Through the years, many Baby Basses of various kinds have come through our shop, so we wanted to add information to this discussion which might help in resolving some of the problems "icebox" is having.
Sometimes people may think there is a problem with their original Ampeg Baby Bass magnetic diaphragm pickup because the old 1960s systems, as well as some of the modern copies, can sound very weak and thin. With proper pickup adjustment and the right amplifier settings, the expected sound is that signature percussive, punchy, thumpy Ampeg Baby Bass thud.
It's sort of a primitive yet complicated little system based on technology available when Jess Oliver devised it. He used parts and materials that were readily available at that time, which included discs and coils used in telephones of that era. The original Ampeg Baby Bass pickup concept was that the flexible diaphragm discs beneath the bridge feet are meant to mimic the vibrating top of an acoustic bass. There are magnetic coils beneath the discs which capture the vibratory action of the strings/bridge/diaphragms. Not what you would normally expect at all from anything called a "magnetic pickup" (like a P bass or Jazz bass type).
Most Ampeg-lovers know just what to do to compensate for the deficiencies of the original Ampeg pickup system. Most use a Gallien-Kruger 400RB or 800RB amplifier. They turn the bass control on the G-K all the way up, and the treble all the way down, with the volume control on the Baby Bass itself maximized. The tone control on the bass can be used to add brightness or "woofy-ness" as desired.
It is also important to ensure that the pickup system itself is at its most optimal setting.
Here are basic instructions for the original Ampeg Baby Bass pickup -
There is an adjustment screw on each side of the bridge. While plucking the G string, turn the adjustment screw (on that side of the bass) to the right (clockwise) until the magnet touches the diaphragm. You can tell when the magnet touches the diaphragm, because the sound seems to diminish or stop entirely. While still plucking the string, give the adjustment screw a 1/4" turn to the left (counterclockwise) just until the sound returns. Repeat the same process on the E string side, and you will obtain optimum efficiency from the pickup adjustment.
Once the pickup is properly set, the tone and volume of the Ampeg Baby Bass should be about the best and most powerful that it can be. But Ampegs are notoriously inconsistent, with some just being more powerful than others, even when optimally adjusted.
We found that augmenting coil strength and incorporating the right preamp into our own Vintage-Style Baby Bass alleviated these issues. We don't want to speculate too much about the MOG, but it sounds like it may need to be adjusted properly, and used with the right preamp and appropriate amplifier settings.
- Jill & Steve Azola www.azola.com