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Suitable JFets for phases?

Started by tehmessiah75, October 29, 2020, 01:15:48 AM

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tehmessiah75

What JFets can be used in phaser projects like the mxr phase 90?

Haberdasher

You can use different types.  2n5952 are good if you can find them.  2n5457 also works well.
BTW, I sell matched sets on my site (in my sig) if you're interested under the name Jay-Fetz.
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

tehmessiah75

Thanks haberdasher, I'll keep that in mind. Do you post to Australia? Everyone I've seen that sells matched sets doesn't ship here.
Will the J107 work?

Haberdasher

I ship there.  I don't have a handle on how long it would take to arrive though.
Sorry, I don't know about the j107's.
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

gordo

I'd be the last one to take food off of Haberdasher's (the one they call Jay Fetz) plate but you could also check out Paul at http://www.diyguitarpedals.com.au/shop

He doesn't have thru hole JFets but has the surface mount and adapter boards.  The surface mounts are mad consistent and with a bit of patience the soldering isn't bad.
Gordy Power
How loud is too loud?  What?

jimilee

If they work, let us know.
Sent from my iPhone using Tapatalk
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

danfrank

Someone here said that J113s work. I thought I'd be smart and bought 100 J112s; they all measure around 2.5-3 volts cutoff. Maybe too high of a cutoff voltage?

tehmessiah75

I bought Paul's phaser but he doesn't sell matched sets. I didn't want to solder 20 smds to the match then.
I found a link in a post on here somewhere and now can't find it to a site the shows jfets with similar stats that you input but now I can't find it.
Someone has linked it searching for the 2n5952 and one of the similar ones was the j107. I can't find the site in my internet history either and don't know enough about jfets.
How close are the smd 2n5457?
Do I need to match them?
Are they that good?

Aentons

#8
Quote from: danfrank on October 29, 2020, 04:12:42 PM
Someone here said that J113s work. I thought I'd be smart and bought 100 J112s; they all measure around 2.5-3 volts cutoff. Maybe too high of a cutoff voltage?

https://www.madbeanpedals.com/forum/index.php?topic=31196.msg300410#msg300410

The DOD Phasor 401 I have uses J113's

From the respective datasheets:
Vgs(off) Min/Max
J113 -0.5V / -3.0V
2N5457 -0.5V / -6.0V
2n5952 -1.3V / -3.5V

mjg

I used some of the smd for a phase 90, I  think I only checked 10 of them, 5 of them were in a group close enough for a phase 90, 3 others were grouped together, 1 outlier, and 1 failed attempt at smd soldering.

So yeah, they are pretty consistent.  I got them from Paul (I'm in Aus too)

tehmessiah75

J107 VGS(off) min/max -0.5/-4.5

Tayda doesn't have J113 at all.
J107 = 255 in stock and they're TO-92

rockola

Quote from: tehmessiah75 on October 29, 2020, 09:29:38 PM
How close are the smd 2n5457?
Do I need to match them?
Are they that good?
I took 2 MMBF5457s off a reel, put them in a Phase 45, and had phasing. Still looking for a sensible process for matching the thousand (minus the two) JFETs left on the reel.

Aentons

#12
Quote from: tehmessiah75 on October 30, 2020, 03:10:35 AM
J107 VGS(off) min/max -0.5/-4.5

Tayda doesn't have J113 at all.
J107 = 255 in stock and they're TO-92
Mouser has a pretty good price break on the J113
Qty.   Unit Price   
Ext. Price
1   $0.41   $0.41
10   $0.276   $2.76
100   $0.129   $12.90
https://www.mouser.com/ProductDetail/ON-Semiconductor-Fairchild/J113?qs=ljbEvF4DwONIvgQL%2FiOeMA%3D%3D

And Small Bear has them too
http://smallbear-electronics.mybigcommerce.com/transistor-fet-j113/

Also, Mind the pinout... the J113 has a couple of interchangeable pins which means they can be reversed and used for phasers designed with the opposite pinout. Not sure if that will be issue for the J107 since I don't see it stated in the spec sheet.

and you should usually match them for the best results...
http://www.geofex.com/article_folders/fetmatch/fetmatch.htm

tehmessiah75

100x J113 for $18.70AU 👍
Postage to Australia $35AU 👎
TOTAL $53.70AU 🤬

TFZ

If you want to match SMD JFETs, consider buying this. The adapter can be bought without pcb too, but then you need to make one yourself, or solder wires to the pins, since they are not in the standard 0.1 format.