Hi there This is a classic amp from marantz, and becoming a collectible these days. You will most probably have issues stemming from old age. The pops are most likely a failing transistors. The semiconductors used in this vintage of gear had a high silver content in the connector leads to the transistors that in turn produced very fine filaments of conductive growth between the leads(causing the popping). We often referred to this phenomenon as "black death" A good indicator of this occurring often can be that the leads to small signal transistors and drive stages appearing to be tarnished black like uncleaned silver Input selector switching and tape monitor switches can also create this sort of problem, but generally manifest more as "crackles" than "pops" This problem can be rectified with careful internal cleaning of the offending controls with a good contact lubricant cleaner spray.
Are you interested in restoring the amp,or just curious to know what may be the problem. Let me know and we can delve further into it. If you have previous electronic repair experience with amplifiers, we can look at some pathways to restoring the amp. I can also help you to find a decent repairer person to assist you. Let me know. Happy to answer any questions you may have; regards robotek
Answers & Comments
Hi there
This is a classic amp from marantz, and becoming a collectible these days. You will most probably have issues stemming from old age.
The pops are most likely a failing transistors. The semiconductors used in this vintage of gear had a high silver content in the connector leads to the transistors that in turn produced very fine filaments of conductive growth between the leads(causing the popping). We often referred to this phenomenon as "black death" A good indicator of this occurring often can be that the leads to small signal transistors and drive stages appearing to be tarnished black like uncleaned silver
Input selector switching and tape monitor switches can also create this sort of problem, but generally manifest more as "crackles" than "pops" This problem can be rectified with careful internal cleaning of the offending controls with a good contact lubricant cleaner spray.
Are you interested in restoring the amp,or just curious to know what may be the problem. Let me know and we can delve further into it. If you have previous electronic repair experience with amplifiers, we can look at some pathways to restoring the amp. I can also help you to find a decent repairer person to assist you. Let me know. Happy to answer any questions you may have;
regards robotek