Music, Audio, and Other Illnesses

What Is a Bass? Part 4: Electronic Guitars

I want to wrap up this attempt to answer the question of what goes into a bass (a question only asked by one person) by talking a little about the electronic circuits that go into stringed instruments. But it occurs to me that some readers may not know why I’m focusing on basses (besides the obvious fact that I’m a bassist). [For the latecomers to this series: Part 1 Part 2 Part 3Ed.]

In the beginning, basses and guitars were different versions of one instrument  (either you thought of it as a bass guitar or an electric bass — but it was still the same thing, however it was referred to). With the innovations that I’ve written about for the past few issues, though, that diverged; not as a matter of design — everything that went into the basses I’ve discussed has been able to go equally into guitars. But one set of musicians embraced the design changes, and one didn’t.

For the most part, electric guitars have been stuck with two basic, and classic, designs: the bolt-on necks of the Fender Telecaster and Stratocaster, and the set neck of the Gibson Les Paul. There are near-infinite variations, of course: hollow-body guitars, both deep (arch-top) and shallow (thin-line Gretsches, Guild Starfires and Gibson 335s), and thin solid-body set-neck guitars, like the Gibson SG. But many of the alternate construction styles and materials, the metal and graphite-and-epoxy necks, haven’t been embraced by guitarists in nearly the same numbers as they have by bassists. Are guitarists more conservative?

Well — yes.

The range of acceptable guitar tones, as prominent as they are in most popular music, is pretty narrow, though it’s more apparent. Or maybe because. There are certainly guitarists who haven’t walked the narrow path — Lindsay Buckingham, Henry Kaiser, Jerry Garcia and Carlos Alomar spring to mind — but they’re few and far between. (Of course, I’m prejudiced.)

In any event — electronics: they can be as simple as no controls at all (just the pickups), or pickups and a volume control, as on my fretless Guild M-85. Most common is passive volume and tone (or treble roll-off), one set per pickup. Bass roll-off controls are incredibly rare –– I’ve got them on a ‘69 Les Paul bass.

Circuits are divided into passive and active — just as in home equipment. I’ve mentioned that Ron Wickersham of Alembic pioneered active circuitry in an instrument and that Ron says that my fretless Guild had the first active circuit, installed in 1969 (prior to the company forming). It was a pair of Darlington emitter followers, used to lower the impedance of the pickups. I don’t know if the bass had any active tone circuit. By the time I got it, it was passive, and now it’s active again.

Jack Casady’s Guild basses were passive, or mostly passive, though his Alembic had a variety of active electronic modules that could be plugged into the bass. Phil Lesh’s Alembicized Guild Starfire and ultimately his Alembic were active, and had what became known as Superfilters. Alembics in general are active: the stock Alembic electronics feature low-impedance, low-gain pickups, that drive a circuit containing a pair of low-pass filters with either switchable or continuously variable “Q”, or resonance, and a differential mode hum-canceller (does any of that need explanation?), a control each for volume and frequency — in this case, being a low-pass filter, it’s a treble cut. A Superfilter is a state-variable filter with five controls per: one for switching the mode between high, low, and band pass (the variable states), a frequency setting (the beginning or the center of the roll-off), a filtered volume, a direct volume, and a continuously variable Q setting.  Add in pickup selection and master volume and some switching for the quad mode (one pickup per string), and Phil’s basses were about as elaborate any ever were. But it was early days. People were exploring.


Phil Lesh’s “Big Brown”.

In the years since, people have tried everything they could think of. Leo Fender’s next venture, after selling Fender itself, was MusicMan, in the mid-70s. MusicMan basses have a strange active, battery-powered circuit, in which the pickups feed treble and bass controls. The treble is very sizzly — I turn mine all the way down.  It really functions as a treble boost, and turning it down apparently just makes it flat. I rely on the bass control, which I boost all the way, to overwhelm the treble. That sound is used for much of the album Tuesday Night Music Club, direct. (With its graphite neck, the MusicMan is sort of my no-issues bass — it would always come along on a session; if I picked one that didn’t work, well, the MusicMan ALWAYS worked).

The ever-reliable Music Man.

Rick Turner (again!) uses a semi-parametric equalizer on his post-Alembic Model One instruments — it’s what Lindsay Buckingham uses. I used a Model Two (a 2 pickup version) on the song “Black Cadillac”. (Semi-parametric means a frequency-selection control and a level control for that frequency.) There’s also a passive treble-cut and a hard-wire bypass of all tone circuits. Generally, I just turn the control until I hear something I like for what I’m doing — for “Black Cadillac” the frequency control was set near the bottom of it’s range and the passive treble was just about all the way off.

The Turner.

The Alembic.

I used to play around with my Alembic’s tone settings, especially the back pickup — tweaking its filter to bring out harmonics is especially satisfying. But since the bass hit it’s magic age, I generally just set it flat — tone controls opened up, “Q” set flat, and do all the tone adjusting with my hands (moving to Thomastik-Infeld flat-wound strings from Superwound helped with that). (I actually went to Alembic in ‘80 or ‘81 and Ron Wickersham and I went into Prairie Sun Recording in order for me to record a demo of how the Alembic electronics worked — but with Ron present, I froze, all the while thinking that he should be doing the talking).

Anyway — what does all this stuff, all these controls, give you? In a word, control. When you hear an electric instrument, you’re really listening to a whole system of materials and electronics — in the instrument, the amplifiers and the recording chain. Just as when you listen to acoustic or classical music, you’re still listening to materials and electronics.

The estimable Rick Turner has a few comments on the progression of this technology:

“Actually, the first on-board active electronics I encountered were on both the Baldwin classical electric guitar and the Gibson C-1E electric classical guitar!  Both were for buffering the actually excellent piezo bridge saddle pickups.  Also, I think Burns of London did some active magnetic pickup guitars in the early 1960s…that bears more looking into.  There is also some weird connection between Burns and either Gibson or Baldwin there, too. More research…   BTW, the Baldwin pickup and electronics are what Willie Nelson has in his Martin classical guitar to this day, and Baldwin made a special amp that sent power, I think in excess of 20 Volts, up to the guitar.  That’s the “PrismaTone” pickup.

“I started mounting battery powered effects on my Peanut guitar in 1967…a “Boss Tone” fuzz, and a Vox treble booster ( trouble booster? ), so in a funny way, I may have beaten Ron to the punch, though my intent was to have the effects…which did also buffer the pickup signal, though I didn’t really understand that yet.  Obviously, by the time that guitar got to Garcia, the effects were history.

“The earliest stuff Ron was doing on the Guild/Hagstrom BiSonic pickups was to buffer the pickup and line drive the signal at low impedance so no highs would be lost.  Gain was not a consideration.  Then when I came along, we realized that we could extend the frequency response of the pickups out past 20 KHz, and make up for lost pickup voltage (lower turns count) by adding some gain…however much was needed to meet or exceed the “normal” output voltage of electric basses and guitars.

“The real Alembic/Wickersham break-through was in putting truly studio quality preamplification and filter/EQ on board the instruments with Jack’s bass being the test bed for all that.

“I’d started literally hand winding pickups in ’68 when I moved to California, and they wound up being relatively low impedance as much because I didn’t know better and because of what wire and other supplies were available to me.  Turned out that they had really wide frequency response when Ron tested them, and we were off to the races.

“The earliest commercial amplified guitar was the Stromberg Electro…1928!  The pickup was magnetic, but sensed top movement, not string movement, and a few years later, Lloyd Loar founded ViViTone making electric guitars, both hollow and solid bodied, mandolin, violin, viola, and upright bass using bridge and top sensitive magnetic pickups.  But then in 1933, out came the Rickenbacher frying pan lap steel with the first really successful string sensitive pickups, and that became the dominant technology…by far.  Once the horseshoes were stripped away, you had what is now known as the Charlie Christian pickup in Gibsons, and the race was on.  With a bunch of odd branches to the tree!

“BTW, I’ve never seen one of the Stromberg Electros, but I do have a ViViTone from 1933.  Stromberg was also Stromberg-Voisinette which became Kay.  Henry Kuhrmeyer, the “K”, designed the pickup for the Electro.  He then took over the company and renamed it.  Clever dude.

“There are persistent rumours of Lloyd Loar experimenting with amplification when he worked at Gibson, but there’s no actual proof…yet. If he did, it may have been essentially a condenser pickup…a copper plate attached to the underside of the top with another closely mounted copper plate.  Charge it with voltage and it would work just like a condenser microphone.  The expert on the history of electric guitar, Lynn Wheelwright, doesn’t think that Loar did.  When I met Seth Lover, he said that he thought he saw some left over experimental stuff at the old Kalamazoo Gibson factory when he started there in the 1940s. Seth was in and out of Gibson several times. Pretty decent Wiki on him.”

[Basses are property of, and photographs courtesy of, the Schwartz California Institute of Bassology–-Ed.]