant when the resistor is located in the core of the coil?
Why have the coil , is this the possible slewing we see on canonnica's amplifier can it be removed ?
Anyway Merry Xmas guys , Joe check under your tree , only 24 as requested ..🙂
Anyway Merry Xmas guys , Joe check under your tree , only 24 as requested ..🙂
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Wayne I believe this coil has something to do with possible ringing of the amplifier at or above 200khz,, It,s acting as a damper . It also helps to stabilize the amplifier. Also reduces the damping factor. My christmas tree died I forgot to give it water. Joe
The most important thing is BMW850 didn't find his MKIII sound nice and after he rewind the coils he said the sound improved.There are some things we can't explain and maybe it's good to have some basic rules like how to wind your coil even if it's just for your peace of mind.
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I'd sure like to hear some technical explanation for why this would make any difference. I have used lots of commercially produced air core inductors (for example in xover networks) and have never seen one marked for polarity or any other indication that they need to be wired into a circuit with a particular orientation. The case of speaker coils is not analogous since they sit in the field of a permanent magnet that has a definite polarity. Air does not have a polarity and neither do resistors.
Steve
It had something to do with the input and output of the coil.I've ask Hugh Dean to give an explanation here.I've checked different commercial amps and all the coils are winded the same direction as I stated.
Search the begining this thread and you may find a link
to the main thread where the amplifier is shown first time....and there you will have layout to etch the pcboard at your own home.
regards,
Carlos
to the main thread where the amplifier is shown first time....and there you will have layout to etch the pcboard at your own home.
regards,
Carlos
Thank you Vostro for taking the time to put together this information. I do understand the concept of emitter degeneration as a method of improving the linearity of an amplifier. There is however some debate about whether this applies to the VAS given its function as a transimpedance amplifier. There is also some evidence that emitter resistors in the VAS stage actually increase distortion. The attached link describes this research in great detail.
http://www.sg-acoustics.ch/analogue_audio/power_amplifiers/pdf/audio_power_amp_design_comments.pdf
Thank you again for your kind response.
So all the typing I did was unnecessary 🙂 hehe.
Im no expert on this small details, so Ill only comment once, and leave it to the experts.
Even in the IPS which is voltage fed, there is noise introduced by the degredation resistors.
Pros and Cons.
I follow convention. But Debates will always be there.
Regards
Im no expert on this small details, so Ill only comment once, and leave it to the experts.
Even in the IPS which is voltage fed, there is noise introduced by the degredation resistors.
Pros and Cons.
I follow convention. But Debates will always be there.
Regards
So.... people found difference in sonics because of coil
winding direction?
This sounds crazy.....but.... thinking a little bit more, this may change the interaction with metalic surrounding parts.
Interesting stuff.
Will try it.
regards,
Carlos
winding direction?
This sounds crazy.....but.... thinking a little bit more, this may change the interaction with metalic surrounding parts.
Interesting stuff.
Will try it.
regards,
Carlos
Hi Carlos,
Maybe it is the coil too close to the small heatsink.
I do not know, have no explanation for.
Regards,
Rudy
Maybe it is the coil too close to the small heatsink.
I do not know, have no explanation for.
Regards,
Rudy
I think all of the surrounding metallic parts are aluminum and therefore should not interact with the coils magnetic field. In any case it doesn't explain why the winding direction of the coil would matter.
I like my Hx so much! It's powerful, precise and punchy. It's my passtime to discover all of its subtelties and to learn on a real big fat amp how stuff works... That's why I decorticate it so much and I put it to the test so much, both sonically and on my test bench as well.
I think I've found what'S causing the dent on the downward slope that occurrs on my test bench. It seems to be caused by the VAS bootstrap. In the simulator, If I only put a CCS, the dent doesn't appear. If I put a bootstrap only, the dent is present. That dent is there while using the initial CCS/bootstrap configuration. For all the tests in simulation, I arrange to have the exact same 16mA at the VAS emittor, and to have 54mV bias.
"curious" Mart...
I think I've found what'S causing the dent on the downward slope that occurrs on my test bench. It seems to be caused by the VAS bootstrap. In the simulator, If I only put a CCS, the dent doesn't appear. If I put a bootstrap only, the dent is present. That dent is there while using the initial CCS/bootstrap configuration. For all the tests in simulation, I arrange to have the exact same 16mA at the VAS emittor, and to have 54mV bias.
"curious" Mart...
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Can't explaine it myself but there is sound improvement and so it has to be noticeable on a scoop no?Sound improvement is only there if your winding direction is (wrong) maybe due fase shift?
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Maybe..... these things are tricky...we must see that
well...we must listen...if you say this way it must be true.
regards,
Carlos
well...we must listen...if you say this way it must be true.
regards,
Carlos
Carlos,
I can test it and let you know.I'd checked my Blame ST and saw that I've wind my coils of both boards differently.This would be a good test to know.
I'm happy I could help Rudy to improve the sound.
I can test it and let you know.I'd checked my Blame ST and saw that I've wind my coils of both boards differently.This would be a good test to know.
I'm happy I could help Rudy to improve the sound.
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Well Meanman, i have to say i trust on you
And this gonna be a great helping hand if you do that.
regards,
Carlos
And this gonna be a great helping hand if you do that.
regards,
Carlos
coil winding direction
Not interaction with non-ferrous surroundings.
The other circuits may have a "directionallity".
If the on board coil "adds" the same directionallity then you get increased antenna/aerial effect when current values change.
If the on board coil "subtracts" from the on board circuit aerials/antennae then you may get less of feedback effect.
It is better to remove the coil from the board and instead insert it in the cable route leading to the speaker terminals.
I have been telling you this for years. Won't you listen?
Now back to the "The other circuits may have a "directionallity"."
After having located the coil OFF board, go back and design the PCB layout to minimise the feedback effects of the trace directionality.
One way to avoid this trace directionality is to ensure that all traces are paired as FLOW and RETURN.. This is the Low Loop Area philosophy.
It is this "rule" that is habitually ignored in all the DX amplifier layouts where the power inputs are on opposite sides of the PCB. The worst way to layout the Power Supplies !!!!!
Not interaction with non-ferrous surroundings.
The other circuits may have a "directionallity".
If the on board coil "adds" the same directionallity then you get increased antenna/aerial effect when current values change.
If the on board coil "subtracts" from the on board circuit aerials/antennae then you may get less of feedback effect.
It is better to remove the coil from the board and instead insert it in the cable route leading to the speaker terminals.
I have been telling you this for years. Won't you listen?
Now back to the "The other circuits may have a "directionallity"."
After having located the coil OFF board, go back and design the PCB layout to minimise the feedback effects of the trace directionality.
One way to avoid this trace directionality is to ensure that all traces are paired as FLOW and RETURN.. This is the Low Loop Area philosophy.
It is this "rule" that is habitually ignored in all the DX amplifier layouts where the power inputs are on opposite sides of the PCB. The worst way to layout the Power Supplies !!!!!
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