Sunday 23 October 2011

Even More Hazarai!

Modifying the Electro Harmonix Stereo Memory Man w/ Hazarai delay pedal for external tap clock. A follow-up to this post.

Two years on from blogging Rechner7's project, I've finally modded my SMMH, a delay which features heavily in my recordings and live sets. I'd never found the original tap tempo function a hindrance to getting interesting echo, but was inspired to give the mod another look after seeing Mr Biggs' video of his project. I'm glad I did, as the additional inputs have yielded a few surprises.

Here's how it sounds: smmh_mod1.mp3

I kept my mod simple, adding one external clock jack, a three-position switch (on + HP filter, off, on without filter) and a softer response tap button. The internal changes consist of Ken Stone's Gate to Trigger and Doepfer's Gate to S-Trigger circuits. Here's my perf-board layout. As r7 originally warned, the most difficult part of the operation was removing the PCB from the enclosure. After a few frustrating attempts, I gave up, masked the PCB with paper and drilled my holes with the board in place.

So, was it worth it? Yes, but not for the reasons I originally assumed. While tempo-syncing is nice, I actually prefer the sound of echos which are not perfectly in time. The new momentary switch was a last minute decision and I'm glad I added it. It's less clunky than the original foot-switch and makes tapping easier. That doesn't mean the clock input is redundant - it comes into its own when fed with random gates, for example from a tail-chasing Wogglebug.

As you can hear, this is where the real fun starts: smmh_mod2.mp3

Thanks to Rechner7 and Mr Biggs for answering my questions and for their encouragement. It's a simple project that helps integrate the SMMH with the modular, so highly recommended. As ever, the usual disclaimer applies: modding you pedal will void your warranty and is carried out at your own risk!


Anonymous said...

neat. does work with 'record' / in loop mode as well?


Navs said...

Thanks. Yes, the switch routes the gate to the gate-to-trigger circuit or bypasses it.

Jan Dybala said...

Thank you so much for this post :]
I tried to do this mod and had some difficulties, now with your layout it becomes very clear.

Is there any specific value or number for the NPN and DIODE you use / or it doesn't matter ?


Navs said...

Glad it helped, Jan.

I think Doepfer names some NPN types on their S-Trig/ DIY page but, no - no specific values.

Jan Dybala said...


Neal Beard said...

Holy moly- whilst accidentally tapping a previous post button reading your blog I came across this post. Externally clicking the ehx mm is something I've thought about for years, but not thought possible! Will definitely try this mod. Thanks for sharing. Love your blog by the way. Very inspiring! :-)

Unknown said...

Hey, your sugar sync files [your perfboard layout, and a zip file on a previous entry] aren't available anymore. Can you re-post?

Navs said...

Layout link fixed. Which ZIP/ blog post? Let me know and I'll sort it, ta.

Unknown said...

Thanks a ton!

The broken zip file is in this post: More Hazarai! EHX SMMH Modification

Navs said...

Ah, it just contains a few more pics and the MP3s, which were also a Sugarsync casualty. Anyway, re-uploaded and link fixed!

benjamin said...

hi, would it be possible to repair the broken links to your perf board layout and the .zip mentioned above? thanks!!