User Profile

jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-27-2015, 11:24 AM
Re: Magnat Phantom Mono-block car amp

When I have IC14 out, there was absolute silence.
I earlier changed caps C107 and C207.
Now I have changed caps C103, C203 and C105.

I think it is working right now.
I need to put it back together and test it in my car... someday..
I inform you, if there is still some problems.

Thanks for everybody who helped me! ...

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-20-2015, 12:03 PM
Re: Magnat Phantom Mono-block car amp

I replaced both IC13 and IC14.
No hum noise anymore.
When audio input (or even cable, with or without anything on other end) is connected to phonos, it makes "blip" or "bliiip" noises randomly. It is very annoying.
If there is no audio input or even phono cables connected, it is silent.

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-20-2015, 11:07 AM
Re: Magnat Phantom Mono-block car amp

I replace those caps. (C83,84,93,94)
And remove IC14 -> no hum or other "extra" sounds anymore.
Should I replace IC14?

All caps are made by HZC.
No other info..

See more | Go to post

Last edited by jansiu; 08-20-2015, 11:08 AM. Reason: extra info
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-19-2015, 12:40 PM
Re: Magnat Phantom Mono-block car amp

I have already checked all of those diodes- they are OK.
I check those caps tomorrow. I have fluke with cap-testing function at work.
And also I post info about those 1000/100 caps...

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-19-2015, 12:02 PM
Re: Magnat Phantom Mono-block car amp

No, I dont have frequency counter..

Is it some of those "RAIL-side" 1000 uF / 100V?
Or some of those whitch are in power input side (2200 uF / 25V)?
Any suggestions?

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-19-2015, 09:32 AM
Re: Magnat Phantom Mono-block car amp

Tested with better power supply, no difference. I have video that you can hear that sound.
Sound does not change if there are phonos connected or not...
[url]https://youtu.be/k9cqQZpS6FI[/url]Re: Magnat Phantom Mono-block car am...qQZpS6FI[/url]

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-18-2015, 01:04 PM
Re: Magnat Phantom Mono-block car amp

I changed IC11 and IC12. Now they all have same voltages. I connect my phone to the input and I get sound out. But if I stop the music, speakers starts keeping humming sound. I dont know if this is caused by bad power supply ( omron 12vdc / 4.2A) or bad rca cable. Or can those coupling capacitors cause this?

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-14-2015, 11:15 AM
Re: Magnat Phantom Mono-block car amp

Yep. Maybe I get next week all of those IC's, that I ordered.
Should I change all of them or just only the IC11?
And should I check some other components or only replace the IC's?

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-14-2015, 10:08 AM
Re: Magnat Phantom Mono-block car amp

I changed them and measured voltages.

IC12
2,5,6 = 30VDC
3 = 0VDC

IC11
All pins 0VDC

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-14-2015, 09:29 AM
Re: Magnat Phantom Mono-block car amp

+/- 15V is OK. (measured 14.9VDC)
RAIL voltages are both +/- 54VDC. They are identical.

IC's voltages measured. Negative probe in pin 4 and positive in pins 2,3,5,6.

IC11
2= 1.4VDC
3= 1.4VDC
5= 1.5VDC
6= 1.5VDC

IC12
2= 0.0VDC
3= 0.0VDC
5= 0.0VDC
6= 0.0VDC

IC13
2= 14.8VDC
3= 14.8VDC (1.0 to 14.8VDC changes if I turn volume knob)
5= 15.5VDC
6= 15.5VDC

IC14
2= 15.3VDC
...

See more | Go to post
Leave a comment:
jansiu replied to Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-11-2015, 01:56 AM
Re: Magnat Phantom Mono-block car amp

Schematics are right ones, checked multiple times.

I already changed those capacitors.
Now I ordered all of those ICs (4x NJM4558D).
When I get and change those ICs, I will let you know what happened......

See more | Go to post
Leave a comment:
jansiu started a topic Magnat Phantom Mono-block car amp

in Troubleshooting Audio Equipment

08-10-2015, 07:44 AM
Magnat Phantom Mono-block car amp

Hi,
Any help with Magnat Phantom Car amplifier?
I bought broken amp. Somebody has shortcutted subwoofer output.
Now I have checked all the mosfets, transistors and diodes. Them are OK.
(Tested with simple mosfet tester circuit, that I found from Google)
When I put the amp on, I hear popping noise from speaker.
And if I turn GAIN (volume) knob, I can hear crakling noise from speaker.
Sound comes out _only_ if I connect some audio device to amplifier RCA output, not when it is connected to amplifier RCA input. That is little bit weird.
...

See more | Go to post
jansiu replied to New Members - please post your introductions here

in Announcements & Related News

08-10-2015, 06:31 AM
Re: New Members - please post your introductions here

Hi everybody!

See more | Go to post
Leave a comment: