Yes, another true bypass story...

Every so often, the topic of the virtues of true bypass comes up, and it is always surrounded by lots of questions. One particular question that keeps returning is wether the whole true bypass thing is completely misguided or not, seeing as some players (like Jimi Hendrix) sounded pretty good without it... Some players even seem to rely on the treble loss casused by using a long coiled cable.

But really, true bypass and treble loss due to coiled/long cables are two entirely separate items that need to be looked at separately. This rant - as so many others - started its life as a reply in a thread at Harmony Central's effects forum, and I decided to save it for posterity. I figured I might as well, considering the amount of time it took to put it together... Anyway, back to the topic at hand:

Cable losses
The treble loss associated with curly cords and pedals with the old-style half-assed bypass (old vox wahs, for instance) is well known. Some players even use/used it to their advantage, to tame an otherwise too bright and brittle sound. Albert Collins used to run a Telecaster into a Fender amp with the treble on 10, and with a 100' cord in between it sounded pretty decent. With a shorter cord... ouch. Brian May used the longest curly cord I've ever heard of, and it helped him get his trademark tone (along with his homemade guitar, treblebooster and AC30TBs, of course). It's all in the combination, and how you put your chain together.

But not all of us want to depend on treble loss in the cables, to get our sound. For instance, most people don't run their amps wide open, and would therefore lose too much treble with a 100' cord or spiral cable - enter the buffer. Let's investigate what that thing actually does...

The buffer
We often call it a device that converts the guitar's fragile high impedance signal to low impedance, making it more durable. While this is true to some extent, what really happens is that the buffer disconnects the source (guitar pickups) from whatever follows, by placing a transistor in between them. Very roughly, the transistor uses the power source to create a copy of the source/input signal. The copy is then sent onward, while the original signal is discarded (if the transistor is asked to amplify the signal, it simply makes the copy more powerful). Since the output impedance of the transistor is much lower than that of a guitar pickup, the new signal can travel much easier through the cords ahead. But the source signal is gone forever, though...
Equal gain buffers are generally pretty good at reproducing the incoming signal, though, and when we compare the sound of a 30' cable to the sound of two 15' cables with a buffer in between, the gains (increased treble response and dynamics) associated with the buffer usually far outshine any losses. But keep in mind how the transistor works - it hears a story (the guitar signal), and then re-tells the same story, but in its own voice. Have you ever told someone a story, and weeks later the story comes back to you via someone else? It usually has changed quite a bit, from all the people adding their "voice" to it...

Stacked buffers
Now, ever since the late '70s, the standard for Boss/Ibanez type pedals have been to have two buffer stages, plus a transistor-based switching system. If we only count buffers, and figure that the pedal is bypassed, what happens? Your original signal is lost at the input buffer, which sends its copy/version forward to the output buffer, which copies that signal, and sends it out via the output jack. Now imagine you combine five such pedals in line, all bypassed. Count 'em... You have the input buffer of the first pedal, where your guitar signal is being copied, and then [b]nine[/b] additional stages, all making a copy of a copy of a copy of.... (ad infinitum). With each step, you move slowly but steadily further away from what was your original signal. You might like the changes, or not, but there's no denying that the difference is there.

But what does all this have to do with true bypass and coiled cords, you may ask? Well, while true bypass removes the "stacked buffer" effect, it will also expose your signal to the treble loss caused by long cables. To a certain extent, some of that signal can be saved by using low capacitance cables like George L's or the Klotz GY107 LaGrange. Remember that the treble roll-off Brian May relied upon only happened between his guitar and treblebooster - after that, the signal was low impedance, and not as sensitive to cables anymore. Thus, the most important cable, tone-wise, is the one from the guitar to the first effect (as long as it is active, that is - if it is true bypass[ed], the following cables may count as well).

The art of compromise
To get the perfect compromise - if there ever can be such a thing - you can insert a permanent buffer stage somewhere in the chain (but just the one instead of 10-20 of them), while keeping the other effects on a true bypass diet. That will help smooth out the signal differences when you bypass and activate the TB pedals, since it will always provide a stable low impedance signal, regardless of what pedals are active or not. At the same time, the true bypass switching on the pedals will keep the number of stacked buffers to a minimum. To drive a long pedalboard-to-amp cable, place it last in the chain. To help push through the pedalboard connections (up to the first active or buffered pedal), place it early, but not before fuzz pedals that don't like low impedance signals. This buffer stage can be a dedicated buffer unit (such as the Axess BS2 or VHT Valvulator), or a booster or eq pedal you always leave on. But it can also be just an ordinary Boss/Ibanez type pedal, left in bypass mode. Of course, if you already have a buffered pedal elsewhere in the chain that you keep permanently active, you are already there.

Again, it's all in how you combine the elements - true bypass doesn't solve any world problems, and neither does a good buffer. But if you put them together (in the right proportions), and couple them with a good low-capacitance cable, they will improve your tone and impact quite a bit. Unless you rely on treble loss for your tone, that is, and can't find your sound by simply turning down the treble knob...

http://www.stinkfoot.se/andreas/diy/articles/bypass2.htm

Rz