ilorev, I ordered printed circuit boards here:
https://www.pcbway.com/project/shareproject/Apex_AX17_amplifier.htmlCan someone who build NX14 can verify this circuit?
If this printed circuit board from the russia site komitart.ru may be errors there. I do not recommend repeating it without checking it out.
I have checked all TO-92 Transistor they all are fine.Check the small signal transistors for right footprint orientation.
can anyone suggest me voltage reference poins for 41VDC so that i can compare those points for inspection. actually i have a very limited knowledge about Class AB Amplifires.
Note - 1N4148 are dropping arround 0.7V . is it fine?
I hope you guys suggest me any solution .
Thanks.
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@Extreme_Boky
MJE340 and MJE350 orientetion is corrrect.
MJE340 and MJE350 orientetion is corrrect.
I have build NX14 and testing with 41VDC . But its outputs DC 38V.
Need help.
@jorgovanko Thanks you so much for your observation . I'll inspect acording to the simulation probes.
three imprented dots on a back side of MJE350 and three imprinted dots on front of MJE340? not likely! use multimeter(Ohm-meter or diode tester) to find base,emiter and colector pins of those transistors that jorgovanko marked in his post..
WhoPlease share it's pcb pdf .thanks
Who edit this???please convert this file in sprint format.Please share it's pcb pdf .thanks
I dont know how should i react now.three imprented dots on a back side of MJE350 and three imprinted dots on front of MJE340? not likely! use multimeter(Ohm-meter or diode tester) to find base,emiter and colector pins of those transistors that jorgovanko marked in his post..I
That chinese MJE350 Transistors Level printing was inverted to the Back side. so that this mistake was happend. i have oriented it now correctly and the amp is functioning flawlessly.
Thank you Guys . @jorgovanko @44250 @Extreme_Boky
Audio DIY life lessons:I dont know how should i react now.
That chinese MJE350 Transistors Level printing was inverted to the Back side. so that this mistake was happend. i have oriented it now correctly and the amp is functioning flawlessly.
Thank you Guys . @jorgovanko @44250 @Extreme_Boky
1) Always use a transistor tester. Try not to buy fake transistors. Purchase transistors from reputable sources, electronics distribution warehouses, i.e. Digikey, Mouser, Farnell, etc…
2) Be suspicious of silkscreening on pcb’s especially if it is a prototype that hasn’t been repeatedly built by multiple members.
3) Trace out the circuit on the pcb and see if it matches the schematic (in this example, where does the collector, base and emitter connect, does it match the schematic?).
All of this takes more time but will ensure a trouble free startup!
Thank you @Extreme_Boky for your eagle eyes!
Best,
Anand.
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