CA3086 transistors in 14pin DIP... matched?

[joelap]

Is it safe to assume on chips like the CA3086 that all the transistors on the chip are matched to each other (within certain tolerances)?  Will the same apply for the Quad N-channel JFET chip that smallbear sells?  Was going to try biasing via current mirrors for s-and-g's.

[Celadine]

ca3086 - yes, 5 matched npn bipolar transistors, 2 of them connected as a differential pair.

Will the same apply for the Quad N-channel JFET chip that smallbear sells?

Do you mean the THATCo. quad arrays?  Those are bipolar transistors.  The THAT 300 is 4 matched npn bipolars, while the THAT 340 has a matched npn pair and matched pnp pair, both also bipolar.

Was going to try biasing via current mirrors for s-and-g's.

Um, whats a 's-and-g'?

[joelap]

Cool.  For the JFETs-on-a-chip I was referring to the LF347N that smallbear sells.  Thanks for the help on that as well.

And S-and-G's stands for a phrase, not sure about the rules on profanity here... but S***s and giggles.

[Celadine]

I see...the lf347 is actually a quad op-amp chip.  Quad Jfet transistor arrays would be sweet, tho! 

[joelap]

Ahh... thanks for that.  I vaguely remember using a chip in an electronics lab a year ago with 4 Fets on a chip... they were probably MOSFETs though.  I'll see if I can dig up a quad JFET array chip somewhere

[Mark Hammer]

Several phasers made in bygone years used FET arrays on a chip.  I think it was an AM97C11.  I recall seeing a schematic for a phaser in an old NatSem book that used it too.  Given the interest in them, and the fact that plenty of companies still try and crank out analog phasers, I would imagine that if anything suitable was out there, we would have seen it by now on Rocktek and similar low-end pedals.

My sense is that the 3086 is better matched.  I was just looking at Jurgen Haible's Tau Pipe phaser the other day, and his notes indicate the need to match 3046 chips if you use them, but a license to use unmatched LM3086 and SSM2210 chips; the assumption being that these already ARE matched.

[Sir H C]

The 4000 series inverters used for some phasers are pretty matched FETs.  When you make an IC usually you can get some pretty good matching without really trying, and if you try, you can get excellent matching.