Parallel input stage idea - 1/2 12AX7 ll LND150 ?

[stephenl]

I was thinking of trying a parallel 12AX7 ll LND150 for an input stage, but I don't have a lot of experience using FETs. I'd like to try the conventional arrangement of common Anode and Cathode resistors...but I'm guessing the LND150 might not like the operating point?.

My understanding is that the LND150 likes to be biased around .4v - .7v

Thanks in advance for any education on this.

[xtian]

Google “MOSFET follies keen” for info. He suggests a MOSFET will be happy wherever a 12A?7 triode lives. Though best for applications where the signal is not distorted. So the first stage in an amp is a viable choice.

[pompeiisneaks]

Google “MOSFET follies keen” for info. He suggests a MOSFET will be happy wherever a 12A?7 triode lives. Though best for applications where the signal is not distorted. So the first stage in an amp is a viable choice.

I've been really wanting to try this out myself at some point, if I could ever find the time.

I did the googling for you:

http://www.geofex.com/Article_Folders/m ... tfolly.htm

~Phil

[stephenl]

Thanks guys,

I tried an LND150 in a Cathodyne (Source-O-Dyne) and it behaved quite well. I used a voltage divider from B+ to give it fixed bias. It was completely transparent...

[ChopSauce]

Did anyone ever use a MOSFET as a cold clipper stage?

[stephenl]

KMG over on MEF seems to have done the most with LND150's for guitar amps. He has a pretty convincing LND150 JCM800.

https://www.ssguitar.com/index.php?topic=2006.0

[roberto]

Take a look at this site:
http://milas.spb.ru/~kmg/irf_en.html