HMP Rat Version

[Cliff Schecht]

I recently built the HMP, not the Lite, and was curious of a few things:

1) Where should the trimpots be set? I haven't noticed much difference no matter where they are set (Except for the drive trimpot off of the second set of diodes)

2) How can I get more drive out of this thing? I like how it has good distortion, just not enough, and is obviously capable of the crunch some friends of mine are looking for.

3) Does anybody need a layout for this? I have a PDF that I made if anyone is interested.

4) What should I build next? I'm looking at the J. Davidson Blackfire and Obsidian, both look like cool circuits.

[MartyMart]

Hi Cliff,
a layout would be nice !
I started a HMP 'ages' ago and got distracted by other things ( vero-layouts etc ) so its not done yet !
I have layouts for the "Vulcan" and the "Blackfire" in my gallery above.
They are both very nice "heavy metal" drivers, for me the "Blackfire" is
the better choice ...  :twisted:

Marty.

[col]

I think that this is the circuit I spent ages doing a stripboard layout for and when I finally finished it I couldn't get a sound I liked out of it! The distortion was very good but there were too many pots and trim pots to adjust and in the end I re-claimed everything I could off the board and gave up.

[RDV]

The trimpots should be set to taste. The trim for the Q of the parametric should certainly do something. Turn the gain almost all the way down and volume all the way up where the pedal acts as a clean booster and you should be able to hear what the parametric does much better.

As for gain, there's a ton, but I also had running the thing into a slightly distorted amp in mind when putting it together. All pedals sound different on all different rigs. A booster in front might do what you want, or even build a front end gain stage if you want.

If you've come up with a different PCB and layout, I'd certainly like to see it. My email is available on my little website.

RDV

[Cliff Schecht]

As far as driving the thing is concerned, I have EMG's in my good old [img=http://www.ibanezrules.com/catalogs/us/1993/r_2.jpg]ibanez[/img] (the tobacco sunburst one) and Phat Cat's in my 70's ES-335, so yeah, a booster might do the trick. Also, I've been running this into a '59 reissue Bassman on fairly low volume, so yeah, no distortion from the amp. Maybe I could get some cool sounds from a not so clean boost... Who knows... Time to play!

As far as layouts go, I happened to @#$% up one part and put the 4558's backwards, so they are basically mounted on the copper side of the board. Should be an easy fix. As for now, I'm off to show my little brothers guitar teacher a tremelo he asked me to build. Up, up, and away!