Has anyone got these phono boards to work yet?
Have these revised pcb's been built up and shown to work before we were sold them please?
I would have though that they would have been.
Have these revised pcb's been built up and shown to work before we were sold them please?
I would have though that they would have been.
Yes, mine are playing since two weeks - and they do sound really sweet, open and - most important - don´t produce any noise.
Are yours the R3 boards and did you stuff them as per the values printed on the PCB?... no changes?
Lets try it the other way. I have another board with the same issue. Here I also checked the stuffing billion times. Let's do a start over. Maybe I measured something wrong. Who knows.
Ok here we go again with the other board.
TP101: 19.66V
TP102: 17.89V
TP103: 23.31V
TP104: 541mV
V(in)=30.14V@186mA
V(L110): 1.92V
V(L111): 1.91V
V(L112): 1.91V
V(BE Q101): 649mV
V(BE Q102): 161mV
V(BE Q103): 634mV
V(BE Q104): 1.69V
Damn it! Now I wracked something while measuring. I believe I short circuited Q104. LEDs L111 and L112 are off. Need to verify these values.
we went through two rounds of betabuilds, and these (R3 accidentally labelled R2) have been confirmed working by a bunch of people, the betabuilders as well as a few GB builders. But with 300 boards out there in the making, you can expect a few hiccups.... Tried to make the assembly guide as complete as possible, and when all boards are built the assembly guide will be finished 😀
Fixed...
TP101: 19.76V
TP102: 17.94V
TP103: 23.12V
TP104: 544mV
V(in)=30.14V@186mA
V(L110): 1.92V
V(L111): 1.71V
V(L112): 1.71V
(LEDs where broken, I only have the orange ones in stock)
V(BE Q101): 664mV
V(BE Q102): 234mV
V(BE Q103): 651mV
V(BE Q104): 1.67V
TP101: 19.76V
TP102: 17.94V
TP103: 23.12V
TP104: 544mV
V(in)=30.14V@186mA
V(L110): 1.92V
V(L111): 1.71V
V(L112): 1.71V
(LEDs where broken, I only have the orange ones in stock)
V(BE Q101): 664mV
V(BE Q102): 234mV
V(BE Q103): 651mV
V(BE Q104): 1.67V
The orange led's will be a bit noisier and the voltage drop of 1.71V is lower than the specified 1.8V for the green led's (but will be no problem 🙂). I did send you a PM.
So far I have tested 73 of the BC337 transistors that came in the parts package. They are very tightly matched and I'll probably stop testing at this point because I have enough tightly grouped specimens.
hFE
521 - 525 / 1x
516 - 520 / 5x
511 - 515 / 9x
506 - 510 / 14x
501 - 505 / 12x
496 - 500 / 12x
491 - 495 / 8x
486 - 490 / 8x
481 - 485 / 3x
431 - 435 / 1x
The BC327 transistors in the parts package are in another universe altogether. The 50 or so that I have checked are centered at hfe 350. There is no overlap between the two populations.
I still got lucky with this shipment, because I had bought a few hundred BC327 and BC337 transistors earlier and had been sitting on unmatched BC327 transistors centered around hfe 500. I'll have to dig those out. They will go nicely with the new crop.
hFE
521 - 525 / 1x
516 - 520 / 5x
511 - 515 / 9x
506 - 510 / 14x
501 - 505 / 12x
496 - 500 / 12x
491 - 495 / 8x
486 - 490 / 8x
481 - 485 / 3x
431 - 435 / 1x
The BC327 transistors in the parts package are in another universe altogether. The 50 or so that I have checked are centered at hfe 350. There is no overlap between the two populations.
I still got lucky with this shipment, because I had bought a few hundred BC327 and BC337 transistors earlier and had been sitting on unmatched BC327 transistors centered around hfe 500. I'll have to dig those out. They will go nicely with the new crop.
I'll take a look at mine again on Thursday. Time to remove the heatsinks and see if there is any shorting going on.
First and foremost this transistors cost pennies so it is not a big deal to order some more.
The only problem is that the convenience factor is zero and i have expressed my disgust about the rather unprofessional handling of the group buy. I had no saying in this one though. That will be different and better the next time when the pre regulator group buy comes about. This time i have chosen the leader of the pack.
I have also successfully traded with another member here.
Also it is not required that the Hfe is particular high. 400 is more then enough.
It is important that you match groups ( input stage, mirrors ) and gender ( PNP. NPN ).
You can put the higher Hfe ones in the input stage and the lower ones in the mirrors, matched PNP to NPN:
The only problem is that the convenience factor is zero and i have expressed my disgust about the rather unprofessional handling of the group buy. I had no saying in this one though. That will be different and better the next time when the pre regulator group buy comes about. This time i have chosen the leader of the pack.
I have also successfully traded with another member here.
Also it is not required that the Hfe is particular high. 400 is more then enough.
It is important that you match groups ( input stage, mirrors ) and gender ( PNP. NPN ).
You can put the higher Hfe ones in the input stage and the lower ones in the mirrors, matched PNP to NPN:
Turns out that about 30% of my 327's are actually 327-40's. Could easily find a quintet with hfe of 463.
Now let's hope the npn's go that low
Now let's hope the npn's go that low
Joe, I'll order some more on ammo tape. The transistors in the group buy had been stripped of nominal values. I'm 100% sure that they had been searched a few times and all the good values removes.
There is simply no way in which transistors measuring 250-600 can all be over 500 . WTF happened to the bell curve?
There is simply no way in which transistors measuring 250-600 can all be over 500 . WTF happened to the bell curve?