Boss - HM-2 Heavy Metal [schematic]
- Greenmachine
- Cap Cooler
Information
- Posts: 616
- Joined: 31 Aug 2008, 17:59
- my favorite amplifier: Fender Blackface Deluxe Reverb
- Completed builds: Electra Distortion
Roger Mayer Octavia
Klon Centaur (Bajaman/Soulsonic)
DOD 440 Envelope Filter
MXR Phase 90
DOD FET Preamp
Dallas Arbiter Fuzz Face
Soulsonic Hunny Bunny Overdrive
BYOC Analog Delay
Craig Anderton Headphone Amp
Anderton Mini Amp
Bajaman Real Tube Overdrive
Fender Deluxe 5E3 with Tone Stack Mod.
Fender Princeton 5F2-a
Keen Neovibe
Aquapuss Delay
Anderton AMS-100 Guitar Synth (abandoned)
DOD 280 Compressor
Weird Sound Generator
Beavis Audio Noisy Cricket
80's Rat
ROG Thor
Big Muff
Green Ringer
Shin-Ei Fuzz
MXR Dynacomp
COT50
Really Cheap Compressor - Location: Jersey City, NJ
- Has thanked: 87 times
- Been thanked: 17 times
- Contact:
"[Y]ou want sketchy, dude? I breadboard on a door." -- RnFR, 2011
"This amp is freakin loud, like crazy, I'm going to kill pets loud." -- mich, 2011
"This amp is freakin loud, like crazy, I'm going to kill pets loud." -- mich, 2011
- Pruttelherrie
- Solder Soldier
That's correct. Take a look at the schematic attached to the top post of page 9.slammer88 wrote:Well, i think this circuit is not true-bypassed, right ?
Q4, Q5, Q10 determine the signal path, they are switched by the flipflop around Q8/Q9.
To make it true-bypass you'd only use the part between Q4 and Q10 (actually C32), but it might end up sounding slightly different because of the extra filtering that's always in the path in the original.
- slammer88
- Breadboard Brother
or use an external millenium by-pass circuit?Pruttelherrie wrote:That's correct. Take a look at the schematic attached to the top post of page 9.slammer88 wrote:Well, i think this circuit is not true-bypassed, right ?
Q4, Q5, Q10 determine the signal path, they are switched by the flipflop around Q8/Q9.
To make it true-bypass you'd only use the part between Q4 and Q10 (actually C32), but it might end up sounding slightly different because of the extra filtering that's always in the path in the original.
- Pruttelherrie
- Solder Soldier
Sure, I don't see why that wouldn't work.slammer88 wrote:or use an external millenium by-pass circuit?Pruttelherrie wrote:That's correct. Take a look at the schematic attached to the top post of page 9.slammer88 wrote:Well, i think this circuit is not true-bypassed, right ?
Q4, Q5, Q10 determine the signal path, they are switched by the flipflop around Q8/Q9.
To make it true-bypass you'd only use the part between Q4 and Q10 (actually C32), but it might end up sounding slightly different because of the extra filtering that's always in the path in the original.
- slammer88
- Breadboard Brother
Actually i dont want to make any changes on the default circuit, as i will only follow the PCB version of it. After finishing and working it properly, i will make an external by-pass circuitPruttelherrie wrote:Sure, I don't see why that wouldn't work.slammer88 wrote:or use an external millenium by-pass circuit?Pruttelherrie wrote:That's correct. Take a look at the schematic attached to the top post of page 9.slammer88 wrote:Well, i think this circuit is not true-bypassed, right ?
Q4, Q5, Q10 determine the signal path, they are switched by the flipflop around Q8/Q9.
To make it true-bypass you'd only use the part between Q4 and Q10 (actually C32), but it might end up sounding slightly different because of the extra filtering that's always in the path in the original.
- Pruttelherrie
- Solder Soldier
In that case, leave out the parts not needed (such as the flipflop) and tie R33 (that drives the diodes to the FETs) to +9V. Or just solder in everything except for R35. (Which is a waste of components)slammer88 wrote:Actually i dont want to make any changes on the default circuit, as i will only follow the PCB version of it. After finishing and working it properly, i will make an external by-pass circuit
Personally, I don't see the need to make these things true-bypass but if it makes you happy
- slammer88
- Breadboard Brother
Actually i did not know that this pedal was not true-bypassed until my friend saw the circuit and said so. Actually i'd like to use it only with 9V Battery, as i don't have an adapter besides this will be my first and last pedal. I'm making this, because there is not any VST version of HM-2 around, only one is the one in Amplitube 3, which is however not so good at all..In this case, i'll solder everything as it has been done in the pictures, eh? And connect 9V Battery Cap instead of DC OutputPruttelherrie wrote:In that case, leave out the parts not needed (such as the flipflop) and tie R33 (that drives the diodes to the FETs) to +9V. Or just solder in everything except for R35. (Which is a waste of components)slammer88 wrote:Actually i dont want to make any changes on the default circuit, as i will only follow the PCB version of it. After finishing and working it properly, i will make an external by-pass circuit
Personally, I don't see the need to make these things true-bypass but if it makes you happy
- slammer88
- Breadboard Brother
I've got some questions..
1- The only type of pot's i could find in my city are B (linear) ones. They said it's really hard to find A (Log) ones..Does it differ that much?
2- I could not find 250K, instead i had to buy 220k. Is it ok ?
3- I will connect a 9V Battery Cap in the place of DC Output, as i want to use the pedal only with 9V..Is that ok?
1- The only type of pot's i could find in my city are B (linear) ones. They said it's really hard to find A (Log) ones..Does it differ that much?
2- I could not find 250K, instead i had to buy 220k. Is it ok ?
3- I will connect a 9V Battery Cap in the place of DC Output, as i want to use the pedal only with 9V..Is that ok?
- Pruttelherrie
- Solder Soldier
For dist. no, you'll want to run the pedal full-on distorted anywayslammer88 wrote:1- The only type of pot's i could find in my city are B (linear) ones. They said it's really hard to find A (Log) ones..Does it differ that much?
But for the tone pots you really need 10k-G (or 20k-W, see [url=viewtopic.php?p=146890#p146890] ths post by Crumbchildz and the posts above that one)
Should be ok.2- I could not find 250K, instead i had to buy 220k. Is it ok ?
Of course! The original has both battery clip *and* DC input, the DC plug disconnects the battery.3- I will connect a 9V Battery Cap in the place of DC Output, as i want to use the pedal only with 9V..Is that ok?
- slammer88
- Breadboard Brother
Well, i guess i won't be able to find G or W Taper pot in Turkey, what happens if i cant find them ?Pruttelherrie wrote:For dist. no, you'll want to run the pedal full-on distorted anywayslammer88 wrote:1- The only type of pot's i could find in my city are B (linear) ones. They said it's really hard to find A (Log) ones..Does it differ that much?
But for the tone pots you really need 10k-G (or 20k-W, see [url=viewtopic.php?p=146890#p146890] ths post by Crumbchildz and the posts above that one)Should be ok.2- I could not find 250K, instead i had to buy 220k. Is it ok ?Of course! The original has both battery clip *and* DC input, the DC plug disconnects the battery.3- I will connect a 9V Battery Cap in the place of DC Output, as i want to use the pedal only with 9V..Is that ok?
- greigoroth
- Breadboard Brother
Try musikding.de or banzai - they're shipping is really reasonable - might cost a bit but it's worth it for an HM-2!
- slammer88
- Breadboard Brother
Ok, i've got all of the parts except 0.1 Ohm Resistors, about which i've been told that i can use just a cable to get that amount of resistance I will start tomorrow and take lots of pictures
- slammer88
- Breadboard Brother
It's ready, but i cant get any sound when i plug the battery. There are no short circuits on the board, i've checked them maybe 5 times, yet it does not work. What would be the problem? I've used sockes for trannies and IC's in order to not to burn them
- slammer88
- Breadboard Brother
OK, its working now! But it lacks a little gain. I do not know why, i'm on it right now. Probably either trannies didnt sit well, or because of the dist. pot, as i only could find 220k..And i can only get dirty sound, when i switch it off, i dont get any clean bypassed sound..
- slammer88
- Breadboard Brother
ALL FIXED! Only thing is, personally, i found the gain level a little less than the original one. Its maybe because of using 220k Pot for Dist., for which actually had to use 250k..
- GodSaveMetal
- Resistor Ronker
I Have that problem wen I made mine, cuze I made the conections with a molex conector an use a pin conector 90º from the pots PCB and one of the pins have a "cold" solder; you must pay attention on that, and PHOTOS of yours!!!!!!!slammer88 wrote:ALL FIXED! Only thing is, personally, i found the gain level a little less than the original one. Its maybe because of using 220k Pot for Dist., for which actually had to use 250k..
The first time I use a B250K and is aprox the sound, the second time I used a damaged?? A250K (in the multimeter is a C250K!!!) and is exactly the original sound!! great man!!!! from 0 disto to aprox max at 12 o´clock and them max to 5 o´clock; in the original that it´s idem!!!!!!!!
- slammer88
- Breadboard Brother
No worries, i will add photos when it's done But first, i have to solve all of the problems..As i said, its impossible to find any A Taper Pot's and also 250K pots in Turkey. Nearest ones are 220k and 500k. I think i will have to use 500k and decrease it into 250k by using an external resistor.GodSaveMetal wrote:I Have that problem wen I made mine, cuze I made the conections with a molex conector an use a pin conector 90º from the pots PCB and one of the pins have a "cold" solder; you must pay attention on that, and PHOTOS of yours!!!!!!!slammer88 wrote:ALL FIXED! Only thing is, personally, i found the gain level a little less than the original one. Its maybe because of using 220k Pot for Dist., for which actually had to use 250k..
The first time I use a B250K and is aprox the sound, the second time I used a damaged?? A250K (in the multimeter is a C250K!!!) and is exactly the original sound!! great man!!!! from 0 disto to aprox max at 12 o´clock and them max to 5 o´clock; in the original that it´s idem!!!!!!!!