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The Daily Insight

Is the Onkyo M-504 solid state power amplifier good?

Author

Daniel Foster

Published Apr 22, 2026

Is the Onkyo M-504 solid state power amplifier good?

This Onkyo M-504 solid state power amplifier is in pretty good cosmetic shape but needs some repair and restoration. The Onkyo M-504 power amplifier is well built and laid out nicely. With the faceplate removed we can clean the chassis. One issue with this onkyo amplifier is that two of the bulbs that light the meter’s are missing in action

How much does the Onkyo m 5000A amplifier cost?

Today Onkyo’s flagship the m 5000a has a list price of 2499.00 and,,, the specs are,,, well,,, not as good as the m-504. Closer to the m-502. Are a few of the new tricks worth giving up power and cleanliness?

What should I use to repair my Onkyo amplifier?

One issue with this onkyo amplifier is that two of the bulbs that light the meter’s are missing in action The lamps were easy to obtain but I didn’t have the green gel boot that was on the original lamp. I obtained some green lighting gel. I rolled the sheet of lighting gel around the lamp and used adhesive to keep it together.

How does Onkyo Integra m-507 audio circuitry work?

The monolithic-IC-ized logarithmic comression circuitry and the special resistance element performed temperature compensation of meter, and a precision and temporal indication error gap are prevented. Thorough low resistor-ization is attained so that a speaker output circuit may not have a part for an excessive resistor.

How much does an Onkyo M504 amplifier cost?

Lastly, The fact that the flagship Onkyo “M” series amp, the M-510 at “300Wpc” and over 30 years old, now go for $6500+. While my pass Labs X-350 “350wpc” $13,000 new. And my McIntosh MC402 “400wpc” $7000 new. Which are both fairly new are both worth 1/3 LESS than the M-510 Speaks volumes!

How to restore Onkyo M-504 solid state power amplifier?

Here are all four lamps installed with two original gels and two gels that were made from lighting gels used in stage lights Removed the bottom cover and cleaned a few years of dust and washed the bottom panel with soap and water. A little bit of bench testing and this Onyko M-504 solid state power amplifier restoration will be complete.

One issue with this onkyo amplifier is that two of the bulbs that light the meter’s are missing in action The lamps were easy to obtain but I didn’t have the green gel boot that was on the original lamp. I obtained some green lighting gel. I rolled the sheet of lighting gel around the lamp and used adhesive to keep it together.

Which is Onkyo amps have the Best Sound?

These vintage “M” series amps from Onkyo are unbelievable. When these were designed/built NO amps from Japan could get better than a “passing” grade regardless of the quality, innovation and sound. That was a mistake that “most” now will admit.