No they are all the same. They may look different but so do we and we are also the same aren't we?
Ok wrong question, I know they are different but what are sonically the mains differences (I hope my question is clearer)
There is one way to find out. As a DIYer you’ll have to wade through the fake/relabelled 2SK170/2SJ74 (that are obsolete for ages) and when you finally have found original ones with correct/matched Idds for way too much money from dubious sources build both. Make sure to start various threads if your 2SK170/2SJ74 are original 🙂 It is all nice & well to those that sit on K170/J74 stocks but those that don’t have them do have a challenge finding them in 2025.
Or just use 2 x OPA828 bought from a distributor as buffers. Combined with a very good ultra low noise PSU of course.
Or just use 2 x OPA828 bought from a distributor as buffers. Combined with a very good ultra low noise PSU of course.
Last edited:
I already got original 2SJ74/2SK170. I also have 2SK209 to replace 2SK170 for a DCB1 for example. PSU will be good shunt reg.
When having original 2SK170/2SJ74 of course build B1 R2. It is one of the best purposes for them.
Yes They are different. The B1R2 uses complementary LSJ74 /LSK170 JFET pairs and the DCB1 uses all LSK170s with one JFET in ech pair acting as a constant current. They are different designs, but have similarities.
I thought 2SK170 and LSK170 were functionally equivalent. But you ae correct in that the matched pairs in the store are the legit '2S' Toshiba parts.
And to get back to the differences between B1, B1R2 and DCB1. The DCB1 buffer stage is more like the original B1 but with a bipolar supply used to obviate the need for an output coupling cap. Output DC should be near 0 with the DCB1. B1R2 takes that a step further with matched complementary pairs.
And to get back to the differences between B1, B1R2 and DCB1. The DCB1 buffer stage is more like the original B1 but with a bipolar supply used to obviate the need for an output coupling cap. Output DC should be near 0 with the DCB1. B1R2 takes that a step further with matched complementary pairs.
It was just joking. The DC offset of DCB1 very strongly depends on matching the JFETs. I managed to match them and have less than 1 mV offset. Saves expensive caps.
The Mezmerize has become a DIYaudio.com classic. More than enough relay controlled inputs, power on/off muting, shunt PSUs, no coupling caps, superior non modular design, the works.
The Mezmerize has become a DIYaudio.com classic. More than enough relay controlled inputs, power on/off muting, shunt PSUs, no coupling caps, superior non modular design, the works.
Last edited:
The 50 ohm pot is used to adjust the ouput so it has no DC voltage present.
Two 22 ohm resistors would not allow such adjustment.
Two 22 ohm resistors would not allow such adjustment.
yeah i understand i also have one question that i would have to designate to the one and only, why the weird resistor values? 221k, 475, etc.
Pinholer has already answered you, values are industry standard values from E96 list resistors (1%).
But you could use 470 ohms, it will also works fine.
Damien
But you could use 470 ohms, it will also works fine.
Damien
Also, Mr. Pass probably has an inventory of thousands of resistors of a variety of values (not all available values, though), and he'll use values that he has on hand that meets his design requirements.