LUXMAN vintage audio
Luxman 707 & SQ-700X amplifier
This amplifier produced in the end of the 1960's & early 1970’s. .
The power amp of the SQ700X is more modern than of the 707.
Schematic diagram in PDF format of the 707
Manual & schematics of the SQ-700X
You can modify this amp, to get better results.
Replace broken power transistors with TO-66 transistors 2SC1445 and PNP 2SA765 (Sanken) instead
of 2SA616 and 2SD155 (NEC), or use plastic transistors like 2SB595/2SD525 (Toshiba)
or 2SA1694 & 2SC4467 (Sanken).
The transistors of the pre stages are often noisy. Use BC550/560C or equivialent,
you can get the noise figure below the original specs of Luxman.
On other places in the amp you can use 2SC1775.
These series of "High Quality" audio components soon got legendary of their outstanding quality and excelend sound quality.
© Hans Hilberink - PE1MMK ® - Last update: 30-01-2012, thanks to Marek Łabuda for the schematic of the SQ700X.