2/10/2014

Silvertone 7407 Refurbish

Picked up this Silvertone from an Antique store for $20 not working. The receiver chassis number is 528.54746 and the Amplifier is 528.69240 There is a number stamped on the amp chassis 30-125-2 or it might be 30-125-2a.
 It was plugged in and probably in use at one time at the antique store.

All it is, is a Silvertone Console Tuner, and amp Chassis inside a table top cabinet.
It appears to be all original inside.

It was in need of a recap.

This is the Schematic of my amp as found.

It has dual station dials, and indicator lights for being on station (in Mono),
 And in Stereo.

I had to replace:
1 - 6be6
1 - em84 with a NOS one from ebay.
2 - 6bq5
The resistor on the em84 eyetube.
all the electrolytics
several resistors on the right channel of the amp (the left all measured good).
There was 1 burned and split resistor in the tuner, and one singed resistor in the power supply.
I blew up a 100uf e-cap in the voltage doubler and had to replace that with a much higher voltage rated one. Seems that the amp originally had a 200vdc cap in the voltage doubler circuit. Why mine blew I do not know. The replacement 450vdc cap works fine. It has a Phono and Tape in. I have a CD player or mp3 player on the Tape In.
For $20+$45 in parts to fix, you can't get much better than that. It sounds really good through my Fisher XP-9C Speakers.

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