Not all strings are created equal! Some strings are bright some are mellow some are coated some are wound some are flat wound! Find a brand that suits you and stick to them. Personally I use D’Addario gauge 11 for that full tone, be aware that they are harder to play but you won’t be disappointed by the tone.
For a more mellow tone I recommend the flat wound strings which are smooth and sound vintage, A Hendrix signature series are available by a company called Dean Markley and reproduce the tone from Hendrix’s early years.
Pull back the gain, if you play on the overdrive channel of the amplifier or overdrive pedal. Dial the gain to a setting of between 4-6 for that snarly blues tone but without the saturation sound that is better suited for hard Rock and metal.
Use the neck pick up for a warm bluesy tone. Every guitar is different and every pick up is different, if using a Les Paul style guitar use the rhythm selection on the pickup selection, if using a Strat style guitar flip the pick up selector over towards the neck for that neck pick up.
The string vibrates at its fastest towards the bridge and the nut of the guitar and at its slowest towards the centre, therefore the bridge pickup will pick up a very bright tone and the neck pickup will pick up a tone that is more mellow, full bodied and bluesy.
Keep those strings clean! If your strings are dead, your tone is dead. Use specialist string cleaners after every practice session to prolong string life and keep those strings sounding great. If in doubt about the need of a string change pinch the 1st string and rub up and down does it feel smooth or rough? If it feels like rusty barbed wire then its time for a string change!
Use a pinch of reverb usually between 1-3 should be fine, this will give your sound a feeling of space and depth. Beware though; reverb can be used just like distortion to substitute for poor technique. Make sure the reverb is not playing you! Keep it moderate and it will polish that sound nicely.
Picks are all different so which one should I use? Typically a gauge 1.00mm-1.5mm should be good for a blues player who wants to get a full and powerful sound, typically if you are playing lead you will not want anything lighter as it will not carry the sound and give you a weaker tone. The harder the pick the louder your tone. 0.5mm-0.7mm picks are best for strumming, as they do not attack the strings as hard. Get a selection of picks and see which ones you like best. I like the Dunlop picks.
Wah Wahs are an essential pedal for any serious blues player. The wah exaggerates certain midrange frequencies, which you as the player can manipulate by the controller pedal. This is great for guitar solos as you can choose to bring out the top mid frequencies for an exciting tone of pull back for a mellow tone. Perhaps one of the most famous examples of the Wah Wah pedal is in the intro to Voodoo Chile. I have played a number of Wah pedals and as a blues player I like the Cry Baby.
Keep it organic sounding. Look back to the equipment that your Blues guitar hero had. Did they use a pedal board with 30 top of the range modulation pedals including flange, phaser digital delay pitch shifter and Bad Horsie Wah Pedal? – Probably not! I tend to keep my line up quite simple. I use the amplifier gain from a tube amp (Vox) and a crybaby and a pinch of reverb. This is not to say don’t use an effects pedal. I have seen people using a boss pedal with great results because they select sounds which are relevant to the genre, for example an overdrive not a distortion, a traditional wah setting not a hybrid setting and a vintage chorus setting or univibe setting.
Learn all that you can about technique. There are countless ways to bend a string and every blues player has a unique way of bending strings. Study your favourite blues guitar player and listen to how they bend the stings, find out which notes of the scale they bend for that signature sound is she bending the minor 3rd? Is she doing a semi tone bend to bring that minor 3rd up to a major 3rd. Put the solo into a program like logic, cubase or even a free version of audacity and loop each phrase to learn from the masters themselves.
Learn your scales. You don’t need to learn all of them! The scales to start with are the Minor pentatonic and the Blues scale.
The minor pentatonic is built from these intervals:
R – b3 – 4 – 5 – b7
In the key of C, that would give us:
C – Eb – F – G – Bb.
The “blues scale” is built from these intervals
R – b3 – 4 – b5 (dim) – 5 – b7
in the key of C, that would give us:
C-Eb- F- Gb- G- Bb
Learn these two scales and you will be well on your way