【Operation Confirmed】YAMAHA CS-10 Synthesizer All Keys Produce Sound OK Yamaha

【Legendary Machine YAMAHA CS-10 For Sale】
This is the legendary monophonic synthesizer CS-10, a cornerstone of Yamaha's analog synth golden age in the late 1970s. I have carefully stored it for many years, but I am now selling it as part of my collection, hoping to pass it on to someone who appreciates its value.

【Cleaning & Condition】
For this listing, I have meticulously cleaned the exterior over an extended period.

The panel's luster and the keyboard's texture are in excellent condition, remarkable for an instrument over 45 years old.

There are no missing knobs or switches. This unit is exceptionally clean for a vintage item.

【Operational Check (Performed March 2026)】
Currently, I do not have a dedicated instrument amplifier on hand, so I tested its operation by connecting it to the auxiliary input (RCA terminals) of a home television.

✅ Sound Output:
By turning the TV volume to maximum, I confirmed that all keys produce characteristic analog synth sounds like bean and biyoon.

✅ Response:
Each time a key is pressed, the TRIGGER lamp on the panel illuminates, confirming normal signal response from the internal circuitry.

✅ Tone Variation:
When manipulating each knob (VCF/VCA/LFO, etc.), I observed dynamic changes in the sound.

✅ Output:
I believe you will be able to enjoy the more powerful, original sound pressure when using an instrument amplifier or similar environment.

【⚠️ Please Read Carefully】
This unit is a very old, vintage precision instrument from around 1979.

✅ Sold As-Is:
While basic operation (sound output and knob response) has been confirmed at this time, future continuous operation cannot be guaranteed.

✅ Maintenance Recommended:
As this is a very old electronic instrument, changes due to vibrations during shipping or unexpected malfunctions cannot be ruled out. Please only bid if you enjoy performing maintenance yourself or understand these conditions.

✅ Agreement:
Due to the nature of the product, we request no claims and no returns.

【Shipping】
As this is a valuable instrument, it will be carefully packed using bubble wrap and a sturdy cardboard box for secure shipping.