Hi
I have acquired a few original 2sk170b and 2sj74
and 10x ( lsk170 free samples ) Idss range 3-4mA
i am looking to build a mezmeriser B1 buffer
a matched quad is needed
and have i got a good enough 2sk170 / 2sj74 match for a stereo complimentary set ?
i have tested what i have see pic
and would the lsk170 be any good in the power supply of the mez idss 3-4mA
20190616_140101 (1) by glenn jarrett, on Flickr
20190616_170008 by glenn jarrett, on Flickr
I have acquired a few original 2sk170b and 2sj74
and 10x ( lsk170 free samples ) Idss range 3-4mA
i am looking to build a mezmeriser B1 buffer
a matched quad is needed
and have i got a good enough 2sk170 / 2sj74 match for a stereo complimentary set ?
i have tested what i have see pic
and would the lsk170 be any good in the power supply of the mez idss 3-4mA
20190616_140101 (1) by glenn jarrett, on Flickr20190616_170008 by glenn jarrett, on Flickr
You don't appear to have great matches, but perhaps they aren't
necessary. Is there a copy of the Mesmerizer circuit to look at?
(the forum search did not show me one)
In any case, Punkydawgs on Ebay will sell you a quad match for $80.
necessary. Is there a copy of the Mesmerizer circuit to look at?
(the forum search did not show me one)
In any case, Punkydawgs on Ebay will sell you a quad match for $80.
sorry its the Mezmerize B1 Buffer pcb on sale here
wondering if the quad of 2sk170b 7.46 7.52 7.55 7.56 would be ok for the buffer
wondering if the quad of 2sk170b 7.46 7.52 7.55 7.56 would be ok for the buffer
I bought some from Punkydawgs so that I could build some more of your designs, and was pleasantly surprised to find out who that really was when I saw the return address...
John LaGrou: Behind the Gear with Millennia Media | Tape Op Magazine | Longform candid interviews with music producers and audio engineers covering mixing, mastering, recording and music production.
At least his name was on the return address, and it is the same address as his company. Punkydawgs could be someone else there, I guess.
--Mark
BTW, from that interview, I love that he got into DIY by building a crystal radio with his Dad...my Dad and I built the exact same radio, right down to the toilet paper tube to wind the inductor. Must have been from the same book...
If you buy all the transistors from same supplier from the same batch number then they should be pretty close.
For J113, within 10 mA or so Idss.
I have my inventory segregated by lot #'s, and there was also
the transition to On Semi, which changed the average figures
quite a bit.
I have my inventory segregated by lot #'s, and there was also
the transition to On Semi, which changed the average figures
quite a bit.
The best example of the variability in commercial products shows up in the cheap Chinese condenser microphones.
Until the last few years, many of these included surplus 2SK170BLs in common source amplifiers, with a fixed bias resistor that is almost never right...often shockingly off, even though these are grouped in IDSS ranges that get you in a ballpark. You can hear the distortion until you go through the process of putting in a temporary pot and finding the resistance that leads to the correct operating point. Then that gets replaced with the closest fixed resistor.
There is a whole aftermarket industry modding these microphones.
If you are a GarageBand teenage rock star, you won’t hear the difference in the original, but if you do, it becomes unusable. It is like anything, you can easily spend 90-99% more of your resources to get that last 10% of performance, but that’s where the glory is. Everyone has their own point where the outcome is just good enough, and most consumers are not very discriminating.
My day job is not electronics, but I have recently become a Pass-inspired FETologist...and have a long way to go, but it seems to me that finding the correct operating point for your actual FET in hand is critical to the type performance we are looking for around here. There doesn’t seem to be an easy shortcut...in a critical circuit, even buying the right 2SK170 subgroup isn’t enough.
Until the last few years, many of these included surplus 2SK170BLs in common source amplifiers, with a fixed bias resistor that is almost never right...often shockingly off, even though these are grouped in IDSS ranges that get you in a ballpark. You can hear the distortion until you go through the process of putting in a temporary pot and finding the resistance that leads to the correct operating point. Then that gets replaced with the closest fixed resistor.
There is a whole aftermarket industry modding these microphones.
If you are a GarageBand teenage rock star, you won’t hear the difference in the original, but if you do, it becomes unusable. It is like anything, you can easily spend 90-99% more of your resources to get that last 10% of performance, but that’s where the glory is. Everyone has their own point where the outcome is just good enough, and most consumers are not very discriminating.
My day job is not electronics, but I have recently become a Pass-inspired FETologist...and have a long way to go, but it seems to me that finding the correct operating point for your actual FET in hand is critical to the type performance we are looking for around here. There doesn’t seem to be an easy shortcut...in a critical circuit, even buying the right 2SK170 subgroup isn’t enough.
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