Means that a modified Self circuit can beat a simple amplifier.
Modified is different than equal.
Beated Dx amplifier in noise level, also into low end.. but amplifiers are much more than only this.
This amplifier, the one posted, is sounding nice...even without modifications...but without modifications....hehe...i promissed not to tell bad things man..do not force me....because i will not do it.
More Dx than Self that one..... even the original schematic, in the spider constructon received modifications.
Do you still believe in complicated things....have to construct and listen them Mr. Andrew T..... constructing, listening, comparing A to B, not only checking calculations.
This is the last answer you will have from me Mr. Andrew.
regards,
Carlos
Modified is different than equal.
Beated Dx amplifier in noise level, also into low end.. but amplifiers are much more than only this.
This amplifier, the one posted, is sounding nice...even without modifications...but without modifications....hehe...i promissed not to tell bad things man..do not force me....because i will not do it.
More Dx than Self that one..... even the original schematic, in the spider constructon received modifications.
Do you still believe in complicated things....have to construct and listen them Mr. Andrew T..... constructing, listening, comparing A to B, not only checking calculations.
This is the last answer you will have from me Mr. Andrew.
regards,
Carlos
Ultra LD 100W
Andrew (and Carlos)
The auditioned amplifier was based loosely on the SC ULD. It had a CFP VAS as well as 30,000uF capacitance per rail, PLUS
several other tweaks, including well matched 2SA970 differential pair (HFE and VBE) and well matched current mirror devices with HFE >800.The original SC ULD also used a separate front end regulated supply. It is not a DS clone, although the new SC 20W Class A admits to implementing some of his findings. My friend hopes to fit his own regulated supply for the frontend this weekend, so performance should be further enhanced.
I hope this is enough for now ?
SandyK
Andrew (and Carlos)
The auditioned amplifier was based loosely on the SC ULD. It had a CFP VAS as well as 30,000uF capacitance per rail, PLUS
several other tweaks, including well matched 2SA970 differential pair (HFE and VBE) and well matched current mirror devices with HFE >800.The original SC ULD also used a separate front end regulated supply. It is not a DS clone, although the new SC 20W Class A admits to implementing some of his findings. My friend hopes to fit his own regulated supply for the frontend this weekend, so performance should be further enhanced.
I hope this is enough for now ?
SandyK
I have lost the interest, as i finally perceive that is another blameless design
Well...i have already made this one twice.... and into testings and comparisons did not made me happy...the opposite.
As i want to be happy and not to modify Blameless designs or something alike....or that even remembers me that design.... i gave up related this one.
My boards, and dat,a gone to the deposit of things that do not makes me motivated.
Sounded fine in some aspects..but sligtly modified...the next board would be hardly modified...not needed, by me, to construct BlameleX
This problem belongs do Doctor Self....his problem..not mine.
I will listen the SAE..for curiosity, to check once more, that complicated designs normally do not sound so good as we imagine.
My material is in the "less motivating things deposit"
Will not test this one anymore...be happy with it folks
regards,
Carlos
Well...i have already made this one twice.... and into testings and comparisons did not made me happy...the opposite.
As i want to be happy and not to modify Blameless designs or something alike....or that even remembers me that design.... i gave up related this one.
My boards, and dat,a gone to the deposit of things that do not makes me motivated.
Sounded fine in some aspects..but sligtly modified...the next board would be hardly modified...not needed, by me, to construct BlameleX
This problem belongs do Doctor Self....his problem..not mine.
I will listen the SAE..for curiosity, to check once more, that complicated designs normally do not sound so good as we imagine.
My material is in the "less motivating things deposit"
Will not test this one anymore...be happy with it folks
regards,
Carlos
Attachments
Why i quit related this one...sorry friends.
There are some folks, because their possible lack of practice
into the nice word or construction and experimentation...the
world of evaluations and comparisons too, than to compensate
their lack in this area, i suppose, they go calculating things
wondering that this is enougth to evaluate sonic qualities.
Many of them, addicted to Doctor Self, alike a bible,[
goes.adorating blameless theories and goes defending
their calculating brothers.
Unfortunatelly, knowledge do not enter under the arm
using skin contact...better to read those books and construct
those circuits found there... in special when people use them
as reference.... even when some of them have never listened.
I am reading, not finished yet, the Doctor Self book...
i made a fast reading, but not the correct complete reading.
It is not a bible to me, but gave me a lot of informs..very
good the book....not that blame amplifier there!
I really thing Doctor Self never have listened his amplifier
using music...maybe only test tones..because the amplifier
sonics do not indicates me that someone have listened and
apreciated. into Self laboratories.
Well.... there are employees that only says positive things...
i think that they are clever... protecting their jobs..but this
behavior did not contributed too much.
Every good thing i would tell about an amplifier that
presents some self feature, will be enougth to some guys
start with their
- “ I told you that..could.you see now?”
They think that some modified VAS or the application
of CCS, the use of mirrored circuits and all that stuff
will connect the unit to Self designs...and worst..they
thing that the advantages or disadvantages of the circuit
can be also applied to Doctor Self designs.
You know.that kind of conclusion...we see those things
in our young childrens and some big folks too:
.- “Self use this CCS....this circuit use this CCS...
this circuit is good..so.... Dr. Self designs are good too.”.
This logical hook is very primary and not precise enougth.
Some feature will not result in good or bad sonics... but
the global circuit features and decision people had made,
and tested in real circuits..... the union of various ideas
can realise a very good amplifier, and the input from
Doctor A, or the VAS from Doctor B...or driver,
from Doctor C will not make those people receive
the value into the global design...if result bad..they (all doctors)
are not bad...if result good, they are not good..this is too
much weak logical conclusion.
Modified VAS and CCS, mirror and all stuff,
are a tool, alike a hook, to make those people match those
things together.... Self good resistor applied to other amplifier
will be good to other amplifier....of course those ideas do
not make sense..there are enormous lack of logic.
- This circuit, used in self, this one!...means that this amplifier was
Self based amplifier.... well.... it is nice that they try to save one
of our best designers, Dr. Self, but,...unfortunattely, he was not so
luck using his ears listening music... was very well succeeded using
measurements.... his amplifier, as i could see some measurements, seems
that measure very good.
Some folks “twist” the reality to adapt it to their needs.
Some sub circuits understood by them as positive things, and
also present in Self designs, turns Self property.,.than
circuits that have 99 percent differences and this single
thing, used also by Self, will make them believe that
result will be applied to Self too.
Negative!....i can produce amplifier sounding worst and
better than the ones self has made just changing sub circuits
and parts...alignment, currents and some other resources
can transform some amplifier sonics, in such a way, that
you will not be able to recognize it once more during na
A to B comparison..
Not all CCS amplifier sound as Blameless.
All amplifiers have transistors....Blameless too...and this
do not make all amplifiers the same as Blameless.
This is a result of some kind of “block diagram analist”
the idea that one single nice stage will decide the global quality.
Also that one sucessful stage will result in the amplifier global
decisions (All them very good, because the first decision made)
related other stages
Also exist persons that think about someone that have wrote a book
as someone “divine”.... when others books gave to the one have
write in last position, all that knowledge you will find there...and
some small personal contributions too...as the text style for instance.
Not a good argument that many stages in sequence, made by
Some sucessfull engineer may work fine globaly...the entire amplifier
Works as a system, and the value will be measure by the weakest stage.
.
.There are a lot of possibilities, too many combinations possible,
and each one of them may result different in the sonic results.
Others prefere to to simplify to make the understanding easier....
.also they bother themselves a lot related constructors and subjectists...
they say that the subjectivists wants to complicate to make their own
subjective knowledge special.... maybe this is righ..but that those ones
that goes hidden behing the instruments had less courage than the
subjectivists.
To measure is extremelly simple..hard is to believe that means something
related sonics.
I gave up related the construction of this amplifier because Mr. Andrew
already made sub logical connections...if sounded good...and remember
Doctor Self design..than maybe his designs are good enought...negative!
Not real, and i do not want to make people be fooled, as i have made many
posts in this forum and many folks perceive that can trust in me.... and this
circuit can be tweaked to sound fine..but standard it is not good enougth...we
have to make many modifications.... i told it sounded fine..... but this is not
something that can be extended to a global aproval of all circuit performance
under listening evaluation....also this do not makes that kind of VAS a good result....
was the first i had removed after listening a little.
The Blameless is a circuit that may sound fine after tweaked...i could not...but you
may have better results.... .i had good bass and interesting power.... everything more
are censored to use into this forum
I gave up, to construct this circuit...a very nice one, as i perceive the risk to “swim a lot, crossing half ocean and end died into the beach”...i have already tried it deeply and did
not result good in my point of view.
It remembers, really, a lot those Self designs.... this do not means that will sound alike...but, those stages were already tweaked and tune to maximum and i gave up in
the past...i do not want to try once more.
I feel sorry dear Alex.... also Andy...but i am out related this one.
Regards,
Carlos
There are some folks, because their possible lack of practice
into the nice word or construction and experimentation...the
world of evaluations and comparisons too, than to compensate
their lack in this area, i suppose, they go calculating things
wondering that this is enougth to evaluate sonic qualities.
Many of them, addicted to Doctor Self, alike a bible,[
goes.adorating blameless theories and goes defending
their calculating brothers.
Unfortunatelly, knowledge do not enter under the arm
using skin contact...better to read those books and construct
those circuits found there... in special when people use them
as reference.... even when some of them have never listened.
I am reading, not finished yet, the Doctor Self book...
i made a fast reading, but not the correct complete reading.
It is not a bible to me, but gave me a lot of informs..very
good the book....not that blame amplifier there!
I really thing Doctor Self never have listened his amplifier
using music...maybe only test tones..because the amplifier
sonics do not indicates me that someone have listened and
apreciated. into Self laboratories.
Well.... there are employees that only says positive things...
i think that they are clever... protecting their jobs..but this
behavior did not contributed too much.
Every good thing i would tell about an amplifier that
presents some self feature, will be enougth to some guys
start with their
- “ I told you that..could.you see now?”
They think that some modified VAS or the application
of CCS, the use of mirrored circuits and all that stuff
will connect the unit to Self designs...and worst..they
thing that the advantages or disadvantages of the circuit
can be also applied to Doctor Self designs.
You know.that kind of conclusion...we see those things
in our young childrens and some big folks too:
.- “Self use this CCS....this circuit use this CCS...
this circuit is good..so.... Dr. Self designs are good too.”.
This logical hook is very primary and not precise enougth.
Some feature will not result in good or bad sonics... but
the global circuit features and decision people had made,
and tested in real circuits..... the union of various ideas
can realise a very good amplifier, and the input from
Doctor A, or the VAS from Doctor B...or driver,
from Doctor C will not make those people receive
the value into the global design...if result bad..they (all doctors)
are not bad...if result good, they are not good..this is too
much weak logical conclusion.
Modified VAS and CCS, mirror and all stuff,
are a tool, alike a hook, to make those people match those
things together.... Self good resistor applied to other amplifier
will be good to other amplifier....of course those ideas do
not make sense..there are enormous lack of logic.
- This circuit, used in self, this one!...means that this amplifier was
Self based amplifier.... well.... it is nice that they try to save one
of our best designers, Dr. Self, but,...unfortunattely, he was not so
luck using his ears listening music... was very well succeeded using
measurements.... his amplifier, as i could see some measurements, seems
that measure very good.
Some folks “twist” the reality to adapt it to their needs.
Some sub circuits understood by them as positive things, and
also present in Self designs, turns Self property.,.than
circuits that have 99 percent differences and this single
thing, used also by Self, will make them believe that
result will be applied to Self too.
Negative!....i can produce amplifier sounding worst and
better than the ones self has made just changing sub circuits
and parts...alignment, currents and some other resources
can transform some amplifier sonics, in such a way, that
you will not be able to recognize it once more during na
A to B comparison..
Not all CCS amplifier sound as Blameless.
All amplifiers have transistors....Blameless too...and this
do not make all amplifiers the same as Blameless.
This is a result of some kind of “block diagram analist”
the idea that one single nice stage will decide the global quality.
Also that one sucessful stage will result in the amplifier global
decisions (All them very good, because the first decision made)
related other stages
Also exist persons that think about someone that have wrote a book
as someone “divine”.... when others books gave to the one have
write in last position, all that knowledge you will find there...and
some small personal contributions too...as the text style for instance.
Not a good argument that many stages in sequence, made by
Some sucessfull engineer may work fine globaly...the entire amplifier
Works as a system, and the value will be measure by the weakest stage.
.
.There are a lot of possibilities, too many combinations possible,
and each one of them may result different in the sonic results.
Others prefere to to simplify to make the understanding easier....
.also they bother themselves a lot related constructors and subjectists...
they say that the subjectivists wants to complicate to make their own
subjective knowledge special.... maybe this is righ..but that those ones
that goes hidden behing the instruments had less courage than the
subjectivists.
To measure is extremelly simple..hard is to believe that means something
related sonics.
I gave up related the construction of this amplifier because Mr. Andrew
already made sub logical connections...if sounded good...and remember
Doctor Self design..than maybe his designs are good enought...negative!
Not real, and i do not want to make people be fooled, as i have made many
posts in this forum and many folks perceive that can trust in me.... and this
circuit can be tweaked to sound fine..but standard it is not good enougth...we
have to make many modifications.... i told it sounded fine..... but this is not
something that can be extended to a global aproval of all circuit performance
under listening evaluation....also this do not makes that kind of VAS a good result....
was the first i had removed after listening a little.
The Blameless is a circuit that may sound fine after tweaked...i could not...but you
may have better results.... .i had good bass and interesting power.... everything more
are censored to use into this forum
I gave up, to construct this circuit...a very nice one, as i perceive the risk to “swim a lot, crossing half ocean and end died into the beach”...i have already tried it deeply and did
not result good in my point of view.
It remembers, really, a lot those Self designs.... this do not means that will sound alike...but, those stages were already tweaked and tune to maximum and i gave up in
the past...i do not want to try once more.
I feel sorry dear Alex.... also Andy...but i am out related this one.
Regards,
Carlos
Ultra -LD 100W
Hartono
You are absolutely correct. IMHO, the fact that this modded version sounded so good, even before the regulated supply was fitted, speaks volumes for the standard of the modified design.
The front end regulation was expected to be completed this long weekend, but unfortunately, the owner is in bed due to a virus.
30,000uF of capacitance for each supply rail certainly didn't hurt either. The amplifier in question has a very large 3D soundstage when playing most material, and despite criticisms of the original design relying on the work of Douglas Self in some areas, does NOT sound bland and unexciting.
Personally, I believe that Doug Self's research has helped in laying the groundwork for a quiet, low distortion amplifier, which is absolutely needed, in order to make the most of the very much lower level ambience present in many recordings. I find that an amplifier has to be very good indeed, to give a good , clean soundstage, with input from sources such as DVB-T, where the recovered audio level is already in the vicinity of -25dB
MAXIMUM. .
The 3 people present at the an audition of this amplifier were all in agreement on the performance of this amplifier.
I was one of the 3 people present.
And, yes, I am a friend of the owner.
The equipment used included a home built Class A preamplifier, a AU$6,000 Krell preamplifier, Marantz SA11 SACD player, and a modified Musical Fidelity X-DAC V3 , as well as a "Transporter" The speakers used were the highly regarded VAF Research DCX.
See also, previous comments by Greg Erskine.
SandyK
Hartono
You are absolutely correct. IMHO, the fact that this modded version sounded so good, even before the regulated supply was fitted, speaks volumes for the standard of the modified design.
The front end regulation was expected to be completed this long weekend, but unfortunately, the owner is in bed due to a virus.
30,000uF of capacitance for each supply rail certainly didn't hurt either. The amplifier in question has a very large 3D soundstage when playing most material, and despite criticisms of the original design relying on the work of Douglas Self in some areas, does NOT sound bland and unexciting.
Personally, I believe that Doug Self's research has helped in laying the groundwork for a quiet, low distortion amplifier, which is absolutely needed, in order to make the most of the very much lower level ambience present in many recordings. I find that an amplifier has to be very good indeed, to give a good , clean soundstage, with input from sources such as DVB-T, where the recovered audio level is already in the vicinity of -25dB
MAXIMUM. .
The 3 people present at the an audition of this amplifier were all in agreement on the performance of this amplifier.
I was one of the 3 people present.
And, yes, I am a friend of the owner.
The equipment used included a home built Class A preamplifier, a AU$6,000 Krell preamplifier, Marantz SA11 SACD player, and a modified Musical Fidelity X-DAC V3 , as well as a "Transporter" The speakers used were the highly regarded VAF Research DCX.
See also, previous comments by Greg Erskine.
SandyK
Carlos et all,
As the owner of the forementioned and highly modified 100W ULD AB amplifier, I have decided that it's now appropriate for me to provide some input. Firstly, I agree with the assessment that the ULD along with my own interpretation are clearly derivatives of the Doug Self blameless amp design. The design of this power amplifier was only undertaken following the successfull development of a ULD class A preamplifier which shares a very similar design. I originally built the preamp as a scaled down version of the SC 15W class A power amplifier published by Silicon Chip. I deemed this to be a very clean and detailed sounding amplifier but also very cool and clinical. I believe that this is the general impression of this design. My modifications of this basic design were done purely to achieve a sweeter treble that was free of grain and the slightly metalic edge that defined the original. During the course of the development, my reference preamps have been a Krell KSP-7B and a musical fidelity A3cr, which are both highly acklaimed preamps. Without going through the very long winded storey of development, the modded preamp relies very heavily on component selections, and this relates particularly to the input and VAS stages. The completed product easily outperforms (sonically) both reference preamps in all areas. I did not attempt to measure the THD until some time after the project was 'closed' but was not surprised to find that IMD and THD were both below normal measurable limits. Measued at 7.1KHz into 600 ohms at full output the preamp returned a THD of <0.0002%. It may then come as a surprise to some that very low THD and excellent subjective performance can and do co-exist with this design. I should also point out that every person I have demo'd this to has arrived at the same conclusion
The similarly designed power amplifier is still in the development phase but already the results are very very encouraging. I will presemt a schematic of these full mods but only when I deem the project to be finalised.
I also welcome any ctitical appraisals and comments no matter how negative. If you call me a Pajero I'm not offended.
As the owner of the forementioned and highly modified 100W ULD AB amplifier, I have decided that it's now appropriate for me to provide some input. Firstly, I agree with the assessment that the ULD along with my own interpretation are clearly derivatives of the Doug Self blameless amp design. The design of this power amplifier was only undertaken following the successfull development of a ULD class A preamplifier which shares a very similar design. I originally built the preamp as a scaled down version of the SC 15W class A power amplifier published by Silicon Chip. I deemed this to be a very clean and detailed sounding amplifier but also very cool and clinical. I believe that this is the general impression of this design. My modifications of this basic design were done purely to achieve a sweeter treble that was free of grain and the slightly metalic edge that defined the original. During the course of the development, my reference preamps have been a Krell KSP-7B and a musical fidelity A3cr, which are both highly acklaimed preamps. Without going through the very long winded storey of development, the modded preamp relies very heavily on component selections, and this relates particularly to the input and VAS stages. The completed product easily outperforms (sonically) both reference preamps in all areas. I did not attempt to measure the THD until some time after the project was 'closed' but was not surprised to find that IMD and THD were both below normal measurable limits. Measued at 7.1KHz into 600 ohms at full output the preamp returned a THD of <0.0002%. It may then come as a surprise to some that very low THD and excellent subjective performance can and do co-exist with this design. I should also point out that every person I have demo'd this to has arrived at the same conclusion
The similarly designed power amplifier is still in the development phase but already the results are very very encouraging. I will presemt a schematic of these full mods but only when I deem the project to be finalised.
I also welcome any ctitical appraisals and comments no matter how negative. If you call me a Pajero I'm not offended.
Hartono said:Hi Allan,
yes, I know the car, I'm just giving a greeting and joke here
Aussie love Holden and Ford debates right ? (better not get into these scary stuff)
"Usually found in shopping centres"
real world use
regards,
Hartono
Hi Hartono
Yep
those shopping centre carparks are dangerous places
allan
ps VHF man
welcome to the forums
No, i do not think Self work is irrelevant or not good or not enougth
I think he is extremelly competent, a nice guy and a very good scientist.
But something failed related that one..the blameless unit.
He is usefull to all of us...his ideas are nice...even what he said about subjectivism are fine and a lot of us can agree with 98 percent of his ideas.
I use to read his pages, there are informs i need that i go there searching for.
I would be deeply honored to met him and do not understand me bad.... an amplifier is an amplifier...a man is another thing.
He was not lucky, not happy, in my point of view, he lost himself trying to produce something above every criticisms made using instruments...but there are humans in this game...and some of them to not give "that" importance to measurements... and i am a single one person...my opinion do not have to be accepted as "the truth".....the forum has thousands of folks and everyone of them has brain too... take Jacco Vermeullen for instance, he has a very analitic brain...many times better than mine......my ideas has not "that" value, as i am an idiot alike many guys are..i have defects, i misunderstood people and things...i am not too much clever...i am a living beeing...so..do not take my works as Judge Sentence, because i am not good enougth to receive all this value.
Friends.... i want to tell you..... really...... loose some time in your life and construct and listen...do it.
You will understand me completelly.... a bad luck do Doctor Self that Blameless......maybe wonderfull to Instruments.....but they do not belong to human kind...they do not buy amplifiers...and instruments measure when humans operate them...they have not will...not a living beeings.
I have ears...alike you have too.... the amplifier was evaluated this way.... anyone of us can do it...
Check by yourself.... and you can dennie all i said or sign under related what i have perceived.
This other amplifier, the Ultra Low distortion have differences, and those ones can change things....even a miller capacitor, beeing reduced change things.
In my mind you have to change a lot to result nice sonics...i have made that in the past...two times...the first time the board received double barreled shots...... the second time i turn deeply sad.... i wanted to change my mind...awfull to say that something is not good.... believe me..i hate to do that!
regards,
Carlos
I think he is extremelly competent, a nice guy and a very good scientist.
But something failed related that one..the blameless unit.
He is usefull to all of us...his ideas are nice...even what he said about subjectivism are fine and a lot of us can agree with 98 percent of his ideas.
I use to read his pages, there are informs i need that i go there searching for.
I would be deeply honored to met him and do not understand me bad.... an amplifier is an amplifier...a man is another thing.
He was not lucky, not happy, in my point of view, he lost himself trying to produce something above every criticisms made using instruments...but there are humans in this game...and some of them to not give "that" importance to measurements... and i am a single one person...my opinion do not have to be accepted as "the truth".....the forum has thousands of folks and everyone of them has brain too... take Jacco Vermeullen for instance, he has a very analitic brain...many times better than mine......my ideas has not "that" value, as i am an idiot alike many guys are..i have defects, i misunderstood people and things...i am not too much clever...i am a living beeing...so..do not take my works as Judge Sentence, because i am not good enougth to receive all this value.
Friends.... i want to tell you..... really...... loose some time in your life and construct and listen...do it.
You will understand me completelly.... a bad luck do Doctor Self that Blameless......maybe wonderfull to Instruments.....but they do not belong to human kind...they do not buy amplifiers...and instruments measure when humans operate them...they have not will...not a living beeings.
I have ears...alike you have too.... the amplifier was evaluated this way.... anyone of us can do it...
Check by yourself.... and you can dennie all i said or sign under related what i have perceived.
This other amplifier, the Ultra Low distortion have differences, and those ones can change things....even a miller capacitor, beeing reduced change things.
In my mind you have to change a lot to result nice sonics...i have made that in the past...two times...the first time the board received double barreled shots...... the second time i turn deeply sad.... i wanted to change my mind...awfull to say that something is not good.... believe me..i hate to do that!
regards,
Carlos
Carlos
It depends on what type of sound you are looking for with an amp or any piece of audio equipment.
Usually when i build an amp i put a scope on the output and test the signal across 4ohm and/or 8ohm dummy loads.
If there is any distorted signal i would investigate further.
Especially before i connect speakers to it.
(speakers don't like nasty signals it does horrorable things to them
).
the SC 15watt amp and now resusected ULD-100w amps didn't show any distorted signals 1Khz to over 10Khz that i could see.
The 15watt has been upgraded years ago (mainly power supply) and it still hasn't blown up yet.
The ULD-100w has just been reserrected hopfully for future mods.
The reason i put the ULD-100 away was the sound.
It was very accurate and detailed but was felt dry,,,, ie "VHF man"
"I deemed this to be a very clean and detailed sounding amplifier but also very cool and clinical."
Good description VHF man
This is not and amp with distortion, if anything it may do with some 2nd and 3rd harmonics to warm the sound.
Being very accurate it does show the good and bad in recorded music material and my system equipment.
sometimes for better or worse.
If you are looking for an amp thats lively and colourful this may not be the amp for you.
If your looking for an amp that just amplifies what it's given then that is what this amp does.
As for symmed distortion
Silicon Chip or D.S. would have picked that up............hopefully
And i should have seen it, so something wrong when i tested it
allan
It depends on what type of sound you are looking for with an amp or any piece of audio equipment.
Usually when i build an amp i put a scope on the output and test the signal across 4ohm and/or 8ohm dummy loads.
If there is any distorted signal i would investigate further.
Especially before i connect speakers to it.
(speakers don't like nasty signals it does horrorable things to them
).the SC 15watt amp and now resusected ULD-100w amps didn't show any distorted signals 1Khz to over 10Khz that i could see.
The 15watt has been upgraded years ago (mainly power supply) and it still hasn't blown up yet.
The ULD-100w has just been reserrected hopfully for future mods.
The reason i put the ULD-100 away was the sound.
It was very accurate and detailed but was felt dry,,,, ie "VHF man"
"I deemed this to be a very clean and detailed sounding amplifier but also very cool and clinical."
Good description VHF man
This is not and amp with distortion, if anything it may do with some 2nd and 3rd harmonics to warm the sound.
Being very accurate it does show the good and bad in recorded music material and my system equipment.
sometimes for better or worse.
If you are looking for an amp thats lively and colourful this may not be the amp for you.
If your looking for an amp that just amplifies what it's given then that is what this amp does.
As for symmed distortion
Silicon Chip or D.S. would have picked that up............hopefully
And i should have seen it, so something wrong when i tested it
allan
*Ultra LD 100W
I suspect that we should be doing a lot more research into improving the power supplies that feed these "Blameless" Amplifiers (and others) My modded SC 15W Class A already had a great soundstage, detail and dynamics. Supplying the front end via a JLH very low Z, and very low noise PSU addon, instead of dual regulated supplies for the whole amplifier, improved virtually everything. INCLUDING a warmer , more natural sound.
I believe that the practice of inserting a series 10R/1,000uF in the -VE supply rail to the front end, fixes one problem, but then the varying impedance (and phase ?) over the spectrum alters tonal balance by a very small, but audible amount. IMHO, front ends are best supplied by very low impedance to >100KHZ, low noise supplies. Ordinary 3 terminal VREGs are not really up to this task.
SandyK
I suspect that we should be doing a lot more research into improving the power supplies that feed these "Blameless" Amplifiers (and others) My modded SC 15W Class A already had a great soundstage, detail and dynamics. Supplying the front end via a JLH very low Z, and very low noise PSU addon, instead of dual regulated supplies for the whole amplifier, improved virtually everything. INCLUDING a warmer , more natural sound.
I believe that the practice of inserting a series 10R/1,000uF in the -VE supply rail to the front end, fixes one problem, but then the varying impedance (and phase ?) over the spectrum alters tonal balance by a very small, but audible amount. IMHO, front ends are best supplied by very low impedance to >100KHZ, low noise supplies. Ordinary 3 terminal VREGs are not really up to this task.
SandyK
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.