Now that the dust has settled on the DIY Sony VFET project, parts 1 and 2
we come to the design which accommodates the 2SJ18 and 2SK60 parts
which you may recall are the 1 die versions of the 2SJ28 and 2SK82 (which
have two of the same devices in parallel in the TO-3 package).
This design is for those transistors, and also for some other variations we might
want to play with, and like the parts 1 and 2 come in the flavor of the N or P
channel parts.
I have tested prototypes and purchased the pc boards and mounting brackets
for 300 channels, (150 of each polarity) and kits will be offered in the store soon.
This kit assumes that you have some of these Sony parts, whether hoarded for
years or freshly scraped out of an old receiver.
Also there are plans for versions using other fets in plastic TO-247 packages
for the store's UMS mounting pattern.
More information and documentation to follow shortly.
we come to the design which accommodates the 2SJ18 and 2SK60 parts
which you may recall are the 1 die versions of the 2SJ28 and 2SK82 (which
have two of the same devices in parallel in the TO-3 package).
This design is for those transistors, and also for some other variations we might
want to play with, and like the parts 1 and 2 come in the flavor of the N or P
channel parts.
I have tested prototypes and purchased the pc boards and mounting brackets
for 300 channels, (150 of each polarity) and kits will be offered in the store soon.
This kit assumes that you have some of these Sony parts, whether hoarded for
years or freshly scraped out of an old receiver.
Also there are plans for versions using other fets in plastic TO-247 packages
for the store's UMS mounting pattern.
More information and documentation to follow shortly.
Thanks you Mr. Pass for all excellent news
Yes! I would love to know if Nelson thinks this is possible since I have a stash now.This could be a fun way to use a pair of Semisouth parts
Best,
Anand.
As with the first series they are pretty similar. Biggest difference is these vfets are biased by current sources which roughly double the appearance of the load impedance. As the optimal impedance for the 2sk82 and 2sj28 was roughly 8 Ohms, the 2sj18 and 2sk60 are more like 16, this because the former has 2 of the die in parallel. So in the case of the 2sj18 we use a mu follower to make the vfet think the load is 16 ohms, and a variation of that for the 2sk60.
This is great news! I hope that I am able to buy one. I (very nobly) did not enter the lottery because I have the 2sk82 and 2sj28 VFETs. Now the time has come. Really looking forward to building the amp into that gorgeous chassis. Just hope I am not too late to the store.
Question: could we modify the CCS that you mention above, Nelson, for the 2sk82 or 2sj28? I want to build the pt.1 or pt.2 version. Thanks!
Question: could we modify the CCS that you mention above, Nelson, for the 2sk82 or 2sj28? I want to build the pt.1 or pt.2 version. Thanks!
