The "right" settings for distortion pedals

Hi,

I've bought a second hand H&K TM 20 a few weeks ago. It's my first tube amp and I love it. I've chosen this amp after trying a few amps in a guitar store and when I saw a chance to get one for a good price on the internet, I went for it.

I really love the clean sound but I find it hard to get the right settings to use my distortion and fuzz pedals : I'm getting way too much bass, even if I set the bass to 0 with the EQ and by using my neck pickup (humbuckers on my Les Paul or single coil on my Stratocaster). I'm feeling like when I reach some level on the pedal, I lose the biting part to win so much bass. I can see that with pedals like an Electro Harmonix Metal Muff, an Walrus Audio Iron Horse V2, even a Fuzz Factory.

I've tried with different power soak - I tend to use it in the 5W mode - and it seems to be the same all the time.

Some kind of trick is to push really far the treble on the EQ from the H&K but when you go back to the clean tone, well, it's way too bright.

I know I'm totally new to this kind of amps and I'm not doing things properly so, well, I need some tips, tricks and advices !

Thanks.

The usual problem with H&K amps is that you get too much biting top end distortion not too much bass. Are you sure the problem is not your pedals? How does the amp sound when you drive it without them, and by that I mean with them totally removed from the signal chain and your guitar plugged straight into the amp, not just bypassed?

Most guitarists don't have a Scoobydoo about the effect of terminating their guitar cable with the right impedance but this can lead to problems just like your own. It comes down to, what is the guitar seeing as the first bit of circuitry it comes to down the cable? There will be a resistive side to that but also a capacitive one. Pickup resistance is the most pointless parameter to measure yet guitarists "just know" it is ultra important. It isn't! It doesn't tell you anything except a rough guess as to how much wire has been used in the coil. The wire thickness also affects this so, without knowing that, it makes the idea of how many turns the pickup has as guesswork. Knowing the inductance is what matters most. The pickup inductance and the capacitance of the cable and the input conditions at the end of it all create a resonant circuit. The level of capacitance tunes it to a particular frequency which you can select for your own taste. The resistive part of that sets how high the resonance is which can affect the liveliness or dullness of the sound. It doesn't require special cables at all, they are generally just another money making scam, just a couple of pointers need to be got right such as basic cable length. This all determines the guitar's top end resonance which gives it the main part of its character. Personally I don't like to play with any pedals without having my own clean flat buffer first in the chain. That way I know the guitar is being matched correctly as I have already played with subtly balancing the tone to suit the particular guitar by adding or removing capacitance and resistance. I can also drive as long a cable following it as I could ever want to do.

Another factor which is ultra important, far more important than any stuff like this month's hyperbolic valve choices and magic tone caps, is speaker choice. I would suspect this could well be a fair bit of your problem too. What are you using?

Hi Bordonbert,

Thanks for your replay.
I'm wondering if I'm not just having trouble by dealing with the gain from the pre-amp of the H&K and the gain provided by the pedals.

If I plug my strat into the amp, driving the clean channel (volume & gain) gives just more output. With the Les Paul, volume and gain at the maximum brings a crunchy sound (and kinda muddy).

I think I have "okay" cables, from the brand cordial. The first pedal is a Fuzz Factory since it can't take anything before or it's impossible to use it. Right after I have a Polytune 3 mini set with the buffer on. I can't notice any difference in the sound if I go through my pedals or straight into the amp.

The speaker is a Fame GN112 Vintage 30, so it's a 12" Celestion Vintage 30.

Still, I think my only trouble is to find unity gain with the pedals, and the good balance with the gain of the clean channel, that I need to push with the single coils. Pushed too far, the fuzz and the distortion are quickly muddy, too heavy in bass frequencies. Also I'm noticing that a power chord can be a bit too loud in the bass frequencies, but playing single notes with the same settings can show too much treble !

I guess I have a lot to learn, especially since I love to switch between the stratocaster and the les paul.

I think you are on the right road as to where your problems lie.  This involves a known area and I have advised on it many times as most people seem to be unaware of how the H&K amps actually do what they do.

You must realise that the input stage of the H&K TMs and GMs is designed to be very versatile.  It acts as a clean buffer, a clean boost pedal, a mild overdrive pedal and a Tubescreamer type distortion pedal according to the signal you put into it.  There is no switching for that, it is unnecessary.  That is one of the ways the amp has the range it has but using it needs to be learned.  We all know you have the valve stages giving their own characteristic sound which is the basis of the amp.  But you also have the Gain control set around an active solid state stage which is designed to add in its own mild overdrive if it is set high.  You then have the input stage which can be made to give TS9 type overdrive/distortion characteristics too.  These are surrounded by absolutely clean control stages, Tone and Volume, which add nothing to the signal at all.

Do not believe the muso hype, transistor/opamp stages neither add nor take away anything from the sound unless they are badly designed.  It is easy to design a SS stage to give 0.01% distortion across its whole range of frequencies and levels.  At the 0.01% level in a guitar amp that is absolutely inaudible.  The idea that they are adding some sort of "blandness" is an absolute nonsense in every way.  Any change in sound comes as a consequence of and can easily be detected as a level of added distortion.  If you genuinely can hear it then it is impossible you can't measure it!  If there is no detectable distortion, and bear in mind test gear is many many times more sensitive than ears here, there can absolutely be no difference in sound to be heard.

A very versatile chain of distortion mechanisms is a deliberate part of the design.  It means you can get a large variety of sounds out of the amp.  The mistake people make is in trying to use all of these methods together.  Distortion on distortion on distortion on distortion WILL sound dire!  You must decide what you want to hear then limit the mechanisms to give what is needed for that to be achieved.  If you want output stage saturation then turn up the MV with the Power Soak as low as you need but also keep the input signal lower and the Gain moderate.  Likewise if you want a good modern high gain sound turn the Gain high with the MV lower and still with a lower signal at the input.  If you want a classic pedal type sound turn the guitar high or use a Clean Boost pedal and adjust the Gain starting from Low until you get the right sound then adjust the MV and Power Soak for level.  Pedals added into the signal chain are meant to be a method of fine tuning the sound, not a way of creating it.  If you want a sound based on a particular pedal (or pedals) then all you need is a flat characterless amp following them.  The amp gives you your sound, the pedals simply tweak it.  You don't need to spend £/$250 on a couple of transistors to do that really.  Most pedals are simply clones of a couple of types.  All back to back diodes do the same job and sound the same.  Look up the "Schockley diode equation".  Here is a link to a nice display of this concept and how it works in the real world too:  Interactive Diode Curve.  You can see that the shape of the curve is the same no matter what the diode is and it is simply a matter of scaling to make them all absolutely the same in use.  There are no "magic mojo types", that is another myth.  A couple of caps and resistors then shape the sound and that is about 20p/¢ worth of components to get a slightly individual sound.

You will create nothing but muck if you try to use a distortion pedal(s), a high level input forcing the input stage into its TS9 distortion, overdrive the Gain stage into distortion, drive the valves into high gain distortion, then try to compensate with the MV.  There are too many distortion mechanisms to sound anything like decent.  I would strongly urge you to start with no pedals at all.  Yes, this goes against modern thinking where, if you are not using at least two high priced (overpriced that is) pedals before your amp you aren't a "real" guitarist.  Keep the guitar volume low and try each of the controls in turn from moderate settings, Gain, MV and PS individually to see their contribution.  Next turn them all down to moderate and hit the front end with a full guitar signal to hear any increase in that front end overdrive.  Then add in a Boost pedal or a distortion pedal set to lower gain to simply lift the signal level to hear the amp front end gradually kick in its full distortion contribution.

Pedals, Input stage, Gain Control stage, Valve stages, Output Stage, all add their own distortions when made to do so.  That's far too much if you try to use them all.  Keep the five mechanisms of distortion separate and only use a couple at a time, sparingly.  That way you will get the right sound without the confusion.  This is a brilliantly designed amp with a variety of ways of getting different sounds out of it.  Very few people I find ever get to the best of them by trying to be the "ultimate mojo guitar warrior" and doing everything that "common knowledge" tells them they should be doing.  Engineering triumphs over mojo every time.

Thanks a lot for your very interesting answer. I guess it would be useful for other players ending here.

For a more than a decade I was playing on SS amps, so I'm really entering a new world. I will spend more time understanding the way the amp works. I own a lot of pedals since I enjoy so many styles of music - still, half of them are in the effect loops - but I'm not looking for stacking things, getting the ultimate distortion - what is it anyway ? I know I like to be able to have access at my feet to a crunch, a good "rock distortion" - sometimes a high gain one, more in a metal style - and I totally dig fuzz. And so these different music styles that I love led me to both enjoy guitars so different like Les Paul and Stratocaster, acting differently with the amp.
I know I still have my Fuzz Factory since it's my first fuzz, but having the Jupiter V2, maybe it could leave the board. Time and tests will tell !