It not only works , but it works while it oscillates (attached). That was with the "slower" MJL21193/4. A perfect sub for the RCA is the lowly 2n3055/2955 , this worked perfectly. In fact, with bc556 for LTP, BD's for VAS/drivers , and the slow OPS ... it worked perfectly - nearly the same as mine with the fast devices.
This confirms that the topology is tailored to the devices, not the other way around. As it is , this EXACT circuit will not run fast OP
devices. Conversely , the new one will run slow or fast drivers.
with a 4 ohm load , I could see the OP clip before the rails (VI limiter)
at about 3 A.
OS
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"Uncle charlie" did not lie (DX = .03%), I did the RCA , the DX , and the "back to the future". By "did" I mean simulate with the .step directive in EVERY way to find the best operating points. By accident , I noticed what effect the small cap (100nf)in parallel with the bootstrap on the DX has at HF. IT could be another "secret".
Starting with the RCA (.08-.1) then the DX (.03-.04) and finally the new one, THD dropped with each generation. This has to be the parts , as all the other aspects of operation (open loop gain , phase margin) were nearly the same. As this is my first real in-depth investigation of the "good ol' amp" topology , I was surprised at sub .02% readings.
The current source , while some say it may detract from the sound, improves things. 1. PSRR , a no brainer. 2. keeps the differential balanced independent of supply voltage (25 -45v),and 3. everything remained the same regardless of output level/frequency.
Balance seems to be the key to good sound, H3 ,offset and total THD dropped , but H2 increased slightly at the "sweetspot" (attached - orange plot is the "sweetspot") With a 4R load ,a larger bootstrap capacitor (100u)makes for better performance as well.
What was amazing is that the RCA could simulate , clip and oscillate simultaniously without a timestep error in LT (the bootstrap will not allow RF oscillation? ) .
The only feature that will be "handy" is a trimmable CCS to balance the LTP , otherwise this should sound as good as the "supersym". Both these and the sym's will be in the same amp , so I can swap front and rears with the PC for a good A/B listening test. Time to finish the boards..
OS
Starting with the RCA (.08-.1) then the DX (.03-.04) and finally the new one, THD dropped with each generation. This has to be the parts , as all the other aspects of operation (open loop gain , phase margin) were nearly the same. As this is my first real in-depth investigation of the "good ol' amp" topology , I was surprised at sub .02% readings.
The current source , while some say it may detract from the sound, improves things. 1. PSRR , a no brainer. 2. keeps the differential balanced independent of supply voltage (25 -45v),and 3. everything remained the same regardless of output level/frequency.
Balance seems to be the key to good sound, H3 ,offset and total THD dropped , but H2 increased slightly at the "sweetspot" (attached - orange plot is the "sweetspot") With a 4R load ,a larger bootstrap capacitor (100u)makes for better performance as well.
What was amazing is that the RCA could simulate , clip and oscillate simultaniously without a timestep error in LT (the bootstrap will not allow RF oscillation? ) .
The only feature that will be "handy" is a trimmable CCS to balance the LTP , otherwise this should sound as good as the "supersym". Both these and the sym's will be in the same amp , so I can swap front and rears with the PC for a good A/B listening test. Time to finish the boards..
OS
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Hi all,
Can somebody explain to me? I'm referring to the circuit input stage posted by OS, i have seen quite a few similar circuits with resistor connected to ground (R27 + diodes) but dont know exactly the purpose, few questions...
1.does it give improvement to sonics, distortion?
2.is it to change the input impedance?
3.is it the one called lifted ground?
Appreciate your feedback.
B.regards,
mannycc
Can somebody explain to me? I'm referring to the circuit input stage posted by OS, i have seen quite a few similar circuits with resistor connected to ground (R27 + diodes) but dont know exactly the purpose, few questions...
1.does it give improvement to sonics, distortion?
2.is it to change the input impedance?
3.is it the one called lifted ground?
Appreciate your feedback.
B.regards,
mannycc
1. no
2. no
3. The resistance (10R or 22r) will reduce a ground loop between different components and in case of a real screwup (live chassis or improper house wiring) , break the connection between signal ground and the real ground (physically burn out). The diodes will short out a minor potential between grounds.
With a minor ground loop the circuit will drastically reduce hum.
If the DC feedback cap and other critical small signal grounds of the amp also go to this "lifted ground" ,they also benefit from this technique. You do not connect the rail capacitor grounds to this point.
OS
2. no
3. The resistance (10R or 22r) will reduce a ground loop between different components and in case of a real screwup (live chassis or improper house wiring) , break the connection between signal ground and the real ground (physically burn out). The diodes will short out a minor potential between grounds.
With a minor ground loop the circuit will drastically reduce hum.
If the DC feedback cap and other critical small signal grounds of the amp also go to this "lifted ground" ,they also benefit from this technique. You do not connect the rail capacitor grounds to this point.
OS
Member
Joined 2009
Paid Member
ostripper said:
That's a nice piece of sim work. I haven't tried the .step before, usually doing it manually. The TGM uses a larger bootstrap than DX, more like 220uF but 100uF is more common in this position.
I think the comments about current sources not sounding nice applies to current mirrors - they behave differently than the simple current source.
When i started to make the Dx, i was thinking it would have 0.5% THD
Was a very nice surprise when i learned how to use the analisis into the simulator.
I really do not think good measurements guarantees good performance, may be a nice indications, that it is possible the amplifier sounds fine... i have listen sterile very low distortion units and lovely high distortion units.
Since very young i found that topologie sounding delicious, listening many brands and building several schematics...has a character, a personalitty, some punch on bass and some warm sound... suddenly pretty good recordings shows it can reproduce treble very well too...not my amplifier quality...the topologie quality..all them had that kind of sonics.
Aksa is different, another decision taken into the bass, having 3 db losses into 40 hertz (decisions taken when he made it i think)..and this to the Aksa 55 standard..he made other ones..Nirvana and Nirvana plus.
You see...the Scott sounds almost the same...and hundreds of others made by Sony, JVC, Kenwood, Marantz, Pioneer and all major brands..the circuit is inside several chip amplifiers, from the STK to some Panasonic 4 channel chip amplifier going to some TDA chips too.
If you keep the long tail with resistances.... the differential colector loads using resistances... the traditional simple VAS without emitter resistance.... bootstrapp and emitter follower, not using mirror, current sinks, CCS, voltage regulators, double differential (complementary alike Leach amplifier), if you do not use tripple darlington (sometimes oscilates..oscilations driven by the signal..superimposed to high frequencies)... them you gonna have this style of sound...marvellous sonics...warm feeling sound... strong punch on bass...interesting sound stage..not wide open, not strange or over dimensioned.
I took the care to try almost everything..maybe not all possible combinations because the number is very high..but i have installed CCS into differential..also current sink into the differential collectors, have installed CCS there too, have installed shunts, voltage regulators, double differential, differential VAS, complementary VAS, darlington VAS, Doctor Self style VAS, over current protection into the output...VBE voltage limiters....CCS into the drivers, and other styles of connection into the output, different from the emitter follower.
Those modifications changed the sound character completelly, as produce another topologie..or a modified topologie...one of them resulted into the HRII...other resulted into the Precision...the ones i have appreciated i have made other amplifiers, other models using them...but sounds different..one has middle range..other plays very loud and you be surprised how powerfull it can be (HRII), other is an earthquake (DHR Turbo)..and so on.
There are hundreds of possibilites with the surrounding parts applied to differential, vas and output..and each one of them will sound different.
My prefered sound, to listen in my home, is the Standard....to a party i would use others, to listen voices another one...and so on.
To listen sound stage, then Aksa is unbeatable, as i do not use black gates to bother me.
I have done those testings you are doing..it is fun to do....enjoy yourselves with that...and i hope you find something different i could not find.
All i have made was to try other currents into differential, into VAS, into driver and also into the output as stand by current and to adjust the final one (capacitors and coupling, and levels, and filters) listening and asking help to friends to evaluate by comparison and calling children to listen (they are not politics, have not preference and will protect nobody and no brand)
Was a hard work but easy to make that topologie sound fine..it sounds fine by it's own nature..you can replace all condensers and listen again and it will sound nice (but not the mutant black gates, this is masoquism to use them..people that wants to suffer)
regards,
Carlos
Was a very nice surprise when i learned how to use the analisis into the simulator.
I really do not think good measurements guarantees good performance, may be a nice indications, that it is possible the amplifier sounds fine... i have listen sterile very low distortion units and lovely high distortion units.
Since very young i found that topologie sounding delicious, listening many brands and building several schematics...has a character, a personalitty, some punch on bass and some warm sound... suddenly pretty good recordings shows it can reproduce treble very well too...not my amplifier quality...the topologie quality..all them had that kind of sonics.
Aksa is different, another decision taken into the bass, having 3 db losses into 40 hertz (decisions taken when he made it i think)..and this to the Aksa 55 standard..he made other ones..Nirvana and Nirvana plus.
You see...the Scott sounds almost the same...and hundreds of others made by Sony, JVC, Kenwood, Marantz, Pioneer and all major brands..the circuit is inside several chip amplifiers, from the STK to some Panasonic 4 channel chip amplifier going to some TDA chips too.
If you keep the long tail with resistances.... the differential colector loads using resistances... the traditional simple VAS without emitter resistance.... bootstrapp and emitter follower, not using mirror, current sinks, CCS, voltage regulators, double differential (complementary alike Leach amplifier), if you do not use tripple darlington (sometimes oscilates..oscilations driven by the signal..superimposed to high frequencies)... them you gonna have this style of sound...marvellous sonics...warm feeling sound... strong punch on bass...interesting sound stage..not wide open, not strange or over dimensioned.
I took the care to try almost everything..maybe not all possible combinations because the number is very high..but i have installed CCS into differential..also current sink into the differential collectors, have installed CCS there too, have installed shunts, voltage regulators, double differential, differential VAS, complementary VAS, darlington VAS, Doctor Self style VAS, over current protection into the output...VBE voltage limiters....CCS into the drivers, and other styles of connection into the output, different from the emitter follower.
Those modifications changed the sound character completelly, as produce another topologie..or a modified topologie...one of them resulted into the HRII...other resulted into the Precision...the ones i have appreciated i have made other amplifiers, other models using them...but sounds different..one has middle range..other plays very loud and you be surprised how powerfull it can be (HRII), other is an earthquake (DHR Turbo)..and so on.
There are hundreds of possibilites with the surrounding parts applied to differential, vas and output..and each one of them will sound different.
My prefered sound, to listen in my home, is the Standard....to a party i would use others, to listen voices another one...and so on.
To listen sound stage, then Aksa is unbeatable, as i do not use black gates to bother me.
I have done those testings you are doing..it is fun to do....enjoy yourselves with that...and i hope you find something different i could not find.
All i have made was to try other currents into differential, into VAS, into driver and also into the output as stand by current and to adjust the final one (capacitors and coupling, and levels, and filters) listening and asking help to friends to evaluate by comparison and calling children to listen (they are not politics, have not preference and will protect nobody and no brand)
Was a hard work but easy to make that topologie sound fine..it sounds fine by it's own nature..you can replace all condensers and listen again and it will sound nice (but not the mutant black gates, this is masoquism to use them..people that wants to suffer)
regards,
Carlos
Member
Joined 2009
Paid Member
Of course...but the test is made by yourself...comparison method
this way you gonna be able, with a fixed speaker, considered reasonable or good, to conclude the amplifier is better.
I mean...it is scientific, by your and me, to say some amplifier is better or tune better than another one, doing a scientifically controled A to B test..a blind test that is something not very easy to do and need a lot of skill to do it.
I hope you know all the steps.
Because i can take two amplifiers..yours and mine..and listen them separatelly, without compare with the same music, same time and same speaker..then i am unable to say the one is better to my taste..... this is already subjective, but entirelly unprecise..one must play followed by the other, same power, same audio source, same music and almost same time..time between one and other cannot be bigger than 1 second.
there's no sound memory...or there's no conditions to evaluate using memory.... this is alike "i think so"...or "it seems to me"..this is not science... a lot of psychological factors enters the judgement....knowing the one you have made..this one gonna be, probable, the winner...because of that blind testing.
I wrote that, tenths of times into the Dx thread...i hope you has this knowledge by yourself, have learned because it is very obvious, or have readed what i have learned with the older folks, more experienced than me, that started that whole thing down the seventies.
Only family is entering, now a days, my mail box... filter applied..a lot of spam and viruses have entered....i have solved the problem but to avoid repeat that stuff i have applied a selective filter to mails to enter.
I would like to know, from you and Ostripper, how old you are folks..sometimes i feel you are very young..sometimes not..can you please inform to your old friend Charlie?
Carlos
this way you gonna be able, with a fixed speaker, considered reasonable or good, to conclude the amplifier is better.
I mean...it is scientific, by your and me, to say some amplifier is better or tune better than another one, doing a scientifically controled A to B test..a blind test that is something not very easy to do and need a lot of skill to do it.
I hope you know all the steps.
Because i can take two amplifiers..yours and mine..and listen them separatelly, without compare with the same music, same time and same speaker..then i am unable to say the one is better to my taste..... this is already subjective, but entirelly unprecise..one must play followed by the other, same power, same audio source, same music and almost same time..time between one and other cannot be bigger than 1 second.
there's no sound memory...or there's no conditions to evaluate using memory.... this is alike "i think so"...or "it seems to me"..this is not science... a lot of psychological factors enters the judgement....knowing the one you have made..this one gonna be, probable, the winner...because of that blind testing.
I wrote that, tenths of times into the Dx thread...i hope you has this knowledge by yourself, have learned because it is very obvious, or have readed what i have learned with the older folks, more experienced than me, that started that whole thing down the seventies.
Only family is entering, now a days, my mail box... filter applied..a lot of spam and viruses have entered....i have solved the problem but to avoid repeat that stuff i have applied a selective filter to mails to enter.
I would like to know, from you and Ostripper, how old you are folks..sometimes i feel you are very young..sometimes not..can you please inform to your old friend Charlie?
Carlos
That is a one of the secrets , Self and even me at first went went to the point of eliminating this resistor and just letting the CCS determine the tail current. when I built the "supersym" I left a set of pads there so I could experiment with tail resistor values of 2k - 15k.
Having the active CCS there is nice because ANY value tail resistor will be compensated for by the CCS (mA stays exactly the same). The sound of any amp is mostly determined by the differential , as is the loopgain , so different components here really make for the character of the amp . The output transistors don't add a lot to the sound unless they are "not up to the job" (too small , not biased properly).
I also did like you and tried no emitter resistor , 22r , 47r on the DX VAS. The bass suffered at 47r , 22 and none (0)was best(BD139). On the faster 2SC/SA's , you had to do 22r , or
you had a oscillator. I tried many flavors of these , and even if they simulate well and work well , they don't SOUND well..
maybe good for PA , outdoors , but not for MY music.This is a good one , like the symasym. I built this one wrong the first time (not big enough). You put the symasym LTP/VAS on a DX turbo output stage and WOW , you have a amp that will push 2 each of your big speakers PER channel (3 ohms) ALL the way and sound wonderful in mids and highs as well (like original sym).
You are welcome to contribute any knowledge or experience . I always welcome a different view . This includes listening (subjective tests) , as this is reason we burn our fingers on the iron
BTW , I am not young (45) , but look 30 ish (Stay out of the sun = hide in the rainforest.OS
I would like to say to you Ostripper, and to bigun, also to all forum folks
In special the ones have scientific minds that we CANNOT trust into audiophile evaluation... we are unfair, we have beliefs, tendences, ideas about... all that stuff influences our evaluations, also our needs, our psychological self, our pride.
Observe what happened that made me LEARN A LOT!
1) I have invited friends to listen the Aksa 55 that arrived i 2004...they were deeply impressed and found it wonderfull..was a figth , as they asked schematics and i could not give them.
2) Invited once again, weeks latter, i was presenting them the Aksa 55 Nirvana Plus, with several modifications into the circuit...amplifier not shown, inside the case, covered...in the reality was my own version of Aksa..something alike the Dx..but worse than the Dx we have now a days... they found better...much better... and once again a figth because the schematics.... attention..was not Aksa..was mine one!...so i have beated Aksa?....NO!
3) Invited them to a comparison with amplifiers...i told them one was Aksa 55 and the other was my amplifier version (that old one
they imagine was Aksa because i have lied to them)..now was comparison... Blind...no one could see the amplifiers..i was there with a switch in my hands, my back to them (not to see my face smile) and sitted over the speaker they were listening.... same power..same musical source...same volume..same...all the same..same speaker..but two different amplifiers...Aksa and mine into a comparative testing, blind, from A to B.
Aksa have smashed my amplifier..all them voted to Aksa...mine one, considered good with the last meeting was considered mufled in trebles, not clear voices and too much bass... and Aksa was considered wonderfull ( and it really is wonderfull )
You see how people behaves....first Aksa was famous..so.. evaluation was good... second was Aksa special, a better Aksa..so... was wonderfull once again...they have evaluated fame, cost and brand..not sound!
But into the comparative..well... the reality comes to us!.
Attention with that stuff folks.... we use to think heavy ones are better... the most pretty ones are better..the most high technological ones are better, the most modern ones are better, the most expensive ones as better, the more rare ones as better and sometimes the most distorted ones (louder, even into the same real power sounds lowder to human ears) are better.
You gonna have a lot of surprises doing serious testing... a lot of surprises, many myths will be smashed facing the reality.
regards,
Carlos
In special the ones have scientific minds that we CANNOT trust into audiophile evaluation... we are unfair, we have beliefs, tendences, ideas about... all that stuff influences our evaluations, also our needs, our psychological self, our pride.
Observe what happened that made me LEARN A LOT!
1) I have invited friends to listen the Aksa 55 that arrived i 2004...they were deeply impressed and found it wonderfull..was a figth , as they asked schematics and i could not give them.
2) Invited once again, weeks latter, i was presenting them the Aksa 55 Nirvana Plus, with several modifications into the circuit...amplifier not shown, inside the case, covered...in the reality was my own version of Aksa..something alike the Dx..but worse than the Dx we have now a days... they found better...much better... and once again a figth because the schematics.... attention..was not Aksa..was mine one!...so i have beated Aksa?....NO!
3) Invited them to a comparison with amplifiers...i told them one was Aksa 55 and the other was my amplifier version (that old one
they imagine was Aksa because i have lied to them)..now was comparison... Blind...no one could see the amplifiers..i was there with a switch in my hands, my back to them (not to see my face smile) and sitted over the speaker they were listening.... same power..same musical source...same volume..same...all the same..same speaker..but two different amplifiers...Aksa and mine into a comparative testing, blind, from A to B.
Aksa have smashed my amplifier..all them voted to Aksa...mine one, considered good with the last meeting was considered mufled in trebles, not clear voices and too much bass... and Aksa was considered wonderfull ( and it really is wonderfull )
You see how people behaves....first Aksa was famous..so.. evaluation was good... second was Aksa special, a better Aksa..so... was wonderfull once again...they have evaluated fame, cost and brand..not sound!
But into the comparative..well... the reality comes to us!.
Attention with that stuff folks.... we use to think heavy ones are better... the most pretty ones are better..the most high technological ones are better, the most modern ones are better, the most expensive ones as better, the more rare ones as better and sometimes the most distorted ones (louder, even into the same real power sounds lowder to human ears) are better.
You gonna have a lot of surprises doing serious testing... a lot of surprises, many myths will be smashed facing the reality.
regards,
Carlos
Member
Joined 2009
Paid Member
I already find it hard to hear some of the differences in sound when I change things in my amplifier, but I can hear something is changing. When I know that a change is made to the amplifier, I expect a change in the sound, this makes it hard to be objective. I ask my wife to listen and when she says there wasn't a change then I know I'm chasing something too small.
I remember seeing on the TV, they fed people orange juice that was not orange colour, they told them it was a different juice. They asked them how it tasted and the people said it tasted good.
I remember seeing on the TV, they fed people orange juice that was not orange colour, they told them it was a different juice. They asked them how it tasted and the people said it tasted good.
Yes..i understand that because i use to make the same
the problem is that we go, sometimes, running in circles, alike a dog trying to catch it's own tail...we go changing, and changing, and changing, and sometimes we mess the whole thing because we loose "Reference".... because of that, another circuit must be left in peace, without tweaks, original, to compare...because we go tweaking, and depending how biased you are... you may mess everything or even not to increase nothing the way you have imagined.
When you place a capacitor into a circuit, dessoldering other, without test that stuff using a switch, to compare carefully one and other, you will start with your "belief" that something may result different... sometimes "nothing" results different into the reality, but you feel, perceive this way, because your own will, this does not depends on your conscience..you never know what is going on deep into your brain, the negotiations running inside your Brain departments about that change.... enters beliefs, pride, spectations, wishes, empathy with the new capacitor colour, the price, the fact cost was high, because it is pretty, because someone told you it is good..because the colour is finer than the other one...man..there's a lot of conversations happening into your brain departments that you=conscience,can know!
Attention with that...the worse enemie we have is ourSELF
Self is a psychologic therm... that may seems pride, self defense, self steem, wishes, desires, feelings, conscience and so on...
I am sorry to say...this is not for you..but to everybody including ME..i do not believe in results, in evaluations, without A to B comparison.
I do not believe you, not the humanity, nor the simulator and not me...only comparison, judged by other folks than me, than the designer..a blind testing..... some other method, as subjective listening and evaluation cannot detect a better one..because the word better, has inside to itself "better than what?"...other methods, i think enter the sector of ridiculous... delirium, imagination and so on..nothing valuable.
I do not think you are idiot..the opposite, not Ostripper and nor forum folks in special....but i think we are not competent to judge audio amplifier performance because depends many things, acoustics, speaker and a lot of other things, including the friends are with you, how you're feeling today and hundreds of things...i think a method, used alike a machine, with humans that have no connection with audio, or you, will evaluate much better, and better than my friends that loves me.
regards,
Carlos
the problem is that we go, sometimes, running in circles, alike a dog trying to catch it's own tail...we go changing, and changing, and changing, and sometimes we mess the whole thing because we loose "Reference".... because of that, another circuit must be left in peace, without tweaks, original, to compare...because we go tweaking, and depending how biased you are... you may mess everything or even not to increase nothing the way you have imagined.
When you place a capacitor into a circuit, dessoldering other, without test that stuff using a switch, to compare carefully one and other, you will start with your "belief" that something may result different... sometimes "nothing" results different into the reality, but you feel, perceive this way, because your own will, this does not depends on your conscience..you never know what is going on deep into your brain, the negotiations running inside your Brain departments about that change.... enters beliefs, pride, spectations, wishes, empathy with the new capacitor colour, the price, the fact cost was high, because it is pretty, because someone told you it is good..because the colour is finer than the other one...man..there's a lot of conversations happening into your brain departments that you=conscience,can know!
Attention with that...the worse enemie we have is ourSELF
Self is a psychologic therm... that may seems pride, self defense, self steem, wishes, desires, feelings, conscience and so on...
I am sorry to say...this is not for you..but to everybody including ME..i do not believe in results, in evaluations, without A to B comparison.
I do not believe you, not the humanity, nor the simulator and not me...only comparison, judged by other folks than me, than the designer..a blind testing..... some other method, as subjective listening and evaluation cannot detect a better one..because the word better, has inside to itself "better than what?"...other methods, i think enter the sector of ridiculous... delirium, imagination and so on..nothing valuable.
I do not think you are idiot..the opposite, not Ostripper and nor forum folks in special....but i think we are not competent to judge audio amplifier performance because depends many things, acoustics, speaker and a lot of other things, including the friends are with you, how you're feeling today and hundreds of things...i think a method, used alike a machine, with humans that have no connection with audio, or you, will evaluate much better, and better than my friends that loves me.
regards,
Carlos
There is a better way.. Listen to your new one for a week , see what it "does for you".. movies , MP3's , CD's .. then go back to the japanese receiver. Sometimes you will be amazed at how good we DIYer's have it. (much better sound).
Another REAL factor that makes our amps sound so much better IS parts. Like the power supply... The japanese unit has 8200 or 10000uf X 2 for both channels 55-0-55v rails, but even my kids little DX clones have 6800u X 2 for each channel and the "supersym" has 31,800uF X 2 for each channel. These are parts , and these are parts you can HEAR (not subjective).
When I make these little bootstrap amps , The 6800uf 's will go RIGHT NEXT to the outputs (1" on PCB).
OS
That's the reason why the myth black gate survived so long time
Giving a break, when return you will listen differences, even when they have not.... maybe even changes..but if does not change, you gonna perceive something different... all illusion when nothing was changes..your mind operating the stuff, your desires, another change to that equipment, or the opposite, you may have the need to smash the equipment because frustration, to judge it bad, to dennie the qualities..frustration, as you have not perceive nothing extra terrestrian or from paradise listening..revolution against the brand, or designer (professor)
Remove the black gates while your evaluator friend is out and call him once again..he will perceive changed.
Them call him once again in the other day and change nothing..play the same music once again and tell him you have changed something...he will feel change..even if you say changed nothing.
When someone comes to evaluate, he is in charge to be competent...he seems your spectation is that he will say something intelligent..this makes the evaluator feel (tune his brain) to listen something different.
We tune, we remove noises, we adjust..we listen basses into portable radios that have no basses, we remove noises when we are talking into the telephone with the woman we love...all the street noises and party noises and musics disappears....you are human..... a much more complex thing than this simple method we use to test things.
We have to take care, or our research will be a joke, something to laugh about!... something that in the future, when you really realise those things, will make you feel ashamed by yourself as i was.
regards,
Carlos
Giving a break, when return you will listen differences, even when they have not.... maybe even changes..but if does not change, you gonna perceive something different... all illusion when nothing was changes..your mind operating the stuff, your desires, another change to that equipment, or the opposite, you may have the need to smash the equipment because frustration, to judge it bad, to dennie the qualities..frustration, as you have not perceive nothing extra terrestrian or from paradise listening..revolution against the brand, or designer (professor)
Remove the black gates while your evaluator friend is out and call him once again..he will perceive changed.
Them call him once again in the other day and change nothing..play the same music once again and tell him you have changed something...he will feel change..even if you say changed nothing.
When someone comes to evaluate, he is in charge to be competent...he seems your spectation is that he will say something intelligent..this makes the evaluator feel (tune his brain) to listen something different.
We tune, we remove noises, we adjust..we listen basses into portable radios that have no basses, we remove noises when we are talking into the telephone with the woman we love...all the street noises and party noises and musics disappears....you are human..... a much more complex thing than this simple method we use to test things.
We have to take care, or our research will be a joke, something to laugh about!... something that in the future, when you really realise those things, will make you feel ashamed by yourself as i was.
regards,
Carlos
Also i do not think, we, dyers are good...i am not
last week i have installed a cheap sound system into the computer, when i used a DHR Turbo.
I found the cheap system very good..costing 20 USD.... having a subwoofer pumping nice 5 volts of bass (TDA2030 in bridge mode) and some satelite speakers, no surround effect or something alike..passive filters to woofer and digital volume to speakers...Durabrand is the name of the thing.
Loose for my audio equipment.... but my condensers cost was more than that whole equipment..so..i have doubts how good we are spending so big money, with so big power, and a Chinese build a box with wood powder and cover with plastic, use a soft efficient speaker to move a lot with 5 yo 7 volts RMS and makes a nice sound...not so clear, not so powerfull, not so loud, but good enougth to be listening.
I think we use to create some targets, some small details to listen, alike the bell to sound alike that bell, not that other bell...something is a little bit crazy.
I said..the stupid, ridiculous system..the chep THING, is producing a nice sound..not so good as my system, but good enougth, beeing small, to me to remove the enormous speaker and enormous amplifiers from my listening room.
So...i do not know if we, dyers, are so good this way.... i think we think we are...but i really have doubts about others.
I am not!...maybe we are only arrogant.
regards,
Carlos
last week i have installed a cheap sound system into the computer, when i used a DHR Turbo.
I found the cheap system very good..costing 20 USD.... having a subwoofer pumping nice 5 volts of bass (TDA2030 in bridge mode) and some satelite speakers, no surround effect or something alike..passive filters to woofer and digital volume to speakers...Durabrand is the name of the thing.
Loose for my audio equipment.... but my condensers cost was more than that whole equipment..so..i have doubts how good we are spending so big money, with so big power, and a Chinese build a box with wood powder and cover with plastic, use a soft efficient speaker to move a lot with 5 yo 7 volts RMS and makes a nice sound...not so clear, not so powerfull, not so loud, but good enougth to be listening.
I think we use to create some targets, some small details to listen, alike the bell to sound alike that bell, not that other bell...something is a little bit crazy.
I said..the stupid, ridiculous system..the chep THING, is producing a nice sound..not so good as my system, but good enougth, beeing small, to me to remove the enormous speaker and enormous amplifiers from my listening room.
So...i do not know if we, dyers, are so good this way.... i think we think we are...but i really have doubts about others.
I am not!...maybe we are only arrogant.
regards,
Carlos
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Even the name of an amp influences the perception. You give it a powerful name , like "terminator 500 watt direct coupled " the perception will be changed. Even if it has 12,800 uf X 2 per side and a small 500VA EI trafo.
I totally agree with the blackgate deal. A 105c nichicon bipolar will sound supreme both for the DC blocker and the bootstrap and will not change at all for many years.
Another thing I stress about is noise and hum. Hum can be avoided by careful layout , decoupling + ground loop resistor. Hiss is in the transistors. Some trannies (BC556 /546) while not bad , one can hear a little hiss , especially with a higher gain amp. My favorites , the 2SA992/2SC1845 are very low noise , can hold your ear right to the tweeter or mid and hear NOTHING. That seems to be a "trick" , using video transistors for audio. The video devices have to be better by design to amplify things in the MHZ, While this does not matter for audio , we can enjoy their low noise. You just have to be careful as the faster device WILL oscillate if you let it (design more carefully).
To put this to the real world , the old RCA used no miller cap at all, just letting the transistor capacitances "take over"
The world is changing , soon it will be all class D or , at best ,aussieamp.com with surfacemount LTP/VAS. Here in the US , the BD's are the first to go (mouser don't have them anymore). This is why I use the KSA/KSC- MJE - NJW outputs , they are VERY available and cheap here. ( $16.40 + $2 for a whole DX turbo) vs.
$50 if I went toshiba... Fairchild is somewhere in the middle (27-$30). So cost is another factor I have to deal with without screwing up the sound to much.
OS
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Joined 2009
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Carlos,
You are not the only one having doubts. You will notice that I talk a lot about TGM2 version and all the good improvements. But I have only built TGM1 so far and it sounds really good to me. Why would I build TGM2 ? perhaps the reason is that I have find out if there is a difference, even if I only imagine it
But there is still a chance I might not, instead I may look into DIY speakers again because I perceive this to be the greatest influence on the sound I hear.
You are not the only one having doubts. You will notice that I talk a lot about TGM2 version and all the good improvements. But I have only built TGM1 so far and it sounds really good to me. Why would I build TGM2 ? perhaps the reason is that I have find out if there is a difference, even if I only imagine it
But there is still a chance I might not, instead I may look into DIY speakers again because I perceive this to be the greatest influence on the sound I hear.
Member
Joined 2009
Paid Member
ostripper said:
It's already here, when I look around I see 99% of amplifiers are mass produced with chips and non-DIY friendly parts and assembly methods. The performance that can be achieved when people go to the trouble to make hi-end Class D is already good enough to get very good reviews published.
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