Ah, yes, the Razorwire, the baby I’ve ben planning for a couple of years now, my own custom body shape and configuration. This guitar has two controls: a volume pot and a rotary switch behind it that switches between neck pickup (active)/bridge pickup (active)/bridge pickup (passive, hardwired straight to the jack).

I would call this a “utility amplifier” because it’s not voiced for a particular sound or configuration; instead my goal was to develop a transparent amp that could be used with guitar, bass, stompboxes and even ampsims and other line-level sources. It’s pretty simple as heads go but it does pack quite a few features for its size:

• 12AX7 preamp section
• 20W solid state power section
• FX loop (preamp out, poweramp in), plus the preamp and power amp can be powered off independently, to be used as needed
• 2 channels: second channel removes preamp negative feedback
• switch-mode power supply for light weight and high efficiency
• controls: gain, master volume, channel, preamp on/off, poweramp on/off

I’ve been tweaking this guitar for years but I think I’m finally done (oh, really?!). Not much to say about this one; it’s obviously a Les Paul copy, certainly has that vintage vibe, with a dash of insanity, topped with Gary Busey’s psychotic grin. Controls are: pickup selector (neck/both out of phase/bridge), tone switch (normal/low pass), volume pot and gain pot for the onboard preamp.

If we’re to talk tech then it’s vital we all speak the same language, so here are some quick initial issues:

If there’s one word guitarists (and musicians in general) misuse, it’s gain. Gain, as you’ll find in any dictionary, means the ability of a circuit to increase the power or amplitude of a signal. Or as a parameter, we can define it as the (mean) ratio of an amplifier’s output signal to its input signal. So if we feed a 2V signal to an amplifier with a gain of 10 (which equates to 20dB), we would measure an output signal of 20V amplitude (provided there’s enough headroom, which is another topic).
For some strange reason, when guitarists say gain they really mean saturation! As in “A Dual Rectifier has more gain then a JCM800.”, which might be true, certainly is something we can determine but is not what the guy is thinking about when he says it. A Recto might sound more saturated then a classic Marshall but we’re really getting into subjective territory: a fully saturated sound is a square wave, and I’m sure people would agree that doesn’t sound as “gainy” as a cranked stack. So it’s not even the level of signal distortion but the specific harmonic content that results. A shrill sound that emphasizez the pick attack might sound more “gainy” then a dull “bluesy” sound, even if it comes from the same amp, at the same gain setting, being just a matter of EQ (or filtering, to be correct). Read the rest of this entry »

… with a new face!
I’ve redesigned the Indefinite Pitch website in the form of the ever-so-popular blog, seeing as I mostly write about music production and instruments anyway. This way projects and notes will be presented in a linear fashion but you can also browse them by topic or skip to a specific month. And finally a word about what you can expect:

• a complete detailed scientific description of the electric guitar signal path in common rigs, plus some advice
• new “signature products”, including  a brand new custom guitar, an LM386 micro combo and soon an all-tube amp
• tales from the studio and the road

And in case you missed Part One or you’ve arrived here by chance, here’s the lowdown: I am Mihai Florea or FiveseveN, usually working as a creative director and designer but sometimes as a sound and light technician in the studio  and on stage with local bands. I also build amps and effects and dabble in lutherie, sharing my experience with the world, which is what this blog is all about.