madbeanpedals::forum

When I got home I had a package from Tayda and diystompboxes.com with some JFETs and decided to post some specs. I have ordered a few 5457's from other sources and will update this when they get here. I hope this information is useful but keep in mind that places like Tayda can be inconstant from order to order.

Tayda:
J201
Vishay 2N5457

DiyStompBoxes:
J201

I used a Peak Atlas DCA Pro and I grabbed 5 of each JFET to test. Here are the results, please post your thoughts.

• Tayda Vishay 2N5457

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-1.16V at Id=1.0µA
Vgs(on)=0.26V at Id=2.89mA
gfs=4.0mA/V at Id=1.7mA to 2.9mA
Id=1.86mA at Vgs=0.00V and Vds=10.78V

Test Result:
N-Ch JFET
Blue-G, Symmetrical Src/Drn
Vgs(off)=-1.10V at Id=0.9µA
Vgs(on)=0.26V at Id=2.51mA
gfs=3.3mA/V at Id=1.5mA to 2.5mA
Id=1.64mA at Vgs=0.00V and Vds=10.92V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-1.77V at Id=1.0µA
Vgs(on)=0.31V at Id=5.00mA
gfs=4.2mA/V at Id=3.0mA to 5.0mA
Id=3.64mA at Vgs=0.00V and Vds=9.57V

Test Result:
N-Ch JFET
Blue-G, Symmetrical Src/Drn
Vgs(off)=-1.60V at Id=1.0µA
Vgs(on)=0.14V at Id=3.39mA
gfs=3.6mA/V at Id=2.0mA to 3.4mA
Id=2.81mA at Vgs=0.00V and Vds=10.13V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-1.83V at Id=1.0µA
Vgs(on)=0.20V at Id=5.01mA
gfs=4.5mA/V at Id=3.0mA to 5.0mA
Id=4.06mA at Vgs=0.00V and Vds=9.29V

• Tayda J201

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.84V at Id=1.1µA
Vgs(on)=0.35V at Id=1.26mA
gfs=1.8mA/V at Id=0.7mA to 1.3mA
Id=0.65mA at Vgs=0.00V and Vds=11.58V

Test Result:
N-Ch JFET
Red-G, Symmetrical Src/Drn
Vgs(off)=-0.60V at Id=1.1µA
Vgs(on)=0.39V at Id=0.99mA
gfs=1.8mA/V at Id=0.6mA to 1.0mA
Id=0.37mA at Vgs=0.00V and Vds=11.76V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.92V at Id=1.0µA
Vgs(on)=0.33V at Id=1.40mA
gfs=1.9mA/V at Id=0.8mA to 1.4mA
Id=0.77mA at Vgs=0.00V and Vds=11.50V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.93V at Id=1.0µA
Vgs(on)=0.32V at Id=1.39mA
gfs=2.0mA/V at Id=0.8mA to 1.4mA
Id=0.77mA at Vgs=0.00V and Vds=11.50V

Test Result:
N-Ch JFET
Red-G, Symmetrical Src/Drn
Vgs(off)=-0.89V at Id=1.1µA
Vgs(on)=0.34V at Id=1.38mA
gfs=1.9mA/V at Id=0.8mA to 1.4mA
Id=0.74mA at Vgs=0.00V and Vds=11.52V

• DIYStompBox.com J201

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.64V at Id=1.2µA
Vgs(on)=0.42V at Id=1.11mA
gfs=1.8mA/V at Id=0.7mA to 1.1mA
Id=0.41mA at Vgs=0.00V and Vds=11.74V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.86V at Id=0.9µA
Vgs(on)=0.37V at Id=1.39mA
gfs=2.0mA/V at Id=0.8mA to 1.4mA
Id=0.69mA at Vgs=0.00V and Vds=11.55V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.50V at Id=1.0µA
Vgs(on)=0.44V at Id=0.92mA
gfs=1.8mA/V at Id=0.5mA to 0.9mA
Id=0.26mA at Vgs=0.00V and Vds=11.84V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.61V at Id=1.0µA
Vgs(on)=0.42V at Id=1.06mA
gfs=1.8mA/V at Id=0.6mA to 1.1mA
Id=0.37mA at Vgs=0.00V and Vds=11.77V

Test Result:
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.54V at Id=0.8µA
Vgs(on)=0.41V at Id=0.93mA
gfs=1.7mA/V at Id=0.6mA to 0.9mA
Id=0.31mA at Vgs=0.00V and Vds=11.81V

I think you won the Tayda lottery.  Those all look OK.

If you test more than that, I'd put the data in a spreadsheet; it'd be easier to compare.

Quote from: pickdropper on May 08, 2014, 05:01:39 AM
I think you won the Tayda lottery.  Those all look OK.

That is what I was thinking. I have had pretty good luck so far.

I only did 5 from the batch to compare for that reason. I still test each one with every build I use but thought I would just do a quick and dirty compare.

Cody

Quote from: pickdropper on May 08, 2014, 05:01:39 AM
I think you won the Tayda lottery.  Those all look OK.

They are all within tolerance, that's true ... it's a small sample, but I noticed that they are mostly at the far ends of the bell curve. EDIT: And they weren't always -- before the FETs went out of production, they had plenty that were good. I made tons of matched sets for phasers that were evenly and properly distributed.

Thanks for the test results, Cody. :)

Quote from: midwayfair on May 08, 2014, 11:46:34 AM

Quote from: pickdropper on May 08, 2014, 05:01:39 AM
I think you won the Tayda lottery.  Those all look OK.

They are all within tolerance, that's true ... it's a small sample, but I noticed that they are mostly at the far ends of the bell curve. EDIT: And they weren't always -- before the FETs went out of production, they had plenty that were good. I made tons of matched sets for phasers that were evenly and properly distributed.

Thanks for the test results, Cody. :)

I think within a given batch that might be true, but the reason why those FETs always had tolerances you could drive a truck through is because the process was somewhat variable.  If Cody feels like taking a larger sample, I have measured a bunch of FETs.  I posted the results from my testing a SMT FETs on here a while back.

I will test all the J201's and the 2N5457's tonight when I get home. I will see if I can export to CSV from the Peak software.

Cody

This is a repost from the other thread, but these are my measurements of one batch of MMBF5458 (SMT) and a batch each of 2n5457 and 2n5952 through-hole.  The SMT are from Mouser, and the other JFETs are older Fairchilds as part of a large batch of transistors a couple of years ago.  I doubt they came from Tayda.

MMBF5458 (n=98)     
Avg VGS   -1.84 mV
Min    -2.1   mV
Max   -1.6   mV
STDev    0.1107827   
     
2n5457 (n=72)     
Avg VGS    -1.28 mV
Min   -1.63    mV
Max   -0.97    mV
STDev 0.169580168   
     
2n5952 (n=99)     
Avg VGS   -2.28 mV
Min   -2.59    mV
Max   -1.78 mV
StDev 0.143183537   

Thanks for posting that Cody, Tayda might get some of my money again....

Quote from: GrindCustoms on May 08, 2014, 09:30:33 PM
Thanks for posting that Cody, Tayda might get some of my money again....

The next batch will all have a VGS of -0.1V OR -5V.  :-)

Roll the dice and make a wish.

Quote from: pickdropper on May 08, 2014, 09:36:20 PM

Quote from: GrindCustoms on May 08, 2014, 09:30:33 PM
Thanks for posting that Cody, Tayda might get some of my money again....

The next batch will all have a VGS of -0.1V OR -5V.  :-)

Roll the dice and make a wish.

«poking the bubble» lol