This is a common problem faced by guitarists in their early career. Unless they were born from the family with deep pocket (which doesn't provide good reasons for being an artist), guitarist always have tight budget for their equipments. I was also in that situation on my first band rehearsal when I first came across these friends who brought along some cool pedal effects from BOSS. I wish I had the money to buy some of those for my own sound. But begging for money from my parents at that time was out of question. So I just crank up my low profile combo amp to its maximum Gain setting for the distortion lead. It sucked but I had to live with it.
It is somewhat true that once you experience a good guitar tone, it's hard to come back and accept the modest thing you already have. That also apply to HIFI sound system and other luxurious things in life. So try to refrain from listening to your guitarist friend's tone once you are satisfied with your own unless you are ready to spend more money to further shape your tone. This article tends to provide some background on guitar effects which are available on the market at the time of this writing. I hope you can make your choice out of millions of options in the marketplace. I'll be able to explain some technical aspects of the effect a little bit more deeply since I have some background on Electrical Engineering from school.
The beginning of it....Amps with pedal effects....
When the electronic signal processing in digital domain was not something that can be taken for granted, the engineer has been crafting the tone using the best valve amps and some analog circuits. Fortunately up until now these vintage tones don't just disappear, thanks to the cool image created by those Guitar Gods with the huge amount of great songs. Up until now the engineer are still trying to recreate those tones in both analog and digital domain. I'm not going to talk about the great valve amps since I don't have much experience on it, but for the pedal I can tell you that the building materials are cheap. It's the design and the brand image that make them priced higher. The main components are normally some transistors/Op-Amp (for gain) with some Resistors and Capasitors (RC circuit) for frequency manipulation. Of course some other type of effects employs different kind of electrical components according to their functions (such as noise gate which use some kind of relay circuit). And nowadays, to make it event fancier, some products add some tubes in their pedal effect.
The point is, you can build your own analog pedal effect with much lower cost provided you have some background in electronics circuit. I have provided some links to the sites that can help you build your own pedal effect below this article.
So....Why go with Analog pedal effects? Good question! Some guitarists claim that they have better sounds compared to digital effect, the sound is fatter, warmer, etc. This statement does not hold true anymore with the advance of the Digital Signal processing. Trust me, I know how good the digital modelling nowadays! But it's true that for sensitive ears, processing the electrical signal in analog domain will retain some of the harmonic artifacts of the signal (or it can even add more harmonic artifacts) which is the favoured by many guitarists. If you already have a good valve amps, take my advice, just buy the analog effect pedal according to the type of sounds you need. Don't spend too much money on digital effect modelling (as I did, unfortunately) which can change overtime. Analog effect pedal can become vintage effects (it's true for the Ibanez Tube Screamer could go as high as 400 USD before the model was reissued), but digital effect modelling will be obsolete once the new DSP (Digital Signal Processor) with a better processing power is manufactured.
The New Era.....DSP based effects......
And why some guitarists prefer digital effect modelling? There are only two good reasons for that: the cost and flexibility, hence they can sacrifice some of the sound quality (I won't consider other reason that some moron are trying to find 'alien tone' from guitar by using special synth digital effects, which defeat the whole purpose of playing guitar, if you want a synth sound, play a synthesizer, sucker!). Buying one digital effect model is much cheaper than stacking some decent analog pedals which can be priced more than 200 USD each. It will be much easier to carry only one effect for rehearsal, not mentioning the size of it that has ben shrinking as the chips are getting smaller. To use the digital effect processor you need an amplifier with a real flat frequency response. If you use some Guitar amplifier with its own sound characteristic, it will be a bit frustrating since the amp will again colour the sound made by the effect adding to the uncertainty of the tone.
What constitute a good Digital Effect Modelling? This is a hard question to answer since people have different hearing sensitivity and finding a gap between the real things and the models requires years of experience. But I can tell you that that gap is so delicate nowadays with the better DSP processing power and higher bit quantization. For example the Mesa Boggie Dual Rectifier sound (which have been imitated by almost all digital effect) in POD XT and V-AMP2 is frighteningly close to the real thing.
So how to choose a decent Digital Effect? Here is some hints:
1. Don't be tricked by the sales promotion saying that the digital effect is modeled according to the detailed circuit of the real amps including all of their electrical components.
This sales trick is so full of crap. I studied electronics before and my final research was using the SPICE program for analog electronics circuit analysis using computer. We can specify the electrical circuits with all of its components model and provide the input, then get the output after the some calculation for the circuit behaviour simulation. It takes HUGE amount processing power. For some complex circuit, the calculation with Pentium processor can take few minutes. So I doubt the tiny and cheap DSP inside the digital guitar effect box can actually handle a complete electronic circuit simulation. Not mentioning how sophisticated the component model used (for your benefit, the component model is basically a mathematical formula that mimics the behaviour or the real electrical component when some input is given). I suppose they employ more block type modelling and processing in the frequency domain using Fast Fourier Transform (FFT). It makes more sense since not only the amps are modelled, but also stomp box, reverb, miking, etc.
