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Laurie
Double Platinum Member
Canada
4854 Posts |
 Posted - 03/04/2008 : 17:34:01
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Thought I'd start a quick new thread - I had asked this question buried deep in another thread.
Does anyone know the "definitive" replacement for the 2SK30 JFET?
ssanyee was kind enouigh to suggest a BF245 in another thread, and I found NTE458 on another forum (I recently tried an NTE458 and it didn't work at all - and I'm certain I had the legs properly oriented as it's different to the 2SK30).
Anyway, what have you used that works as a replacement part?
FYI - I am using RC4558 opamps as replacements for the TL022 (it's all the local shop had in stock) and they work fine. Haven't checked the current draw on the pedal yet though...
Thanks, and regards,
Laurie
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 03/06/2008 : 17:02:03
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Just bought some 2SK30s from Thailand on ebay - $8 including shipping for a quantity of 20.
I'll be interested to see what turns up (and when)...
Laurie. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/05/2008 : 02:22:11
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Along this line of thinking...
I am about to repair my PW-2 which is full of 2SK118 FETs. The electrical specs on the 2SK118 and 2SK30 are identical... I suspect boss just bought a shipment from a different supplier. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/05/2008 : 03:31:16
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quote:
Originally posted by lauries2
Along this line of thinking...
I am about to repair my PW-2 which is full of 2SK118 FETs. The electrical specs on the 2SK118 and 2SK30 are identical... I suspect boss just bought a shipment from a different supplier.
Hi lauries2
Do you need the full datasheets of both?
If you can wait till Monday, I will get them for you.
If you get really stuck, use J201's.
Regards Dr. Bob |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/05/2008 : 07:50:40
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quote:
Originally posted by Dr. Bob
Do you need the full datasheets of both?
Thank you for the kind offer Dr. Bob! I have both the complete data sheets  (and a stock of 2SK30 FETs so i should be ok if that's what's broken.
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Von
Copper Member
Australia
26 Posts |
Posted - 04/09/2008 : 11:56:21
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| How about a replacement for the C2458's that are found in the flip flop circut of the MT-2............. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/09/2008 : 15:27:38
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quote:
Originally posted by Von
How about a replacement for the C2458's that are found in the flip flop circut of the MT-2.............
These look like a garden variety small signal NPN to me. If I ever need to replace one, I intend to use one of the BC548 transistors in my parts box (gain is about the same). Particularly in the flip-flop - there is no audio going through them. I'd probably replace both if I had to replace one to keep the circuit symmetric.
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/09/2008 : 16:15:43
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Hi Von
lauries2 is correct, the 2SC2458's are just GP (General Purpose) Silicon NPN transistors.
If you need specific information, & a data-sheet?
look here:
www.datsheet4u.com
As lauries2 said, replace both in a flip flop.
Do you have flip flop that isn't working?
Not all Boss pedals use discrete transistors, in that part of the circuit.
Some use a 4013 Dual D-Type flip flop IC.
Regards Dr. Bob |
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Von
Copper Member
Australia
26 Posts |
Posted - 04/11/2008 : 13:37:58
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Thanks guys
Yeah..........I've got a MT-2 that died while I was modding it.......One second it worked fine the next nothing.........I've replaced the power supply caps and diode.........still can;t get a sound from it.......thought maybe the fets. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/11/2008 : 15:13:23
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quote:
Originally posted by Von
Thanks guys
Yeah..........I've got a MT-2 that died while I was modding it.......One second it worked fine the next nothing.........I've replaced the power supply caps and diode.........still can;t get a sound from it.......thought maybe the fets.
Hi Von
If you tell us, how, why, when, where, what happened to it before, after & during your modding.
We might be able to help you.
Have you tried to unmod it, put it back to stock components?
Did you maybe short out something, or reverse polarity it?
Which of the MT-2 mods were you doing, & was it from a kit, or did you get all the parts yourself?
And as lauries2, would-will ask, are you familiar with using test equipment like a multimeter, & do you have access to one?
Regards Dr. Bob
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hardcore misery
Copper Member
Philippines
32 Posts |
Posted - 04/13/2008 : 05:03:22
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^^ what's the problem with your MT2? the LED indicator won't light up as you switch it on? it lights up, but there's no output sound? or the indicator does'nt light up, and there's no clean tone sound? or it light's up, and only clean tone sound is present...
the Jfets are the main culprit IMHO,
c2458 can be replaced by c3378,c3267,c2710 and c2459.
2sk30a can be replaced by 2sc9014.
you might check the SIP opamps on your MT2, i've troubleshoot a BOSS hm-3, and the indicator lights on as you switch the pedal, but only a clean tone is present, replacing one of the SIP opamp cured the problem..
note: transistors brokes easily when you are using a high wattage soldering iron. |
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Von
Copper Member
Australia
26 Posts |
Posted - 04/24/2008 : 03:19:38
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Hi guys
Thanks for the help.........I had this MT-2 fully working after the mods went in, but the distortion wasn't sounding right, as I turned the dist knob to hear the sound change the AC power lead shorted against the chasie......after that nothing........no sound, no led...nothing..........
And while we're on the topic of replacement fets........The MT-2 also uses 2SK184.......2SC3378.......2SK118........what can these be replaced with.......If you don't mine me asking? |
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moonmarkcus
Silver Member
Nicaragua
224 Posts |
Posted - 01/08/2010 : 23:53:47
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HI, I just bought and DS2, with a lot of rust inside and all transistors have rusted legs, so I need to change all transistors and some caps.
I have spare C1815(a lot) and K30, also I have a death CS3...But I dont know :
1. Replacement for C3378 are C1815 but � Legs are in the same position? I mean �Can I replace directly without leg change?
2. Replacemente for 2SA1048GR, 2SK184GR and 2SA1335 ... Can I use C1815 or another from death CS-3? |
Edited by - moonmarkcus on 01/08/2010 23:54:45 |
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Topic |
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Replacement for 2SK30 JFET?
