NAP-140 Clone Amp Kit on eBay

If you connect the Q5 incorrectly, you need to check TIP41C, TIP42C and 2sc5200.

Q5 is suppose to maintain 1.8V - 2.4V Vceo across these 4 transistors.

Without Q5 functional correctly, these 4 transistor may receive +/- 20V bias which may cause damage

I have exchanged Q5 and TIP41C, TIP42C now a couple of times, I am still getting smoke at 100R :(
Do i need to put in 2sc5200 or a diode to check voltages?
 
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Im just trying to understand the grounding issue before i test my boards..

what did you change that fixed the Hum? are your pictures in posts 380 and 388 the same? Also do you ground to chassis under your terminal board between the tranny and the power supply?

thanks

A photo of my layout without hum. Use the two psu boards. Use a star ground at the output of one of the boards and connect psu v+ and v- of the two boards. See the photo:
ignatius little projects
 
Hi,

ok maybe a dumb question but I have limited amp building experience (only a gainclone).

Is it okay to use a potentiometer to control volume on these amps and if so any recommendation on the pot value 100k, 50K? i havnt seen anyone doing it with this amp..

I'm building my integrated nap140 with a passive preamp, only a switch and a 50k potentiometer. I was thinking in using some kind of small preamplifier kit but after several weeks listening the nap140, i think it would be far better to use it without any kind o active preamp. Theoretically the lowest the potentiometer value is the best option, you can probe with 5-10-20pots. Tell me how it works.
¿have you any speakers protection kit for this amplifier? If you use it without any speakers protection kit you will see a violent movement of about 1cm in the woofer when you turn on the amplifier.
 
I.. lowest the potentiometer value is the best option, you can probe with 5-10-20pots. Tell me how it works.
¿have you any speakers protection kit for this amplifier? ...

thanks
I just ordered a speaker protection kit today. As far as pots i have a 100k stereo pot and maybe some single pots of different values i can check out eventually, assuming my amp doesnt go up in smoke..
 
Hello
At first I connected my CD player which has adjustable line out 5K Alps Blue potentiometer and did work fine .
But I have another CD player with out adjustable line out . I use a 10K pot and works fine .
I would advise use a 10K pot if you have at home that will do the job well .
Greets
 
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