Kazinator

Anyone who says "turn up the mids; don't scoop them" should be pointed to Deadly Sin 5 in this article.

Generally, the higher the distortion setting, the more treble you'll need to add. The reason is that the more distorted your signal, the more compressed it becomes, and compression rolls off high frequencies. Distortion creates high frequencies which are not there, which have to be carefully controlled. The more distortion, the more highs there are. Fuzz-type distortion can cut out high frequencies that were present in the clean signal, but that happens because the high frequencies are basically ripple that rides on much larger low frequency waves. When these big low-frequency waveforms are clipped flat by the fuzz, much of the ripple which is riding on them is cut away too. Non-fuzz type chunky distortion prevents this problem by high-pass filtering the clean signal first to diminish the low frequencies. Then the higher frequencies in the signal can cut through (resulting in that property that we call "chunk"), and can get louder with more distortion. Bass can be boosted after the distortion to recover the bass response that was rolled off on input. Distortion requires a careful EQ of the high frequencies. Enough high end has to be retained so that the tone has definition and brilliance, without being harsh and fizzy. A lot of this critical action takes place in the 6 kHz to 16 kHz range.

Re: "Telefunken, Mullard, GE, RCA, Sylvania, Groove Tubes, Sovtek, JJ and countless other new and NOS (new, old stock) tube brands." There is no such thing as NOS tubes. Telefunken, Mullard, GE, RCA and Sylvania have not made tubes in decades. The old stocks are all gone, and these companies absolutely do not produce "re-issues" of vacuum tubes either. Everything sold under these names is fake: counterfeit labels put on JJ, Sovteks, Shuguang or whatever new tubes. Or worse: used, old tubes cosmetically refurbished to look like new. It's a scam to separate audiophools from their money, just like two hundred dollar power cords made from solid silver or directional audio cables. Groove Tubes is not a tube manufacturer, but an OEM label. You're getting JJ's, Sovteks or whatever. Supposedly they provide value by selecting, grading, and (when applicable) matching tubes. The only way you're going to get some genuine old brand-name tube is if by dumb luck you discover a cache of them in some forgotten cabinet in a run down building somewhere. Or pull a used one from a vintage piece of equipment.

I use Canare video cable (model LV-61S) for all my unbalanced patch cords and instrument cables. They make instrument cables, but the video cable has better specs (those picofarads per foot): it is 21 pf per foot. Compare this with the Canare GS-6 cable (more than twice as capacitive at 49 pf/foot) and the Canare GS-4 (47 pf/foot). This LV-61S video cable is a flexible coax which looks and feels like instrument cable. It has a braided copper cable shield and a braided core conductor. It does not resemble CATV cable at all. CATV cable has a steel wire core that is coated with a thin copper layer, which is fine for VHF and UHF transmissions but not for audio, and tends to have aluminum cable shields which are difficult to solder . The frequency response through the Canare LV-61S cable is great. I would like to use LV-77S which is even better: it has a double layer of braided insulation! Check it out: http://www.canare.com/productitemdisplay.aspx?productitemid=74 It's hard for me to find locally, though. Double shields provide better coverage against interference. So why do Canare bother even making instrument cable? There is something special about the GS-4 and GS-6 cables. In addition to the braided copper shield, they have a conductive carbon shield inside of that one. This supposedly reduces microphonics. This material could be why the capacitance is greater.

"If one dirt box is good, why not two — or even three?" Good question; let me take a crack at it: Each box has additional buffer and amplification stages which are made of some crappy transistor and op-amp circuits that add decibels of noise to your signal. Each box contains numerous contact points: two jack-plug contacts, contacts in the "true bypass" switch, and wiper contacts in the potentiometer. As all these things wear and oxidize, they suck tone, which means they are all maintenance items: they need cleaning or replacing. More boxes, more maintenance. You have to step on three boxes to put all the dirt on bypass, unless you add yet another piece of gear that will switch them as one loop (like that "true bypass looper pedal" mentioned in the article). You have to lug all this extra gear and ensure that it is powered.

DC offset does not cause a drastic reduction in headroom. It only looks that way on linear graphs. A 5V offset that reduces a 15V headroom to 10V looks like, oh my gosh, a 33% headroom loss! But actually, it's only 3.6 decibels which we can calculate as 20 * log10 (0.66) = -3.6. It is common for analog gear to work on +/- 15V rails, because, in a nutshell, the op-amps used "like" a decent voltage across them for best performance. That doesn't mean we want to drive anywhere near a +/- 15V signal through these devices! The distortion performance of the op-amps will degrade with larger voltage swings. It's best to put line level signals through your equalizers and whatnot, with an amplitude of about a volt. Suppose that you have a +/-15V supply and you can use about 13V of that (since the devices inside the signal processor do not swing rail to rail). If your signal has a 1V peak amplitude, what is the headroom in that device? The voltage can go 13X more than the 1V peak, and thus: 20 * log10 (13) = 22.3 dB. It's quite a generous padding.