[JN] solid state triode

peter sikking guigurus at xs4all.nl
Sat Apr 24 11:18:08 CDT 2010


Guido wrote:

>>>>> someone applying feedback is weird ?
>>
>> back to your feedback remark: yes that does bother me.
>> the curve trace of the triodised fet gives me peace of
>> mind that that is something that is going to sound good
>> when hooked up in a linear way (a aikido out of fets? hmmm)
>
> The linearity hugely depends on the loadig, one cannot judge that  
> based on the curves only

I am sure that everybody on this list has several strategies for
hooking it up in a linear way. but the curves _do_ show that
regardless of the _quantity_ of linearity one achieves with
a loading strategy, the _quality_ will always be alright
(if sometimes a bit romantic when the quantity is high;
note: not my choice) because this composite device is
intrinsically linear.

>> the time smearing aspects of feedback can be minimised by
>> making the feedback resistor an smd one across the fet legs,
>> smack against the fet body (bit of 47labs, there).
>
> so you are saying that time smear is caused by a few cm of wire ?


well, 30cm (a foot) is more like it in an old-skool tube amp.
I know that the propagation delay of the devices is something
we cannot do anything about, but getting the feedback loop down
to ~3mm is knocking an order or two of one smearing factor.
when looking at the bumbling, frequency-dependent speed that
the part of the signal field that actually goes through the
wire has...

     --ps

         street photographer : ultra-fi builder : on drums...

         sound practices reading club:
         http://ultra-fi.blogspot.com/search/label/sprc








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