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TagBoard Jfet Tester

Started by lego4040, March 10, 2017, 06:23:24 PM

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lego4040

Help, I'm about to test my j201's and I need a TL071 or Similar. I can't find those in my stash of coarse but I do have a TL082,JRC4558D and NEC5532. A quick internet check says those are good audio subs but I'd like to get a Amen from guys I trust over here. I'll try and do a short video and post today or tomorrow

Haberdasher

the rest of those you listed are dual opamps, and those would be okay subs for a tl072.  but a tl071 is a single opamp with a different pin arrangement.  therefore none of them will work as a plug-in sub for your tester.

ne5534, tl071, lf351 are subs but it doesn't sound like you have any of those so you might as well hit tayda up for a 071.  or try the parts jar area in the b/s/t.
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

lego4040

Banging head against wall, I know I have some but that will be ordered on next parts list order. I got the Boneyard PCB in  ;D looks awesome Haberdasher

shedland

Hi

Not sure what testing you were planning on doing, but if it were FET matching, this uses a TL072.

shedland


Haberdasher

huh, yeah that linked one says you can use 072.  the one i etched a long time ago used tl071 so I ass-umed it was the same design, doh!.

Quote from: lego4040 on March 10, 2017, 07:52:13 PM
Banging head against wall, I know I have some but that will be ordered on next parts list order. I got the Boneyard PCB in  ;D looks awesome Haberdasher
thanks dude
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

lego4040

Hmm, on the tag board site the one I'm looking at and built uses the tl071. I will look at this page again and see if it's a typo. This is for Jfet matching


lego4040

#8
Ok so I have a TL082 which I'll use for the T072 version. I have another perfect I can use but apparently theirs is this version that uses no Op Amp and is just as good

lego4040

So I built the one shedland postedhttp://tagboardeffects.blogspot.co.nz/2012/07/greatly-improved-jfet-matcher.htmland it works  :) Tim for bed, will post readings tomorrow night after a day of running around. Oh I I built it in a kitty cat can

EBRAddict

If you have the pinouts right, I doubt anyone could notice a difference in the TL072, 4558 or TL082 used for JFET matching.

lego4040

These are my numbers using the TL802. Switch up for idss and switch down for vps
I'm no guru but I'll use the closest 6 and continue building from there. I've had nothing but setbacks all week. I blew out my ankle and spent evening I ER last week and found out my car was towed this morning  >:( so no we got to get car before we go go to confirmation

Muadzin

Maybe the universe is trying to tell you something in regards to the use of JFET's?  ;)


Seriously, that's tough luck. Here's to hoping your luck will improve. Best wishes!

lego4040

Well the good thing is that the pedal works. I'm waiting for enclosures to come in so I can trim everything and box it up. The Wampler Pinnacle sounds great, from clean boost to subtle Gain to over the top crunch. I hear ya on the Jfet's tho, I just bought a matched quad of 5457's Jfet from smallbear for the Nom Nom@10 bucks. Yeah, I'll buy a fistful of smd's and make my from now on.