Sounds like oscillation - if the bias is changing dramatically. Here is a voltage schematic, may not be exact if you used different PSU voltages, but you shuld be able to see which transistor or resistor is causing the problem.
Attachments
Shouldn’t matter but short it to be safe. Also use a current limiter, a slip of the probe can cause a lot damage.
hi thank you for your time.
i dont touch any thing. i just now go for make mesurements and its look ok i dont understand now bias stay at 8.4mV.
i make some mesurement.
R7, R6 : 0,28V
R14: 1,22
R15: 1,48V
R20: 1,12V
R3: 10V
output ofset is one channel 20mV other is 2.3mv i dont know how its possible.
that mesurements same on booth channels only the ofset is different. i make it work 5 min heat sink is warm witouth fan. sound is good.
NOT: i remember that 2.3V ofset channel i change C8 only different is that but it can effect that much ofset? i will change other channel and write here.
karachay - sounds good to me. Did you figure out the issue, or are you listening to find out if there really is a problem?
Got do the etching for my A38/40 this evening. Hopefully tomorrow I can get to do the drilling. Actually cant wait to hear this amp sing, as well as my NX14 that Im almost finished with.
hi. i trying to find what was the problem cause i didnt fix it.
i dont do nothing, after you write me voltage mesurements i open it again and check it and all is look like normal.
and i am thinking is it done or not. just i dont want it burn after i close case.
now the only problem is 1 channel ofset is 20mV and other is -2.3mV. C8 can do that? cause you can see on the picture i send, one channel have small orange colour 100n and other is grey. grey one have 20mV ofset orange one have -2.3V. i take that cap from old board. booth is 100n. do you think its cause of that cap?
What do you suggest abouth it
P30ZF pdfs & gerbers
Ballisticz,
Please see attached. Hope this is what you need.
RegardsView attachment P30 ZF GERBERS.zip
View attachment BOT1.pdf
View attachment TOP1.pdf
View attachment TOP MR1.pdf
Ballisticz,
Please see attached. Hope this is what you need.
RegardsView attachment P30 ZF GERBERS.zip
View attachment BOT1.pdf
View attachment TOP1.pdf
View attachment TOP MR1.pdf
Sam,
I do not know, I had 2 boards to build, but I sold them about a month ago. Dominique "Pinocchio" from Quebec built one, he may know the sound.
Regards
I do not know, I had 2 boards to build, but I sold them about a month ago. Dominique "Pinocchio" from Quebec built one, he may know the sound.
Regards
Check out post 12872. Pinnochio built them, Alexmm built them, search the Apex threads and find some info that satisfies you. Good luck.
hi mr. mile and all diyer friends.
i finish 2 channel ax14 and feed them with f100 PSU.
i get some problems but for now its look ok but i cannot be sure.
f100PSU =
1. clip leds resistors 6k8 1w, i make them 2w but still too much hot. do i need 5w on them or some thing is wrong?
2. how can i test short circuit protection working or not.
ax14 =
one channel ofset 20mV, other is 2.3mV. what can i chech for make them same.
i finish 2 channel ax14 and feed them with f100 PSU.
i get some problems but for now its look ok but i cannot be sure.
f100PSU =
1. clip leds resistors 6k8 1w, i make them 2w but still too much hot. do i need 5w on them or some thing is wrong?
2. how can i test short circuit protection working or not.
ax14 =
one channel ofset 20mV, other is 2.3mV. what can i chech for make them same.
1. 6k8 must be hot that is OK
2. You can use input pair with same hfe for beter DC offset but 20mV is OK
mr mile i want to add your fan control too i make it but i cannot make it work. i have 18v ac. if you have another fan control can you share it plsease? it can be work on main heatsink too no problem just it need to be small 😀😀😀
edit: i have 24v fans and have 18-0-18Vac
edit: i have 24v fans and have 18-0-18Vac
Last edited: