There is an element of truth, and a great deal of ongoing debate on each of these issues, these are our thoughts from experience and research.
Speaker Cables & Instrument cables
Many believe these cables are interchangeable, or even the same, but this is simply not the case. Speaker cables contain much thicker wires (two wires in fact) to handle the high power signal from the amp. – They are low impedance and don’t get as hot during use. Instrument cables contain a single wire and shielding and are high impedance.
Speaker cables are not shielded as the high power signal is not susceptible to noise, but use a speaker cable for your bass or guitar and it will sound horribly noisy, they are not interchangeable. Using an instrument cable between a head and cab could potentially break the connection due to heat, which would in turn damage the head.
The belief is that a pedal without true-bypass is inferior and will ruin your tone. This belief stems from the fact that a normal guitar pedal, when connected but not engaged can still affect (or colour) the signal passing through.
True bypass “bypasses” or removes the pedals circuitry from the signal chain completely, travelling from the pedal’s input to output jack without colouration. It is true that a pedal without TB’s buffer stage is active when connected, but only in poor quality pedals does the buffer have a negative effect on tone.
So why even have a buffer? Well the buffer is there to boost the signal, converting it from high impedance to low impedance, this allows it to travel a greater length of cable without signal loss. So as you can see, a good quality buffer will actually prevent colouration from the cable. This complicates the debate considerably and makes it down to individual circumstances: what pedals? how long a cable? etc.
I think the important thing to take away is that both options have pros and cons, don’t just buy into the hype and go straight for all true-bypass pedals, or think that a pedal that is not true-bypass will not be good. One popular method to get the best of both is to incorporate two buffered pedals, one first in the chain and one last, using true bypass pedals for the rest. On a similar note, many people believe single pedals are better than multi fx, but it is not that simple. Good quality multi fx pedals can do digital effects well and as with most things beauty is in the eye (or ear) of the beholder!
Bigger Amp = Bigger Sound?
The smaller/lower wattage tube amps when cranked are being used at their full potential, and can sound bigger than an amp many times it’s pricetag, so a smaller amp may sound better. With solid state amps there’s not a lot of difference in sound from a more powerful/higher wattage amp vs a small one and they do not respond to “cranking” the volume in the same way. With speakers however, a 4×12 cab will most likely sound “bigger” than a single speaker combo. The type of speaker also comes into play at this point though. Unless you’re playing stadiums, a 50-100w valve combo is plenty for a live rig and your back will thank you, it will often be miked up anyway. I’ve even gigged on an 18w valve head and had headroom to spare. Remember doubling wattage does not double volume, in fact 100w is only slightly louder than 50w! Buying an amp which is appropriate for the situation it will be used in is the best approach.
While I agree that a good quality cable will often sound better than a particularly poor quality cable due to shielding etc, virtually any cable from a reputable guitar store will be good enough quality. The capacitance of a cable does cause some of the top end to be rolled off, and this is often undesired, but remember this: most of the legendary tones we guitarists try to emulate, were made using poor quality cables. The most important factors when choosing a cable is length (this increases capacitance), followed by quality of shielding and durability. Consider what sound you want before spending big money on something which will only have a relatively small bearing on tone. You can even learn to solder your own cable fairly easily, getting the best of both, quality & value.
Particularly high quality cables often last longer and/or come with a guarantee so it may be worth paying that little bit extra for peace of mind, depending on the price. Gold plating does not have any affect on sound quality, though it can potentially increase life of the cable.
Getting What You Pay For
This comes on from the previous point nicely, the same concept applies to all sorts of guitar/audio equipment. For example two “identically” specced, guitars will often sound significantly different with one being inferior to the other. There are some quality bargain equipment steals out there. There’s plenty of guitars which have been well thought out, expertly crafted and sold at a reasonable margin for whatever reason: unpopular/new brand, low marketing budget, discontinuing stock etc. Research, shop around, haggle and most importantly try out the guitar before buying, whenever possible try the EXACT guitar you are paying for to make sure it is right for you. Don’t just buy into the brand instead of working out what you want.