Hughes & Kettner Cream Machine

[Carlosraj]

Dear Friends,

A local musician and a friend of mine brought a Hughes & Kettner Cream Machine guitar amplifier and ask me for help to modify the amp by adding in the Bass, Mid and Treble tone controls, since the amp has no tone controls. Can some one please give me clues or ideas how to modify this amp. I have attached a schematic of this amp.

Please Help

Carlos Rajoo

 

[JMFahey]

Not impossible, of course, but "very" impractical, for various reasons:
1) to begin with this is not an amplifier but a distortion pedal.
2) it *does* include a small, way less than 1W (probably around 250mW) "power stage" but it's meant to add "power tube distortion", not meant to be used to play to an audience.
Well, a few ants might consider this Woodstock or something
You can also plug, say, a 4x12" into it, mike it into a recording so you include speaker sound (good idea ) , and add all EQ you wish "in the mix", all this being done in an appartment at 3A; without disturbing the neighbours.
3) you don't have the physical space to add those pots plus the necessary extra tube
4) it's not a "flat" circuit by any means, it has been carefully tweaked (H&K know their trade) to get a killer high gain distortion sound , still clear and fast, without mud or shrillness.
Since all tube stages are clipping (and probably the last driving Op Amp too), adding a lossy passive tone control (say, a Marshall type one) will mess with everything, in a bad way.
In a nutshell: leave it as is, EQ it in the mix if recording, or use the reamping tone controls if used as a pedal or if you feed it straight into a PA, add a 31 band EQ after it and create **killer** sounds.
Excellent pedal, use it as the creators meant and you'll be happy.

And if you want to use it as a 3AM bedroom amp, just plug it into a good cabinet (a single 12" Celestion is fine) and shred away.

 

[sonofspy]

Of course you can do this!

The Cream Machine (I own one) is full 1Watt complete tube amplifier
with a 12ax7 as the preamp and a 12au7 for the power amp.

It is no distortion pedal!

Here's a mod to add a Marshall style tonestack to the Cream Machine with
bass, mids, and treble...
Google Translate

*Please note that a requirement is to change the master volume to a 500K audio (log) taper pot.

Those of you who think you know it all are very annoying to those of us who do!

 

[tibrocks]

Hi All and sorry to post in an old thread - just a quick question if anyone can recommend the best way to lower the gain on the Cream Machine?

The NE5532 has too much gain for my taste, any way I can lower it and let the preamp tube do the work?

Thanks!

 

[PRR]

> The NE5532 has too much gain

Op-amp gain is ALL about the resistors.

In this case, ratio R4/R6, or R3/R2.

Try R6 or R2 twice as big, or bigger.

 

[tibrocks]

> The NE5532 has too much gain

Op-amp gain is ALL about the resistors.

In this case, ratio R4/R6, or R3/R2.

Try R6 or R2 twice as big, or bigger.

Thanks for this, should I change both R6 + R2 with bigger values or one at a time?