Help, Can anyone tell the correct pinout of a Thoshiba 2SK30A

[solderman]

Hello
I am right now putting together a BOSS SG-1 from GGG (slow gear at GGG)
It contains a odd Toshiba FET 2SK30A  witch I cant get hold of so I have to change that for a other one. The thing is that I need to know the pinout of this one. When I read the datasheet I get to the conclusion hat it is DGS if you look at the bottom of it with the flat side towards you. But I'm not sure since I don't know if I'm reading the sheet correctly. Could someone confirm that I'm correct pleas??

Datasheet
http://www.datasheetcatalog.org/datasheet/toshiba/1032.pdf

The 2SK30A has a Vgd=50V   Ig=10mA
I plan to exchange this for 2N5457 or MPF102 or 2N5485 all of them has a Vgd=25 Ig=10mA. Whats your opinion??


BTW it is an effect that works in the opposite way of a compressor. It starts by cutting the volume to zero and then gradually raising it. You can get pretty cool backwards effect from It

Listen to it
http://www.zeta-sound.se/Slow_gear/SG-1.mp3

Sound taken from
http://www.zeta-sound.se/effects.html

//Solderman

[davent]

Hello Anders,
The first image on the datasheet is with the  flat side of the transistor facing you and the second view is the bottom. I've a Sanyo datasheet for the 2sk30 and it matches the Toshiba. I've read that in most cases with a jFet, the source and drain are interchangeable. Not sure where you are but if you're anywhere near Toronto, Honson Computers has had 2sk30's in the recent past.



dave

[solderman]

Thanks Dave

Not that close , I'm pu in the north of Europe 
The most importent though was that you helped me to be sure about the pinout. I was 90% sure but 10% to much when the thing won't work and you have to troubleshot. With less things to suspect the easer the troubleshooting will be.

//Solderman

[cathexis]

Anders,
Ta en titt på min veroboard-layout för Slow Gear på:
http://www.aronnelson.com/gallery/main.php/v/cathexis/
Jag provade med en 2N5457 och det funkade lika bra. På layouten finns pinouts för båda.
Kul att se en till stockholmare på forumet. Får du trassel får jag väl skänka dig en 2SK30A, tror jag har nån över...

To everyone else: sorry about the swedish gobbledygook, won't do it again...

LARS

[solderman]

Hej Lars
Kul med lite fler Stockholmare här. Som du ser nedan så gick SG-1 bygget inte så bra hittills men förr eller senare brukar dom hoppa igång. Jag provade flera FET och kom ram till att 2N5457 var den som funkade bäst. Hur funkar ditt bygga??

OK, end of awnser in the swedish gobbledygook, won't do it again...



Hi
I just finished a BOSS SG-1 clone Slow Gear from GGG. It works but only when the attack pot is almost contraclockwise (~0,5K) and the sensitivity is almost clockwise (~18K) in this position it does what it should. The volume rice is OK but the decay is very choppy. In all other positions wont open or close depending on where the pots are. The trimpot is almost clockwise. No soldering bridges or tracecuts etc found and all components checked for value and polarity.

No components from the schematics are changed except the FET that is replaced by a 2N5457 that is proven to work in this thing and the C17 that is exchanged 100mF but I have intrepid this as a filter cap so it shouldn't matter.


Does anyone have any suggestions, I´m quite stuck here. The thing works but then again it does not???

Link to schematics

http://www.generalguitargadgets.com/pdf/ggg_sgo_sc.pdf



LM741
1=0
2=4,46
3=4,36
4=0
5=0
6=4,49
7=8,65
8=0

Q1
C=8,95
B=3,94
E=3,52

Q2
D=5,63
G=5,1
S=5,63

Q3
C=8,95
B=6,15
E=5,95

Q4
C=6,08
B=3,41
E=2,88


Q5
C=5,60
B=2,1 and descending slowly to near 0 while measuring
E= 2,2 and descending slowly to near 0 while measuring

Q6
C=5,60
B=2,2 and descending slowly to near 0 while measuring
E=3,0 and descending slowly to near 0 while measuring

//Solderman