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ricard · 13th Dec 2013, 9:12 am

The 'Pilottonverstärker' section reads:

The pilot tone amplifier

The most common faults turn up in the pilot tone amplifier Vr. Also here are the electrolytics involved. The coupling capacitors C601 (5µF) and C605 (100µF) and the frequency governing capacitor C608 (5µF) as well as the smoothing cap C609 (50µF) need replacing. Here it is worth noting that the manufacturer on some machines has changed the value of C607 from 1µF to 3.3µF and C608 from 5µF to 10µF. The reason for this is probably to reduce the upper frequency limit. The relay Rls 601 needs to be tested and potentially replaced by a 12 V PCB mounting type.

A simple function test can be done as follows:
Set the center part in playback mode, and select an unrecorded track with the track selector. Connecting R833 (330 ohms) to C831 (10µF) (left upper corner on the playback PCB) will result in a loud hum. It will be heard in the loudspeaker. After 2-3 seconds the playback should be interrupted and rewind engaged.

13th Dec 2013, 9:12 am	#13
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Schaub Lorenz 5001 help needed The 'Pilottonverstärker' section reads: The pilot tone amplifier The most common faults turn up in the pilot tone amplifier Vr. Also here are the electrolytics involved. The coupling capacitors C601 (5µF) and C605 (100µF) and the frequency governing capacitor C608 (5µF) as well as the smoothing cap C609 (50µF) need replacing. Here it is worth noting that the manufacturer on some machines has changed the value of C607 from 1µF to 3.3µF and C608 from 5µF to 10µF. The reason for this is probably to reduce the upper frequency limit. The relay Rls 601 needs to be tested and potentially replaced by a 12 V PCB mounting type. A simple function test can be done as follows: Set the center part in playback mode, and select an unrecorded track with the track selector. Connecting R833 (330 ohms) to C831 (10µF) (left upper corner on the playback PCB) will result in a loud hum. It will be heard in the loudspeaker. After 2-3 seconds the playback should be interrupted and rewind engaged.