I have long regarded Sherwood gear as sleepers. In my young adulthood it was a brand that I could afford (via Illinois Audio: ahh, the days of discount mail order) and their receivers sounded good to my young ears. The 7310 is the middle of the line from about 1975 and boasts 38 real world, rms watts. Original list price was $380. I purchased a new 7210 in 1975, and remember it fondly.
Sherwood build quality is not as impressive as Marantz, but manages a significant sonic mojo. The receivers sound bigger than their advertised wattage and the tuners are solid all 'round performers. Cosmetically, Sherwood lags a bit behind Marantz, but a clean example represents '70s hifi style very well.
The 7310 offers the David Hafler's Dynaquad circuitry, an island of sanity in this era of quad madness:This 7310 worked well on arrival. Even the lamps worked. So, on with the restoration! The board layout is straight forward with only the treble/bass board presenting a significant challenge. Here is the bird's eye view from the top:
The power supply board is at the lower right, below the transformer. The output boards are in the upper middle and are accessible from below. The tuning capacitor is at the upper left, shielded. Immediately below it are the AM and FM boards that required removal of 4 screws and some tugging to restore. But whither phono?The phono board is located underneath the unit, at the upper left in this photo. Note the two power supply filter caps in the upper right corner. These slightly obscure the treble/bass board that hides just behind the face of the unit. Changing the caps on this board requires peeling the face and unclamping the filter caps. As luck would have it, my back order of Elna Silmic II caps had just arrived so the 8 4.7 mfd caps on this small board were replaced with silk. The tone control circuit is not defeatable, so it better sound sweet when driven by the cd player not yet imagined in 1975.
All other caps were replaced with Panasonic FCs with extra margin on the voltages. A total of 50 caps were replaced, the 6.8k main filters were left as is. Pots and switches were cleaned with Blue Foam and Deoxit Gold. The tuning capacitor was spritzed with Deoxit Gold.
The end result of my labors was a very sweet sounding unit that should last for another 20-30 years. The overall sound is lush for a string quartet with enough punch to do justice to Metallica. And it looks good. One more look with a bit of drama: