Yes..that search is interesting..the imagination that one day we gonna face the
perfect one.... and will happens, when someone create another kind of speaker..maybe plasma or something alike..i do not know what will be.
Amplifiers, even the simple ones, sounds good enougth... difference from the normal, standard one is in the reality very small...some small details and a lot of dollares you gonna pay for that difference.
I think it is nice to try, it is something that i love to do.... so friends, go ahead and try, and take care of those things.... not to let you to be fooled by yourself.... yourself is the most clever guy you have in your home..yourself can fool you easy!
Your amplifier, the number two, will be compared with the number one and you gonna have differences..not you have a tool..the number one!
regards,
Carlos
perfect one.... and will happens, when someone create another kind of speaker..maybe plasma or something alike..i do not know what will be.
Amplifiers, even the simple ones, sounds good enougth... difference from the normal, standard one is in the reality very small...some small details and a lot of dollares you gonna pay for that difference.
I think it is nice to try, it is something that i love to do.... so friends, go ahead and try, and take care of those things.... not to let you to be fooled by yourself.... yourself is the most clever guy you have in your home..yourself can fool you easy!
Your amplifier, the number two, will be compared with the number one and you gonna have differences..not you have a tool..the number one!
regards,
Carlos
I do think, alike you Bigun, that speakers are the most important piece into the
audio chain...the weekest one... there all the quality goes by.
It distorts more than the amplifier, so our worries about are only academic...something we like to worry about and to try to make perfect..an exercise of nothing with no purpose..just for fun (at least me!)...and to communicate with the others believe that measurements are the most important indicator (that will show us) amplifier qualities.....hummmmm..i use that language from time to time, it is alike an international language to audiophile..distortion..they love that..sometimes harmonics..sometimes damping...i use that when i need..but i really do not bother with those things....means nothing to my ignorance.
Not only speakers but room acoustics...some equalizer that can sense (using microphone) the room acoustics and adjust may be a good thing for us (and was down the eigthies).
But the best thing is to try to reach the unreachable sonic paradise..this will keep us together our partners in this never ending voyage to the imagination.
regards,
Carlos
audio chain...the weekest one... there all the quality goes by.
It distorts more than the amplifier, so our worries about are only academic...something we like to worry about and to try to make perfect..an exercise of nothing with no purpose..just for fun (at least me!)...and to communicate with the others believe that measurements are the most important indicator (that will show us) amplifier qualities.....hummmmm..i use that language from time to time, it is alike an international language to audiophile..distortion..they love that..sometimes harmonics..sometimes damping...i use that when i need..but i really do not bother with those things....means nothing to my ignorance.
Not only speakers but room acoustics...some equalizer that can sense (using microphone) the room acoustics and adjust may be a good thing for us (and was down the eigthies).
But the best thing is to try to reach the unreachable sonic paradise..this will keep us together our partners in this never ending voyage to the imagination.
regards,
Carlos
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OK OK, please tell us, tell us your crazy thoughts !
And I most likely will build the TGM number 2 because if I don't, I will always be wondering about it.
EDIT: ps. even more than speakers, the key is recording quality. I think I shouldn't spend any more money on amplifiers, I should send it all to Chesky...
And I most likely will build the TGM number 2 because if I don't, I will always be wondering about it.
EDIT: ps. even more than speakers, the key is recording quality. I think I shouldn't spend any more money on amplifiers, I should send it all to Chesky...
hehehe... the idea is to use a double coil woofer
and let pass 10 watts inside.... the transistor colector to emitter current into one of those coils..so, audio will be there too... in stand by, 10 volts and 1 ampere, the other 10 volts will be into the transistor....so, the coil will be the transistor load... a class A amplifier, having 1 ampere of current, 20 volts into the supply..the transistor colector with 10 volts (or fet)...them.... 10 watts into the speaker (loading coil) and 10 watts into the transistor.
This will be good to audio transference, as not condenser will be used, and no transformer will be used.
BUT..doing that, the speaker cone will move forward or backwards.
To compensate, you gonna spend more 10 watts, sending 1 ampere and 10 volts (other supply) to the second coil, forcing the speaker to return to the resting place.
I have never made that... as i have no a double coil speaker!
regards,
Carlos
......................................................
As i told you...... wasting energy... but interesting as an exercise!
and let pass 10 watts inside.... the transistor colector to emitter current into one of those coils..so, audio will be there too... in stand by, 10 volts and 1 ampere, the other 10 volts will be into the transistor....so, the coil will be the transistor load... a class A amplifier, having 1 ampere of current, 20 volts into the supply..the transistor colector with 10 volts (or fet)...them.... 10 watts into the speaker (loading coil) and 10 watts into the transistor.
This will be good to audio transference, as not condenser will be used, and no transformer will be used.
BUT..doing that, the speaker cone will move forward or backwards.
To compensate, you gonna spend more 10 watts, sending 1 ampere and 10 volts (other supply) to the second coil, forcing the speaker to return to the resting place.
I have never made that... as i have no a double coil speaker!
regards,
Carlos
......................................................
As i told you...... wasting energy... but interesting as an exercise!
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flipping heck Carlos, that's a huge power to dump into the coil, the full Class A bias current. I don't know that we could make a coil light and small enough for good sound which can also handle that power. The coil has few options to dissipate it's heat because it can't touch a heat sink, it has to be free to move according the magnetic field. I'm not a speaker coil expert - perhaps I don't understand ??
Maybe this is what you want: http://www.youtube.com/watch?v=rasp88nbsRw
Maybe this is what you want: http://www.youtube.com/watch?v=rasp88nbsRw
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Returning to Topic...
I explored a quasi-differential VAS, seemed like a simple and innocent change based on something I saw in D.Self.
I did the sims on TGM1 but same general topology. I saw that harmonics are worse, especially H3. Why no benefit ? - perhaps my implementation is too simple, typical newbie error ?
Attached is the schematic, simply the emitter of the VAS is connected to collector from the inverting input device and held off the -ve rail with a resistor. Plenty of current through the LTP. I cut off from the circuit to keep it small but in the space below is a duplicate with the regular TGM1 so that I can do a simple AB comparison.
I explored a quasi-differential VAS, seemed like a simple and innocent change based on something I saw in D.Self.
I did the sims on TGM1 but same general topology. I saw that harmonics are worse, especially H3. Why no benefit ? - perhaps my implementation is too simple, typical newbie error ?
Attached is the schematic, simply the emitter of the VAS is connected to collector from the inverting input device and held off the -ve rail with a resistor. Plenty of current through the LTP. I cut off from the circuit to keep it small but in the space below is a duplicate with the regular TGM1 so that I can do a simple AB comparison.
Attachments
You seem to be going the route of the folded cascode. Try locking the base of the VAS device to a set voltage point (zener/green LED -resistor + decoupling cap) , like 2-4v above negative rail.
Use Just one device of the LPT to drive it.
A folded cascode bootstrapped amp , I'll have to try it.
OS
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Ah, but will adding another active device take it away from being the Back To The Future amp ? However, from a purely selfish view I have been struggling to incorporate the Lender VAS into TGM1 so I am grateful for some direction so that I can use it over there too 
Why is it called a 'folded cascode' ?
Does the simple LTP have enough current drive for this VAS ?
Would we consider a change in the diff input pair to JFET - they have the benefit of higher input impedance, I thought also that they are able to handle a wider input voltage swing ??
Why is it called a 'folded cascode' ?
Does the simple LTP have enough current drive for this VAS ?
Would we consider a change in the diff input pair to JFET - they have the benefit of higher input impedance, I thought also that they are able to handle a wider input voltage swing ??
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ostripper said:
Is there some benefit in terms of PSRR if the base is simply connected to a resistive divider between the power rails, so that noise on the supply is fed back ? (I saw something like this in a common grid tube amp on the internet tonight)
EDIT: no, you already thought of this, we want to stop noise from the -ve rail. Referencing off -ve rail is the right way. Especially with bootstrap.
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I was wondering, since this topology is well suited to a small single sided pcb if a single-board stereo design would appeal ? Perhaps including some elements of power supply and volume control. KISS.
There are tradeoffs, there will be those worrying about stereo separation. Well there are always tradeoffs but I don't see this as needing to be a major one. I guess the benefits aren't that huge either.
Anyhow, I enjoyed toying around with the TGM pcb design so it would give me an excuse to toy around with it a bit more
There are tradeoffs, there will be those worrying about stereo separation. Well there are always tradeoffs but I don't see this as needing to be a major one. I guess the benefits aren't that huge either.
Anyhow, I enjoyed toying around with the TGM pcb design so it would give me an excuse to toy around with it a bit more
And were is the amplifier?... is it ready?
Have you made the simulation?
Made boards layout?
Have built the prototype?
Where is the RCA updated and upgraded?
I am curious what you gonna do with that.
In my Orkut, all folks there have built amplifiers based into that topologie...was nice to see all them have learned how to do that, i felt happy with that, as i could help them a lot....but the most intersting thing is that all amplifier were sligtly different.
They have designed, or calculated using ohms law all resistances, also they have calculated capacitors too...nice to see how different they were... one sent me his first "made by himself" amplifier and i played it in my home.... sounded almost the same, despite he have exagerated into the driver current..but that topologie sonics was present.
Decisions taken into current were the most important differences, and all them failed to produce a non thumpy power on.
It is a very hard work to produce an amplifier and make it ready to go..also people will trust to build if you show board made, assembled and tested..otherwise...not deal.
Orkut is very popular in Brasil, more than 60 millions are using, this means one in three brazilians use....so..this means almost all homes have at least one guy using it.
regards,
Carlos
Have you made the simulation?
Made boards layout?
Have built the prototype?
Where is the RCA updated and upgraded?
I am curious what you gonna do with that.
In my Orkut, all folks there have built amplifiers based into that topologie...was nice to see all them have learned how to do that, i felt happy with that, as i could help them a lot....but the most intersting thing is that all amplifier were sligtly different.
They have designed, or calculated using ohms law all resistances, also they have calculated capacitors too...nice to see how different they were... one sent me his first "made by himself" amplifier and i played it in my home.... sounded almost the same, despite he have exagerated into the driver current..but that topologie sonics was present.
Decisions taken into current were the most important differences, and all them failed to produce a non thumpy power on.
It is a very hard work to produce an amplifier and make it ready to go..also people will trust to build if you show board made, assembled and tested..otherwise...not deal.
Orkut is very popular in Brasil, more than 60 millions are using, this means one in three brazilians use....so..this means almost all homes have at least one guy using it.
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
The RCA reference design that I think of as the basis for a lot of this work is the Quasi Comp design in the 1969 RCA transistor manual.
The Harman Kardon Citation 12 is essentially this design with bigger caps in the signal path to lower the LF -3dB point and transistor substitutions. Here is the manual:
http://manuals.harman.com/hk/Service Manual/Citation twelve sm.pdf
These ran on the fairly common +/-42V rails for about 60W/ch output into 8 ohms.
They could obviously be made into true complementary.
Pete B.
The Harman Kardon Citation 12 is essentially this design with bigger caps in the signal path to lower the LF -3dB point and transistor substitutions. Here is the manual:
http://manuals.harman.com/hk/Service Manual/Citation twelve sm.pdf
These ran on the fairly common +/-42V rails for about 60W/ch output into 8 ohms.
They could obviously be made into true complementary.
Pete B.
Fear not , Uncle Charlie. This will be done right. No BS.
Got # 1 - simulation is golden.
Also # 3 - Already have 2 of the NPN LTP versions , so I KNOW it works !!
The harder part.. board layout, is just about fine tuned .. all by hand , no layout program.
The "E , B, C" is the bd139/mje340 Vbe (on wires , like the aska)
Blue are Caps , red is resistors, yellow are the semi's. You need no power supply , it is on board (use 3300 - 10000uF !!) ,6A flat bridge is also there. One could easily make a true DX with just a couple jumpers. The "lifted ground" (22R) and a True output inductor is also there (green). 99% there (forgot the LED CCS resistor to ground).
OS
Got # 1 - simulation is golden.
Also # 3 - Already have 2 of the NPN LTP versions , so I KNOW it works !!
The harder part.. board layout, is just about fine tuned .. all by hand , no layout program.
The "E , B, C" is the bd139/mje340 Vbe (on wires , like the aska)
Blue are Caps , red is resistors, yellow are the semi's. You need no power supply , it is on board (use 3300 - 10000uF !!) ,6A flat bridge is also there. One could easily make a true DX with just a couple jumpers. The "lifted ground" (22R) and a True output inductor is also there (green). 99% there (forgot the LED CCS resistor to ground).
OS
Almost the same board.. alike mine one
Because the topologie, as you see, the only logical solution.
I would like to ask you to remove the Dx from your amplifier... Dx brand name is not authorized to use.... use Dx style.... Compact Dx style..but not something that connects your creative design with my amplifier.
Or at least, if you want to have this connection, do not publish, because the Dx is alike a DIY trade mark.... it is sold, usually, in this forum by ZERO dollares... payment is a smile and the builder happyness...put your name, or you brand in the first position.... then, if you want, say is Dx Style, or Dx inspired or something you like....i would be more happy without that mention... this way, forum will have more options into the forum, even beeing boostrapped topologie that uses to sound alike.
In other words, if you need some connections with Dx, then put it into a secondary position, to be very clear i am not responsable from this one..that has another owner, another designer, another responsable.
Not Dx by Ostripper, but Ostripper Dx Style.. is more rational i think.
You see... you have made Ostripper, something that remembers that topologie, with a current mirror, or CCS..well, a minor modifications that, at least, will modify the sound...but basically, is the same schematic with some retouches you gave.
MJL21XXX has made another one, a bootstrapped one, that looks alike the HRII.... this way, we are not offering too much different ideas to forum folks to build.
Bigun also made something alike....what gonna result..forum will be invaded with multiple designs that will be sligtly different in topologie and sonics... this is not very clever to the forum...will be poor to the forum if you want to know.
If this continues..forum will be www.DIYdxalike.com
really this turns forum too much poor...we have already 4 options.
and i will let registered..waste of time to make it perfect alike Aksa...only using Aksa secrets on it.
regards,
Carlos
Because the topologie, as you see, the only logical solution.
I would like to ask you to remove the Dx from your amplifier... Dx brand name is not authorized to use.... use Dx style.... Compact Dx style..but not something that connects your creative design with my amplifier.
Or at least, if you want to have this connection, do not publish, because the Dx is alike a DIY trade mark.... it is sold, usually, in this forum by ZERO dollares... payment is a smile and the builder happyness...put your name, or you brand in the first position.... then, if you want, say is Dx Style, or Dx inspired or something you like....i would be more happy without that mention... this way, forum will have more options into the forum, even beeing boostrapped topologie that uses to sound alike.
In other words, if you need some connections with Dx, then put it into a secondary position, to be very clear i am not responsable from this one..that has another owner, another designer, another responsable.
Not Dx by Ostripper, but Ostripper Dx Style.. is more rational i think.
You see... you have made Ostripper, something that remembers that topologie, with a current mirror, or CCS..well, a minor modifications that, at least, will modify the sound...but basically, is the same schematic with some retouches you gave.
MJL21XXX has made another one, a bootstrapped one, that looks alike the HRII.... this way, we are not offering too much different ideas to forum folks to build.
Bigun also made something alike....what gonna result..forum will be invaded with multiple designs that will be sligtly different in topologie and sonics... this is not very clever to the forum...will be poor to the forum if you want to know.
If this continues..forum will be www.DIYdxalike.com
really this turns forum too much poor...we have already 4 options.
and i will let registered..waste of time to make it perfect alike Aksa...only using Aksa secrets on it.
regards,
Carlos
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I have to say i do not know exactly what you have made
When i saw your schematics and i have perceive will sound not so different... then i loose interest..why to bother with almost the same old story... i would like to see more creativity, as i had not that creativity, almost copying the Aksa!.
i loose interest to MJL thread, also yours and bigun...as those ones would result in something alike, not too much different than the amplifier options i have made into the standard, the HRII and the Precision 1.... i found nothing very interesting or new to me to be there.
There are other options that we need to explore, also Jan Dupont style appear into the Quasi... almost alike.
We may try to do something more creative..alike to simplify Kleindschmidt hyper complicated schematic to make it usefull to DIYer for instance... or to create something new for us.
You see...we have Kleinschmidt.... Nelson Pass style... Aksa and Dx Style (almost the same)... your ideas...also almost the same...JLH ideas, Quasi idea that has something alike Jan Dupont schematic, with quasi complementary and without the chip into the input..also alike some Rodd Elliot design.
You see..some others that i have not mentioned exists too...but you see...very poor to the elite of audiophiles joined into this forum..very poor creativity..one of the main amplifier we have is alike mine one... an old boostrapp idea from the seventies.
Man!...we are more than 70 thousand... are we not able to have better ideas than those ones?
I would like to say , i am sorry, to the ones i forgot..maybe because they have entered and fast disappeared from our main page...maybe some others exists.... but we use to be pride, thinking we can do things alike professionals do... some thinks we can do even better.
This way?.... repeating ideas and schematics?
You see...my last amplifier was the Trust... something mummified came from the old egypt i think... from Tutankamon or something..this is all i could do... i am not someone to be followed to leader a modern forum tendence.... try to find another idea folks!
regards,
Carlos
When i saw your schematics and i have perceive will sound not so different... then i loose interest..why to bother with almost the same old story... i would like to see more creativity, as i had not that creativity, almost copying the Aksa!.
i loose interest to MJL thread, also yours and bigun...as those ones would result in something alike, not too much different than the amplifier options i have made into the standard, the HRII and the Precision 1.... i found nothing very interesting or new to me to be there.
There are other options that we need to explore, also Jan Dupont style appear into the Quasi... almost alike.
We may try to do something more creative..alike to simplify Kleindschmidt hyper complicated schematic to make it usefull to DIYer for instance... or to create something new for us.
You see...we have Kleinschmidt.... Nelson Pass style... Aksa and Dx Style (almost the same)... your ideas...also almost the same...JLH ideas, Quasi idea that has something alike Jan Dupont schematic, with quasi complementary and without the chip into the input..also alike some Rodd Elliot design.
You see..some others that i have not mentioned exists too...but you see...very poor to the elite of audiophiles joined into this forum..very poor creativity..one of the main amplifier we have is alike mine one... an old boostrapp idea from the seventies.
Man!...we are more than 70 thousand... are we not able to have better ideas than those ones?
I would like to say , i am sorry, to the ones i forgot..maybe because they have entered and fast disappeared from our main page...maybe some others exists.... but we use to be pride, thinking we can do things alike professionals do... some thinks we can do even better.
This way?.... repeating ideas and schematics?
You see...my last amplifier was the Trust... something mummified came from the old egypt i think... from Tutankamon or something..this is all i could do... i am not someone to be followed to leader a modern forum tendence.... try to find another idea folks!
regards,
Carlos
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