CG said:
Not at all. You were pretty close to the mark. I just wanted to dot the "i"s and cross the "t"s.
And while I consider myself something of an "apprentice" to Mr. Curl, sometimes the apprentice can do good work as well. I am very happy with the way that my latest preamp (the Ayre KX-R) came out. I think it would hold up well against the Blowtorch, and perhaps even surpass it. (Of course, the Blowtorch is several years old now and perhaps Mr. Curl has another preamp up his sleeve.)
I've never had the pleasure to hear a Blowtorch, but we've sold well over 100 KX-R's world-wide, so perhaps somebody will get a chance to do a comparison. The KX-R will be reviewed in the November issue of Stereophile, I believe.
The KX-R has a very similar input stage to the Blowtorch. However, I have changed to current mirrors instead of the folded cascode. Also the KX-R has a variable gain stage, eliminating the need for a attenuator-based volume control. The KX-R has a FET buffer output stage, while the Blowtorch runs as a transimpedance amplifier.
I'm just the kind of guy that always wants to put my own signature on a design. I don't really like to just make a copy of something. Back when the Audio Research SP-3 was the hot preamp (I'm showing my age here), they used to publish the schematic in the owner's manual. I worked as a tech for a dealer and so had easy access to the schematic. I didn't have the money to buy one ($495 list price back then), so I built a "copy". But of course, I had to make my own "improvements" to it. Who knows if they were really improvements, but I thought they were at the time...
Mr.Hansen,
Thanks for claering some misconceptions here.
Would you care to shed some more light on the volume control for the KX-R? Is overloading a reason for concern at the input stage and how is the condition of zero output attained?
Regards,
Jam
Thanks for claering some misconceptions here.
Would you care to shed some more light on the volume control for the KX-R? Is overloading a reason for concern at the input stage and how is the condition of zero output attained?
Regards,
Jam
john curl said:
From looking at the pictures I'd guess that the end results suffer a bit from the implememtation, relative to the Blowtorch. Good intentions or not, giving someone a schematic does not guarantee results.
Mike
It is true that providing a schematic does not guarantee results. However, it makes me responsible for the design, and then IF something goes wrong, I am asked to fix it.
Re: Re: Re: Re: Re: Re: Re: Re: tone controls
In the case of the Studer and the later model Revox decks, the capstan motor is not a simple synchronous motor - it is a servo feedback system with a sensor on the rotating part, thus one can alter the driver or the feedback and make it run at a different speed.
The older Ampex and Scully decks did use simple synchronos motors, and a stable frequency generator + Crown DC-300 connected to the motor's AC line in were used to vari-speed those decks.
_-_-bear
PMA said:
In the case of the Studer and the later model Revox decks, the capstan motor is not a simple synchronous motor - it is a servo feedback system with a sensor on the rotating part, thus one can alter the driver or the feedback and make it run at a different speed.
The older Ampex and Scully decks did use simple synchronos motors, and a stable frequency generator + Crown DC-300 connected to the motor's AC line in were used to vari-speed those decks.
_-_-bear
KBK said:
KBK, I guess it is too much to ask to explain to us where exactly these researchrs made mistakes, and what they did wrong? Why their conclusions are wrong?
Jan Didden
lumanauw said:
Give him my regards.
As to the live performance, if it was better coming from the monitor, you could have chucked the mic and just record directly from the mixer. Less noise 😉
Jan Didden
Wavebourn said:
Even if your gradient search manages to avoid a local 'dimple', you're implicitly stating that you've found the perfect objective function. So exactly what weighting should I give that 7th harmonic, montonicity, etc.... Please do share.
And heaven forfend that the objective function should be in the least bit subjective.......
Agree with Wavebourn.
Not exactly cristal clear what this means.
And yet, I think am rather good in english, compared to many from Asia, Africa and South-America.
Sometimes I even think some highly university educated english speaking
use their language to try to float above & avoid people to be able to responde.
However in this case it is easily fixed.
as the one who wrote it is clever member
and can give us one plain english version, too.
thanks
I keep an eye on this topic
because once in a while I can even learn some new good things here.
Not too very often, though 😀
Lineup
The author (moamps) is not averse to giving credit for 'prior art' for others designs on the website. See http://www.moxtone.com/Tube-buffered Gainclone.htm
However the link is in English whereas the pseudo-Blowtorch requires translation from the original - in my case, using a web translation tool, which was entertaining in itself.
You have the right to remain silent
you too, my friend
in fact as my memory is so very good
i can use anything you said against you, edmund
not only what you try to say
regards lineup
you too, my friend
in fact as my memory is so very good
i can use anything you said against you, edmund
not only what you try to say
regards lineup
Wavebourn said:
Anatoliy,
Apologies for my previous lack of clarity. My question is how exactly do you define optimal? If it is based on measurements, do you use more than one measurement and how do you weight them?
I'm leaving out subjective measures as one man's optimal, is another man's mush...... but ultimately, from my perspective, my subjective ascessment determines whether I want to listen to it in my system.
Regards.
Paul
I'm not him, but I'll take a crack at what I think his meaning is/was:
- Even if your search for the correct EQ manages to correct a small variation(s) in frequency response, you are implying that you have then found an inverse filter that perfectly corrects ("perfect objective function"). If so, what weighting ought to be given WRT that 7th harmonic, monotonicity, etc, given the effect of an EQ upon these things...?-
I think that's the idea.
_-_-bear
PS. I don't actually know anything.
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