Designers preference for the gate f3 in MOSFETS?
The users notes suggest about a gig. I see designs between 200K to a gig.
I am guessing one would want it as high as possible without oscillation?
Looking at all the lessons learned in "third generation" as EB put it for the Servo-100, it would seem he got them well tamed and the f3 is quite high, hence the slew rate is quite high. Good thing, right? By the time line, I am guessing the Servo 100 was with all lessons learned from the DH-220. Probably a place to start when I get to that one. Or should I say THAT one as I am planning on THAT diff input receivers. Next year.
The users notes suggest about a gig. I see designs between 200K to a gig.
I am guessing one would want it as high as possible without oscillation?
Looking at all the lessons learned in "third generation" as EB put it for the Servo-100, it would seem he got them well tamed and the f3 is quite high, hence the slew rate is quite high. Good thing, right? By the time line, I am guessing the Servo 100 was with all lessons learned from the DH-220. Probably a place to start when I get to that one. Or should I say THAT one as I am planning on THAT diff input receivers. Next year.
OK. What I should have posted was simply "The difference between capacitors' sound is unmeasurable as far as we know." I wasn't claiming that all capacitors are physically the same size, or have the same ESL, ESR etc.
This was the sort of article I was thinking of, that seems to suggest that capacitors have no 'sound' in audio circuits:
Capacitor Characteristics
And then, in this case, the capacitor is inside the feedback loop of the amplifier. I was just amazed that a change of capacitor type could introduce a clearly audible "warm flavour" when according to the quote above the effect should be almost infinitessimally small.
I cannot speak to measurements (Mssrs Bateman, etal) but I can state that over thirty years of listening by myself and others whose ears I trust (many of them, myself included) classical recordng engineers- we have all heard an improvement in clarity when teflon capacitors are used in the signal path, in place of other types including polyprop and foil. This is particularly evident in soundstage replication, and we were all there for the original recording. I think we knew what the venue sounded like. Regards
SG-Acoustics · Samuel Groner · Analogue Audio
A wealth of practical experience. Thanks for that tip too.
A wealth of practical experience. Thanks for that tip too.
Rather than the 1N4148, 4pF, 4nS, there is the 1N4448/1N916A at 2pF 4nS.
Or BAW76 at 2pF, 2nS with a little lower PIV. If buying new, why not, but in the circuit I have, what would be expected? If it is for protection, then being faster than what it protects is probably smart. In other words, how would this reduce what types of distortion?
Or BAW76 at 2pF, 2nS with a little lower PIV. If buying new, why not, but in the circuit I have, what would be expected? If it is for protection, then being faster than what it protects is probably smart. In other words, how would this reduce what types of distortion?
Wen transistor saturates minority charges accumulate in it's base. When we decrease voltage on it's base it does not folow immediately because this charges have to recombinate. Diode feedback that helps to avoid saturation is known since 1950'th as the measure to make transistor switches faster.
Even if it is 2 nS, it is hundred times faster than turn-off time of typical transistor with Ft of 200 MHz. No real difference between 2 and 4 nS. But Shottky diodes would be preferable because of less voltage drop.
Edit: I forgot to answer your question about which distortions. Well, it is recovery time after clipping. As I described earlier, it looks like the author of the design was very much concentrated on recovery after clipping.
Even if it is 2 nS, it is hundred times faster than turn-off time of typical transistor with Ft of 200 MHz. No real difference between 2 and 4 nS. But Shottky diodes would be preferable because of less voltage drop.
Edit: I forgot to answer your question about which distortions. Well, it is recovery time after clipping. As I described earlier, it looks like the author of the design was very much concentrated on recovery after clipping.
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The 4448 is I think usually a test grade-out of the same basic diode, so it's not as big a difference as one might imagine.
There are some ancient older parts with smaller Cj (FD700 for example), and the voltage the diode sees is small, but this application is not as critical as one (me!) initially thought, as the loading is pretty low impedance. If there were a very high impedance buffer added in the middle there, there might be a measurable effect.
In any event, don't worry about PIV since the voltage swing is small, if I have the right circuit.
If you consider schottky, for the smaller forward current-rated ones, note that some have rather high bulk resistance. So what might be a nominal 400mV drop can be higher at a given working current.
There are some ancient older parts with smaller Cj (FD700 for example), and the voltage the diode sees is small, but this application is not as critical as one (me!) initially thought, as the loading is pretty low impedance. If there were a very high impedance buffer added in the middle there, there might be a measurable effect.
In any event, don't worry about PIV since the voltage swing is small, if I have the right circuit.
If you consider schottky, for the smaller forward current-rated ones, note that some have rather high bulk resistance. So what might be a nominal 400mV drop can be higher at a given working current.
The diodes (well some of them) in that circuit make what's called a Baker Clamp, which as Wavebourn just said, and has been said earlier, keeps the transistors out of saturation when extra-large signals come through, making for cleaner and faster recovery from a clipping situation. Wikipedia has a description:
Baker clamp - Wikipedia, the free encyclopedia
Also, a diode's reverse-bias capacitance varies with voltage (see varactor diode for an application that takes advantage of this), which it would logically follow causes distortion (especially with such a diode right across the BC junction of the VAS). Two to four pF seems pretty low in absolute terms, but it stands to reason that a lower capacitance diode has less capacitance variation and would not cause as much distortion.
Baker clamp - Wikipedia, the free encyclopedia
Also, a diode's reverse-bias capacitance varies with voltage (see varactor diode for an application that takes advantage of this), which it would logically follow causes distortion (especially with such a diode right across the BC junction of the VAS). Two to four pF seems pretty low in absolute terms, but it stands to reason that a lower capacitance diode has less capacitance variation and would not cause as much distortion.
The same care about clipping/recovery behavior. Anyway, replacing of diodes would not improve things.
TL,
One of your favorite sounding amps, sweet , sweet THD ? ..
Frankly we can throw away measurements now ..
http://www.stereophile.com/content/audio-note-jinro-integrated-amplifier
One of your favorite sounding amps, sweet , sweet THD ? ..
Frankly we can throw away measurements now ..http://www.stereophile.com/content/audio-note-jinro-integrated-amplifier
Attachments
"Conclusions
Do single-ended triode amplifiers sound wonderful because they're uniquely true to the music, or do they sound wonderful because they falsify and misshape the music, however appealingly? In short: Do single-ended amplifiers sound wonderful because they're right or because they're wrong? "
-Art Dudley ...
Do single-ended triode amplifiers sound wonderful because they're uniquely true to the music, or do they sound wonderful because they falsify and misshape the music, however appealingly? In short: Do single-ended amplifiers sound wonderful because they're right or because they're wrong? "
-Art Dudley ...
Hi,
Well, NOT that one. That is Audio Note UK and not a Kondo design (I spare you the stories of maciavellian doings and happenings behind this).
HOWEVER, a Kondo Amplifier would not measure dramatically different, at least not orders of magnitude different.
And no, I do not like this amplifier because it has high THD, but despite that (I also rather like some very low THD Solid State Amplifiers).
First, some may argue that indeed, if this amplifier (be it the original Ongaku or this rather different AN UK one or indeed any of my own hardcore SE Tube designs) sound any good at all, we must conclude that all common measurements for amplifiers are useless.
While I would not go so far, I suggest that you listen to such a kind of amplifier, using speakers that make a sympathetic match* (that is crucial, many if not most HiFi/High End Speakers just will not work) before making any particular call on the issue.
Moreover, you may think the AN Jinro Amplifier measures not that horrorshow by the common standards, BUT, do you know what speakers measure like?
You may find this pair of articles useful in gauging what speakers actually do:
MONITORS versus HI-FI SPEAKERS Part 1
MONITORS versus HI-FI SPEAKERS Part 2
Note that these are from a Studio focused publication and around 10 Years old, but they remain very valid.
So, with a reference to Speakers operated at rated power I would say that the distortion and frequency response performance of the Audio Jinro amplifier would not perturb me unduly.
In fact, I would consider anyone who really aggressively criticises relatively high distortion amplifiers but continues to use common speakers as one who, like that Yeshuah dude put it two millennia ago, "strains out the gnat but gulps down the camel"...
Ciao T
* To define a speaker that would match the Jinro well, it should be able to produce at least 105dB/1m with around 20W continous power (that is around 92dB/1W/1m - that is @ 1W electrical not 2.83V) and as the amplifier has only a single output impedance the Speakers impedance should not really drop much below 6 Ohm AND it should not have a bass alignment that greatly sensitive to highish source impedances.
Broadly speaking, something like an AN UK Model E would have such traits, as would have for example a Tannoy Monitor Gold 15" in a suitable cabinet, Urei 813 or larger would also work, as well as many large format TAD and JBL Studio Monitors, others exist.
One of your favorite sounding amps, sweet , sweet THD ? ..
Audio Note Jinro integrated amplifier | Stereophile.com
Well, NOT that one. That is Audio Note UK and not a Kondo design (I spare you the stories of maciavellian doings and happenings behind this).
HOWEVER, a Kondo Amplifier would not measure dramatically different, at least not orders of magnitude different.
And no, I do not like this amplifier because it has high THD, but despite that (I also rather like some very low THD Solid State Amplifiers).
Frankly we can throw away measurements now ..
First, some may argue that indeed, if this amplifier (be it the original Ongaku or this rather different AN UK one or indeed any of my own hardcore SE Tube designs) sound any good at all, we must conclude that all common measurements for amplifiers are useless.
While I would not go so far, I suggest that you listen to such a kind of amplifier, using speakers that make a sympathetic match* (that is crucial, many if not most HiFi/High End Speakers just will not work) before making any particular call on the issue.
Moreover, you may think the AN Jinro Amplifier measures not that horrorshow by the common standards, BUT, do you know what speakers measure like?
You may find this pair of articles useful in gauging what speakers actually do:
MONITORS versus HI-FI SPEAKERS Part 1
MONITORS versus HI-FI SPEAKERS Part 2
Note that these are from a Studio focused publication and around 10 Years old, but they remain very valid.
So, with a reference to Speakers operated at rated power I would say that the distortion and frequency response performance of the Audio Jinro amplifier would not perturb me unduly.
In fact, I would consider anyone who really aggressively criticises relatively high distortion amplifiers but continues to use common speakers as one who, like that Yeshuah dude put it two millennia ago, "strains out the gnat but gulps down the camel"...
Ciao T
* To define a speaker that would match the Jinro well, it should be able to produce at least 105dB/1m with around 20W continous power (that is around 92dB/1W/1m - that is @ 1W electrical not 2.83V) and as the amplifier has only a single output impedance the Speakers impedance should not really drop much below 6 Ohm AND it should not have a bass alignment that greatly sensitive to highish source impedances.
Broadly speaking, something like an AN UK Model E would have such traits, as would have for example a Tannoy Monitor Gold 15" in a suitable cabinet, Urei 813 or larger would also work, as well as many large format TAD and JBL Studio Monitors, others exist.
Hi,
My rather considered opinion on the topic, with an EE degree, a history in music recording and live sound, as designer/builder of PA Amplifiers and Speakers in the 80's as well as designer of studio electronics in the same time, plus one who has at times reviewed HiFi gear and has to his direct or indirect credit quite a few of well received HiFi designs is:
"Because they are right in some ways that we have been unable to quantify so far."
Ciao T
My rather considered opinion on the topic, with an EE degree, a history in music recording and live sound, as designer/builder of PA Amplifiers and Speakers in the 80's as well as designer of studio electronics in the same time, plus one who has at times reviewed HiFi gear and has to his direct or indirect credit quite a few of well received HiFi designs is:
"Because they are right in some ways that we have been unable to quantify so far."
Ciao T
I have heard the Audio Note amplifier, as a matter of a fact had to spend a couple hrs at lunch one day ( NYC 1996) listening to how great the 1st watt is and why the need for only 5 watts ....blah, blah, blah , ....
The best SE amp i have ever heard is Dennis Had's 805B's , i was not taken with the Audio Note as i was with the cary's, to be fair i heard the Audio note at the show and later in a private session, the cary's i was able to listen to in my settings and with our designed speakers.
Frankly for an amplifier to have such high orders of distortion and still sound , not only "good" , but "great" , is vey telling ...
The best SE amp i have ever heard is Dennis Had's 805B's , i was not taken with the Audio Note as i was with the cary's, to be fair i heard the Audio note at the show and later in a private session, the cary's i was able to listen to in my settings and with our designed speakers.
Frankly for an amplifier to have such high orders of distortion and still sound , not only "good" , but "great" , is vey telling ...
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