Case No. 2) Vintage Marantz 7 Preamplifier

This customer came in with a functioning 1959 Marantz 7 Preamplifier.  He was told by his friends that "the Marantz 7 would perform well only if major components are upgraded, such as capacitors, resistors and attenuators".

We performed a bench test on the unit and found very few components which needed to be replaced (4 resistors, and 2 capacitors). We also performed the following test:

• L/R Balance check

• Amplifier noise and hum check

• Line output distortion check

• RCA and Tube sockets, integrity and oxidation check

• Power capacitor leakage check

• Phono stage noise and distortion check

• RIAA check

The unit was bench tested again to ensure all factory specifications were met.

We advised the customer not to proceed with the optional "exotic" upgrades, which in our opinion were unnecessary.  He welcomed and accepted our advice.

Total Cost of Upgrade: $ 80 dollars including parts

Turnaround Time: 2 hours, repaired on spot.