Q about Phase 90 fets (and NTE search)

[Thomas P.]

I'd like to build a phase 90 but I can't get the 2N5952 here in germany. I searched for the datasheet to see if there are substitutes which are available here. Therefor I used the NTE cross-reference search (which the most of you might know). The product NTE showed as a substitute was a NTE312. Not a big deal, I can't get NTEs.
Today I looked around for a datasheet of the 2N3819 and guess what: The NTE type was also NTE312!
Now I have the problem of decideing wheter their engine is stupid or if I can use a 2N3819 to phase up the 90.

Anyone tried to use other fets with good results in this???

[Joep]

Hi Tomboy,

Smallbear has them, but I used J201, more type should work like the 2N3819. I have no idea how the difference type of fets compere soundwise....

Bye,

Joep

[idlefaction]

pretty much any FET will work in the circuit, hooray!  

J201 has a very low Vgs (about 0.3 i think) and it's easier to get the circuit to work with higher Vgs types with Vgs of more like 1.5-3V, like 2N5458, 2N5484, 2N5485.  i used 2N5484 cos they were easy to get and cheap.

btw, NTE just make generic FETs and grade them into groups depending on the characteristics of the batch.  each NTE part replaces hundreds of different other devices (supposedly).  a lot of the time if a specification is critical, the NTE replacement won't work at all in the circuit!  so if you're using an NTE replacement it's best to ask first if anyone thinks it won't go in your circuit.  

[petemoore]

Crosses to J201, but I think they're a teeny bit hotter,
 Any of them IMO even MPF102's sound good, mainly just a little different...in the boosters I've tried them in.

[Thomas P.]

Thanks guys!!!

I think I'll use sockeds and try some.
So far I did a layout for the Phase 180+ with 8 stages and the possibility to switch between 4,6 and 8. Let's see how useful it is :wink: