Mistakes and Flukes

[KarenColumbo]

Just got my AllPCB boards - amongst them a Fet Twin like envisioned by Medved. It was late, I was tired but wanted to solder it so I made a mistake and soldered in a FET the wrong way round - in the schematic it's "T2", the upper one in the first totem pole.

And: It sounded very, very good.

I used 9V - but this thing stayed ultra clean - no matter how much gain I dialed in - and responsive and almost excessively lively. Kind of a "Fenderizer". (Have to add: I put a 100k pot in place of R5 as a "Bias" control.)

I ironed out the mistake and put in another J201 the right way round. Now the whole thing works as expected, it goes into saturation easily. Still sounds great, but my question is:

What happened when, at the FET in question, Gate became Drain, and thus Drain got 4.5V and Gate got the whole 9 Volts? Did I take it out of the (Mu Amp) equation completely? Did I just mis-bias it? Did I cut down the totem pole and made it a single FET booster stage?