Low gain J201

[SillyOctpuss]

So I have about 30 very low gain J201s. Is there anything I could realistically use these for or should I consign them to the trash?

 

[caiofilipini]

Maybe use them in buffer stages? Not an expert, so I'm not sure that's actually a good idea, just throwing it out there.

 

[Feral Feline]

Another way to use them: Clipping diodes.

NEVER TRASH ANYTHING!

There's always some use. Art... for example. Decorate a build with a diorama ...

 

[temol]

What do you mean by "low gain" J201?

 

[Chuck D. Bones]

What do you mean by "low gain" J201?

Yeah! Inquiring minds want to know!

 

[SillyOctpuss]

What do you mean by "low gain" J201?

That's basically how I think of them tbh. Any circuit I've tried them in has sounded pants and has had virtually no gain/drive e.g. a plexi drive etc I don't know if they're fake or just out of spec parts

 

[Chuck D. Bones]

Maybe they're not biased correctly. Or they might not even be JFETs. Have you tried measuring them?

 

[Barry]

My money is on fakes

 

[temol]

Measure Vp and Idss of one or two transistors and we'll find out if those are fakes. Report results here. Where did you buy the transistors?

A closer look at the Fetzer Valve

I second what CDB said - could be incorrect biasing.

 

[SillyOctpuss]

Measure Vp and Idss of one or two transistors and we'll find out if those are fakes. Report results here. Where did you buy the transistors?

A closer look at the Fetzer Valve

I second what CDB said - could be incorrect biasing.

I did measure them using the improved jfet matcher on tagboard effects ages ago and from memory they were technically in spec but only just. I'll pop a few onto the transistor tester shortly and let you know.

 

[SillyOctpuss]

I chucked a couple in the transistor tester I just bought and have put the results below. I can breadboard the one from tagboard effects again later if this isn't helpful

1 -
ID = 0.25mA
VG = 172mV
2 -
ID = 0.36mA
VG = 254mV
3 -
ID = 0.44mA
VG = 307mV
4 -
ID = 0.15mA
VG = 106mV


So what do we think? Fake or shit?

 

[temol]

There's something odd with your readings. What is VG? Can you breadboard a circuit from Runoffgroove website?

 

[SillyOctpuss]

There's something odd with your readings. What is VG? Can you breadboard a circuit from Runoffgroove website?

Yes I have done it before a long time ago and they checked out as being in spec but literally only just. I don't think they're fake to be honest but I do think they're rejects which have been resold. I bought them shortly after I started building pedals in 2015ish when I didn't know any better.

 

[temol]

From my experience with J201 - for Vp, readings between 0.6 and 0.9V are ok. As for the Idss - 0.5 to 0.7mA.

 

[SillyOctpuss]

From my experience with J201 - for Vp, readings between 0.6 and 0.9V are ok. As for the Idss - 0.5 to 0.7mA.

Either way I don't think the j201s I have are going to be useful for anything I'd actually like to use them for