~ 1948 Supro Lap Steel Refurbishment ~
Page 16; Stringing and Adjusting Pickup for Strings Volume Balance:
The 1st and 6th strings are intalled first, to check in-tolerance alignments of the strings, fingerboard, pickup and nut. The camera was slightly off to the left of center for this shot which makes it appear that the strings are shifted to the right.
Again the camera is slightly left of center, but these pics show the process to check alignments.
A Valco / Supros pole pieces / screws MUST be free to turn without any force; And if any one is not free, then the electronics plate will have to be removed and a drop of penetrating oil put on the BOTTOM of each pole piece screw coming out the BOTTOM of the electronics plate / threads. Otherwise the chances are VERY GOOD that the delicate pole piece screw heads will strip off from any appreciable turning force.
To adjust the pickup pole pieces for volume balance between strings, I remove the pickup's top plate to access the pickup pole pieces directly rather than inserting a screwdriver through the top plate's holes provided for that purpose. The reason I remove the top plate is because the pole piece screws and the pickup coil assemblies are delicate and I find it much better to be able to see the pole pieces screws well during adjustments.
To begin adjusting the pickup pole pieces, I remember that I refreshed / doweled all of the wood-screw holes in the body, and therefore know that the electronics plate's 2 large rear screws will stand up to the strings tension. I next remove the pickup's front 2 machine screws and rear 2 wood screws, ...which will allow me to lift off the pickup cap plate and replace it a number of times to BETTER access the string pole pieces for adjustments with the guitar plugged into an amplifier. The magnets amply hold the top plate in place for these adjustments.
Top plate removed giving easy access to the pole piece screws.
I use a jewelers screwdrive that fits the pole piece screws exacly. The tabs that form the screw head slots are quite delicate to over-torque or sloppy leverage. Better to be safe than sorry.
A good starting point for pole piece screw heights is 3 threads above the pickup casing top for the 1st string, and successively 1/4 turn downward (clockwise) across each of the remaining strings. Choose the string that has the best volume and tone, and adjust the other strings pole pieces to that volume.
Each Valco / Supro I've worked on required different pole piece height settings to get a good volume balance between strings without any wolf tones on any string. Wolf tones are caused by pole pieces being too close to certain gauges of strings. When a wolf tone is encountered, I lower the pole piece and adjust the other pole pieces accordingly.
The pole piece screws will go closer to the strings, but my judgement is that Valco / Supro steels sound and play better (confidently and not timid of pickup sensitivity) with the pole piece settings not quite as hot (close to the strings) as they can be with fresh / refreshed magnets. Adjustments closer to the strings are often required for old aged magnets.
To access each pole piece screw, simply move and hold the string away from the screw head with the thumb of the hand not operating the screw driver.
HERE SHE IS tuned up and pickup adjusted. She sounds and plays like a dream ....as Valcos / Supros should !
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End of pictures and information about refurbishing this fine Supro. The pictures above were the last before my digital camera gave up it's ghost and went to the Big Picture in the sky; The third digital camera I've worn out. Otherwise I would have gotten pictures of me playing this steel with a BIG smile on my face.
This fine Supro is packed for shipping and will soon be in the hands of it's new Owner, a happy and proud one I feel certain. It has been a very enjoyable journey to have been allowed ample time to refurbish this Supro; It looks almost new .....and plays like the steel guitar dream most Valcos / Supros do if their electronics are up to snuff.
