With capacitance of colector to ground is conected in parallel supply capacitance, remember on it ...
Upupa Epops said:
Hmm, i always thought of the MJL3281/1302 as "superquality" device ! 😀
I still have to be convinced of the Toshibas beeing better, i will hear !
Mike
Order PCB and construction units yesterday
Hello MikeB,
yesterday i order 4pcs PCB with the symasym5-2 layout over the german PCB contructor jo-ton.de, DE-ebayalias: jonasklein.
The price is excelent and i hope the PCBs also !
And today the most of the construction units of you amp by reichelt.de.
Perhaps at the weekend i can construct the amp and listen to it !
my project page - symasym5-2
Hello MikeB,
yesterday i order 4pcs PCB with the symasym5-2 layout over the german PCB contructor jo-ton.de, DE-ebayalias: jonasklein.
The price is excelent and i hope the PCBs also !
And today the most of the construction units of you amp by reichelt.de.
Perhaps at the weekend i can construct the amp and listen to it !
my project page - symasym5-2
A nearly blown symasym came to life!
Tonight I tried to troubleshoot yesterday's "damage" and try to fix it. I didn't have to! My amps still work ok, voltages measure ok and sound is undistorted. So what was yesterday's distortion? Perhaps it was caused by overheat? But you could still keep your hand on the aluminium "L"s for as long as you wanted, it wasn't that hot
Anyway, perhaps I just was lucky and got away with it at the last minute..
Now I followed Pavel's advice first and lowered Iq to 10 mA. Then I listened for an hour or so. The difference was great. Much much better.
And more closely to the sound I had heard with my previous (wirenest) contruction. I think 80% of the original sound has come back, bass came back, and no harsh high's either🙂
But there's another 20% missing. And I really don't know why. If it doesn't oscillate then what? Perhaps because of low bias? (I had biased my original work to 47mV between output transistor's emitters-that resulted at over 100mA Iq!)
Anyway, I know that remembering what I had heard a few weeks ago, can be very deceptive, and a comparison is not possible anymore. But I really would like to substitute 2SC5200 to my "fake" 2SC3281 and listen to the result. Just in case... 😉
Mike, capacitors that seem alike (100pf and 22pF), are same externally but each one has correct value. They are "precision ceramics" instead of plain ceramics and they are considered better than ceramics. Of course your mileage may vary!
More experiments to come. Play with base stoppers is in the way. Suggestions welcome. I want my symasym sound back!
😎
Tonight I tried to troubleshoot yesterday's "damage" and try to fix it. I didn't have to! My amps still work ok, voltages measure ok and sound is undistorted. So what was yesterday's distortion? Perhaps it was caused by overheat? But you could still keep your hand on the aluminium "L"s for as long as you wanted, it wasn't that hot
Anyway, perhaps I just was lucky and got away with it at the last minute..
Now I followed Pavel's advice first and lowered Iq to 10 mA. Then I listened for an hour or so. The difference was great. Much much better.
And more closely to the sound I had heard with my previous (wirenest) contruction. I think 80% of the original sound has come back, bass came back, and no harsh high's either🙂
But there's another 20% missing. And I really don't know why. If it doesn't oscillate then what? Perhaps because of low bias? (I had biased my original work to 47mV between output transistor's emitters-that resulted at over 100mA Iq!)
Anyway, I know that remembering what I had heard a few weeks ago, can be very deceptive, and a comparison is not possible anymore. But I really would like to substitute 2SC5200 to my "fake" 2SC3281 and listen to the result. Just in case... 😉
Mike, capacitors that seem alike (100pf and 22pF), are same externally but each one has correct value. They are "precision ceramics" instead of plain ceramics and they are considered better than ceramics. Of course your mileage may vary!
More experiments to come. Play with base stoppers is in the way. Suggestions welcome. I want my symasym sound back!
😎
Hi guys,
have followed the thread in the background.. 🙂
Oscillations: May I suggest to connect a capacitor directly from Collector of heatsink on output transistors.
The value can be 100 nF, solder the cap directly to the Collector leg as close as possible to the package(Not PCB!) and the other legg connected directly to heatsink as close as possible to the transistor package with as short leggs as possible.
The other legg of capacitor can be soldered to a crimp connector of ring model(attached a picture) that can be screwed to the heatsink.
Cheers Michael
EDIT: Picture attachement don't work for the moment.. see DIYaudio info.
have followed the thread in the background.. 🙂
Oscillations: May I suggest to connect a capacitor directly from Collector of heatsink on output transistors.
The value can be 100 nF, solder the cap directly to the Collector leg as close as possible to the package(Not PCB!) and the other legg connected directly to heatsink as close as possible to the transistor package with as short leggs as possible.
The other legg of capacitor can be soldered to a crimp connector of ring model(attached a picture) that can be screwed to the heatsink.
Cheers Michael
EDIT: Picture attachement don't work for the moment.. see DIYaudio info.
Hi !
I just tested basestoppers of 4.7ohms and 10pf as feedbackcap, it does not cause problems, but the 10pF does not make me completely lucky, stepresponse degraded a bit, no overshoot yet, just no longer the "perfect" one...
Ah, only scoped, not listened yet ! I only checked for problems after the experience with the removed 22ohms basestoppers...
Mike
I just tested basestoppers of 4.7ohms and 10pf as feedbackcap, it does not cause problems, but the 10pF does not make me completely lucky, stepresponse degraded a bit, no overshoot yet, just no longer the "perfect" one...
Ah, only scoped, not listened yet ! I only checked for problems after the experience with the removed 22ohms basestoppers...
Mike
Re: A nearly blown symasym came to life!
Hi Dimitris,
at first my congratulations to your decision to lower Iq to 10mA, this will guarantee your amplifier alive.
Now let me explain a little bit:
Q:My amps still work ok, voltages measure ok and sound is undistorted. So what was yesterday's distortion?
A: This was really a result of HF oscillations. Their amplitude is Iq dependent, thus temperature dependent, and unfortunately load dependent as well. After turn-on you had oscillations resulting in flat sound. The HF oscillations warmed output devices and shifted their operating points and Gm doubling region, resulting in higher amplitude of oscillations, etc. etc. The other day you switched on the amp the initial conditions of oscillations might have been different (temperature of heatsink) /for the other readers, I am not the Sibylle, but I went through this route/.
10 mA is very wise to assure stability margin in every case but -
Q:I think 80% of the original sound has come back, bass came back, and no harsh high's either🙂 But there's another 20% missing.
A: Right. 10 mA is a little bit underbiased class B output stage. It should be possible to hear it.
For know, 10mA will save the amplifier. For those who prefer olé .... lambada .... let's dance ...... don't worry be happy ..... turn the bias pot to make it hot, but the amp will be smashed.
Of course 10mA is not a final solution, we shall bring the serious one. Maybe base stoppers for Toshibas, maybe to reduce OLG by resistor in parallel to C dom VAS capacitor, maybe playing a game with feedback capacitor (22pf), the weakest point of this topology.
Cheers,
Pavel
dtrif said:Tonight I tried to troubleshoot yesterday's "damage" and try to fix it. I didn't have to! My amps still work ok, voltages measure ok and sound is undistorted. So what was yesterday's distortion? Perhaps it was caused by overheat? But you could still keep your hand on the aluminium "L"s for as long as you wanted, it wasn't that hot
Anyway, perhaps I just was lucky and got away with it at the last minute..
Now I followed Pavel's advice first and lowered Iq to 10 mA. Then I listened for an hour or so. The difference was great. Much much better.
And more closely to the sound I had heard with my previous (wirenest) contruction. I think 80% of the original sound has come back, bass came back, and no harsh high's either🙂
But there's another 20% missing. And I really don't know why. If it doesn't oscillate then what? Perhaps because of low bias? (I had biased my original work to 47mV between output transistor's emitters-that resulted at over 100mA Iq!)
Anyway, I know that remembering what I had heard a few weeks ago, can be very deceptive, and a comparison is not possible anymore. But I really would like to substitute 2SC5200 to my "fake" 2SC3281 and listen to the result. Just in case... 😉
Mike, capacitors that seem alike (100pf and 22pF), are same externally but each one has correct value. They are "precision ceramics" instead of plain ceramics and they are considered better than ceramics. Of course your mileage may vary!
More experiments to come. Play with base stoppers is in the way. Suggestions welcome. I want my symasym sound back!
😎
Hi Dimitris,
at first my congratulations to your decision to lower Iq to 10mA, this will guarantee your amplifier alive.
Now let me explain a little bit:
Q:My amps still work ok, voltages measure ok and sound is undistorted. So what was yesterday's distortion?
A: This was really a result of HF oscillations. Their amplitude is Iq dependent, thus temperature dependent, and unfortunately load dependent as well. After turn-on you had oscillations resulting in flat sound. The HF oscillations warmed output devices and shifted their operating points and Gm doubling region, resulting in higher amplitude of oscillations, etc. etc. The other day you switched on the amp the initial conditions of oscillations might have been different (temperature of heatsink) /for the other readers, I am not the Sibylle, but I went through this route/.
10 mA is very wise to assure stability margin in every case but -
Q:I think 80% of the original sound has come back, bass came back, and no harsh high's either🙂 But there's another 20% missing.
A: Right. 10 mA is a little bit underbiased class B output stage. It should be possible to hear it.
For know, 10mA will save the amplifier. For those who prefer olé .... lambada .... let's dance ...... don't worry be happy ..... turn the bias pot to make it hot, but the amp will be smashed.
Of course 10mA is not a final solution, we shall bring the serious one. Maybe base stoppers for Toshibas, maybe to reduce OLG by resistor in parallel to C dom VAS capacitor, maybe playing a game with feedback capacitor (22pf), the weakest point of this topology.
Cheers,
Pavel
Yesterday I measured the the emitted RF field from the amp. Magnetic compound by loop, electric compound by high impedance probe. Everything in the vicinity of different components on the PCB.
For Iq=10mA, there is no trace of any emitted inner oscillations. Only rectifier 100Hz peaks through 1000uF capacitors can be seen on electric field measurement. The amp is completely stable. This is true for my sample, assembled with Toshiba 2SC5200/2SA1943
When single unshielded piece of wire is connected to input, local AM residuals can be detected in the structure. Shield well your input cables 😉
For Iq=10mA, there is no trace of any emitted inner oscillations. Only rectifier 100Hz peaks through 1000uF capacitors can be seen on electric field measurement. The amp is completely stable. This is true for my sample, assembled with Toshiba 2SC5200/2SA1943
When single unshielded piece of wire is connected to input, local AM residuals can be detected in the structure. Shield well your input cables 😉
Well, i hate discussions, but you count ten steps, and turn to shot Pavel!!!
Of course with water toy pistols.
But you are not observing Charlie red thinking on you now.
My dear extremelly skilled Docktor Pavel
I will ask you to not say that people is lucky because their amplifier did not burn, because oscilate in High Frequencies or Radio Amateur Spectrum...under my nose!...when i am a 35 years experienced Class A Radio Amateur....my 2 Symassyms do not do that...i have Radio frequency probe and RF milivoltimeter in my home....so, i imagine that will be much better if you say that people has much more luck than you have, because i have my strong suspections that a black Nimbus is always sttopped over your home producing that "gray feeling" of tragedy.
Here, sunny place, my Symassym do not oscilate, do not have flat sound, or it has, when i install a pré amplifier on it and i adjust tone controls to flat, or even when i bypass the tone controls to gain one buffers let the signal flow.
Your honored Symassym is not the only Symassym produced in this world, and as there are many working.....not dtriff was lucky because did not explode!.....you and driff had the bad luck to face those problems!...but many others don't!
As i made to your honored person, the invitation to test the equipment, because skilled, i also imagine that i can suggest you to finish and listen to it....and better than that, do not go believing that your sample is the most well constructed wide world sample, as others, not so well constructed, are working fine...so...this criteria...that basis to evaluate, may have some logical problem..... the best constructed are not working...and the worst constructed are working.....of course you did not told us that your construction is the best...but beeing skilled and experienced, it may be, and i suppose that can be very well constructed.... the hipothesis is well accepted by me, that was perfectly done.
I am listening a cold amplifier, with 100 miliampéres, that is the standard current for it.... decided when researching by Bittner.... around 60 miliamps only to output, and other stages need to be "on" too...need to be biased too...AB class,not cutted devices, no device off....off course off devices will not oscilate..... and audio amplifier is called audio oscilator too..... not a steady tone oscilator of a VFO oscilator,but something that oscilates, following the audio input, giving it more amplitude and current....an input tracking amplifier oscilating device....audio oscilates over some zero level, as you learn in your first lesson in school.
I also suggest you to switch the "humble" button, as in near future, the amplifier may work fine and you will have to "eat with ketchup" those oscilating words...ahahahahhaha!
Skilled, better than us, more developed Enginner, invited as beeing some honored Personality, hardly experienced, so good that construct metering to others less skilled enginners, precision electronics......but this can represent a problem, if you decide to inspect if the electron is fat or thin, if it is flowing at 0.99987 of the ligth speed or 0.9989 of the ligth speed as you perceive as better.
You told me that the amplifier have not output coil...that is not finished...so.... alike an airplane with half the jet turbine...and checking if working well!.... stage by stage checking.... some kind of "morge" post morten examination..... well.... this one is alive, and need all parts together...maybe something not misterious, very scientific can help if entire circuit is powered and connected, as more capacitances, inductances and a lot of wonderfull things will help to ballance or unballance this circuit.
I repeat...my "spider", fast construction are not oscilating.... there are no milivolt in any frequency, as i have a Grid Dip meter here, that can capture oscilations till 200 Megahertz...also i have HF receiver in my home...that can detect 0.25 microvolts of radio frequencies, modulated or not...in any kind of modulation, and also suppressed carrier is detected here....my unit....a common unit, a common amplifier, not a lucky amplifier (they are two amplifiers...constructed completelly different one related the other...you can see pictures in this thread..or i can provide new ones) not shielded...one of them inside a MDF box...ahahahah...near transformer..but transformer was turned to dip the magnetic field to minimum signal to first stage.....there are not "star" ground...it is a ring ground and ground plane ground...the rail resistor was increased to 220 ohms, despite the losses of signal level from input...all condensers of course bypassed with 100N...and not more different from Bittner design....oh!...my transistor have small gain related Bittner design....not that i decided to make it better....no!...no!....no!.... i could not find the correct units...so, my input have only 250 gain transistors....matched under 5 percent.... the voltage amplifier BC639 are 140 gain...not good too...the drivers i used some that Hugh prefer, and also are not high gain...the opposite.... and my output are Sankens...gain 90 and 100 respectivelly NPN and PNP.
My amplifier can receive my finger in the input without capture broadcasting...of course some small oscilation will happen, as i have watter inside my flesh...but without beating of frequency, detecting nothing, and i have transistors that can go up to 100 megahertz in all stages, except the output.
I am having the idea that you are thinking that your unit constructed is the best sample...... even not thinking that.... i can, in advance, inform the respectable docktor..that it is not!...as best sample may sound good and not oscilate....mine may be best sample, or sheldon's, or bittner's or someone else...alike Dtriff that made an "spider construction" that sounded good...and the new board did not worked properly.
A long time ago, the first problem was indicated by an old fellow, the Saint Ivy Baron, that the board was problematic....he had hissing...he made his own board and stopped...with the same parts...so...those "misterious" things, considered "magic" by scientists happens...as my magic misterious amplifier is working, and the scientist unit is not.
I am not entirelly happy with you my dear....as you are not the center of the universe...you are red (less than i am because i am furious) but not red enougth to be compared to the center of the earth...as there are too much hot.... and result is not red..it is yellow.
When you reduce my friend's design, to something that can be perceive as not burned because the guy was lucky!....grumpf....10 steps and turn man!
regards...grrrrrrrr!
Carlos😡 😡 😡 😡 😡 😡 😡 😡
Of course with water toy pistols.
But you are not observing Charlie red thinking on you now.
My dear extremelly skilled Docktor Pavel
I will ask you to not say that people is lucky because their amplifier did not burn, because oscilate in High Frequencies or Radio Amateur Spectrum...under my nose!...when i am a 35 years experienced Class A Radio Amateur....my 2 Symassyms do not do that...i have Radio frequency probe and RF milivoltimeter in my home....so, i imagine that will be much better if you say that people has much more luck than you have, because i have my strong suspections that a black Nimbus is always sttopped over your home producing that "gray feeling" of tragedy.
Here, sunny place, my Symassym do not oscilate, do not have flat sound, or it has, when i install a pré amplifier on it and i adjust tone controls to flat, or even when i bypass the tone controls to gain one buffers let the signal flow.
Your honored Symassym is not the only Symassym produced in this world, and as there are many working.....not dtriff was lucky because did not explode!.....you and driff had the bad luck to face those problems!...but many others don't!
As i made to your honored person, the invitation to test the equipment, because skilled, i also imagine that i can suggest you to finish and listen to it....and better than that, do not go believing that your sample is the most well constructed wide world sample, as others, not so well constructed, are working fine...so...this criteria...that basis to evaluate, may have some logical problem..... the best constructed are not working...and the worst constructed are working.....of course you did not told us that your construction is the best...but beeing skilled and experienced, it may be, and i suppose that can be very well constructed.... the hipothesis is well accepted by me, that was perfectly done.
I am listening a cold amplifier, with 100 miliampéres, that is the standard current for it.... decided when researching by Bittner.... around 60 miliamps only to output, and other stages need to be "on" too...need to be biased too...AB class,not cutted devices, no device off....off course off devices will not oscilate..... and audio amplifier is called audio oscilator too..... not a steady tone oscilator of a VFO oscilator,but something that oscilates, following the audio input, giving it more amplitude and current....an input tracking amplifier oscilating device....audio oscilates over some zero level, as you learn in your first lesson in school.
I also suggest you to switch the "humble" button, as in near future, the amplifier may work fine and you will have to "eat with ketchup" those oscilating words...ahahahahhaha!
Skilled, better than us, more developed Enginner, invited as beeing some honored Personality, hardly experienced, so good that construct metering to others less skilled enginners, precision electronics......but this can represent a problem, if you decide to inspect if the electron is fat or thin, if it is flowing at 0.99987 of the ligth speed or 0.9989 of the ligth speed as you perceive as better.
You told me that the amplifier have not output coil...that is not finished...so.... alike an airplane with half the jet turbine...and checking if working well!.... stage by stage checking.... some kind of "morge" post morten examination..... well.... this one is alive, and need all parts together...maybe something not misterious, very scientific can help if entire circuit is powered and connected, as more capacitances, inductances and a lot of wonderfull things will help to ballance or unballance this circuit.
I repeat...my "spider", fast construction are not oscilating.... there are no milivolt in any frequency, as i have a Grid Dip meter here, that can capture oscilations till 200 Megahertz...also i have HF receiver in my home...that can detect 0.25 microvolts of radio frequencies, modulated or not...in any kind of modulation, and also suppressed carrier is detected here....my unit....a common unit, a common amplifier, not a lucky amplifier (they are two amplifiers...constructed completelly different one related the other...you can see pictures in this thread..or i can provide new ones) not shielded...one of them inside a MDF box...ahahahah...near transformer..but transformer was turned to dip the magnetic field to minimum signal to first stage.....there are not "star" ground...it is a ring ground and ground plane ground...the rail resistor was increased to 220 ohms, despite the losses of signal level from input...all condensers of course bypassed with 100N...and not more different from Bittner design....oh!...my transistor have small gain related Bittner design....not that i decided to make it better....no!...no!....no!.... i could not find the correct units...so, my input have only 250 gain transistors....matched under 5 percent.... the voltage amplifier BC639 are 140 gain...not good too...the drivers i used some that Hugh prefer, and also are not high gain...the opposite.... and my output are Sankens...gain 90 and 100 respectivelly NPN and PNP.
My amplifier can receive my finger in the input without capture broadcasting...of course some small oscilation will happen, as i have watter inside my flesh...but without beating of frequency, detecting nothing, and i have transistors that can go up to 100 megahertz in all stages, except the output.
I am having the idea that you are thinking that your unit constructed is the best sample...... even not thinking that.... i can, in advance, inform the respectable docktor..that it is not!...as best sample may sound good and not oscilate....mine may be best sample, or sheldon's, or bittner's or someone else...alike Dtriff that made an "spider construction" that sounded good...and the new board did not worked properly.
A long time ago, the first problem was indicated by an old fellow, the Saint Ivy Baron, that the board was problematic....he had hissing...he made his own board and stopped...with the same parts...so...those "misterious" things, considered "magic" by scientists happens...as my magic misterious amplifier is working, and the scientist unit is not.
I am not entirelly happy with you my dear....as you are not the center of the universe...you are red (less than i am because i am furious) but not red enougth to be compared to the center of the earth...as there are too much hot.... and result is not red..it is yellow.
When you reduce my friend's design, to something that can be perceive as not burned because the guy was lucky!....grumpf....10 steps and turn man!
regards...grrrrrrrr!
Carlos😡 😡 😡 😡 😡 😡 😡 😡
Carlos, pitty you still were not able to get the point at all. Symasyms with 5200/1943 output transistors have problems, those with 3281/1302 have not problems. All my gray view is valid only for 5200/1943, and my gray view rescued Dimitri's amplifier, though your lambada view would send it to hell. The symasym topology is very close to stability edge (this I declare after many hours of simulation of open-loop, closed-loop Bode plots and try to find the cure), on better side with 3281/1302, on worse side with 5200/1943, though they are similar devices. This is not a good indication.
I will refrain from any technical discussion with you for the future, as it is totally uselles. I have to keep me temper well controlled not to break the Forum rules.
I will refrain from any technical discussion with you for the future, as it is totally uselles. I have to keep me temper well controlled not to break the Forum rules.
I apologize if i was rude, my dear Pavel (forum rules)
I stand with my words.
Symassym is a very good amplifier, sound great, have dinamics, good bass, wonderfull sound stage, clear no harshing trebles, astounding voices, compared to JLH (DOZ).
Mine do not oscilate...as i have good transistors....magic ones maybe...as mine may be not scientifical transistors.
I worked 7 years fixing precision instruments.... before you arrive with this job, the had problems...i used to fix them.
Oscilation i face first time when you had 5 years old.... i started my ham station with 9.
Bi stable multivibrator is the way i work.... your switch connected to pride i will turn red..... your switch turn to humble, i will turn friendly.
I hate discussions!....so, because of that, i am not discussing dear Pavel....just debating some aspects of your brilliant analisis...congratulations to you that you could remove the oscilator transistor and replace by a non oscilating unit...goood!
Also i do not feel good when i see people burning Symassym image,....Oh...big fat Charlie cry very much....and sometimes turn red....hehe...may be ashamed red...as furious is not proper to forum rules...so...i am never furious......and it is not kind, when i know (knowledge, skilled ears)
that it is good....if Michael do not want to defend his product....freely offered to forum guys, as a good will gift...i will be ahead of him to be his shield!
If this one oscilates.... well, my dear.... i humble suggest you to replace it to not oscilating device, as people do not want to discover how to destroy the amplifier.
Symassym 4 and 5 are stable, so near the distortion as many others, as almost all amplifiers that sounds good are near the unstability, also GEM is a very nice amplifier, that can oscilate sometimes as result of contruction...a Miller capacitor (not recomended by Graham can fix the problem)......people should not remove the input GEM series resistor too...because speaker will be under risk when you power the amplifier....Aksa is a magnificent, astoundingly superior amplifier.
All those amplifier have my guarantee...everyone can have mine units, non oscilating units, if bring me the faulty unit related those brands!...i will give you mine unit not oscilating and will keep your unit.... guaranteed!
Related Hugh...if someone is faulty...he will give you another one as a compensation gift...will go to your home, if Australia, to replace....as never happened before...will be a kind exception to him to ride his powerfull sport cars over Aussie roads.
regards,
Carlos
I stand with my words.
Symassym is a very good amplifier, sound great, have dinamics, good bass, wonderfull sound stage, clear no harshing trebles, astounding voices, compared to JLH (DOZ).
Mine do not oscilate...as i have good transistors....magic ones maybe...as mine may be not scientifical transistors.
I worked 7 years fixing precision instruments.... before you arrive with this job, the had problems...i used to fix them.
Oscilation i face first time when you had 5 years old.... i started my ham station with 9.
Bi stable multivibrator is the way i work.... your switch connected to pride i will turn red..... your switch turn to humble, i will turn friendly.
I hate discussions!....so, because of that, i am not discussing dear Pavel....just debating some aspects of your brilliant analisis...congratulations to you that you could remove the oscilator transistor and replace by a non oscilating unit...goood!
Also i do not feel good when i see people burning Symassym image,....Oh...big fat Charlie cry very much....and sometimes turn red....hehe...may be ashamed red...as furious is not proper to forum rules...so...i am never furious......and it is not kind, when i know (knowledge, skilled ears)
that it is good....if Michael do not want to defend his product....freely offered to forum guys, as a good will gift...i will be ahead of him to be his shield!
If this one oscilates.... well, my dear.... i humble suggest you to replace it to not oscilating device, as people do not want to discover how to destroy the amplifier.
Symassym 4 and 5 are stable, so near the distortion as many others, as almost all amplifiers that sounds good are near the unstability, also GEM is a very nice amplifier, that can oscilate sometimes as result of contruction...a Miller capacitor (not recomended by Graham can fix the problem)......people should not remove the input GEM series resistor too...because speaker will be under risk when you power the amplifier....Aksa is a magnificent, astoundingly superior amplifier.
All those amplifier have my guarantee...everyone can have mine units, non oscilating units, if bring me the faulty unit related those brands!...i will give you mine unit not oscilating and will keep your unit.... guaranteed!
Related Hugh...if someone is faulty...he will give you another one as a compensation gift...will go to your home, if Australia, to replace....as never happened before...will be a kind exception to him to ride his powerfull sport cars over Aussie roads.
regards,
Carlos
Carlos,
you do not have the point again. I have nothing against symasym, if I had, I would not evaluate it.
The product offered to DIYers must have enough margins to resist component tolerances, ageing, different manufacturers. IMHO this is not the strong point of symasym, but I know that Michael will solve it, as this is beta version.
Regarding my relation to Michael - he is very, very talented, skilled, diligent man and I am proud to co-operate with him. What more, he is very predictable, I know, what behaviour of him I can assume. This is one of the most important qualities for us, living in this part of Europe.
I would not recommend to start with pioneer stories who was younger when sat at the scope first, I also did it from my childhood, and I do not understand why should it be any fault that I went through university.
you do not have the point again. I have nothing against symasym, if I had, I would not evaluate it.
The product offered to DIYers must have enough margins to resist component tolerances, ageing, different manufacturers. IMHO this is not the strong point of symasym, but I know that Michael will solve it, as this is beta version.
Regarding my relation to Michael - he is very, very talented, skilled, diligent man and I am proud to co-operate with him. What more, he is very predictable, I know, what behaviour of him I can assume. This is one of the most important qualities for us, living in this part of Europe.
I would not recommend to start with pioneer stories who was younger when sat at the scope first, I also did it from my childhood, and I do not understand why should it be any fault that I went through university.
I love you with the humble circuit on.
You turn so kind and gentle that i feel the need to go to your town to have a beer with you.
Yeah...i may have misunderstood everything..isnt'it!
All rigth...i will be the nice guy that i always be...hehe....just a moment of passion.
Those thing of the life.... misunderstoodings, amplifiers oscilating...those things..... without too much importance.
As amplifier is guaranteed!
Carlos
You turn so kind and gentle that i feel the need to go to your town to have a beer with you.
Yeah...i may have misunderstood everything..isnt'it!
All rigth...i will be the nice guy that i always be...hehe....just a moment of passion.
Those thing of the life.... misunderstoodings, amplifiers oscilating...those things..... without too much importance.
As amplifier is guaranteed!
Carlos
Carlos, thanks for protecting me/my design, but i don't get your point ?
We have one very simple problem, with the Toshibas used as output devices symasym oscillates !
Well, if these Toshibas would be some rare exotic devices, i would say, ignore it, don't use them !
But, sadly, these Toshibas are the most common used output bjts today, after i ordered some i know why...
They cost only a third of the MJLs...
No one is burning the image of symasym, Pavel confirmed symasym very stable if outputdevices not bugging it.
Pavel also made torture test, passed. He confirmed perfect step response. And no local parasitic oscillations.
After symasym has passed all tests from Pavel, it's image is boosted.
And this is not about skills, Dimitris version is built very well and obviously Pavels and Dimitris's amps behave exactly the same. Jarkaa confirmed that with underbiasing the symasym looses some quality, so after having found the cure, Dimitris and Pavels amps will sing with 100% symasym sound !
Finally, after Pavel has finished with his work, we really can guarantee satisfaction !
We believe you that yours do not oscillate, you use the "much" slower Sankens...
And if i remember correct, you already use 3.3ohms basestoppers.
So, after having survived this "crisis", symasym can be recommended for diy without any doubts or weird feelings...
And i thank Pavel for doing a very complete evaluation.
Michael
We have one very simple problem, with the Toshibas used as output devices symasym oscillates !
Well, if these Toshibas would be some rare exotic devices, i would say, ignore it, don't use them !
But, sadly, these Toshibas are the most common used output bjts today, after i ordered some i know why...
They cost only a third of the MJLs...
No one is burning the image of symasym, Pavel confirmed symasym very stable if outputdevices not bugging it.
Pavel also made torture test, passed. He confirmed perfect step response. And no local parasitic oscillations.
After symasym has passed all tests from Pavel, it's image is boosted.
And this is not about skills, Dimitris version is built very well and obviously Pavels and Dimitris's amps behave exactly the same. Jarkaa confirmed that with underbiasing the symasym looses some quality, so after having found the cure, Dimitris and Pavels amps will sing with 100% symasym sound !
Finally, after Pavel has finished with his work, we really can guarantee satisfaction !
We believe you that yours do not oscillate, you use the "much" slower Sankens...
And if i remember correct, you already use 3.3ohms basestoppers.
So, after having survived this "crisis", symasym can be recommended for diy without any doubts or weird feelings...
And i thank Pavel for doing a very complete evaluation.
Michael
The more distant memory i have from you, is that you dream to see many Symassym
producing pleasure to our forum friends, and this represents almost all forum.
I jumped into your "boat"...because this is something positive, the kind of idea i bougth fast...cooperation!....no money envolved!, no intentions to beat this one, this other, to be better than the other one...well....non competitive idea, only to be happy, to feel good contributing, and to receive some mails of happy guys....our payment is this one.
But we know very well, that many of our forum guys have enormous fear to construct those diy designs, and not from an EE, they turn more and more reserved to construct.
To encourage them, we made all possible tests and three of us constructed and evaluate to search for something near the maximum you could do as designer, and the maximum i could do as a "bad mood listener", trying to find defects...to help the development, having a terrible criticisms aproach...many times you said i smashed you design...and silent for 48 hours feeling bad related me (remenber?)
You produce the schematic and you told...those are the transistors...with those, amplifier is good, is working fine, tested! and i told guys that was guaranteed.
The best can be the analisis system, used by our PHD Docktored In High Electronics, he is using another transistor, and evaluating each stage, searching for unstabilities with the amplifier not complete!, and not with the suggested parts!.
And repeating that oscilates.....that inform, from a man like him, strongly respected in this forum, is something tragic!...as many guys will forget Symassym, the opposite related our needs...in name of micro electronics research.... stage by stage analisis, to prove this, that or those,... forum guys may already perceive the amplifier that may be something alike some "Grenade without pin"...ready to explode if some small mistake is done..... terrible related our intentions!..... Docktor said too, that my personal, and dear friend, that constructed Symassym (dtriff) because i asked him to do, i suggested him strongly to produce, Doc. is saying to him that he is lucky that do not had bigger problems...so...killing softly, i can believe that this is beeing done without any bad intentions, but killing soflty Symassym!.....knowing Dimitris Trifonopoulos as i know, the sacrifice, the effort made to produce, to someone so important in Greece as he is, that have not spare time to mistakes...hundreds of people trying to be with him, to have his professional assistance...he sacrifice his family time to construct, had some fail that is connected obviously with the construction, or parts used, because in the spider mode he had constructed earlier, he had entire success, and in that one not... he receive this cold shower in his heart....with respectable skilled docktor saying that he is happy that nothing worst happened!
So..... pulling the symassym carpet soflty, even without any evil intention , the fact is that Doc. is killing symassym image clearly!
We know how hard is to convince our friends to construct, they feel fear that will not work properly, that may have problems...and listening that some "sixtenth harmonic", for instance as no one said that foolish!.... have something different, many of them will give up...will jump out of the boat and forget Symassym.
Mr. respectable docktor was invited because he use to see defects in almost everything, including his own things...the one is enormously critical person....so..... my conclusion was, if passed as beeing something that people can listen without turn nervous...having hundred defects but beeing listenable, many guys will be encouraged to produce...but always keeping that dark cloud following him..... a very negative feeling, searching for micro oscilations of milivolts..... deducing that those oscilations dinamically will turn enormous milivolts modulating the wave shape.that may be amplified and destroy everything....well..this shows something, to my ignorance, that the amplifier is worst than the gases spelled by the bandit's horse or something alike the half of nothing!
And worst than that...i am having not those oscilations here, and i have two symassym assembled, working fine, with 100 miliamps.
Well man...you asked me to test your car...and them i remove your motor and i installed other that i think may be better.....and the car resulted worst...them i tell you that the car is not fast! and that the exaust tubes have vibrations when car is not in movement.
I do not agree with you Michael, but because my respect on you, because you are the Designer, i will silent about that subject, and will not shield you anymore.
The thread is now very well tracked by you, there are many guys constructing, so, i will take care of my personal mails, as i am very delayed with those friends.
Future will show us the real thing.... and the size of the real thing!
regards,
Carlos
producing pleasure to our forum friends, and this represents almost all forum.
I jumped into your "boat"...because this is something positive, the kind of idea i bougth fast...cooperation!....no money envolved!, no intentions to beat this one, this other, to be better than the other one...well....non competitive idea, only to be happy, to feel good contributing, and to receive some mails of happy guys....our payment is this one.
But we know very well, that many of our forum guys have enormous fear to construct those diy designs, and not from an EE, they turn more and more reserved to construct.
To encourage them, we made all possible tests and three of us constructed and evaluate to search for something near the maximum you could do as designer, and the maximum i could do as a "bad mood listener", trying to find defects...to help the development, having a terrible criticisms aproach...many times you said i smashed you design...and silent for 48 hours feeling bad related me (remenber?)
You produce the schematic and you told...those are the transistors...with those, amplifier is good, is working fine, tested! and i told guys that was guaranteed.
The best can be the analisis system, used by our PHD Docktored In High Electronics, he is using another transistor, and evaluating each stage, searching for unstabilities with the amplifier not complete!, and not with the suggested parts!.
And repeating that oscilates.....that inform, from a man like him, strongly respected in this forum, is something tragic!...as many guys will forget Symassym, the opposite related our needs...in name of micro electronics research.... stage by stage analisis, to prove this, that or those,... forum guys may already perceive the amplifier that may be something alike some "Grenade without pin"...ready to explode if some small mistake is done..... terrible related our intentions!..... Docktor said too, that my personal, and dear friend, that constructed Symassym (dtriff) because i asked him to do, i suggested him strongly to produce, Doc. is saying to him that he is lucky that do not had bigger problems...so...killing softly, i can believe that this is beeing done without any bad intentions, but killing soflty Symassym!.....knowing Dimitris Trifonopoulos as i know, the sacrifice, the effort made to produce, to someone so important in Greece as he is, that have not spare time to mistakes...hundreds of people trying to be with him, to have his professional assistance...he sacrifice his family time to construct, had some fail that is connected obviously with the construction, or parts used, because in the spider mode he had constructed earlier, he had entire success, and in that one not... he receive this cold shower in his heart....with respectable skilled docktor saying that he is happy that nothing worst happened!
So..... pulling the symassym carpet soflty, even without any evil intention , the fact is that Doc. is killing symassym image clearly!
We know how hard is to convince our friends to construct, they feel fear that will not work properly, that may have problems...and listening that some "sixtenth harmonic", for instance as no one said that foolish!.... have something different, many of them will give up...will jump out of the boat and forget Symassym.
Mr. respectable docktor was invited because he use to see defects in almost everything, including his own things...the one is enormously critical person....so..... my conclusion was, if passed as beeing something that people can listen without turn nervous...having hundred defects but beeing listenable, many guys will be encouraged to produce...but always keeping that dark cloud following him..... a very negative feeling, searching for micro oscilations of milivolts..... deducing that those oscilations dinamically will turn enormous milivolts modulating the wave shape.that may be amplified and destroy everything....well..this shows something, to my ignorance, that the amplifier is worst than the gases spelled by the bandit's horse or something alike the half of nothing!
And worst than that...i am having not those oscilations here, and i have two symassym assembled, working fine, with 100 miliamps.
Well man...you asked me to test your car...and them i remove your motor and i installed other that i think may be better.....and the car resulted worst...them i tell you that the car is not fast! and that the exaust tubes have vibrations when car is not in movement.
I do not agree with you Michael, but because my respect on you, because you are the Designer, i will silent about that subject, and will not shield you anymore.
The thread is now very well tracked by you, there are many guys constructing, so, i will take care of my personal mails, as i am very delayed with those friends.
Future will show us the real thing.... and the size of the real thing!
regards,
Carlos
UNTRUE!!!!!!!!!!!
You only mystify, Carlos. In spider mode PCB, Dimitris used 3281/1302 output transistors. With PCB, he used the 5200/1943!!! And you used Sankens?
I am giving up. These banana conditions are the last I am interested in.
You only mystify, Carlos. In spider mode PCB, Dimitris used 3281/1302 output transistors. With PCB, he used the 5200/1943!!! And you used Sankens?
I am giving up. These banana conditions are the last I am interested in.
Carlos, Pavel clearly said that symasym oscillates using these Toshibas... That's the only defect Pavel was able to find until now.
Dimitris used slightly different outputdevices in his first version.
Symasym does not oscillate using the MJLs.
I risk saying: Symasym only oscillates when using Toshibas sc5200/sa1943.
Michael
Dimitris used slightly different outputdevices in his first version.
Symasym does not oscillate using the MJLs.
I risk saying: Symasym only oscillates when using Toshibas sc5200/sa1943.
Michael
Bananas!... could i perceive some racism or something strange?
Well boys.... all i said is untrue.... dtrif used other transistors.
Poor Pavel is beeing attacked by me..... Monster i may be.
Do not need to give up...do not run now!....first finish and make your amplifier work fine.
I will go Michael.... giving up from the thread, gladly, to left room enougth to Mr. Pavel Macura.
I apologize, as i may be delirating because medicine i use to loss weigth.
Bye to all friends..... i am already in the forum...but this thread will be let in the Mr Pavel and Mr Bittner hands.
Bananas have potassium, very good food to fix water in the organism, it produces also some oil that turn us healthy, it is cheap, founded in tropical countries, and also it is used to a lot of animals as food...in special the apes, that apreciate fruits very much.
regards,
Carlos
Well boys.... all i said is untrue.... dtrif used other transistors.
Poor Pavel is beeing attacked by me..... Monster i may be.
Do not need to give up...do not run now!....first finish and make your amplifier work fine.
I will go Michael.... giving up from the thread, gladly, to left room enougth to Mr. Pavel Macura.
I apologize, as i may be delirating because medicine i use to loss weigth.
Bye to all friends..... i am already in the forum...but this thread will be let in the Mr Pavel and Mr Bittner hands.
Bananas have potassium, very good food to fix water in the organism, it produces also some oil that turn us healthy, it is cheap, founded in tropical countries, and also it is used to a lot of animals as food...in special the apes, that apreciate fruits very much.
regards,
Carlos
Re: Order PCB and construction units yesterday
That's great ! 🙂 Which outputdevices are you going to use ?
I am not sure if the MJLs Reichelt is selling, are genuines... (too cheap)
On the other hand, i am not aware of any other manufacturer building them.
Mike
dx.master said:Hello MikeB,
yesterday i order 4pcs PCB with the symasym5-2 layout over the german PCB contructor jo-ton.de, DE-ebayalias: jonasklein.
The price is excelent and i hope the PCBs also !
And today the most of the construction units of you amp by reichelt.de.
Perhaps at the weekend i can construct the amp and listen to it !
my project page - symasym5-2
That's great ! 🙂 Which outputdevices are you going to use ?
I am not sure if the MJLs Reichelt is selling, are genuines... (too cheap)
On the other hand, i am not aware of any other manufacturer building them.
Mike