Today, we’re gonna be talking about one of my favorite subjects. GEAR! Specifically, Preamplifiers. I’ve only used two, but they are both easily in the top 3 for rockabilly upright bassists using a piezo pickup system.
Why is a preamp necessary for a piezo pickup? Input impedance. Bass guitar amplifiers are designed to accommodate input devices with what is commonly called ‘high impedance’ which is around 50,000 ohms. Magnetic pickups are a good example of a High Impedance input device.
Piezo pickups, in contrast, are ULTRA high impedance (1-10 million+ ohms ). A preamp’s main function, in this setting, is to ‘buffer’ the impedance, or lower the impedance of your instrument’s signal to a value that your amp is designed to use. In other words, if you don’t match the impudence of your pickup, with the input impedance specs of your amp, it is almost certainly going to sound like crap: Tinny, one-dimensional, and no bottom end whatsoever.
Some other reasons for using a preamp in your upright bass signal chain are improved features, usually designed specifically for upright bass. These can include channel mixing, precision tone and volume control, EQ, phase reversal (used for feedback killing) and high pass filter all of which you can operate without standing in front of your amp (feedback!) Enough the technical crap, on to the reviews!
Of the two preamps we’ll be looking at today, probably the most well-known, and often tried preamp for rockabilly upright bass is the K&K Rockabilly Two Channel Preamplifier, often sold with K&K’s 2 pickup system as the Bass Master Rockabilly+ System. This is a small, convenient preamp/blender that is most often mounted to the tailpiece of your bass. Being designed specifically for the aforementioned rockabilly+ two pickup system, it allows you to split the signals of the two pickups’ stereo TRS 1/4″ output (one in the bridge wing for the bass voice, one on the back of the fingerboard for slap-click) and easily control the volume of each independently. It also features 4 internal EQ trim pots for each channel (bass, mids, treble and gain), and finally sending your buffered, blended and EQ’d signal through to your amplifier/pa via a single 1/4″ instrument cable. It runs on a 9V volt battery (also internal, only accessible by removing a screw and pulling off the cover).
This is my main problem with this system. That damn battery. The battery life started out great, but as time went on, it became shorter and more unpredictable. One minute it would sound fine, the next my tone would just turn muddy, dull, and undefined. It got to the point where I was installing a new battery before every gig, because it is NOT a quick change, especially if you’ve got it welded to your tailpiece. You can modify it to accept a wall adapter, but that defeats the convenience of having the controls at your fingertips. My other gripe with it is the (in my opinion) finicky and inadequate EQ trim pots. I spent hours and hours adjusting it at home, but I never got my tone dialed in the way I wanted it. That being said, this is one of the most popular, most affordable, and highly touted preamps for upright bass. Hey; I loved it for at least a year, myself. While I ditched the preamp, I kept, and even bought another of the K&K Rockabilly+ Transducer network. Perfect pickup system, in my opinion.
When I had finally had enough of the K&K’s unpredictability and declining quality of tone, I did a LOT of shopping around, and research and finally settled on a fairly new product; The D-TAR (Duncan Turner Acoustic Research) Solstice Two Channel Mixer.
While this is over twice the cost of the K&K blender, ($130 versus $330) it, in my humble opinion, stomps thee shit out of it’s more affordable competitor. The only tradeoff, other than price, is the size. You’re not mounting this on your bass. As described on the product website:
“Solstice is a high quality two channel preamp mixer that blends virtually any type of sound source. The low-noise hybrid circuitry and internally adjustable gain from 0 to 24DB make it suitable for both live and studio use. Solstice is the perfect solution for musicians looking to live-mix up to four sources such as piezo pickups, magnetic pickups, standard mics, and high output condenser mics.”
This is the last preamp you’ll ever need. As each channel has one 1/4″ and one Balanced XLR Mic input with separate volume controls for each, you can potentially blend up to FOUR DIFFERENT INPUTS. Also, either channel’s 1/4″ input accepts a stereo TRS jack, like the one used in K&K’s rockabilly pickups, and automatically splits the signal between the two channels. There is a mountain of other useful and insane features such as individual 3-band EQ, effects loop, and balanced direct output per channel, switchable 15v phantom power, phase reverse switch (kills feedback), mute switch, tuner output, and clip indicator.
After that rundown of specs, I’ll just say this: Complete tone control. Amazing EQ, ridiculous input/output options, and an effective feedback killer. Pretty much everything you could ever need for live or studio applications, save a compressor, and HPF, in one box. With the optional mic stand mount, it’s almost as convenient as a bass mounted preamp. In my opinion, no contest. If there’s one thing I’ve learned in my search for ‘the perfect tone’ is that you always end up spending the money, no matter what you start off with, so just save up for what you really want/need
Well, that concludes my first blog entry, and I hope SOMEONE reads it and gets some use from it! I’m not usually one to give away free advertising, but both of these products are available at http://www.gollihurmusic.com They have everything you could possibly need for upright bass, and with their HUGE knowledge base, and amazing customer service, I don’t buy bass gear anywhere else.
Thanks for reading, and check back here for more reviews, tips, and random thoughts about everything upright bass.