Seeburg L100 Volume Issue

Hi, I have a little problem with my Seeburg. Every time a new record begins, the volume starts out a little low and then gets louder to the set volume of the control knob. It does this each time. The machine has a new volume knob/pot, all new capacitors on all circuit boards. I checked the tubes, replaced the bad ones - one of the 6L6 tubes is showing a question mark on the tester. I suspect the automatic volume control board. Could it be bypassed to test? Or, could it be a bad resistor in that board? Other than that, the machine plays great. Thanks for any help. Joe

Hi Joe,
Yes--anything on that board can be "bad"--
You can easily "bypass" the whole AVC section on a K/L model phono.
Just remove the plug that connects the AVC board to the main amp board, and install the input plug (which was in the AVC board) into the main board.. I would check to see if the AVC updates were done on the AVC board. If it were mine, this would drive me "nutzer" then I am as I hate not having AVC. AVC updates are: R-186 should be 6.8meg. A 2.2K 1 watt resistor must be added to the mechanism, if not already done ( look at terminal strip lugs 2-5)( add wire from lug 5, to top blade of MS switch).--C 171. must be a .22x400. Cut trace of xv253 (12AX7) pin 7, to R263 on power board. Insert a 10 k 1/2 watt resistor over cut-- Ron Rich

The fade up is a function of the squelch bias voltage applied to the AGC to prevent blasting at the beginning of a record.

Under the original gain structure and output from the original pickup with mono styli, a loud record would start at-level and only a low cut record would have a noticeable fade-up.

If a fade-up is happening consistently it probably indicate that there is lower output from the pickup or the (crappy) original preamp on the mech isn't producing enough output.

The AGC can be disabled via two methods: Simply remove the reactance tube (6BJ6) or simply plug the 7-pin plug that comes from the mech directly into the tone control board -this is the specified approach. Understand that the levels will now be "all over the place" .

I've owned three "L" and have a K w/later electronics on-location. In all cases I eliminated the original preamp and used an outboard unit. This provides much better gain so that newer pickups can be used while still having enough gain to drive the AGC and level the records. It also greatly improves frequency response and overall quality.

http://s1192.photobucket.com/user/Rob-N ... ort=3&o=58

Rob-NYCT