In this classic-rock themed issue, we thought it would be interesting to take a look at acoustic guitar components common to that era, and compare them to modern components. In some instances, the song remains similar or the same, in other cases, massive ch-ch-ch-changes!
Located on the headstock, tuning machines or “machine heads” are geared mechanisms designed to raise and lower string tension. Tuning machines were traditionally made out of die-cast metal with tuning keys or “buttons” made of either molded plastic or metal, and that’s still standard—although lighter options made of aluminum or titanium are now available. Some modern tuners include graphite designed to reduce friction. Open-gear tuners expose the gears inside. They were popular before classic rock, and have enjoyed recent resurgence. Locking machine heads include a device to fasten the gears in place, and are more common on electric guitars with tremolo systems.
Gear ratio is a huge factor. Old tuners often had lower ratios, while high-end modern tuners may run ratios as high as 21:1—meaning it takes 21 turns of the key for the post or “capstan” to complete a single revolution. The reward for that is a fine-tuning experience, and, once in tune, very little slippage or “backlash.” The cutting edge of tuner ratio technology lies in sets that vary greatly from string to string, rather than sticking to a single ratio for the whole set. The concept is to optimize the ratio at each string position, thereby creating a more consistent response from string to string.
The nut is a grooved sliver between the neck and the headstock that the strings pass through, and it is essentially the top end point for string vibration. Dense materials work well, and a quality acoustic from before rock’s classic period likely had a bone nut, while a cheaper model might have had a nut made of plastic—which isn’t great because of its softness. Manufacturers such as Martin started using synthetic bone substitutes such as micarta during the ’60s. Bone nuts are still popular, and a modern Martin D-28, for example, is still equipped with a bone nut, but huge advancements in “self lubricating” synthetics such as Tusq have led leading manufactures to include them on many of their high-end acoustics. NuBone is a similar but more affordable synthetic. Arguments can be made about the organic sound of bone versus the high-def, consistent tone of synthetics, but there’s no doubt about synthetics being generally more affordable.
The wooden plate anchoring the strings to the body is super important to an acoustic’s tone because it transmits string vibrations to the guitar. Quality classic acoustic bridges were made out of tonewoods such as ebony and rosewood. That’s still true today.
The saddle transmits vibrations to the bridge, which, in turn, transmits them to the top and body. The saddle is a strip of hard material set into the bridge, and the chronology of saddle materials is similar to the nut, as is the tonal conversation. Regardless of material, the saddle’s job is to support the strings at their appropriate height and angle. “Compensating” the saddle fine-tunes it according to the optimal length for each string’s intonation. Compensations consist of carving away at either side of the saddle in order to adjust the point at which the string breaks over it. Carving the saddle on the side nearest the soundhole microtonally lengthens the string, lowering its pitch, while doing so on the other side has the opposite effect. Most acoustics from the classic-rock era did not have compensated saddles, but it’s standard equipment on most modern acoustics.
Bridge pins secure the strings behind the saddle, and they are integral to smooth sonic flow. Classic-era bridge pins were generally made of bone, wood, or plastic, and while those materials are still popular, materials on offer these days include synthetics, as well as metals such as brass, aluminum, and titanium designed to deliver modern aesthetics, as well as bell-like tone enhancement and greater sustain.
The post where the back end of the guitar strap connects has become increasingly significant over time as more acoustics come with onboard electronics, and the endpin often doubles as the output jack for a guitar cable. That can mean a different shaped endpin, so it’s worth checking to make sure that the strap you’re considering has a hole that fits.