Thank you very much...it is not finished yet..but i can see it already very good
I will keep you informed dear Gaetan, using direct mail.
This is not the final schematic..the final one, with values, description and voltages will be released into the Christmas.
My gift to forum friends.
regards,
Carlos
I will keep you informed dear Gaetan, using direct mail.
This is not the final schematic..the final one, with values, description and voltages will be released into the Christmas.
My gift to forum friends.
regards,
Carlos
Attachments
What is different into Precision that makes it sound better?
This differential.
Very good people use this idea.... even Hugh Dean from Aspen have used, but different and sligtly better than this one (hugh one is more complex)...also Cyrus, and my dear friend (forum folk) Giaime.
This last one had published his amplifier into our forum, was called "My amp", and there he show me this idea, i said immediatelly that would try it.
His input was captured, copied, with his agreement, and this was written in this forum, and in very clear words.... he said:
- No problems... just tell my name informing where you found this good.
-Is this differential better to use?
NO!
It is a hell to adjust..those resistances from the extra transistors base to emitter need tweaking..also the current that will cross the differential is critical.... also sounds awfull when not well matched..terrible.
-Is this differential sounding better?
YES!...and much better
And what is the difference..is it clear to perceive?
In the first second you play....bass is more present, not more strong, it is even more controled, more precise, sound is more focused... there are some compression into low levels of audio..the lower volume moments (the pianissimo) sounds that were recorded at the same level... something alike a compander.... so..you perceive them more clear... but even this way, it produced more dinamics into the power... and this is not only something we can perceive..we can measure that too.
-How you conclude that?
Installing one and installing other...replacing one circuit by the other..both matched... i have made that three times.... A and B...three times made A and B.... also i have listened BBC production about the Blue Planet...a DVD that has interesting Deep bass from the ocean deep and sub watter noises and sound effects.
-Are you sure?
Absolutelly sure.
- Will this circuit be keept to use into the future released Precision model?
- Yes..this one is guaranteed that will come to stay.
regards,
Carlos
This differential.
Very good people use this idea.... even Hugh Dean from Aspen have used, but different and sligtly better than this one (hugh one is more complex)...also Cyrus, and my dear friend (forum folk) Giaime.
This last one had published his amplifier into our forum, was called "My amp", and there he show me this idea, i said immediatelly that would try it.
His input was captured, copied, with his agreement, and this was written in this forum, and in very clear words.... he said:
- No problems... just tell my name informing where you found this good.
-Is this differential better to use?
NO!
It is a hell to adjust..those resistances from the extra transistors base to emitter need tweaking..also the current that will cross the differential is critical.... also sounds awfull when not well matched..terrible.
-Is this differential sounding better?
YES!...and much better
And what is the difference..is it clear to perceive?
In the first second you play....bass is more present, not more strong, it is even more controled, more precise, sound is more focused... there are some compression into low levels of audio..the lower volume moments (the pianissimo) sounds that were recorded at the same level... something alike a compander.... so..you perceive them more clear... but even this way, it produced more dinamics into the power... and this is not only something we can perceive..we can measure that too.
-How you conclude that?
Installing one and installing other...replacing one circuit by the other..both matched... i have made that three times.... A and B...three times made A and B.... also i have listened BBC production about the Blue Planet...a DVD that has interesting Deep bass from the ocean deep and sub watter noises and sound effects.
-Are you sure?
Absolutelly sure.
- Will this circuit be keept to use into the future released Precision model?
- Yes..this one is guaranteed that will come to stay.
regards,
Carlos
Attachments
This current sink...CCS or VAS mirror... do not know the name
This circuit made the bass more strong.... made the distortion lower.... made 1.5 volts loss into the output and seems that helped the dinamics a little.
This one is subjected to modification for improovement....but my dear old and good bootstrap is beeing abandoned because of distortion.
regards,
Carlos
This circuit made the bass more strong.... made the distortion lower.... made 1.5 volts loss into the output and seems that helped the dinamics a little.
This one is subjected to modification for improovement....but my dear old and good bootstrap is beeing abandoned because of distortion.
regards,
Carlos
Attachments
I have removed the CCS i was using into the drivers emitters
I did that because i perceived that this circuit have increased the power of the bass into a very high level...bass dominated the whole thing.
Also i think (not sure) that i have losses into the treble..this is hard to perceive..because increasing in basses seems losses in treble too.... very hard to perceive... a very good circuit that my friend from Croatia have discovered.
It seems that was based into some Electrocompaniet model.
I made tests just switching from the this CCS aided circuit to the standard using switches..... i like the result with the CCS, but i felt more ballanced (audio equalization) without the CCS.
regards,
Carlos
I did that because i perceived that this circuit have increased the power of the bass into a very high level...bass dominated the whole thing.
Also i think (not sure) that i have losses into the treble..this is hard to perceive..because increasing in basses seems losses in treble too.... very hard to perceive... a very good circuit that my friend from Croatia have discovered.
It seems that was based into some Electrocompaniet model.
I made tests just switching from the this CCS aided circuit to the standard using switches..... i like the result with the CCS, but i felt more ballanced (audio equalization) without the CCS.
regards,
Carlos
Because of some folks i have include the VAS protection into the future Dx Precision
The Chief Couselor from Destroyer Corporation, Doctor Graham Maynard.
Important forum member, Mr. Andrew T
Dear hiper important nephew Nordic
more two forum members and one close friend.
Because of that it is included... i will think and try, how to minimize the effects into the audio..but will left the protection into the circuit.
In my own constructions the circuit will be "off".
Green line is audio into the VAS
Orange line is the protection line... draining audio to negative rail.
My resistance to use this was deeply explained into some previous posts.... even knowing that they think will be better to have more safety.
regards,
Carlos
........................................................................................................
All rigth dear Graham.
I will take care of that problem.
regards,
Carlos
The Chief Couselor from Destroyer Corporation, Doctor Graham Maynard.
Important forum member, Mr. Andrew T
Dear hiper important nephew Nordic
more two forum members and one close friend.
Because of that it is included... i will think and try, how to minimize the effects into the audio..but will left the protection into the circuit.
In my own constructions the circuit will be "off".
Green line is audio into the VAS
Orange line is the protection line... draining audio to negative rail.
My resistance to use this was deeply explained into some previous posts.... even knowing that they think will be better to have more safety.
regards,
Carlos
........................................................................................................
All rigth dear Graham.
I will take care of that problem.
regards,
Carlos
Attachments
Hi Destroyer,
are you thinking of making provision for the protection transistor in your next layout?
If you think it can be made to protect without ruining the sound quality, then consider the following amendments:-
Split resistor R28 into R28u and R28L.
As discovered during MJL's experimental sims, add a resistor into the collector to ground trace of Q5.
Leave two optional pads for Q17 collector. One as shown on Q5 base and the second pad on Q5 emitter.
That leaves all the options open, from no protection, to only protecting the VAS and with any current limit without affecting the degeneration value of Q6.
This can be done with just two extra resistors and one extra pad.
BTW,
your detection of sound quality issues confirms at least two problems.
Firstly, extra capacitance load on the LTP collector is bad for sound. I have been telling people that is likely to be one of the main reasons for D.Self's Blameless Cdom to sound less than perfect.
Secondly, you're saying, you are hearing the transient peaks being clipped. If this is indeed the case then it indicates just how high these peaks are above the average level. More argument for maintaining that +20 to +30db of headroom that we are supposed to need.
Your comment makes we wonder how high your average level was during your listening tests and how much headroom you had to spare. It also prompts the question of whether your +?db of HF gain was boosting the transients and making them more in need of clipping to avoid overloading the subsequent stages.
But in any case, thanks for taking the time to carry out those experiments on our behalf.
are you thinking of making provision for the protection transistor in your next layout?
If you think it can be made to protect without ruining the sound quality, then consider the following amendments:-
Split resistor R28 into R28u and R28L.
As discovered during MJL's experimental sims, add a resistor into the collector to ground trace of Q5.
Leave two optional pads for Q17 collector. One as shown on Q5 base and the second pad on Q5 emitter.
That leaves all the options open, from no protection, to only protecting the VAS and with any current limit without affecting the degeneration value of Q6.
This can be done with just two extra resistors and one extra pad.
BTW,
your detection of sound quality issues confirms at least two problems.
Firstly, extra capacitance load on the LTP collector is bad for sound. I have been telling people that is likely to be one of the main reasons for D.Self's Blameless Cdom to sound less than perfect.
Secondly, you're saying, you are hearing the transient peaks being clipped. If this is indeed the case then it indicates just how high these peaks are above the average level. More argument for maintaining that +20 to +30db of headroom that we are supposed to need.
Your comment makes we wonder how high your average level was during your listening tests and how much headroom you had to spare. It also prompts the question of whether your +?db of HF gain was boosting the transients and making them more in need of clipping to avoid overloading the subsequent stages.
But in any case, thanks for taking the time to carry out those experiments on our behalf.
I'm just pondering here:
So, Q17 is required for protection, protection such that Q6 is not overdriven ?
If Q6 is not been overdriven then it would be better if Q17 were not in the circuit ?
What are problems when Q6 is overdriven ?
Is it possible to say that the overdriven condition can exist for, say 1/10 second, before causing serious harm ?
What is the cause of this overdrive condition ?
Please forgive the silly questions
So, Q17 is required for protection, protection such that Q6 is not overdriven ?
If Q6 is not been overdriven then it would be better if Q17 were not in the circuit ?
What are problems when Q6 is overdriven ?
Is it possible to say that the overdriven condition can exist for, say 1/10 second, before causing serious harm ?
What is the cause of this overdrive condition ?
Please forgive the silly questions
Re: What is different into Precision that makes it sound better?
Glad to hear this, Carlos. I've not tested yet my circuit, too many projects going on
However yes, very very important to match transistors for beta and Vbe at the real Ic current (for example directly in circuit). And couple them thermically (the PNP ones in your schematic)!
I will be happy if you mention my name and my website, just for the inspiration of the circuit (as you correctly said, I never invented anything) when you give away definitive schematics here and in other websites (such as that really nice looking site on the DxAmp). That will satisfy me
destroyer X said:
Glad to hear this, Carlos. I've not tested yet my circuit, too many projects going on
However yes, very very important to match transistors for beta and Vbe at the real Ic current (for example directly in circuit). And couple them thermically (the PNP ones in your schematic)!
I will be happy if you mention my name and my website, just for the inspiration of the circuit (as you correctly said, I never invented anything) when you give away definitive schematics here and in other websites (such as that really nice looking site on the DxAmp). That will satisfy me
Hi ecat.
When loaded output devices cannot quickly enough follow the input waveform, the input/NFB sensed differential can increase current output from the differential input pair into the VAS. A series output choke allows the outputs to follow voltage before current flows, and thus protects the VAS from input overload, but not output overloading.
Whatever the total differential tail current is, this can flow straight into the base of Q5 with its near rail Vcc. Then, if Q5 does not fuse 100 to 300 times that tail current could flow into the base of Q6.
Q17 prevents both Q5 and Q6 from over-currenting.
Q6 cannot draw less current than zero, thus the peak positive drive to the output stage can be no more than that of the VAS bias as provided by the VAS CCS or bootstrapped resistors.
However the peak negative drive current can be like a VAS short to rail through the series negative base driver resistor.
This could lead to considerable current/voltage imbalance at the VAS collector with deep LS breathing under output overload conditions.
R28 would best not turn on Q17 until the VAS was conduction just over twice its steady VAS current.
Hi Carlos,
When I simulated circuits I always put current and voltage sensing meters at the bases, collectors and emitters to watch out for too-high peak currents under simulated overload conditions.
Cheers ......... Graham.
When loaded output devices cannot quickly enough follow the input waveform, the input/NFB sensed differential can increase current output from the differential input pair into the VAS. A series output choke allows the outputs to follow voltage before current flows, and thus protects the VAS from input overload, but not output overloading.
Whatever the total differential tail current is, this can flow straight into the base of Q5 with its near rail Vcc. Then, if Q5 does not fuse 100 to 300 times that tail current could flow into the base of Q6.
Q17 prevents both Q5 and Q6 from over-currenting.
Q6 cannot draw less current than zero, thus the peak positive drive to the output stage can be no more than that of the VAS bias as provided by the VAS CCS or bootstrapped resistors.
However the peak negative drive current can be like a VAS short to rail through the series negative base driver resistor.
This could lead to considerable current/voltage imbalance at the VAS collector with deep LS breathing under output overload conditions.
R28 would best not turn on Q17 until the VAS was conduction just over twice its steady VAS current.
Hi Carlos,
When I simulated circuits I always put current and voltage sensing meters at the bases, collectors and emitters to watch out for too-high peak currents under simulated overload conditions.
Cheers ......... Graham.
I will be happy to see a sketch from your idea Andrew...sorry, i have some real
problems with language.
A sketch could be helpfull....but if you have some impeachment to provide the sketch, i will print and follow your ideas watching the parts number for identification..i have not them into my memory.
regards,
Carlos
.......................................................................................................
Dear Ecat
Soon as i start to understand what Andrew told us, i will tell you something about.
I have received some interesting suggestion few minutes ago.
Now i will stop with electronics, my daugther arrived to stay with me...also i will clean the prototype to produce some pictures tomorrow.
regards,
Carlos
problems with language.
A sketch could be helpfull....but if you have some impeachment to provide the sketch, i will print and follow your ideas watching the parts number for identification..i have not them into my memory.
regards,
Carlos
.......................................................................................................
Dear Ecat
Soon as i start to understand what Andrew told us, i will tell you something about.
I have received some interesting suggestion few minutes ago.
Now i will stop with electronics, my daugther arrived to stay with me...also i will clean the prototype to produce some pictures tomorrow.
regards,
Carlos
Attachments
Thank you Graham, i will be reading your post soon
Your text was already printed, also Ecat and Andrew T text.
regards,
Carlos
.......................................................................................
Giaime
Va benne fratello d'acordo.
arrivederci
Carlos
Your text was already printed, also Ecat and Andrew T text.
regards,
Carlos
.......................................................................................
Giaime
Va benne fratello d'acordo.
arrivederci
Carlos
Attachments
Hi Graham,
Thank you for the excellent description.
So this is not an 'error' condition or a 'failure' condition, rather is it a condition that could theoretically occur intermittently during the playback of normal audio ?
I see. I was thinking that with some digital magic (A2D, pic and relay perhaps ) Q17 could be switched in to the circuit as required. This probably isn't feasible if the switching were to be required on a frequent basis
Carlos,
Your daughter deserves you attention, hope you both have a fun time
Thank you for the excellent description.
So this is not an 'error' condition or a 'failure' condition, rather is it a condition that could theoretically occur intermittently during the playback of normal audio ?
I see. I was thinking that with some digital magic (A2D, pic and relay perhaps ) Q17 could be switched in to the circuit as required. This probably isn't feasible if the switching were to be required on a frequent basis
Carlos,
Your daughter deserves you attention, hope you both have a fun time
Wanna know the sonic differences of this one compared to the High Resolution II
Put your High Resolution to play low volume...less than 1 volt of audio.
then listen with your speaker into your ears level..... 6 foot distant from your head..... now listen and try to remember the sound.
Now remove the speaker cloth grille, turn your speaker treble control to + 3 dB.
Now reduce the distance to 3 feet.
This is the Dx Precision sound.... the way it is today.
regards,
Carlos
Put your High Resolution to play low volume...less than 1 volt of audio.
then listen with your speaker into your ears level..... 6 foot distant from your head..... now listen and try to remember the sound.
Now remove the speaker cloth grille, turn your speaker treble control to + 3 dB.
Now reduce the distance to 3 feet.
This is the Dx Precision sound.... the way it is today.
regards,
Carlos
Attachments
OH OH, sounds like old japanese tweeters
Dear Carlos, thank you so much for the opportunity to do the groupbuy, I hope I can make the best of all the chances it provides to make a start.
The DX shop is now open, allthough I need to change the menus in the rest of the site tommorrow to integrate the catalog and the site.
I hope we can make a plan to get your set in Brasil without you paying too much or any customs. Do you have to pay customs on things marked; $0 - Sample not for resale ?
There is now a new benchmark for measuring buying power in countries, the Ipod, and on that scale I could see that you guys pay even more for imports than we do.
Please come and have a look some time, I will be adding a few things that will hopefully help me break even when all is done.
https://www.dxamp.com/catalog/
Dear Carlos, thank you so much for the opportunity to do the groupbuy, I hope I can make the best of all the chances it provides to make a start.
The DX shop is now open, allthough I need to change the menus in the rest of the site tommorrow to integrate the catalog and the site.
I hope we can make a plan to get your set in Brasil without you paying too much or any customs. Do you have to pay customs on things marked; $0 - Sample not for resale ?
There is now a new benchmark for measuring buying power in countries, the Ipod, and on that scale I could see that you guys pay even more for imports than we do.
Please come and have a look some time, I will be adding a few things that will hopefully help me break even when all is done.
https://www.dxamp.com/catalog/
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