I can’t seem to find anywhere whether the newer Toshiba 2SK30AMT-GR is a direct replacement for the previous 2SK30A-GR.
I am trying to get a hold of one to replace a bad one on the outputs of my Jupiter 4.
The spec sheet seems to be the same but not sure what the “A” vs “AMT” is. It does say MOSFET is some places but I assume this is still a JFET? Just want to keep it as stock as possible and not mess with the sound at all. Again these are the 2 that come after the volume pot going to the 2 outputs.
Thanks
Need to know which circuit it’s in. The originals are definitely JFET’s usually used as switches so doubt will have any effect on the sound
On the Jupiter 4 they are used on the output…after the dual gang volume pot. There is a 4558 IC op amp and a couple of resistors with these on that circuit then each signal goes to an output. Same signal each side but has the chorus ensemble to give it the pseudo stereo. I confirmed with another synth repair site that these are the same spec transistor just a newer make and should work fine.
https://dl.lojinx.com/analoghell/RolandJupiter4-ServiceNotes.pdf
page 42 board A Q1 and Q2.
Thanks