Boss HM-3 Hyper Metal Mods

A forum devoted to mod, tips and suggestions for upgrading and rehousing your VERY CHEAP commercial stompbox to near boutique excellence.
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thetragichero
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Post by thetragichero »

searched google for a topic here and didn't find one
bought one relatively cheap, thought maybe i could turn it into a poor man's hm2 to use for my bass. not exactly what i got, but it sounds like a good overdrive/distortion. heavy enough in front of a distorted Marshall-type circuit but not nearly as heavy as an hm2 or mt2. wanted a pedal for bass and this should fit the bill.

let more bass in: c1 47nf to 220nf (would've used 100nf but this was what i kept pulling from the bin so...)

tone stack to hm2 values:
c29 39nf to 150nf
c30 8n2 to 6n8
c31 22nf to 100nf
c32 1n2 to 4n7
r48 180k to 100k

more headroom, louder (mine didn't give the kind of boost i like in front of a tube amp): change d4, d5, d6 to led (i used 3mm green because i got 100 for like a buck from futurelec)

less tone suck in bypass (originally had the caps to complete the cornish buffer but one or both did not like being slammed by the distortion so i cut them out. still a huge improvement):
r24 10k to 7k5 (i have a bunch of these. use whatever standard value works. if 6k8 seems too gainy in bypass, go with 8k1. haven't tried myself but you could try dropping r3 to 8k1 as well)
r25 100k to 22k

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mojah63
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Post by mojah63 »

I was thinking of getting a hm3 since the hm2's are so stupid expensive now. They are not that different that you can't mod one to the other. :applause:

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thetragichero
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Post by thetragichero »

it seems fuller/more mids than the hm2, which is not a bad thing
did some recording with it with my mockingbird through a jtm60 head (the head is super bright). everything dimed except distortion, which was at zero (didn't like what it added... maybe I'm not totally done modding lol), everything dimed on amp. have some great thrash-type tones, which was what i was going for

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Gila_Crisis
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Post by Gila_Crisis »

I love the HM2 fuzzy sound (to cover this I have an Earthbound Throat Locust), but once I also got for cheap a HM3, which i love a lot too, same very earthshaking lowend as the HM2.
I like the high control having a different range than the HM2, but in order to have that same mid hump, if needed, i added a switch, which put 2 caps in parallel on one of the gyrator:
C31 // 82n
C32 // 3n3

This way the tone is more or less in the same HM2 range.
Zwischen Ordnung und Chaos fangt die Musik an

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thetragichero
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Post by thetragichero »

i made a YouTube demo before i sold it

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