Integra M-508 (1987)
The Integra M-508 is one of the less-documented members of Onkyo's "Grand Integra" series. It was the power-amplifier half of a pair with the Grand Integra P-308 preamplifier. Almost everything that survives about it comes from a few 1987 advertisements and one short review in Audio.
That review in Audio (September 1987, p.102) called the M-508 a high-quality, full-featured audiophile amp, and said its $1,150 price was still moderate for the category. The same review and Onkyo's own ads (May 1987, p.5) put continuous output at 200 watts per channel into 8 ohms. It uses a dual-mono layout and Onkyo's "Real Phase" design. The advertising also said the M-508 carried over design concepts from Onkyo's larger M-510 amplifier.
Past these basics, the record goes quiet. No technical manual or measured test report has been preserved in this archive, and almost no user commentary survives from the period. What is known can be summarized quickly:
- Dual-mono power amplifier, Grand Integra series
- 200 W/ch into 8 ohms
- Onkyo Real Phase technology
- Design related to Onkyo M-510
- Original price in 1987: $1,150
If you own an M-508 and have a copy of the manual, measured results, or any documentation, this page is worth updating.
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