MXR Noise Gate question

[morthek]

Hi...I am buiding tonepad´s Noise GAte,and i can´t find 2N5952 trasistor, so looked for the normal substitutions(as in the book: 2N5485, BC264, BF410C, 2SK147, 2SK168) and can´t find them either... weel my question is can i sustitute these for another?which? Help please :cry:  . thanks :lol:

[morthek]

no clue?

[GuitarLord5000]

You can find the transistor at smallbearelec.com.  I just bought three from there specifically for the MXR noise gate.  If you dont have the funds right now, or dont wanna buy just one tranny online, gimme your address and I'll send you one.

[morthek]

i don´t know if SmallBear ship for brazil ,and as you said is a lot of trouble for only one transistor.i thank you a lot , but i dont want to give you trouble  :lol: . lets try to find a substitution first ... if we can´t... well there must be a way!   i was looking here and i have a MPF102, their especifications(MPF102 and 2N5458) look similar any one knows if it fits?(i am no good in electronics)

[morthek]

mistake... where 2N5458 is 2N5952

[Maneco]

Hi,
i'm from Uruguay,and Steve Daniels ships to my country,but for the fet for the noise gate,i would suggest a bf245 or 2sk30,at least those are common here ,and i think they are made in Brazil !!!!...i'm not a big fan of the mpf102,because i once became frustrated when using them for a six stage phaser...they did not work,while the bf245,although unmatched,sounded cool...

parabens

curta,

Maneco

[GuitarLord5000]

Why dont you try this?  Socket the transistor.  Put a trimming pot on the bias resistor.  (I think it is the 22k resistor to the right and slightly above the FET on tonepads layut, but I'm pretty new to this, so I may be wrong.)  Try different JFETS and adjust the trimming pot.  If you find one you like, you can measure the resistance with a DMM and put a fixed resistor in its place.  Or, if you've already commited the circuit to PCB, socket the MPF102 and see if it works.  I've already commited the circuit to PCB and I'll be testing tomorrow.  I'll try the MPF102 and see if it works.  On tonepads layout, it says that other FET's WILL work, so it cant hurt to try.

*EDIT - The 500k pot might also be biasing the FET somehow.  If this is the case, it would probably be easy to replace the FET with any other similar FET with little problems.  One of the big guns here should be able to let you know if this is the case.

[morthek]

ok, i will try and post the results here .... port yours hero too guitarlord  :lol:

[morthek]

:cry:  it didn´t work! i used first bf245 instead of 2N5952 and no change in the sound created( the noise was still there), so i tried MPF102 and the volume cut of  +/- 70% and still noise ... in both cases the sensivity pot doesnt seem to make any chages..... does anyone has the voltages so i can check it? or maybe is the transistor type problem?

[toneless]

Morthek I think that transistors are ok but you may have something wrong connected.Check your wiring,layout etc
Perhaps you can find some info if you read the buil reports at tonepad.com
Hope this helps

[GuitarLord5000]

I have the correct JFET, but the wrong transistor.  (2N5089 instead of the 3904).  I dont have any gating at all.  No volume changes, tone changes or anything.  The sensitivity control seems to do nothing.  Agh!  It's times like these that I rethink my hobbies.  :x

[morthek]

weel. mine is bad too.... i built using Tonepad first noise gate layout. i´ve already searched for wrong connections and havent find them... i used TL072 IC( the layout says it works ).... the only difference between mine and tonepad-s is that i use bf245 instead of 2N5952, and i use a linear pot not a log..... well i think i will send FP a email and ask if he could change this JFET type on his simulator... so i can be sure that this JFET works or not.....  :wink:

[GuitarLord5000]

Gee...If you could ask him to try a 2N5089 in the Q2 slot, it would really help me out a lot!   :wink:

[morthek]

sent the e-mail... i assumed that not many people know about gating ... since not many help we had .... maybe he shows up here