TAKES PEDALS WELL first appeared in Gearphoria magazine July/Au 2016 issue

I HAVE A friend who jokes that the oft-witnessed Craigslist descrip- tion “takes pedals well” means an amp sounds bad by itself and needs some window dressing in order to sound good. He may be right on some level. I have a more technical approach... I propose an amp takes pedals best when it has adequate input headroom.

A guitar spits out an AC voltage that can be understood in terms of a waveform. When a note is struck, there is an initial attack where the voltage spikes, and then settles quickly down into the sustained decay of the note which is many magnitudes smaller than the initial attack voltage. Most guitar amps clip off the attack slightly even when set clean, but it is so instantaneous you can barely make out that anything is happening. It usually translates as a slight chirp of harmonics that sounds great. It’s part of what makes a guitar amp a guitar amp. It’s the decay voltage... the body of the note... that we are concerned with.

Most note decays straight out of a guitar pickup register somewhere between 0.3 and 0.6 volts AC, ac- cording to my experience. Add a pedal and you might double this to between 0.6 and 1.2 volts AC. Most Fender-style Input 1 jacks are de- signed to handle about 1.3 volts AC before they clip... this voltage is the same as the bias between the grid and the cathode for you amp nerds... so I would consider a Fender Input 1 jack to have adequate input headroom be- cause the guitar signal, even doubled with pedals, is not more than the amp input can handle. By the way, the attenuated Input 2 jack has at least twice the headroom so don’t be terrified of it guys, it might work better.

Part of Fender’s genius design was settling on an input circuit that ac- commodates whatever guitar signal is presented to it. But there were many other designs that were less pedal friendly. Ampeg and Gibson and many other designs utilized either grid leak biasing, or tried to wring every ounce of gain from the first tube stage, both of which brings the headroom down. In most grid leak biased amps like an Ampeg Por- taflex, the input headroom is about 0.4 volts. It works great with low wind Strat or P Bass pickups straight in, but boost that with a pedal over 0.4 volts and it will sound like fuzzy oatmeal, which could sound pretty cool and unique, but you won’t be hearing the pedal or guitar as much as the amp input distorting.

Practically speaking, if you have an amp that is not pedal friendly to your liking, there is a fix! You need to decrease the signal going into the amp input. A clean boost that can be set less than unity gain, or even a volume pedal set halfway down as the last thing in your pedal chain might yield the results you’ re looking for. It’s not intuitive, since any loss of gain is considered less “awesome”, but it might mean not having to change up your rig. 

 

 

TOO MUCH INFORMATION first appeared in Gearphoria magazine May/June 2016 issue

ONE OF THE biggest mistakes I see players making with their rigs is supplying too much information. More specifically, the wrong information. I’m speaking mainly about bass and treble frequencies here. When Fender was coming up with his most famous amp designs culminating in the black panel circuits in the mid 1960s, he had a specific goal in mind... leave a large gap in the midrange frequencies in order to blend well with the human voice in order to avoid something mix engineers call “masking”.

Fender did an admirable job and created the iconic classy scooped midrange clean tones we all love... fat bass and sparkling treble frequencies. Practically all Fender amps made since then (and many other manufactures) use the same basic black panel tone stack. I’m not going to lie... I love it. It is instantly recognizable and sounds amazing. But I could never use it live, and here’s why: It creates problems. Fender was designing around the popular music of the time... western swing, surf, and early rock-and-roll.

In the 1970’s, tastes changed and technology improved and thunderous kick drum and bass guitar tones on the low-end and bright cymbals and treble-voiced vocal microphones began to compete with the frequencies Fender amps were known for... leading to the very thing Fender was trying to avoid — masking. Fender didn’t adapt, and lost large parts of their market to Marshall and top boost Vox (Ironically, both somewhat based on earlier Fender designs) that boasted more cutting mid-range tones that were able to cut through a mix like a knife, both live and in the studio.

Today, little has changed. Beginning guitarists dial in a fat and sparkly tone in their living room at home that sounds gorgeous in its broad frequency spectrum glory, and then bring their rig to a rehearsal or gig with drums and bass and nobody can hear what they are doing.

My plea is that players view electric guitar (in most situations) as a mid- range instrument. Don’t worry about getting a fat bass at 100Hz. Forget about everything over about 5k. Give the bare minimum in the bass and treble. No one will ever hear them, and it will cause problems. Don’t make your sound guy or mix engineer roll the bass and treble frequencies out of the mix...you’re giving him too much information.

If you think you might be experiencing this problem, don’t put your vintage Fender on Craigslist yet! There are some fixes. A Fender has a flat(ter) frequency response when the controls are set around Bass = 2, Mid-range = 10, Treble = 3 [Fig. 2]... try that as a starting point and see if your mid-range pokes through more. Another potential fix is the Ibanez Tube Screamer circuit or a variant. They provide a mid-range bump that counteracts the mid scoop of a Fender bringing it flatter (with the added benefit of some compression and grit). You can do a similar thing with a basic EQ pedal. A side benefit to losing the bass frequencies is one might find their amp breaking up smoother and with better harmonics (I’m not sure why it leads to smoother breakup, butI suspect it has something to do with intermodulation distortion being shifted into a more pleasing region of the frequency spectrum).

To be clear, too much information isn’t a problem for every player, in every genre of music, with every guitar, in every situation. Sometimes the wrong thing is the right thing, and rules were meant to be broken. But, if you play in a conventional setting with a drummer and bassist and find yourself not cutting through, it might be time to find a mirror and ask “Is it me?”, as well as its awesome sister question “Do I need to change my rig up?”