My old emails seem to be a treasure trove of advice! Here’s one I wrote to someone who is looking for the Holy Grail of rock and blues guitar:  a tone that is clean when you play with moderate force but starts to break up the harder you play. A number of people have made (and spent) small fortunes on this quest. Here’s my two cents, based on the assumption that you don’t have a small fortune to spend.

There are four different ways to get distortion.

• You can introduce the distortion before you get to the amp input (with a fuzz box, amp simulator, or anything that adds an extra gain stage and level control in the circuit).
• You can introduce the distortion by overloading the preamp circuit (the little tubes). This is how early master volume circuits like the Mesa/Boogie worked. They simply took a two channel Fender amp and ran the output of one preamp stage into the input of the next stage.
• You can overwork the power tubes (this is what you do when you turn a one-tube amp like a Champ up all the way).
• Or you can overwork the speaker.

For completeness, I must also add that if you are recording or miking the amp, you can also introduce distortion in that process (the guitars on “Revolution” were recorded direct into the board and the channel outputs were cascaded; it was a tube board which is a lot more forgiving). There are also lots of excellent sounding amp simulation plugins. I use them myself a lot in the studio. But this won’t help you for live applications unless you want to bring your laptop to the gig and patch it into your rig. There are people who do this, but they usually have road crews and large budgets. I don’t recommend it; there are too many things that can go wrong.

Each of these types of distortion has a characteristic sound, with pluses and minuses. A distortion pedal allows you to dial in a good clean sound on the amp and modify it for solos, but often the solo sound isn’t as convincing as the clean sound. Preamp distortion often sounds overly compressed (think Larry Carlton seventies session stuff, a great sound but not a lot of dynamic range). Power tube distortion often sounds the best, but it generally involves running the amp up at least 3/4 of the way, depending on the circuit, and with a big amp that gets LOUD. And speaker distortion risks frying the speakers. Also, with power amp and speaker distortion, the bass strings can get floppy.

Probably some combination of the various types of distortion will give you what you want. To control distortion from the guitar’s volume knob effectively, at least one gain stage, and probably two, have to be distorting when the guitar is up all the way.

First, get the speaker up off the floor so that it’s out of the equation. Put it on a chair or small table so it decouples from the floor. (The floor can add bass and be very deceptive when trying to figure out how the amp works.) Start with your guitar’s tone control up al the way and your volume pot at around seven. If there are two inputs, plug into both of them in turn and start with the louder one if there is a difference. If there’s a bright switch, turn it on. Pick a bit lighter than normal. Then set the amp with modest settings on your tone controls (all on 5) and gradually turn up the amp until it distorts noticeably on your lowest note.

Do you like how it sounds? If so, now experiment with your guitar volume and see where it cleans up to the extent you want it to. Now use the amp tone controls to EQ your clean tone to where you want it, and you’re done. (They have much less effect at higher volumes.) Turn it back up to your solo volume. If the lowest note is woofy, roll off some bass, then check your clean setting again. Go back and forth until you find a medium you like.

If you don’t like the sound, analyze the problem. If you are basically happy with the tone you’re getting but it’s too loud, you need to cut the efficiency of the power tubes.

The first thing I would try is running the amp with a mismatched impedance, if you have that option. For example, if you have an 8 ohm speaker, use the 4 ohm speaker output. This will make the amp operate less efficiently and will also change how it responds to the speaker. You’ll have to turn it up louder to get the same amount of volume so the power tubes will have to work harder. (Larry Carlton used to do this back in the day.) You will wear out the tubes a bit faster, but as long as the differential is within a factor of 2 it’s not a big deal. However, the speaker resistance should always be equal to or greater than the amp’s output impedance. A 4 ohm amp into an 8 ohm speaker is fine. (I do this all the time with my 1962 Bassman.) An 8 ohm amp into a 4 ohm speaker is not a good idea for the speaker. A 4 ohm amp into a 16 amp speaker will work, but maybe not for long depending on how overbuilt it is. Old Fenders can take a surprising amount of electrical abuse both at the input and the output stages, but I can’t promise the same for newer ones, or any other model for that matter.

The next option is to pull two of the power tubes. Yes, you can do this! On a Fender style four tube amp, pull out the two middle ones. (Use gloves and be careful, they get hot.) This cuts your power by half and also induces an impedance mismatch, so it’s a more radical effect than just an impedance mismatch. If you don’t like how it sounds put them back in. I would call a tech first though to make sure that this will work with your particular amp. There are a LOT of circuit designs out there these days, not like 30 years ago.

To overload the preamp section in a non-master volume control amp, you will need to introduce a gain stage in front of it. This can either be a distortion/fuzz box or simply any preamp that you can patch into the circuit. (People used to use Revox tape recorders back in the day, among other things. The preamp circuit sounded great for guitar.) Tube preamps are particularly good, but anything that boosts your signal can work.

You can turn most distortion boxes into more or less clean boosts by turning the volume all the way up and the gain almost all the way down. Turn down your amp volume and, with your guitar volume on about 8, turn the gain/distortion/preamp up until the amp distorts. Now bring your amp volume up. It will be a lot louder! Hopefully you will like what this does to the sound. If it’s much too loud try either the impedance mismatch or removing the tubes to tame it.

If the sound is close, start playing with the amp eq to tailor it a bit. Remember in most tube amps the tone controls are passive, meaning that they are “flat” (no guitar amp is flat) when turned up all the way. So when you turn up the treble, you are actually letting the treble the amp is generating actually pass through to the output stage, for example.

Another thing you can try with a passive EQ is to turn all the tone controls down all the way. With a Fender style circuit you will get either no volume or very little. Then turn up the amp to, say 8. Now, GRADUALLY turn the EQ up a number at a time until you start getting the volume you want, balancing the tone as you do. I don’t like how this sounds but some people swear by it.

What you are trying to do with all this fiddling is get to a place where the power amp and preamp are both working pretty hard, to the point of overload. At that point, a number or two on your guitar’s volume control will make a lot of difference in the amount of distortion you hear. Note also that most guitar volume controls are tapered so that most of the volume increase happens between 7 and 10. If you tweak your amp so it’s clean at 4 or 5, a small adjustment will get you into distorto world. But it will also give you a big volume boost more often than not.

With master volume amps (any amp with two volume controls on the same channel), with your guitar at around 7 or 8 set the first volume control up to the point of distortion with the master down to maybe 3 or 4. Then turn up the master volume to the volume you want. Now when you turn your guitar down it should clean up nicely.

Here are a couple of further thoughts. First of all, not all distortion boxes are created equal! My old yellow Boss one lets lots of articulation through. My Tube Screamers, less so. But I like their midrange peak because I play clean Fenders a lot and they work well for the two or three solos I take a night in that setting. I wouldn’t use one as my main distortion sound for a rock gig. I just got a Carl Martin one that does an amazing, just about amp-proof Marshall simulation into the most characterless amps you can imagine, and it has a clean boost too.

What I do on rock and blues gigs is to either bring my weird 100 watt Marshall combo (which defaults to distortion even at low volumes) or, for smaller rooms, I bring a couple of small amps that break up well and patch them together with my stereo chorus or echo. I have an Ampeg Gemini I which sounds absolutely amazing and works just as you describe without any additional gear needed, but isn’t loud enough to get over a strong drummer, as well as an Epiphone Valve Jr. that does a great AC 30 imitation at a quarter of the volume.

With two small amps you can also run stereo effects if you like that sort of thing. The disadvantages are that they aren’t necessarily any lighter and it’s really hard to carry two amps on a train. You might want to look into the Fender Blues Jr. amps, which are quite loud for their size and very portable, especially if you are being miked up.

Any old Silvertone amp will break up nicely. They used to be very affordable before that horrible Jack White drove up the price by getting popular. Look around for off-brand old tube amps of any description, not just guitar amps. Look for old PA heads too. Some of them are super cheap and built with very similar circuits to guitar amps.

If you ever come into some money, look into the Dr. Z amps. They do what you describe very well, aren’t unbearably expensive for a boutique amp, and hold up on the road. The new Vox AC-15 with Celestions sounds great too, though I don’t think it will travel as well without a good road case.

While cleaning out my email, I found some tips on slide playing that I sent to one of my son Ethan’s friends. It occurred to me that they might be useful to others too, so here they are.

Playing slide well is a combination of three things: being able to hear the note and how close you are to it, the muscle memory to get close to the note without hearing it, and the ability to adjust when you miss.

Remember that NOBODY on an unfretted instrument plays totally in tune all the time. Not Heifetz. Not Casals. Nobody. The trick is to develop good muscle memory and quick ears so that you adjust quickly enough so that the listener can’t hear when you miss.

I find that slide is best played with fingers (either with finger picks or bare fingers) rather than a flat pick, as you can use the fingers to damp the unused strings. Start with resting the little finger on the high E, the ring on the B, and so on. The thumb covers the low A and E. Dedicate a right hand finger to each string, and damp with the fingers that aren’t in use. It takes a while to get the hang of this but you will have very clean results. If you need to play fast quickly before you master this, alternate your thumb and first finger, using your palm to damp.

I put the slide on my little finger so as to be able to fret with the others. You may find that you have more control with your ring finger. Bonnie Raitt uses her middle finger. Try them all and see what works for you.

It’s a good idea to have a guitar set up for slide if you own more than one. That way you can raise the strings enough so the slide doesn’t rattle or fret out. I also recommend at least an .012 set for slide, and you should consider a wound third and heavier strings.

Tunings for slide are a whole other world, but apart from standard tuning you should experiment with at least open D (DADF#AD, low to high) and open G (DGDGBD, low to high). It’s a gross oversimplification, but open D sounds like Elmore James or Duane Allman and open G sounds like Keith Richards or Robert Johnson. The big difference is that in open G the third is on the top two strings while in open D the third is between the fourth and the third. In standard tuning the third is between the third and second string, so learning an open tuning means that the chord forms you know either don’t work, or produce a chord you don’t expect. It didn’t take me that long to find most of them in open tuning though.

Here are a bunch of slide exercises for any tuning.

Hit an open string, for example the low E, and let it ring. Then slowly slide up or down to an E on any other string and listen to the beat frequencies as you bring the note in tune with the open string. Take your time and try to relax your left arm.

Then do the same thing with fifths, fourths, thirds, etc. Spend a lot of time with each interval, hearing what it sounds like against an open string. Check your work often by fretting a note, then sliding to it.

If you have a good tuner, play plugged into the tuner, and observe what happens as you gradually bring the note in tune. Then go to another note without looking at the tuner and see how far off you are.

Then try the same thing in different keys, moving the drone chromatically up the neck. A loop or delay pedal is good for this. You can loop your drone note in any key and play all the intervals against it.

Then try going for specific intervals starting from each note of the chromatic scale. (Do each of these exercises on one string. If you can do it on one string, it translates to all.) Start on, say, F. Then hit an F an octave higher and go back down, both sounding the slide between the notes and muting it. Then go from F to E. Then F to Eb, etc. Then reverse the process.

Do NOT do these exercises fast. Do them slowly and listen and correct yourself. Train yourself not to get angry when you miss, but adjust.

After you’re sick of this stuff, play a simple tune with a diatonic melody. I like “Amazing Grace” or “Silent Night.” But pick one you really like, because you are going to play it OVER and OVER again until it glistens. Play it on one string first. Then two, then on however many strings you like. Play it in every register on the guitar, starting on every string.

Now experiment with the articulation. Play every note separately, as if they were fretted. You want to be able to simulate fretted playing with the slide, as the contrast will be much more effective when you start adding the articulations. Then start connecting the notes, sliding into them from above and below, and so on. Play the tune very slowly and LISTEN to the effect of the glissandos.

Once you can nail diatonic tunes, work on a standard such as “All The Things You Are” that has a simple melody and moves through a number of keys.

If you like blues or country slide, experiment with sliding up to just under the third, fifth, and flat seventh. Slide is about the infinite number of pitches between two points on a string. (So is string bending.) Try to find as many of them as you can, and observe how they make you feel emotionally.

Once you can play a standard in tune, start copying female singers note for note, inflection for inflection. Try to match their vibrato. How fast is it? How wide is it? Does it start at the beginning of the note or come in after the pitch is established? Slowing this stuff down can be really instructive.

Dionne Warwick is a good one to start with; classic phrasing, great pitch and time, without a lot of extraneous flash. But pick one or two you really like. The more melismatic singers like Patti LaBelle or Aretha are for more advanced study if you want to go down this path. I spent two weeks with an Aretha Franklin greatest hits tape once and it was one of the best things I ever did. You should do this with your regular string bending also.

Remember that tempered tuning is not the same as the intervals generated from the overtone series of a vibrating string. Learn to hear both, so that you can play “in tune” with a keyboard or a tuner, or “in tune” with your vibrating strings and harmonics. Thirds in particular are slightly different in each case.

To develop your vibrato, start slow, with quarter notes on the metronome. Move up and down equally distant from the center pitch. Then systematically speed it up a few beats at a time. Like delay, vibrato is very effective if it has a rhythmic relationship to the beat. Don’t be wedded to this concept but be aware of what you can do with it.

Once you have all this together, if you want a real challenge, you can start learning things like bebop heads or Bach cello suites on slide. Hours and hours of family fun! But no matter how far you get, do basic intonation work (intervals sounding against a reference pitch) at least fifteen minutes a day. In my experience, intonation, vibrato, and sight reading are the musical skills that deteriorate fastest if you don’t practice them consistently.

This should keep you busy for a while!