A Beginner question on MXR phase 45 TL072 & 2N5952

[killerkev]

Intersted in building phase 45. Went to Mouser with the inventory list from Tonepad. I type in the search area 2N5952 but the only thing that comes up is a TO92 (3 pin capped transistor) package from Fairchild. I'm expecting to see a 8 pin IC. This is what I believe I need to match with guidance from Geofx. When I type in TL072 I get a few options, one being from Texas instrument which is a 8 pin IC. Can some one help me along with this? I know Small Bear sells this but I like to order from one place that has it all. If anyone has the correct part numbers with Mouser would be immensly apprieciated. Don't want to order the wrong stuff. Thanks!

[ulysses]

595-TL072CP will be fine

cheers
ulysses

[zyxwyvu]

The 2N5952 is a JFET (http://en.wikipedia.org/wiki/JFET), and should come in a TO-92 package. The TL072 is a dual opamp (http://en.wikipedia.org/wiki/Operational_amplifier), and should be an 8 pin DIP IC, as you said. The part number ulysses mentioned will work for the TL072, and 512-2N5952 will work for the JFET. Make sure to buy enough so that you can get a good matched pair.

[D Wagner]

killerkev,

Remember to order a lot of the FETs, since you have to match them for the best phase effect.  If your FETs do not match, you may get no phase at all.  If you buy 100 of the Fairchild 2N5952, it will only cost $7.00 from Mouser.  You could probably get by with only 20, and find a good set or two.

I matched 75 FETs, trying to get a matched set of four for a Phase 90.  I did not get a single set of four that I would consider matched.  I got several sets of three, and a dozen or more sets of two.  YMMV.

The FET matcher can be found at GEOFEX http://www.geofex.com/.  It is an easy build, and works great.  And, it is a must for FET based Phase effects.

Derek

[killerkev]

I think I may still be missing something here....The TL072 is the 8-pin IC and this is what needs to be matched with guidance from Geofx? Is this correct? Or does the 2N5952 also have to be matched also?  I understand that you need a lot of them to find a match but I'm trying to find out if I need to buy a lot of TL072's or 2N5952's or both.

[ulysses]

the tl072's dont need to match, the two 2N5952's need to be matched.

first you need to build a jfet matcher and buy a multimeter.

set your cheap multimeter to read low voltages (under 2v) and use RG's matcher to match the fets.

ie, matching fets will both show the same result on the multimeter 1.086 and 1.086. 1.086 and 1.094 are not a match and will not phase at all.

you need to buy a lot of 2N5952 and write down the value of each one. then refer to your notes to find two that have the same result.

cheers
ulysses

[ulysses]

you may also want to buy cradles for the ic's as they are easy for beginners to damage with a soldering iron.

cheers
ulysses

[killerkev]

Question answered! Hum, does sound like a lot of work thought!

[ulysses]

you may want to start off with an easier project like a modern day fuzz.

simple builds with common parts.

cheers
ulysses