I will definately keep the both! 😀 It’s nice to have some alternatives at hand for different kind of genres and listening moods.
I still haven’t tried the X-feed on PSL so that might be a joker card for it to shine even more.
I still haven’t tried the X-feed on PSL so that might be a joker card for it to shine even more.
BTW would you mind tell me your matching distribution for the NPN's & PNP's ?
You can PM me if you do not want to disclose in public.
Patrick
You can PM me if you do not want to disclose in public.
Patrick
Here's what I was able to gather at this point. I ordered 100 pcs of both 2SA and 2SC devices, but the sums say I have lost almost ten of each. 😀 Anyway, it seems that the HFE values are much higher with the batches I got compared to the Fig. 5 in the pdf guide. The overlapping region with my devices is approx. 590-625 while in the pdf it is 480-520.
Attachments
These cheap DMM are not accurate on absolute hfe values.
So what you measure as 600 may well be 550 on my meter.
But the distribution does not look too different.
The PNPs have higher average and the overlap is small.
Patrick
So what you measure as 600 may well be 550 on my meter.
But the distribution does not look too different.
The PNPs have higher average and the overlap is small.
Patrick
The hfe distribution of the 2SC3324/2SA1312 shown by SB is consistent with my experience and that of Morde.
Judging from what was shown in the photos I believe you can find enough pairs for the build.
As already mentioned in the article,
"For minimising even harmonic distortion, it is important that :
1) Q1,2,7,8 are hfe matched;
2) Q11,12, are hfe matched, as are Q13,14;
3) Q3,5,9 are hfe matched; as are Q4,6,10;
But the hfe between 1), 2) and 3) can be different.
Patrick
Judging from what was shown in the photos I believe you can find enough pairs for the build.
As already mentioned in the article,
"For minimising even harmonic distortion, it is important that :
1) Q1,2,7,8 are hfe matched;
2) Q11,12, are hfe matched, as are Q13,14;
3) Q3,5,9 are hfe matched; as are Q4,6,10;
But the hfe between 1), 2) and 3) can be different.
Patrick
Here my own distribution, tested using PEAK DCA55 semiconductor analyzer and the PEAK SOT23 adapter.
Indeed the HFE reading change slightly from measurements to measurement, but remain in the range I indicated... And the actual HFE reading may be different from meter to meter, but whit the same meter, in the same condition, temperature, etc, the same batch measurements are an indication of the range of HFE. To make sure I re-tested the NPN or PNP to make sure the tester was not changing/Drifting, but the reading were consistent, and repetitive, within a range, for example I was measuring 410 on time, then 418 the next time, but certainly not 480. As usual the PNP have a greater variation of HFE than the NPN that are more consistent. I saw this behavior with other transistors. Seem to make sense...
Indeed the HFE reading change slightly from measurements to measurement, but remain in the range I indicated... And the actual HFE reading may be different from meter to meter, but whit the same meter, in the same condition, temperature, etc, the same batch measurements are an indication of the range of HFE. To make sure I re-tested the NPN or PNP to make sure the tester was not changing/Drifting, but the reading were consistent, and repetitive, within a range, for example I was measuring 410 on time, then 418 the next time, but certainly not 480. As usual the PNP have a greater variation of HFE than the NPN that are more consistent. I saw this behavior with other transistors. Seem to make sense...
Attachments
Last edited:
Yes, as I already said, consistent with what Morde and I have also measured.
So I would not worry about the measurements.
Just follow post #130.
And even not perfect match is always better than no match at all.
Patrick
So I would not worry about the measurements.
Just follow post #130.
And even not perfect match is always better than no match at all.
Patrick
I'll make a mother board, style F5HA, to mount all the different pcb, and the supply with heatsink, here the design. Don't get excited, I'll only make my own handmade pcb, one side, no pcb order...
Attachments
Last edited:
Super excited. 🙂
See post #97 re the intended way to mount the CCS board.
Of course you are free to mount them otherwise.
Well done,
Patrick
See post #97 re the intended way to mount the CCS board.
Of course you are free to mount them otherwise.
Well done,
Patrick
Very good, thanks for the info. I'll do the same then. Some more real estate to show off on my board then 😉
Yes I will. This board fits nicely into the ebay chassis I bought, and left enough space at both chassis ends for the input connectors and AC inlet on the back, and ALPS pot (with your XFeed pcb, headphone connector and power switch on the front.
Also I'm limited to 6''x9'' pcb material size, so my pcb has to be smaller than that...
SB
Also I'm limited to 6''x9'' pcb material size, so my pcb has to be smaller than that...
SB