back to reality , day or two after
I found what's wrong with EMU - lack of brain combined with defective LCH output
switched to RCH output and all is well
of course that I made a mistake , while making new interface box wit bal in/bal out capability - I put it in plastic box .... forgetting that steel is better , esecially when dealing with lower level signals
one thing more to re-do
that time I'm going to put some protection zenners , at side looking back in sound card ; I don't need them , but who knows what's going to happen if I stumble on cable , while going on/from bench
I finally found the 'magic box' from your journal but am I right that you are handling all attenuation through the pots as I don't see any divider resistors. Do you just start from 0V and just start turning both pots until you see the desired output on the scope? Do I need to worry about limiting current at all?
With a little luck I will be getting a new (very old and used) toy this week. I will call them 'P3 glasses' ...
sorry Twitchie ...... have no time now for proper explanation (my famous routines are Shoot and Pray , also Futile Attempts Method ) , because in this very moment I'm packing something with your name on it
EMU1212 output - pot 10Klog - amp input - dummy load (with CRO across , to observe sine form and level) - back to interface box - 10Klog pot (zeners across wiper-GND) - EMU1212 input
EMU1212 output - pot 10Klog - amp input - dummy load (with CRO across , to observe sine form and level) - back to interface box - 10Klog pot (zeners across wiper-GND) - EMU1212 input
I found this. Hope it can help others in the future:
http://www.artalabs.hr/appnotes/ap1_measuringbox-rev4eng.pdf
@Dennis ... he has 3, are you interested in a mini-GB?
http://www.artalabs.hr/appnotes/ap1_measuringbox-rev4eng.pdf
@Dennis ... he has 3, are you interested in a mini-GB?
sorry Twitchie ...... have no time now for proper explanation (my famous routines are Shoot and Pray , also Futile Attempts Method ) , because in this very moment I'm packing something with your name on it
EMU1212 output - pot 10Klog - amp input - dummy load (with CRO across , to observe sine form and level) - back to interface box - 10Klog pot (zeners across wiper-GND) - EMU1212 input
Thank you Mighty ZM, that is plenty of information and I hope you were not momentarily distracted and accidentally dropped Papa's Koan in my box ... or Iron Pumpkin ... or Babelfish J2X ... or ...
Time to go measure some 2SJ201 and wait for mail delivery person to bring me a nice surprise! Thank you for that as well! When it arrives, you can be sure it will be not only 'Babelfish M25 gone Berserk'!
That's interesting, twitchie !
Will you be building a SissySIT with the 2SJ201 ?
I have already measured and set aside two pairs of THF-51S / 2SJ201 and am awaiting the SissySIT PCBs ...
Best regards,
Claas
I would have to speak from memory here ... have measured at 24V / 2.0A and 25V / 2.0A.
I think one pair was 1.7V for THF-51S and 2.3V for 2SJ201, the other 1.9V for THF-51S and 2.5V for 2SJ201.
I gathered from your responses in various posts in the SissySIT threads that Delta Ugs of 0.5V - 0.6V should work definitely for opto coupler, and down to 0.3V ought to work ...
So I would like to try and monitor closely; could always change to IRFP 9140 if it doesn't work ...
Best regards,
Claas
by numbers , you're good
however , what's going to happen with THD spectra , I can't say ...... didn't tried it and maybe just in week or so will have time to try
2Sj201 in place of IRFP P channel mosfet - lesser xconductance and ( I believe) higher Rdson
will it be Sissier ...... most probably , will it be better , leading to greater Verity , dunno
for capable Greedy Boy , with enough time on hands , easy to try and decide
however , what's going to happen with THD spectra , I can't say ...... didn't tried it and maybe just in week or so will have time to try
2Sj201 in place of IRFP P channel mosfet - lesser xconductance and ( I believe) higher Rdson
will it be Sissier ...... most probably , will it be better , leading to greater Verity , dunno
for capable Greedy Boy , with enough time on hands , easy to try and decide
Every thread for me seems to be the off-topic thread but since you asked, I will be building Sissysit with IRFP9140 and my THF-51 are in -2.93 to -3.0V range as measured by me but within 0.07 of what was written so I am happy. The important thing is they are consistent and they are matched (thank you Pras1170).
My 2SJ201 are -2.14 to -2.3V (I have 6 pcs only so far) but heatsink was different from when I did THF measurement (smaller) and it got hot so I will measure again under better controlled conditions if it's important but at least I know rough values for now.
My 2SJ201 are -2.14 to -2.3V (I have 6 pcs only so far) but heatsink was different from when I did THF measurement (smaller) and it got hot so I will measure again under better controlled conditions if it's important but at least I know rough values for now.
Yes, they will be part of another Evil Scheme of Papa's ... just not this one
Can never have enough of Papa's creations
I think this is a DEEEEP hole, I find myself listening to sissy while reading about other greedy plans and trying to decide which one!
I have some plans ... Babelfish M2 & SEF amp on same pcb ..... having no doubts about M2 , SEF still needing in vivo confirmation , after that LuDEF amp , after that Babelfish XA25
so , considering level of my enthusiasm , combined with level of my ignorance ..... everything is possible , existing in same realm as wooden stove
so , considering level of my enthusiasm , combined with level of my ignorance ..... everything is possible , existing in same realm as wooden stove
