ok that, I was asking about sound in main setup
and for pics
no pics, it didn't happen
be happy that nobody here is askin' you to post pics on bloody fbook

and for pics
no pics, it didn't happen
be happy that nobody here is askin' you to post pics on bloody fbook

I was comparing the XA252 to the Babefish F8 tonight and noticed I had hum in both speakers when I put my ear to the driver. So just for fun I thought I would try what MEPER did and bypass the GBR, guess what, this amp is now the quietest amp in my collection. Of course your milage may very but it worked for me.
The 2 amps definitely have their own sound. To me the F8 sounds more focused and a bit softer in the treble, images slighty better than the XA252. Both amps tested with Iron Pre and Miro's ad1862 dac.
The 2 amps definitely have their own sound. To me the F8 sounds more focused and a bit softer in the treble, images slighty better than the XA252. Both amps tested with Iron Pre and Miro's ad1862 dac.
Attachments
well, it's written on schm "0/15R"
it seems I need to add a note ....... "start with 0R, use a piece of your precioussssss silver wire for shortie.......... and go for 15R (I've sent) in one channel if you have Marshal buzz, or go for 15R (I've sent) in both channels if Marshal is really bad"

it seems I need to add a note ....... "start with 0R, use a piece of your precioussssss silver wire for shortie.......... and go for 15R (I've sent) in one channel if you have Marshal buzz, or go for 15R (I've sent) in both channels if Marshal is really bad"

The 'interesting part' is that I was en route to make FB on my choke loaded. I cannot get that stable with this driver hanging on the choke and further the same way: up till now the driver is very overdriven. I'll forget that idea. I'll go for a common drain (the 2SK182-common source is nice very warm on a horn for dinner but did not eat Maggies for breakfast).now, there's a trick; Herr Schade never had intention as we are having now - using his name and tricks to mimic triode with non-triode-like part ........ his tricks were made for bettering entire circuit, in most cases much better than simply changing parts in no-nfb circuit and hoping for best; I mean, guy was a Scholar and Engineer, for start
as a matter of fact, any sort of feedback is in general changing transfer function of entire circuit in a way that it can easily resembles having triode in circ, even if there is not one
so ............ call it as you like, but I confess that my predetermined and twisted mind first acted thinking - wtf is now with making triode more triode ...... using Schade feedback on SIT part
anyhow, if you like it, go for it!
I will never go so far as to say that the driver I made for the 2SJ28 VFET MU-build has a Schade feedback (dass ist schade, nicht).
But as to use a compound single stage feedback in a MU-follower, yes that gave a surprising good effect on paper.
Indeed, the feedback in two cascoded mosfets (for example the RA7 preamp) is something different from this; an original type of this feedback of a SRPP with screen feedback on bottom pentode is known to me, perhaps this is an old Philips design:

SRPP with screen feedback on bottom pentode
after half of coffee - isn't it on top pentode?
As I mentioned previously, using smaller heatsinks. Iq set to 1.3ADC, DC fails set to +/-23VDC on the cap mx supplies and the offset sits at less than 5mV after warm up. Heatsink temp is 50 deg C.
Yes ZM, sound is beautiful on the test speakers, will leave it there for a few more days to run in though and then recheck bias /offset.
Thanks for the comments.
Big thanks to Zen Mod, for the design, Mark Johnson for the Amy Alice SMPS filter boards and Cap mx circuit and member birdbox for the great wiring diagram using twin SMPS with 4 filter boards for dual +/- supplies.
Big thanks to Zen Mod, for the design, Mark Johnson for the Amy Alice SMPS filter boards and Cap mx circuit and member birdbox for the great wiring diagram using twin SMPS with 4 filter boards for dual +/- supplies.
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very good, best that all are going to use switchers for PSU
more proper Donuts on ZM's disposal

more proper Donuts on ZM's disposal

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