I am watching the blameless VAS into the simulator, i found something strange.
The first cicle distortion..when simulations start it distorts during some cicles and the distortion disappears.
I made it work with global feedback and without it..using my Dx amplifier as a model
The differential emitter resistances were replaced to work together an emitter follower i found in ULD or in some schematic from Dr. Self book.
I had to change the original 2K resistance to allow better Vbe "distribution"..let's say this way...one VBE was small and the second was too much big...now more ballanced, they are not the same but the difference was reduced...the first one was near to be cutted and the second was more to the saturation side.
I found that distortion using the standard resistance, also using the modified one..using BC546 and BC546.... using BC546 as the first one and BD139 as the second one and using both beeing BD139...... the voltage was adjusted, from the differential colector, to match the 1.3 volts need...also i have tried a CCS there, the current sink..... i could not avoid the distortion.... inserting global feedback and removing it in the style used into the ULD.
I am interested into this stage..... maybe the one has some responsability into the strange sonics i have perceived.
I am still into the simulators...but i will do all those testing into my prototype to listen the results in the real world.
I am extremelly curious about that..... i just cannot believe what my ears told me monthes ago when i have listened that blameless.... and there are something into ULD that remembers me deeply the blameless..... something must be the one to blame to make the blameless...less elected, at least by me, to receive some blame.
I will try each blameless circuit separated....one each time...will apply it into the dx amplifier as "a very basic thing to start".... and i will listen into sonics, to see if some stage is responsible related the "effect"..observe that i am avoiding the name defect , that i could listen.
Yes.....maybe all them together produces that...well.... this i will conclude easy after my tries.
If i concluded some stage, i will open my big mouth to inform to finish with this chapter in my life...but if they together, all them together, all the blameless stages produces....well...i will be silent not to continue to bother the Blameless lovers...also not to bother Self, as he is also an inspiration to me.
This amplifier..the one bother me...is just an amplifier...a machine...that can have problems inside valves, carbons, ignition points, injections..well...a system that need some research to "tune" into sonics.
regards,
Carlos
The first cicle distortion..when simulations start it distorts during some cicles and the distortion disappears.
I made it work with global feedback and without it..using my Dx amplifier as a model
The differential emitter resistances were replaced to work together an emitter follower i found in ULD or in some schematic from Dr. Self book.
I had to change the original 2K resistance to allow better Vbe "distribution"..let's say this way...one VBE was small and the second was too much big...now more ballanced, they are not the same but the difference was reduced...the first one was near to be cutted and the second was more to the saturation side.
I found that distortion using the standard resistance, also using the modified one..using BC546 and BC546.... using BC546 as the first one and BD139 as the second one and using both beeing BD139...... the voltage was adjusted, from the differential colector, to match the 1.3 volts need...also i have tried a CCS there, the current sink..... i could not avoid the distortion.... inserting global feedback and removing it in the style used into the ULD.
I am interested into this stage..... maybe the one has some responsability into the strange sonics i have perceived.
I am still into the simulators...but i will do all those testing into my prototype to listen the results in the real world.
I am extremelly curious about that..... i just cannot believe what my ears told me monthes ago when i have listened that blameless.... and there are something into ULD that remembers me deeply the blameless..... something must be the one to blame to make the blameless...less elected, at least by me, to receive some blame.
I will try each blameless circuit separated....one each time...will apply it into the dx amplifier as "a very basic thing to start".... and i will listen into sonics, to see if some stage is responsible related the "effect"..observe that i am avoiding the name defect , that i could listen.
Yes.....maybe all them together produces that...well.... this i will conclude easy after my tries.
If i concluded some stage, i will open my big mouth to inform to finish with this chapter in my life...but if they together, all them together, all the blameless stages produces....well...i will be silent not to continue to bother the Blameless lovers...also not to bother Self, as he is also an inspiration to me.
This amplifier..the one bother me...is just an amplifier...a machine...that can have problems inside valves, carbons, ignition points, injections..well...a system that need some research to "tune" into sonics.
regards,
Carlos
Attachments
I am using the Dx amplifier as i know how it sounds
So... increasings of sonics or even decreasings, because of this stage, will be fast perceived.
I have another "very secret" modification a friend have sent me...and another 2 ideas, one from ULD and other from Doctor Self....i want to try all them...first into the simulator, and than i will put them to sound.
If doubts...i will call friends to make a session of A to B blind using friends to judge, also my daugther and some other small children that lives in this same building i am..... hard to fool children.
The Vas circuit is shown in one of the pictures attached... the emitter follower.
" Is this one better Suzie? "
Answer comes fast...and use to be very precise.
hehe
Carlos
So... increasings of sonics or even decreasings, because of this stage, will be fast perceived.
I have another "very secret" modification a friend have sent me...and another 2 ideas, one from ULD and other from Doctor Self....i want to try all them...first into the simulator, and than i will put them to sound.
If doubts...i will call friends to make a session of A to B blind using friends to judge, also my daugther and some other small children that lives in this same building i am..... hard to fool children.
The Vas circuit is shown in one of the pictures attached... the emitter follower.
" Is this one better Suzie? "
Answer comes fast...and use to be very precise.
hehe
Carlos
I am trying to find the "strange" sonics reasons...maybe i am lost related the track
This distortion may not produce that sound i have heard.
This distortion may produce stronger and clear result into sound reproduction, more easy to perceive.
I am searching, i continue searching into the computer, now i have Graham cooperation.. he will be over my shoulders into this research.
He has things to be confirmed, i have things to be tested...and i hope, we can succeed.
DS standard VAS do not produce distortions, at least not this one i have shown...but also, it sounds nice and good...but not that incredible high end so... the original and old circuit.
I do not think i am hardly off topic...as there are similarities between the focused amplifier in this thread and blameless.... and VAS is beeing inspectioned.
The one that opened this thread, please, feeling bothered, just tell me and i will open another one about VAS only.
regards Allan
Carlos
This distortion may not produce that sound i have heard.
This distortion may produce stronger and clear result into sound reproduction, more easy to perceive.
I am searching, i continue searching into the computer, now i have Graham cooperation.. he will be over my shoulders into this research.
He has things to be confirmed, i have things to be tested...and i hope, we can succeed.
DS standard VAS do not produce distortions, at least not this one i have shown...but also, it sounds nice and good...but not that incredible high end so... the original and old circuit.
I do not think i am hardly off topic...as there are similarities between the focused amplifier in this thread and blameless.... and VAS is beeing inspectioned.
The one that opened this thread, please, feeling bothered, just tell me and i will open another one about VAS only.
regards Allan
Carlos
Carlos
yes there are similarities between the ULD and the Blameless IMHO
but there are differences to
ULD is CFP output, different VAS, different current regulator.
actually it has properties from the D.S. trimodal amp too.
and if i go thoughter through D.S's books i'll probably find a few more.
But SC have implemented D.S's ideas well IMHO
and the amp works well.
SC circuit board layout is well thoughout too.
Isn't D.Self trying to give his ideas on how to make an amp and what he has found in the presuite of low distortion.
allan
ps compared ULD circuit diagram with page 266 of Douglas Self's Audio power Amplifier Design Handbook 3rd edition
yes there are similarities between the ULD and the Blameless IMHO
but there are differences to
ULD is CFP output, different VAS, different current regulator.
actually it has properties from the D.S. trimodal amp too.
and if i go thoughter through D.S's books i'll probably find a few more.
But SC have implemented D.S's ideas well IMHO
and the amp works well.
SC circuit board layout is well thoughout too.
Isn't D.Self trying to give his ideas on how to make an amp and what he has found in the presuite of low distortion.
allan
ps compared ULD circuit diagram with page 266 of Douglas Self's Audio power Amplifier Design Handbook 3rd edition
Yes..there are many options into Self's book
And many things are not Self creations, only re-creations, or copies, or new studies based in, referenced in "now a days audio technologies."
We cannot believe, or at least i cannot believe that all schematics used inside Doctor Self book are his property...in the reality belong to the audio community since was published in a book... and was used as examples only, to help him to describe functions, graphics and ideas.
It is wrong when people concluded that something that, "just remembers Self," can be used to blame Self or even to increase his value.
My own Dx amplifier, my dear toy amplifier, was based in sub-circuits that he show in his book...and Doctor Self was a very young boy during the Beatles and Rolling Stones Era...when Shuzo
Yoshida designed the first bootstrapped into Sony Atsugi plant, now a days dedicated to Video Professional.... well..he told me that, as i could be his friend...down the seventies the design was made... alike mine, alike P3A and alike Aksa and hundreds of other brands that used and still use it (Yamaha, the natural sound)
Many are using the topologie, the most simple bootstrapped one, i am using to my lovely toy amplifier (50 watts only)..... and Hugh Dean, as developed that circuit to the maximum possible audible quality can be the one deserve the title of owner....also Vicente Pinzon had visited America in advance related others... had also Brasil, South America, and we have nearby my place the ruines of his first construction made to protect himself against the native indians... all this happened, a couple of years in advance related the "oficial" discoverers of America... the entitled as discoverers.
Also the first that take off and landed using motorized aircraft...that started without any aid was Santos Dumont...not Writgh brothers.... those ones were the first to crash into the sand trying to control the flytgh sand...not really landed...and used hills, strong winds against and a lot of other aids not used by Santos Dumont.
USA was not that power the country is now a days to decide the ones are entitled or not to discover things...so responsible Dumont felt himself by the airplane discovery that he suicide...he killed himself when new that his invention were being used into the first world war bombing...as people sent grenades and bombs manually into the enemies.... used for war!
Well...just talking a little.
regards,
Carlos
And many things are not Self creations, only re-creations, or copies, or new studies based in, referenced in "now a days audio technologies."
We cannot believe, or at least i cannot believe that all schematics used inside Doctor Self book are his property...in the reality belong to the audio community since was published in a book... and was used as examples only, to help him to describe functions, graphics and ideas.
It is wrong when people concluded that something that, "just remembers Self," can be used to blame Self or even to increase his value.
My own Dx amplifier, my dear toy amplifier, was based in sub-circuits that he show in his book...and Doctor Self was a very young boy during the Beatles and Rolling Stones Era...when Shuzo
Yoshida designed the first bootstrapped into Sony Atsugi plant, now a days dedicated to Video Professional.... well..he told me that, as i could be his friend...down the seventies the design was made... alike mine, alike P3A and alike Aksa and hundreds of other brands that used and still use it (Yamaha, the natural sound)
Many are using the topologie, the most simple bootstrapped one, i am using to my lovely toy amplifier (50 watts only)..... and Hugh Dean, as developed that circuit to the maximum possible audible quality can be the one deserve the title of owner....also Vicente Pinzon had visited America in advance related others... had also Brasil, South America, and we have nearby my place the ruines of his first construction made to protect himself against the native indians... all this happened, a couple of years in advance related the "oficial" discoverers of America... the entitled as discoverers.
Also the first that take off and landed using motorized aircraft...that started without any aid was Santos Dumont...not Writgh brothers.... those ones were the first to crash into the sand trying to control the flytgh sand...not really landed...and used hills, strong winds against and a lot of other aids not used by Santos Dumont.
USA was not that power the country is now a days to decide the ones are entitled or not to discover things...so responsible Dumont felt himself by the airplane discovery that he suicide...he killed himself when new that his invention were being used into the first world war bombing...as people sent grenades and bombs manually into the enemies.... used for war!
Well...just talking a little.
regards,
Carlos
Well folks, i have tried three VAS inspired into Self designs.
One of them was the ULD...also i have tried a secret one a friend sent me.
They sounded almost the same...differences hardly could be perceived, and as i did not made A to B comparison, they was perceived as very good.
Nothing bad with that VAS.
The secret one seemed to have 3 dimensional sound stage...multi layers of instruments...but is some personal property and we must wait the one decide to show us.
My curiosity about this subject finished now.
regards,
Carlos
One of them was the ULD...also i have tried a secret one a friend sent me.
They sounded almost the same...differences hardly could be perceived, and as i did not made A to B comparison, they was perceived as very good.
Nothing bad with that VAS.
The secret one seemed to have 3 dimensional sound stage...multi layers of instruments...but is some personal property and we must wait the one decide to show us.
My curiosity about this subject finished now.
regards,
Carlos
SC 20W Class A
Andrew
Part 2 was only just published in the June issue. There are no kits available yet. I believe that Altronics is sponsoring the project. Their website is announcing them as coming. Even if anyone made their own PCBs ( there is no artwork released yet)and had all the parts, there is a note that a special settting up procedure is necessary. This won't be published until July.
SandyK
Andrew
Part 2 was only just published in the June issue. There are no kits available yet. I believe that Altronics is sponsoring the project. Their website is announcing them as coming. Even if anyone made their own PCBs ( there is no artwork released yet)and had all the parts, there is a note that a special settting up procedure is necessary. This won't be published until July.
SandyK
SC 20W Class A
Andrew
Do you think that many people who already had the original would race in and build this one just to get an increase of 5W power which is very minor, as well as a small reduction in the already very low levels of distortion ? I don't like the inclusion of10R/1,1000uF in the -ve supply to the front end, as recommended by Douglas Self, either.I believe that it fixes one problem, then alters slightly the overall tonal balance due to impedance variation over the audible range and beyond.
I am a firm believer in low impedance regulated power supplies for at least the front end.
SandyK
Andrew
Do you think that many people who already had the original would race in and build this one just to get an increase of 5W power which is very minor, as well as a small reduction in the already very low levels of distortion ? I don't like the inclusion of10R/1,1000uF in the -ve supply to the front end, as recommended by Douglas Self, either.I believe that it fixes one problem, then alters slightly the overall tonal balance due to impedance variation over the audible range and beyond.
I am a firm believer in low impedance regulated power supplies for at least the front end.
SandyK
Hmm.. I did a similar design but with mosfets (except for vas bd139). I'm satisfied with the simulation results and even more with real life results, BUT beeing mosfet and ccs(gets a bit warm yes) driving ouput follower directly I'ts not very fast only 10-15V/us measured.. Tried buffering the signals and it worked better but now I found it a bit un-interresting design, I want to simplify it and make it complementary, hmm in fact I did that already in the computer and an ugly prototype but my toyota celica supra 7mgte turbo project needs some attention too :-D..
http://dsl.mine.nu/ampsida/hemmabio.jpg Both amps, total of 6 dcdc vicor modules..(They're great)
http://dsl.mine.nu/ampsida/hemmabio.jpg Both amps, total of 6 dcdc vicor modules..(They're great)
I see SC have published a updated version of UltraLD now rated a bit higher in terms of power and using the newer thermaltrak transistors with inbuilt diodes............
Will be interesting to see how it turns out.
see here for some details :
http://www.siliconchip.com.au/cms/A_110797/article.html
They have posted the cct in the public domain so looking at it shouldn't be any Copyright issue ???
Will be interesting to see how it turns out.
see here for some details :
http://www.siliconchip.com.au/cms/A_110797/article.html
They have posted the cct in the public domain so looking at it shouldn't be any Copyright issue ???
It's an updated D.Self design using integrated diode temperature compensation (but badly due to insufficient understanding of the temp comp/coef required).andrew01 said:
Except, they have disregarded the ClassAB bias distortion recommendation and gone to needless high bias ClassAB.
edit;
something does not add up.
The schematic shows 70mV to 100mV across each output emitter resistor.
The biasing of the output stage shows 2.2V across the drivers+outputs+emitter resistors.
That implies 550mV across each diode (believable)
and 500mV to 515mVbe across all the output transistor base/emitter. (that seems unbelievable).
What's are they not telling us?
Re: I am studying and producing my own modifications into the simulator
Carlos,
I just knocked it up in Ltspice and same results. Biggest
problem seems to stem from the cfp OP stage. Also the driver has
too low bias current.
Into 20kHz / 4ohms the performance is not so good.
I substituted a triple darlington OP stage, used some HQ jap bjts in
the voltage stage, dropped the miller C to 33p, dropped the IP pair
degen to 20 ohms per leg.
Much better.
More later.
cheers
Terry
destroyer X said:
Carlos,
I just knocked it up in Ltspice and same results. Biggest
problem seems to stem from the cfp OP stage. Also the driver has
too low bias current.
Into 20kHz / 4ohms the performance is not so good.
I substituted a triple darlington OP stage, used some HQ jap bjts in
the voltage stage, dropped the miller C to 33p, dropped the IP pair
degen to 20 ohms per leg.
Much better.
More later.
cheers
Terry
I have made modifications Terry... and found the amplifier very good
The DHR Turbo has something alike.... the audio quality is almost the same, despite my unit is a little bit different, in special into the VAS.
I have it no more... the one was dismounted... i have decided to make something better.... i could not.... sounded almost the same.... well.... it is very hard to increase a little above some good quality level of sonics...it is a hell difficult.
Now a days i am playing with chip amplifiers... i have a lot here and friends have sent me....so...not fair not to use them.... was gift...not fair to be always into my stock without be used.
The one is interesting me is the last model..... i could see something strange and i will wait Magazine people discover and correct.... by the way.... maybe for a while i will try it next month or the other one.
Will not publish the modifications i have made..... i do not like to behave into this kind of "negative" way... repairing or pointing errors or defects into other folks designs... will do my mods and will be silent.... you know...i feel that is very easy to be criticising... really hard is to produce, to make, to create...i feel i have to respect those folks into the Aussie Magazine.... giving time to them to correct typing errors and things alike.
Well... this is personal....my own way to see things now a days.... i understand that is not wrong to tell forum folks, to help them not to make the same errors, into a positive approach to help folks not to assemble wrongly...i have no problems with others when they do that (exception is when the guy ONLY do that!).... i cannot behave this way, mum have teached me to be good...not to be bad (or try to)... i do not feel confortable doing that....it is a hard work to create and produce something..in special when sounds great alike those Aussie Magazine things... i think we can forgive some small failures for a while and wait them to fix.
This is Ultra Low Distortion, MKII... i am thinking about this unit - This one is 200 "Wiskies"
regards,
Carlos
The DHR Turbo has something alike.... the audio quality is almost the same, despite my unit is a little bit different, in special into the VAS.
I have it no more... the one was dismounted... i have decided to make something better.... i could not.... sounded almost the same.... well.... it is very hard to increase a little above some good quality level of sonics...it is a hell difficult.
Now a days i am playing with chip amplifiers... i have a lot here and friends have sent me....so...not fair not to use them.... was gift...not fair to be always into my stock without be used.
The one is interesting me is the last model..... i could see something strange and i will wait Magazine people discover and correct.... by the way.... maybe for a while i will try it next month or the other one.
Will not publish the modifications i have made..... i do not like to behave into this kind of "negative" way... repairing or pointing errors or defects into other folks designs... will do my mods and will be silent.... you know...i feel that is very easy to be criticising... really hard is to produce, to make, to create...i feel i have to respect those folks into the Aussie Magazine.... giving time to them to correct typing errors and things alike.
Well... this is personal....my own way to see things now a days.... i understand that is not wrong to tell forum folks, to help them not to make the same errors, into a positive approach to help folks not to assemble wrongly...i have no problems with others when they do that (exception is when the guy ONLY do that!).... i cannot behave this way, mum have teached me to be good...not to be bad (or try to)... i do not feel confortable doing that....it is a hard work to create and produce something..in special when sounds great alike those Aussie Magazine things... i think we can forgive some small failures for a while and wait them to fix.
This is Ultra Low Distortion, MKII... i am thinking about this unit - This one is 200 "Wiskies"
regards,
Carlos
Attachments
Well, Destroyer X likes the "blameless" design. cool..
It is funny, but the "Quasi" and "brother of Quasi" are modified
versions of this design as well. On quasi's thread I asked him
if he read D.self's book and if his design was based on it
and he said he didn't know.
After collecting all the class AB designs I could find
as well as building a pair of each of them ,I have come to
a few conclusions.
DX amp (original)- Good sounding, very simple, durable, best for
harsh environments and rock music. Based on old time proven design
(I've seen "DX/bootstrap" amps in alot of older mid-priced receivers). Destroyer has done a good job of optimizing this
classic topology (ESP project 03) for DIY use.
Douglas self (blameless amp /Quasi) -
This is the one I chose as my main audio amp. It can be tricky to get this one right. With the right layout, components and TLC, this topology can really be a
smooth performer. I have a hard time measuring it's noise because my sound cards noise floor is higher than than
the amp's! (-125db),
the sound of this amp lends itself to a soundstage (classical/vocals)
and is suited to fullrange.(30pf comp.is just right .)
The leach amp- This is even trickier (twin LTP fully complimentary)
you need to match components and it has a larger component count,
but it sounds a lot like a blameless except for tighter bass
in a sealed HT sub (am I hearing them triple darlingtons?)
BTW , if you want a real simple leach amp ,the lm4702/lme49830
high volt driver IC's are the way to go. I've seen the internals
of these IC's and they are a fully matched leach amp in a
15 pin package.(you design the Vbe and output stage,..MOSFET/BJT).
I don't come to these conclusions lightly, Ive used the Blameless
and the DX clone as a sub amp and vice versa, ran the snot out of them
at parties at 40C degrees and listening tests with my beloved
M-audio sound card with Lossless flac at high volumes.
I also made changes to these amps for safety reasons.
All of these Amp's are
FAR better than most commercial offerings(Sony,JVC,etc.)We use
bigger ,better derated caps,thicker wires, better components in
general.
well, enough ..my 2 cents..
OS
It is funny, but the "Quasi" and "brother of Quasi" are modified
versions of this design as well. On quasi's thread I asked him
if he read D.self's book and if his design was based on it
and he said he didn't know.
After collecting all the class AB designs I could find
as well as building a pair of each of them ,I have come to
a few conclusions.
DX amp (original)- Good sounding, very simple, durable, best for
harsh environments and rock music. Based on old time proven design
(I've seen "DX/bootstrap" amps in alot of older mid-priced receivers). Destroyer has done a good job of optimizing this
classic topology (ESP project 03) for DIY use.
Douglas self (blameless amp /Quasi) -
This is the one I chose as my main audio amp. It can be tricky to get this one right. With the right layout, components and TLC, this topology can really be a
smooth performer. I have a hard time measuring it's noise because my sound cards noise floor is higher than than
the amp's! (-125db),
the sound of this amp lends itself to a soundstage (classical/vocals)
and is suited to fullrange.(30pf comp.is just right .)
The leach amp- This is even trickier (twin LTP fully complimentary)
you need to match components and it has a larger component count,
but it sounds a lot like a blameless except for tighter bass
in a sealed HT sub (am I hearing them triple darlingtons?)
BTW , if you want a real simple leach amp ,the lm4702/lme49830
high volt driver IC's are the way to go. I've seen the internals
of these IC's and they are a fully matched leach amp in a
15 pin package.(you design the Vbe and output stage,..MOSFET/BJT).
I don't come to these conclusions lightly, Ive used the Blameless
and the DX clone as a sub amp and vice versa, ran the snot out of them
at parties at 40C degrees and listening tests with my beloved
M-audio sound card with Lossless flac at high volumes.
I also made changes to these amps for safety reasons.
All of these Amp's are
FAR better than most commercial offerings(Sony,JVC,etc.)We use
bigger ,better derated caps,thicker wires, better components in
general.
well, enough ..my 2 cents..
OS
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