Dumb question about "matched transistors"

[swyse]

I'll update this thread when I get to building. But you can build the Phase II and skip all this crap

I appreciate the recommendation, this wasn't on my radar at all. I just checked that out, and I think I prefer the more subtle phasers, so after seeing it had 6 stages I jumped down the rabbit hole and after a video I found I liked the 2 stage phase 45 more it turns out, but then I saw people comparing it to the univibe and now I don't even know what I want.

 

[Chuck D. Bones]

You can always stagger-tune each phase-shift stage à la the UniVibe. I could describe the sonic difference between a UniVibe & Phase 90 and effect of stagger-tuning, but it's out of scope for this discussion. Maybe I'll write something about it in The Boneyard.

 

[MichaelW]

I appreciate the recommendation, this wasn't on my radar at all. I just checked that out, and I think I prefer the more subtle phasers, so after seeing it had 6 stages I jumped down the rabbit hole and after a video I found I liked the 2 stage phase 45 more it turns out, but then I saw people comparing it to the univibe and now I don't even know what I want.

It's definitely different sound than the Phase 90/45. But I found that I could get a less "squishy" effect with the Depth knob. I used it on the first solo on my Pink Floyd demo. It's definitely there and it's a more filtered sound than the MXR. Which is why I'm building the XC I want the options hahah.

 

[Robert]

Ok, I made a little jig to test SMD JFETs...

I pulled 10 MMBF5457's and unfortunately none of them were close. VGs off measured in the -.5-.7 range on all 10.

I wonder if its because they were MMBF5457LT1's. I'm not completely sure what the LT1 designation denotes.

The ones you sent me test around -1.4

How are you attaching them to the through-hole adapter?

 

[MichaelW]

The ones you sent me test around -1.4

How are you attaching them to the through-hole adapter?

I'm laying them on the pads then pressing down on them lightly with a pencil eraser.

What are you testing them on?

 

[Robert]

I'm using a DCA75 with SMD adapter.

I tested a few MMBFJ201s similar to how you did it, then tested them again with the SMD adapter and got completely different measurements.

 

[fig]

I have matched sets if needed.

 

[MichaelW]

I'm using a DCA75 with SMD adapter.

I tested a few MMBFJ201s similar to how you did it, then tested them again with the SMD adapter and got completely different measurements.

arrrghhhh....that means my numbers are useless...heh....

wait did you solder them then test them?

Or is there some gizmo to hold one of those little jumping beans down?

 

[MichaelW]

I have matched sets if needed.

I have a matched set on the way. But I'm invested, committed, deep down the rabbit hole trying to figure this out hahahah....

But THANK YOU AS AWAYS!

 

[MichaelW]

arrrghhhh....that means my numbers are useless...heh....

wait did you solder them then test them?

Or is there some gizmo to hold one of those little jumping beans down?

Ahhh is it one of these gizmos?

 

[fig]

That's the one.

https://forum.pedalpcb.com/threads/guess-how-many-iv.10997/post-111043

 

[Robert]

Your numbers might be correct, but considering they're a bit out the expected range (and from what I measured on a few from the same batch) they could be incorrect.

Yep, that's the gadget.

 

[Locrian99]

Not sure if I was just incredibly lucky but I purchased 10 2n5457's from Stompboxparts and got 2 matched sets of quads. 1 set was Incredibly well matched. I would go this route again rather than buying a matched set. Theres a vero layout for doing the matching over at tagboardeffects very easy to toss on a breadboard the link to it is in the phase 90 build.

 

[MichaelW]

Your numbers might be correct, but considering they're a bit out the expected range (and from what I measured on a few from the same batch) they could be incorrect.

Yep, that's the gadget.

Ok, on the hunt for one that's NOT $50......heh

 

[MichaelW]

That's the one.

https://forum.pedalpcb.com/threads/guess-how-many-iv.10997/post-111043

I can't keep track of all the contests......

 

[HamishR]

Reading all of this makes me grateful I don't like phasers.

 

[fig]

Reading all of this makes me grateful I don't like phasers.

It can become a real FET-ish

 

[andare]

Just found this video helpful

 

[Robert]

Ok, on the hunt for one that's NOT $50......heh

DigiKey has it for $31, you probably won't find one for a much better price than that. I paid $23 for the socket alone, no PCB included.

 

[MichaelW]

DigiKey has it for $31, you probably won't find one for a much better price than that. I paid $23 for the socket alone, no PCB included.

I found it at a couple places for around that but it's the shipping that gets you. Of course now I have to look for some other stuff to make the shipping worthwhile