Hi guys. At first i must admit that English is not my native language. I know its not at good level, but i hope you can understand what i mean.
I recently bought an Autotek 99 car amplifier, made by Zed Audio 1994.
(The PCB board tell us its Revision C which i cant find on google image)
It cost me 25$. I saw that couple of them was sold on this forum for 100$+, so i thought it was a good price. Seller told me that he is not first owner and he dont know if the amp was repaired, but its fully working. I bought it without asking for photos of inside, just to not waste time (someone else may take it in any moment)
I connected an amp when it arrives. both of two channels works identically, there is no crappy sound or distortions (i only tried to playin at 2/10 of volume, but i hope thats enought to say its working correctly)
When i opened it i did sad face, because it was repaired by someone.
i removed the IMG tags because photos are too big
http://i.imgur.com/nNvoD2Y.jpg
1. Somebody added a capacitor (Nichicon 3300uF 35v). It's probably connected between B+ (12v) input signal and this small black diode.
2. The coil is also smeared with silicon (maybe to reduce the noise of coil?)
3. Im not 100% sure, but also some of the left side transistors looks like they was resoldered (i cant look closer, cause i dont know how to remove those black clips between the transistors and metal. They are very strong and i won't to break anything.)
Questions:
Can you explain what somebody wanted to achieve by adding this one more capacitor?
Transistors looks like resoldered.. Is there chance that somebody inserted a fake's transistors? If yes, does it means that amp is worthless?
I have a chance to replace this Autotek for used Boston Acoustics GTA802, fully working in a good condition. Shall i do it? Im looking for strong mono/2channel amp for my rockford fosgate sub. Which of those two will be better?
Also, shouldnt the input level potentiometer act like regular volume control?
I mean if i connect this amp in home (i dont have my car audio completed yet), to the PC using 2x cinch > jack cable, even if the input level on amp is at minimum and the windows control is at 20/100 it sounds loud. If i set a input level higher volume get increased by little, so the potentiometer by self is working.
If you need additional informations or photos, just tell me. I would really appreciate your help. I'm starting my journey with Car Audio.
More photos:
http://i.imgur.com/KtJdAVV.jpg
http://i.imgur.com/6FYuZF1.jpg
http://i.imgur.com/LpNTI1T.jpg
I recently bought an Autotek 99 car amplifier, made by Zed Audio 1994.
(The PCB board tell us its Revision C which i cant find on google image)
It cost me 25$. I saw that couple of them was sold on this forum for 100$+, so i thought it was a good price. Seller told me that he is not first owner and he dont know if the amp was repaired, but its fully working. I bought it without asking for photos of inside, just to not waste time (someone else may take it in any moment)
I connected an amp when it arrives. both of two channels works identically, there is no crappy sound or distortions (i only tried to playin at 2/10 of volume, but i hope thats enought to say its working correctly)
When i opened it i did sad face, because it was repaired by someone.
i removed the IMG tags because photos are too big
http://i.imgur.com/nNvoD2Y.jpg
1. Somebody added a capacitor (Nichicon 3300uF 35v). It's probably connected between B+ (12v) input signal and this small black diode.
2. The coil is also smeared with silicon (maybe to reduce the noise of coil?)
3. Im not 100% sure, but also some of the left side transistors looks like they was resoldered (i cant look closer, cause i dont know how to remove those black clips between the transistors and metal. They are very strong and i won't to break anything.)
Questions:
Can you explain what somebody wanted to achieve by adding this one more capacitor?
Transistors looks like resoldered.. Is there chance that somebody inserted a fake's transistors? If yes, does it means that amp is worthless?
I have a chance to replace this Autotek for used Boston Acoustics GTA802, fully working in a good condition. Shall i do it? Im looking for strong mono/2channel amp for my rockford fosgate sub. Which of those two will be better?
Also, shouldnt the input level potentiometer act like regular volume control?
I mean if i connect this amp in home (i dont have my car audio completed yet), to the PC using 2x cinch > jack cable, even if the input level on amp is at minimum and the windows control is at 20/100 it sounds loud. If i set a input level higher volume get increased by little, so the potentiometer by self is working.
If you need additional informations or photos, just tell me. I would really appreciate your help. I'm starting my journey with Car Audio.
More photos:
http://i.imgur.com/KtJdAVV.jpg
http://i.imgur.com/6FYuZF1.jpg
http://i.imgur.com/LpNTI1T.jpg