Hi PMA,
And you are evading. Censor exists for a reason.
I agree there really ought to be a resistive component in series with the cap. Otherwise the amplifier may be unstable with this unrealistic load.
-Chris
And you are evading. Censor exists for a reason.
I agree there really ought to be a resistive component in series with the cap. Otherwise the amplifier may be unstable with this unrealistic load.
-Chris
> why do you need it?
Cause it shows also an info about the amp, and i'am curious. Thats all.
Cause it shows also an info about the amp, and i'am curious. Thats all.
Cortez,
PMA is correct; the only purpose of this test would be to assess the stability of the amp with a large electrostatic speaker, though the usual capacitance chosen is 2uF.
In this connection only the test is valid. It's hard work finding amps suitable for ES speakers, and generally only tubes do it comfortably, particularly if you can direct couple.
Cheers,
Hugh
PMA is correct; the only purpose of this test would be to assess the stability of the amp with a large electrostatic speaker, though the usual capacitance chosen is 2uF.
In this connection only the test is valid. It's hard work finding amps suitable for ES speakers, and generally only tubes do it comfortably, particularly if you can direct couple.
Cheers,
Hugh
Hi !
I have designed symasym around "normal" dynamic speakers, and symasym4 at least was not able to drive ESLs, jmateus tried and the outputstage instantly blew. (no chance to hear a single note playing)
Yesterday i finished stereo version of symasym5_3, wow ! The increase in quality is well audible, i don't know if my previous version had a "defect" or new pcb sounds definitely better...
The sound got cleaner/clearer, more detailed, the topend plays "perfect". And i perceived the amp as "quieter", i don't know how to describe that, it's easier to focus on single instruments, you don't have the feeling that there are other sounds masking/hiding the details, the music is flowing more relaxed. Not a single sign of harshness.
Fascinating, regarding the fact that the circuit itself kept unchanged and all parts are the same... Maybe high gain amps are extremely sensitive to layout ?
I still have to check stability of new board, but showing this quality it is unlikely to have any problems... So i can recommend the new pcb. I used the Toshibas as outputdevice and the feedback cap with 10pf, biasing ~50ma.
The next days i will compare different outputdevices, MJL3281/1302,MJL21193/4,SC5200/SA1943, and later MJL0281/0302...
Mike
I have designed symasym around "normal" dynamic speakers, and symasym4 at least was not able to drive ESLs, jmateus tried and the outputstage instantly blew. (no chance to hear a single note playing)
Yesterday i finished stereo version of symasym5_3, wow ! The increase in quality is well audible, i don't know if my previous version had a "defect" or new pcb sounds definitely better...
The sound got cleaner/clearer, more detailed, the topend plays "perfect". And i perceived the amp as "quieter", i don't know how to describe that, it's easier to focus on single instruments, you don't have the feeling that there are other sounds masking/hiding the details, the music is flowing more relaxed. Not a single sign of harshness.
Fascinating, regarding the fact that the circuit itself kept unchanged and all parts are the same... Maybe high gain amps are extremely sensitive to layout ?
I still have to check stability of new board, but showing this quality it is unlikely to have any problems... So i can recommend the new pcb. I used the Toshibas as outputdevice and the feedback cap with 10pf, biasing ~50ma.
The next days i will compare different outputdevices, MJL3281/1302,MJL21193/4,SC5200/SA1943, and later MJL0281/0302...
Mike
Regarding stability under capacitive load
In case the aim is to know stability under capacitive load, different values must be verified. Cortez, start at 100pF and go thru whole range, like 100pf, 1nF, 10nF, 100nF, (1uF). Often interesting results can be seen. The amp may oscillate at 1500pF and may be stable at 1uF. Bode plots ... 😉
In case the aim is to know stability under capacitive load, different values must be verified. Cortez, start at 100pF and go thru whole range, like 100pf, 1nF, 10nF, 100nF, (1uF). Often interesting results can be seen. The amp may oscillate at 1500pF and may be stable at 1uF. Bode plots ... 😉
MikeB said:
Amps with higher gain will usually tend to have higher-impedance nodes, I think, so it seems reasonable that the layout should matter more.
PMA said:
hmm, so much about even harmonics adding richness to the sound ? Might have been too much... The ear seems to be very sensitive to such errors... Interesting how distortions can change sound without sounding distorted... But, it still sounds very musical.Mike
MikeB said:
Do you want a pair of sanken's to try out? email me
I am looking forward to see the mods to the pcb.
Directly from Barcelona.... Symassym has not distortion problems above 2 Kilohertz
Pavel instruments are bad calibrated, bad adjusted.
No distortion, the amplifier sounds fine...only his instruments can see those distortions..so...instrument distortions...may appear in other amplifiers...ahahahaha!
A Christmas gift to Pavel..... an instrument...very usefull...yes...having problems to remove distortion parts from your instruments.
Call something that can fix it to you Pavel.
regards,
Carlos
Pavel instruments are bad calibrated, bad adjusted.
No distortion, the amplifier sounds fine...only his instruments can see those distortions..so...instrument distortions...may appear in other amplifiers...ahahahaha!
A Christmas gift to Pavel..... an instrument...very usefull...yes...having problems to remove distortion parts from your instruments.
Call something that can fix it to you Pavel.
regards,
Carlos
Attachments
Re: Directly from Barcelona.... Symassym has not distortion problems above 2 Kilohert
Carlos ! These distortions were created by my pcb layout, i also measured them...
How is Barcelona ?
Mike
destroyer X said:
Carlos ! These distortions were created by my pcb layout, i also measured them...
How is Barcelona ?
Mike
All rigth...now is clear Mike....your lay out...my circuits have no problem..imagine!
And around 2 Kilohertz!.... impossible for your good symassym.... remove the modifications you done, and install the Miller.
You will see the distortion go away.
Observe Symassym 4...... have it distortions too.... even in your board?...
Well, do not need to answer....may be...because of board.
Well, Hugh is always telling this to us...but some guys listen, others not.
Also he tells that Miller is a need.
That stop resistors are important
That CCS is not the only good idea
That you have too much small current in voltage amplifier circuit.
That some components are very critical related final performance...those silver Mica is one example...remove them and check.
And that humans apreciate some distortions, as tube amplifiers have a lot of them, and thousands love tubes.
Well...at least related the board he prove's that he is rigth.... i think that also related Miller....others things, maybe the future.
He is a too much experienced.... related circuits and sound reproduction result...he already tested all those circuits, i suppose including our beloved Symassym.
You can accept that distortion....in your circuit..
Here!...no distortions....nothing audible....if instruments are showing...shot the instrument!
Barcelona is not so cold, related temperature, referenced what i hope for...maybe my sensorial instruments need some technical, Step by step sequential adjustments.....too!
regards,
Carlos
And around 2 Kilohertz!.... impossible for your good symassym.... remove the modifications you done, and install the Miller.
You will see the distortion go away.
Observe Symassym 4...... have it distortions too.... even in your board?...
Well, do not need to answer....may be...because of board.
Well, Hugh is always telling this to us...but some guys listen, others not.
Also he tells that Miller is a need.
That stop resistors are important
That CCS is not the only good idea
That you have too much small current in voltage amplifier circuit.
That some components are very critical related final performance...those silver Mica is one example...remove them and check.
And that humans apreciate some distortions, as tube amplifiers have a lot of them, and thousands love tubes.
Well...at least related the board he prove's that he is rigth.... i think that also related Miller....others things, maybe the future.
He is a too much experienced.... related circuits and sound reproduction result...he already tested all those circuits, i suppose including our beloved Symassym.
You can accept that distortion....in your circuit..
Here!...no distortions....nothing audible....if instruments are showing...shot the instrument!
Barcelona is not so cold, related temperature, referenced what i hope for...maybe my sensorial instruments need some technical, Step by step sequential adjustments.....too!
regards,
Carlos
Dear Carlos 😉 ,
there was no "special" distortion at 2kHz. The distortion value started to rise with +6dB/oct slope from some 1-2kHz. This is very normal at most amplifiers and those you adore have much higher distortion.
The Mike's had some 0.007% up to 1kHz and some 0.04% at 5kHz, still remarkable values. Both at 16W/4ohm.
there was no "special" distortion at 2kHz. The distortion value started to rise with +6dB/oct slope from some 1-2kHz. This is very normal at most amplifiers and those you adore have much higher distortion.
The Mike's had some 0.007% up to 1kHz and some 0.04% at 5kHz, still remarkable values. Both at 16W/4ohm.
Oh!...dear Pavel, i hope you have enjoyed the gift.
Have a good use with it!
In my Country we have a say...that can be applied related Hugh Dean...the Aksa Chairman...well suceeded man!
" When we are going with the corn to feed our chickens, Hugh is already returning with a fat feeded chicken!"
When Mike was start to walk....Hugh was already comparing amplifiers.
In the same time, Pavel was discussing, argue with friends, that Multimeter is not a thing...that the multitester is an important electronic instrument.
I was assembling other guys amplifiers and i have not that experience...only to listen good amplifiers.
And you can say thousand times about distortions and i will be here to dennie.
Will not transform the sky that is blue in green, just because you want it.
Sky is blue guys!
regards,
Carlos
Have a good use with it!
In my Country we have a say...that can be applied related Hugh Dean...the Aksa Chairman...well suceeded man!
" When we are going with the corn to feed our chickens, Hugh is already returning with a fat feeded chicken!"
When Mike was start to walk....Hugh was already comparing amplifiers.
In the same time, Pavel was discussing, argue with friends, that Multimeter is not a thing...that the multitester is an important electronic instrument.
I was assembling other guys amplifiers and i have not that experience...only to listen good amplifiers.
And you can say thousand times about distortions and i will be here to dennie.
Will not transform the sky that is blue in green, just because you want it.
Sky is blue guys!
regards,
Carlos
There's no audible distortion in my Symassym amplifiers.
And no one of my friends said that too.
So....or your distortion is something very small...something that may bother some bacteria, not bothering humans, or you may have uncalibrated instruments.
Will go out of hotel...bye guys...
Call someone to adjust.
regards
Carlos
And no one of my friends said that too.
So....or your distortion is something very small...something that may bother some bacteria, not bothering humans, or you may have uncalibrated instruments.
Will go out of hotel...bye guys...
Call someone to adjust.
regards
Carlos