Transistor used for tremolo?

[BadCatCubII]

Hi everyone,
Long story short, I'm planning to build a single-ended amp with tremolo hoping to use only one triode of a 12ax7 for that effect.

I would like to vary the bias of a pre-amp tube, and I found this thread here: https://el34world.com/Forum/index.php?topic=9255.0

I am especially interested in the attached schematic from that thread but can't find the transistor listed, and don't know squat about transistors.

My questions are:
1) Will this work if I attach the port marked "trem" to the cathode of a preamp tube?
2) I can't find the mosfet that is listed in the schematic, will this one work as a subsitute? https://www.digikey.com/en/products/detail/onsemi/SSN1N45BTA/1052982

Anything else I need to know?

Thanks in advance,
Ben

[shooter]

Transistors - FETs, MOSFETs - Single | Electronic Components Distributor DigiKey


you're looking for a 500V P-Channel mosfet

[sluckey]

The LED is backwards.

[BadCatCubII]

Thanks, Sluckey and Shooter!

I had noticed that the LED was opposite from the way it is on Merlin's site, so thanks for confirming that, Slucky.

I don't doubt what you say about needing a P-channel, Shooter, but I was able to find a datasheet for the MOSFET in the schematic and it is a 450 volt P-Channel. That is why I suggested the one I did. How do I know what i need?

Do you think this would work: https://www.digikey.com/en/products/detail/microchip-technology/VP0550N3-G/4902412

Thanks again!

[PRR]

you're looking for a 500V P-Channel mosfet

I don't doubt what you say about needing a P-channel, Shooter, but I was able to find a datasheet for the MOSFET in the schematic and it is a 450 volt P-Channel.

NO!! It is a N channel! On the schematic and on the datasheet!

[shooter]

 
used the transistor "jingle"
N(ot) pointing IN
P(ointing) IN

[Joel]

I built this Mosfet tremolo into my Single Channel Reverb about 18 months ago: https://el34world.com/Forum/index.php?topic=26928.msg295792#msg295792  Still happy with it.

[thetragichero]

used the transistor "jingle"
N(ot) pointing IN
P(ointing) IN

works for bjt

i was scratching my head at all the mention of p-channel fets (i'm sure i have a few, but i have about 500x more n-channel) but hadn't bothered to open up a schematic so just kept my mouth shut

[BadCatCubII]

This is helpful, thanks! Like I said, I am totally clueless about transistors. :)

I built this Mosfet tremolo into my Single Channel Reverb about 18 months ago: https://el34world.com/Forum/index.php?topic=26928.msg295792#msg295792  Still happy with it.

That looks super interesting, Joel, I have some reading to do. :)