Matching Transistors

[s.r.v.]

I've looked around but I can't figure out how to match transistors! i need 4 matched 2N5952 trannies for a phase 90, but they have to be matched. How would i do this?

[Hiwatt25]

I believe MarkM has a layout for a JFET matcher in his layouts folder.  It can be built quickly and cheaply and you should get good results.  Give that a try.

[Papa_lazerous]

Its your lucky day........Somebody has done all the hard work here for you!

To save you the bother of using the search funtion, which trust me you will get told to do if you ask without looking a little first.  Just head over to RG's site www.geofex.com and its in there.  I am not going to post a direct link.  Just read through the whole site theres LOTS there and you will fill your brain up with useful stuff

Enjoy

[Papa_lazerous]

Hiwatt you beat me by a cats whisker, I wanted a virgin post to reply on hahaha

[s.r.v.]

if i need 4 matched for a build, how many should i buy to assure that i get a good set?

[Papa_lazerous]

I think I bought 50 lol but then I like to over order so I can have a stockpile for a rainy day.  I'd say 20 at least then you can get perfect matches

[brett]

Hi
given that there's no such thing as a perfect match, and slight mismatches aren't a big deal, and most outlets will be selling out of the same batch, you could get away with 10 if you are on a budget.
I believe that the chart at RG's site indicates that JFETs come in "clusters" and don't have uniform distributions wrt Vgs vs R.
cheers

[Papa_lazerous]

Hi
given that there's no such thing as a perfect match, and slight mismatches aren't a big deal, and most outlets will be selling out of the same batch, you could get away with 10 if you are on a budget.
I believe that the chart at RG's site indicates that JFETs come in "clusters" and don't have uniform distributions wrt Vgs vs R.
cheers

I'd say not matching them prefectly ( or as close as you possible can) is a big deal on a phase 90.  They dont work too well if not matched properly.  And yeah sure they probably do come off in clusters but you are not getting them straight off the production line, rest assured they will have been mixed thoroughly

Have a look over at smallbear they are cheap enough to buy a glut of them

[Mark Hammer]

better matching = nicer sweep
lesser matching = sweep, but just not as good

Less than perfect matching does NOT equal not working

I suspect if you bought yourself 10-12, you'd get something that sounded halfway decent.  Maybe not as good as it could sound, but halfway decent.  Bang on is better, but close ain't exactly a poke in the eye with a sharp stick.

Where one notices it is apparently at the turnaround points of sweeps, though I imagine that would depend on the sweep width too.  It is quite likely that many trannies that come up as unmatched using standard measurement methods might be quite sufficient if the pedal is biased a little differently and the sweep width is reduced.  Still, if ultra-wide sweeps is what you crave, then better matching is preferred.

You know, I'm surprised that the folks here have not started trading leftover 2N5952s with each other on the For Sale subforum based on known Vgs measurements.  I mean, somewhere out there is someone with 2-3 matched trannies to complement the singleton leftover that someone else has.  It seems a damn shame to have all these leftovers just because someone had to buy way more than they really needed just to be able to snag 4.

[Fuzzy-Train]

I didn't match mine for my TP phase 90... sounds great. But now I'm wondering what it could sound like (to me) with matched fets. I also used 4 J201's.

[Papa_lazerous]

Well NoNothing it would only take 5 minutes to switch them out and try some matched ones   2 minutes if you where all sissy and socketed them 

[Fuzzy-Train]

LOL When it comes to transistors & IC's I'm ALL sissy... better safe then sorry.

EDIT: I don't have any matched or made the device to match them though.

[Papa_lazerous]

I NEVER EVER socket my transistors its just a waste of my time, I generally bradboard things if I am doing something new so I can decide what sounds best.  I sometimes socket IC's depends on the project.  Never fried one yet touch wood

Are you in the UK NoNothing?  I have a large stash of FET's for phase 90 all bagged up and matched in sets if you are local I'll send you some otherwise you'll have to rely on kindness from someone your side of the pond as it wouldnt be worth the postage

[Fuzzy-Train]

^ This is why this is one of the best communities on the internet.

Thanks for the offer but I'm in Canada. I think one day I'll match some up and test them out... for now though, it sounds fine anyways.

[Paul Perry (Frostwave)]

I guess this is why the PWM phaser was designed - look ma, no matching!

[bumblebee]

to SRV,
i'd buy 30 at least, 30's a lucky number with matching imo.

also,matchings not always good........fuzz for example,keep that in mind!