my hm-2 mods heavy metal scooped mids mod

[Quackzed]

I havent really researched any other mods people have written up other than removing the in-line diodes to get rid of the crossover distortion.
but here are the mods i did to mine after reading up on gyrators at geofex. thanks R.G. !
search for the 'Simple, Easy Parametric and Graphic EQ's, Plus Peaks and Notches' article. good stuff!
and also thanks to amz for their online gyrator calculator. very helpfull.

and the mods...
1. jumper across d6 and d7 ,this is the popular jumpering of the inline crossover diodes. removes the 'unique' fizzy dist of the hm2
2. remove d3 d4 d5. . gets rid of smoothness or mellowness and adds edgyness. basically takes the slight tubescreamery dist out of it.
3. add a 1n4148 diode in series with d9 (same direction as d9) also add a diode in series with d8(same direction as d8) more volume/ vry slightly less dist
4. remove c27 (.0068uf cap)<we'er gonna re-use it in mod #7>  this 'basically' makes the mid gyrator peak/notch into a full bandwidth boost/cut...
5. replace r44(100k) with a 51k or 47k whichever you have, this and the next mod widens the peak/notch to @ an octave and sets the center freq @ 850hz
6. replace r45(330) with a 1.5k resistor
7. place a .0068uf cap (from 4.) and a 10k resistor in series, doesnt matter which is first/second in line, and place this string around c16(.001) cuts a bitof fizz

[Quackzed]

so those are my mods for a more modern scooped tone from a hm-2 pedal
basically i used the high gyrator to create a wider more modern recto type mid scoop
it still has plenty of mids and high end available from noon to max but from noon to min it has a wider palette of mid scooped tones available.
the bass pot still acts the same though i may widen that in the future. but its much meaner sounding now. less harsh and can get dark without being muddy
came out pretty good.
also removing the feedback loop diodes gave it a less mushy tone. better without as a high gainer.
btw if you want to try making the bass knob q wider or widen the bandwidth of these type gyrators you just (looking at the bass .068 gyrator) halve r51(100k)
and double r47(330) so you could make r51 a 50k and r47 a 660 ohm. this is basically what i did with the 'high' gyrator, though not exactly as i also wanted to move it lower in the frquency band... mess with the amz gyrator calculator and cross reference Q to octaves for a visual idea on how wide any q value is in octaves.
anyway, figured i'd post what i ended up with for posterity or if any of yehs wanned a moah modenah mid scooped dool rectafiyah typah tone outta yuh hm-2
\m/      \m/
                 

[pinkjimiphoton]

any clips possible bro?

[Quackzed]

sure, i bought me a tascam digital recorder so i could record my bands live stuff.
i'll try and post some clips tonight if i have time. tho i dont have any before recordings for reference,but if you're interested you probably know what the stock unit sounds like anyways... those gyrators are pretty cool once you get how they work (i only kind of do) in your head. in so far as they can do a hefty notch or boost, much moreso than your average 6db per octave type passives. 

[pinkjimiphoton]

cool, would love to hear it!

i just got one of these off fleabay, had planned on modding the hell out of it cuz as i recalled from many years ago i couldn't stand 'em, but had heard some nice demos of the pedal after some
mods..

i kinda dig it stock, which really surprised me!

[Quackzed]

i meant to get some clips up the other day, but had some fun car problems (whoo hoo) all fixed tho. and between that and some other things i didnt get around to it yet. so sorry for the wait.
and yeah actually there are some decent tones available from it stock, though usually with the eq set crosseyed or nearly so, at the extremes the eq pots get a bit peaky and imho the majority of the eq settings tend to be real treble heavy... ill get some clips up tomorrow for ya. least i can do after all the nerdy fun ive had watching your stupid pedal tricks. and if you do end up modding it or tweaking it a bit i can probably help to shed a little light on those weird gyrators it uses for eq. apparently those gyrators show up here and there in the 'metal' genre pedals, like the metal zone, hyper metal, fab metal, and probably other pedals in that genre... after all the word gyrator is spelled funny and that makes it pyrfekt for metyl right?

[pinkjimiphoton]

\m/ \m/

[Quackzed]

o.k here we go, clips of my hm-2 mods as posted above in this thread, for my man pinkjimiphoton!
btw these are the mods i mention in this thread, i did more than just remove the in-line diodes and feedback loop diodes, see above.  
sorry if its a bit lengthy, im new at this kinda thing, in the future i'll try and hone it down a bit.
the first half or so is with the bass on 12, not really bassy enough imho, so most of the heavy scooped sounds (lows cranked or mostly cranked) are toward the end of the clip fyi
but i wanted to put it through its paces and give a more broad ranged idea of the eq options...
i also had the pedal volume kinda low here and i noticed theres definately more bass available at higher pedal volume settings so the clip isnt as bassy as the pedal gets when you turn up the volume more, just listened and noticed the clip isnt as bassy as in real life, maybee its my amp so if it sounds a little lacking in the bass, thats probably because the volume was set pretty low on the pedal or my amp or my recorder, but its got lotsa bass in real life!
https://www.dropbox.com/s/zg0rqs3u1a0idgj/quackzedsHM2mods.mp3

[pinkjimiphoton]

thanks bro!! this sounds the same..but different, way more refined kinda....no fizzy crappy spam suckin' trailer trash tone.

much warmer and more realistic sounding... nice!!

gets brootal with the lows up!!! nice!! sounds a lot like a mesa studio pre i molested years ago...

and it lost that nasty nasal tube screamer on steroids sound.  i likey!!! at about 4:52 ...hot DAMN!!!!!

one more thing to add to the list of things to play with and mod, thanks quackzed!!!

[Quackzed]

no problem pinkjimi! and also in case you missed my updated post, in real life theres actually more bass and its a bit beefeier than in the clip...
and yeah the nasaly ts vibe is gone now. it definately gets pretty brutal and has bass and scoop to spare!
cheers!

[korgat]

I can't download sound sample. Would you re-upload it, please? Greetings!

[Quackzed]

here ya go! sorry bout the wait, i missed that i had mail...
i think i took it down when uploading a bunch of band shtuff, buy i still had it tucked away, i think this'll let you play the file without a soundcloud account etc... post in here if you have any trouble getting it...

https://soundcloud.com/gil-feeney/dr0000_0058mp3

[korgat]

Wow! Thank you very much, mate!
Soon I will get my custom (from Ian Rajder) hm2 + your mods. I will post it here, when it will be done. Cheers!

[Quackzed]

  cool man! hope you like it!              \m/ \m/

[Agung Kurniawan]

If you brave enough, I have a massive mod for this HM-2.
1. Remove the mid-freq gyrators
2. Set the high-freq gyrators to 5Khz or 7KHz
3. Add a sweepable mid-freq tone control. You can use anything as far as it has a variable freq. You can parametric with variable Q or use a Wien Bridge like MT-2 does.
4. Pick the last opamp section of the Zoom Trimetal (also, pick the gyrators on the +in on the opamp)  and add it into your last section on the HM-2 signal chain. Add a spdt switch to enggage or bypassing this section

This mod will give you a rich tone from your HM-2. You can dial the tone from a nu-metal to the almighty progressive metal genre. I have do this one to my own distortrion pedal design, I call it 'Metal Monsters'. And I tottaly like the way it sound. Its more brutal and wider than my MT-2