Python

Classy, warm, smooth tone hug

 

 

 

The GT Python compressor rack effect module compares to the Boss CS-2 Compression Sustainer pedal.  This 80's MIJ classic is still loved and used by many, including David Gilmour.  It is often described as smooth, warm, and musical, providing natural, subtle compression with an acceptable noise level.  

 

Description

The Boss CS-2 Compression Sustainer pedal is a classic among compressor pedals.  The controls are simple and the overall compression and sustain are considered more natural or musical sounding than many other compressors.  The circuit is similar to the older Ross and Dynacomp circuits but differs in several ways to make it unique.  The CS-2 pedals were built from 1981 to 1986.  The CS-1 which came before and the CS-3 and others that came later are different.  Fans of the CS-2 still seek out the original vintage pedals, which have continued to be used by top artists for decades.

The GT Python compares to the Boss CS-2 Compression Sustainer pedal.

Compressors are sometimes described as the effect you shouldn't be able to hear when they are used correctly.  Perhaps compressors would be better described as the effect that makes your playing sound more like you intended it to sound.  Of course, guitarists have a variety of experiences and opinions about compression in general, as well as specific compressors.  The Boss CS-2 is no exception.  Some think it is the best compressor ever, others aren't so impressed.  We have a theory that compression is more specific to your setup and playing style than other effects.  If you have a relatively quiet rig and relatively smooth picking and strumming technique, a compressor may be more subtle.  But if you have a bit of noise, the noise can be made worse.  Or if you have a very dynamic picking/strumming style, you may not think the compression is at all subtle.  Perhaps the less you need it, the better it works...?

The one thing we know for sure is that the debate will continue.  To our ears, and with our setup and playing style, the Python is subtle, adding a very warm, smooth, and pleasant polish to our tone.  We can't tell it from our original MIJ CS-2 pedal.  It seems like both the highs and lows are very lightly trimmed to help smooth the tone.  The Attack, Sustain, and Level controls are all familiar to compressor users.  The Attack controls how quickly the compression begins.  Sustain controls how long it acts.  Level is a basic volume control.  If you turn up the Level and or Sustain to the point where you are boosting the signal, then there is some increased noise.  But if you keep Level and Sustain closer to noon, there is little to no added noise.  The full range of Attack is reasonably subtle for us, but you may well have a different experience.  Also, as with most compressors, if you increase the Level, you may get some clipping distortion.  If you like the CS-2, but you find it clips a bit much with your setup, you might want to try our option to run it at 12V for a bit more headroom.  Once you try it, It's easy to see why David Gilmour uses the CS-2 to feed some of his amazing, smooth, and sophisticated fuzz and drive tones.

Roland/Boss began long ago to use custom chips in their circuits.  The CS-2 uses a custom chip they had built by Rohm, the BA662A.  That chip was made only for Boss, and they were used in several different pedals until newer, better chips replaced them.  Since they were proprietary, BA662A chips are not available the way other vintage chips are.  For many years, there was no way to buy them (and there still isn't), so clones and derivatives of the CS-2 circuit are even more rare than the CS-2 pedals themselves.

But it turns out that the BA662A chip is nearly the same as another Rohm chip, the BA6110, if you include some extra components on the board.  There is no audible difference between the BA662A and the BA6110 with the extra components, assuming of course that you add the extra components correctly.  The BA6110, even with the extra components, is usually available, although it is also a vintage chip.  

There are also newer, current production chips that do the same thing as the BA662.  Among them are the LM13600 and LM13700.  The audible differences between the original and newer chips are small enough that you shouldn't be able to tell any difference from the original BA662A.

And finally, you can find reproductions of the BA662A.  That chip sounds like it does because it has over a dozen closely-matched transistors built into the circuit.  In fact, that's about all it is.  Those same transistors are still available in surface mount form, closely matched.  You can (at least for now) purchase a small board with all the right stuff built onto it to produce a BA662A clone that essentially is a BA662A.  The sound is indistinguishable from the original, but there is some extra cost.

In our Python module, you have three choices for the replacement of the BA662A chip.  They are described below - just pick the one you prefer.  We have also changed from the old Boss power to standard 9V operation, which is what the original used internally.  If you want more headroom than the original pedal had, we can use 12V instead.  Of course, the Boss pedals are famous for being in your chain even when they are off.  When our modules are off, the effect and buffer are out of your chain.

This circuit works well for bass guitars, but you may want to consider the Bass mod below.

 

Configurations

  • Python - Compares to the Boss CS-2 Compression Sustainer

 

Options

Note:  In the picture above, the discontinued Switchable More Bass option is shown.  We still offer a More Bass option, but it is not switchable (see below).

  • 12V Power - Like most compressors, if you crank the Sustain and Volume you'll likely get some clipping distortion.  By default we use 9V power, like the original pedal.  If you want more headroom, maybe a touch less distortion, we can use 12V instead.  This may help with bass or hot/active pickups that might normally overload a CS-2 pedal even at lower Level and Sustain settings.
  • Chip Choice - As noted above, you must choose a replacement for the BA662A chip in the circuit.  By default you'll get LM13600 or LM13700.  The choices are:
    • BA6110 - adds some extra components with the BA6110 to make it work and sound like the BA662A
    • LM13600 / LM13700 - current production chip, should be indistinguishable from the BA662A .  Either one works fine.  You get one of these if you choose the Baja Mods option.
    • BA662A clone (when available) - we have a supplier that builds the BA662A internal circuit on a surface-mount board using the correct surface-mount components, the same components built inside the original chip.  Virtually identical to the BA662A.  Indistinguishable from the original.
  • Baja Mods - There is a "Baja" or "Baja Mods" CS-2 Compression Sustainer that you may have seen.  It is one of the few attempts to clone the original CS-2 pedal.  It uses the LM13600/LM13700 chip to replace the BA662A.  It has a few tweaks to the voicing, Attack control, and uses some different transistors (little to no difference).  If you know this circuit derivative and like it, select this option and you'll get those mods.  
  • Modern Components - Except for the Baja Mods option and BA662A replacement of your choice, we use components selected to be quiet.  We also use the same transistors and diodes as the original circuit.  Those were all "nothing special" parts.  If you would like for us to use modern parts instead, we can do that.  The result may reduce the noise level a small amount, although the circuit is not normally that noisy to begin with, at least compared to other vintage compressors.  The modern parts cost a small amount less.

 

Front Panel

  • On/Off indicator LED
  • Attack control
  • Sustain control
  • Level control

 

Rear Panel

  • Audio In
  • Audio Out
  • On/Off Footswitch
  • On/Off Override
  • DC Power
  • DC Power LED

 

Module Width

  • 1.5", with 2" left and 1.5" right wing configurations also available

 

Power Consumption (aprox)

10 - 15mA

 

Base Configurations

Part # Description List Price
MOD-PYTHON Python Compressor module  $224

 

Options

Part # Description List Price
MOPT-PYTHON-12V  12V Option  $0
MOPT-PYTHON-BA6110 Use BA6110 chip $5
MOPT-PYTHON-BA662A Use BA662A chip board $20
MOPT-PYTHON-LM Use LM13600/LM13700 chip $0
MOPT-PYTHON-BAJA Baja Mods -$5