Okay so I found out what was wrong, but honestly it's leading to more questions than answers lol. So if I tweak the Cutoff pot on the filter section, it's changing the attack of the drums. Once again, I'm not sure if this is user error but as I'm pressing the keys for drums and turning the knob, it's adjusting the attack as opposed to the envelope doing that. No idea why lolIt sounds like you’ve done a great job getting that MC-505 back in shape, but this issue with the drums fading in could be related to a few potential causes:
1. Capacitor Issue:
Symptom: Fading or inconsistent sound can often be caused by failing capacitors, especially in older electronics. The fact that it happens after the unit has been powered on for a few minutes suggests something might be temperature-related?
Solution: Inspect the capacitors, especially those related to the drum circuitry. Look for any signs of bulging, leakage, or heat damage. If you have access to an ESR meter, you can check their performance more accurately.
2. DAC (Digital-to-Analog Converter) Problem:
Symptom: Since only the drums are affected, there could be an issue with how the DAC handles those samples versus the synth sounds.
Solution: Try running a full reset on the machine and reloading the drum samples to see if the problem persists. If it’s a hardware issue, you may need to inspect the DAC or related components for the drum output.
3. Voltage Drop / Power Supply Issue:
Symptom: Inconsistent power can cause audio artifacts or unusual behavior in specific parts of the circuitry.
Solution: Check the power supply for any irregularities, particularly focusing on the parts of the circuit feeding the drum section. Even though the synth parts are working fine, the drums might be more sensitive to power fluctuations.
4. Envelope Control Fault:
Symptom: If the drum sounds are fading in, there could be a malfunction in the circuitry controlling the envelope (even if you haven’t physically adjusted it).
Solution: Carefully inspect the pots or ICs responsible for envelope control, especially if the problem is intermittent.
5. Firmware/Software Glitch:
Symptom: Since this problem only happens after the unit has been running for a while, it could be a firmware-related issue.
Solution: If possible, check if there's any firmware update available (?), or perform a factory reset and see if that resolves the issue.
Diagnostic Steps:
Try swapping out different parts and see if the issue persists across different patches or just the drum kits.
Monitor the machine’s temperature and see if any components are heating up more than they should.
If the problem is temperature-related, you could try cooling the unit down (e.g., using compressed air) and observe if that alters the behavior of the drums.
Let me know if any of these steps help, or if you need further troubleshooting! I have a MC-505 but haven't turned it on in quite some time.
Statistics: Posted by gm.v2 — Wed Sep 25, 2024 6:24 pm
