My old 1979 Technics ST-9038 digital tuner has never been serviced, but is still going strong (although it has plenty of scratches on the cover). Is this unit worth tweaking/servicing? I've heard audio repair service fees run $60+ an hour + parts. If it's not worth servicing the ST-9038 (worth around $100 dollars on the used audio market), what would be a another choice for a tuner that would out noticeably outperform my ST-9038 for around $400-500 on the used audio market? Thank you in advance for your advice.