I dont know
But last time I looked it seemed ground is almost single point ground
It seemed to me like added coupling caps would mess it up
Not sure, but I dont think Nelson have left out coupling caps because he dont like them
Maybe they will just disturb the curcuit
Well, Im just guessing
But last time I looked it seemed ground is almost single point ground
It seemed to me like added coupling caps would mess it up
Not sure, but I dont think Nelson have left out coupling caps because he dont like them
Maybe they will just disturb the curcuit
Well, Im just guessing
Anyway Bobo, this could bring loop ground problems, not to the problem that I have. Hope..
The only difference in the actual schematic, is that I am using IPFP140 IRFP9140N, but I have already used this couple in the other project, and they seems to work enough well togeather, clipping both at 36V
The only difference in the actual schematic, is that I am using IPFP140 IRFP9140N, but I have already used this couple in the other project, and they seems to work enough well togeather, clipping both at 36V
Ehh, I will try
Your "filter" el-caps are auxilary supply caps
The film caps are supposed to improve high frequency, smoothing any remaining high frequency ripple
Accurate size should be determined by a scope
Using a wrong size may screw up things even worse than with no cap added
I never liked them, others think they have to be there
Filter/coupling caps on sensible curcuits to cure high frequency stability problems is a different matter
Mostly in the "pf" range
Doesnt matter
The point is that you are creating ground connection thats not supposed to be there from start
Your "filter" el-caps are auxilary supply caps
The film caps are supposed to improve high frequency, smoothing any remaining high frequency ripple
Accurate size should be determined by a scope
Using a wrong size may screw up things even worse than with no cap added
I never liked them, others think they have to be there
Filter/coupling caps on sensible curcuits to cure high frequency stability problems is a different matter
Mostly in the "pf" range
Doesnt matter
The point is that you are creating ground connection thats not supposed to be there from start
Unbelievable
I would not have ever believed.
Without caps
About 19V clips the positive, the negative something more.
Is it normal 200-300 mV of offset at this voltage?
I would not have ever believed.
Without caps
An externally hosted image should be here but it was not working when we last tested it.
About 19V clips the positive, the negative something more.
Is it normal 200-300 mV of offset at this voltage?
MONO 
but sounds
no hum, very clear. I have measured about 1hom of output impedence. Bias is 350mA, enough for the FIRST WATT in class A.
maybe I'll leave it with this bias, so I can listen in summertime also, withot sweating. I have already the Zen V4 for this
An externally hosted image should be here but it was not working when we last tested it.
but sounds
no hum, very clear. I have measured about 1hom of output impedence. Bias is 350mA, enough for the FIRST WATT in class A.
maybe I'll leave it with this bias, so I can listen in summertime also, withot sweating. I have already the Zen V4 for this
R21-R22 10K.
Maybe the mains was a little bit low because was 23.3 VDC or the couple not matched of IRFP 140N/9140.
Bobo I measured 21.2 V without load, and then 19V with 8 hom load. So 19V/8hom=2.375A. 2.375A/2.1V(the difference beetwen Unloaded and loaded) =1.13 hom. DF=8/1.13=7.
Or not
Mr Pass, this morning I have read the review of your XP-15 phono stage. One of the best in the world at that price.
Ccongratulations.
Maybe the mains was a little bit low because was 23.3 VDC or the couple not matched of IRFP 140N/9140.
Bobo I measured 21.2 V without load, and then 19V with 8 hom load. So 19V/8hom=2.375A. 2.375A/2.1V(the difference beetwen Unloaded and loaded) =1.13 hom. DF=8/1.13=7.
Or not
Mr Pass, this morning I have read the review of your XP-15 phono stage. One of the best in the world at that price.
Ccongratulations.
Do you mean Peak to Peak output voltages ?
The voltage difference is mostly due to output devices residual voltage and emittor resistors drop out.
So, you dit not evaluate the dynamic output Z ( Z speaker / Damping factor) which takes NFB in account.
Though i cannot tell how to measure it...
Bobo, the measure is made on a resistor.
This is the dark side of the moon.
Andrew, actually the bias is only 350mV so no class A at clipping, but I will do some measure at lower level, as you say, and i'll report results.
This is the dark side of the moon.
An externally hosted image should be here but it was not working when we last tested it.
Andrew, actually the bias is only 350mV so no class A at clipping, but I will do some measure at lower level, as you say, and i'll report results.