Folks are correct saying that the "ACA" pedal works on 9V internally. The Boss "ACA" supply has a higher voltage and the "ACA" pedals reduce that higher power input to ~9V internally. Those pedals work about the same on a (fresh) 9V battery as they do on an ACA power supply. The old Boss ACA power supply is NOT regulated and can be anything from about 10V to 14V depending on how much current the pedal draws, variations in the mains voltage, etc., etc. The ACA pedals were specifically designed to handle that variation in the voltage. The later Boss PSA power supply is a regulated 9V (or actually 9.6V...) that hardly varies at all with changes in load current or mains voltage. Old "ACA" pedals usually work reasonably on a regulated 9V supply, but are running on something below 9V internally: The dim LED is the clue to this. Pedals that were designed for 9V might or might not "be happy" when run at higher voltages. Some won't care, some will sound different, some will decide you aren't their friend and will never work for you again. If you plug an ACA pedal and a PSA pedal together into the same 9V supply, the patch cable between the pedals basically bypasses the circuitry in the ACA pedal that drops the power voltage from ACA level to 9V, which is why that seems to work... but it means you are also transferring a little bit of power through the patch cable between the pedals, which isn't a great idea for good sound. Each pedal really should have its own isolated power supply, with the vintage ACA pedals given about 12V and newer PSA pedals (and other brands) given 9V. And then there is the whole argument about vintage fuzz pedals and dying batteries and driving them at even lower voltages from a supply with a "high" impedance... For some pedals this may sound better to some people, but I get the impression that it varies with each individual pedal in the same kind of way that those old pedals each sounded a little different. You need to experiment with each pedal individually to find the sweet spot that sounds the way you like. And that is a whole different discussion. I have a few pedals, including a vintage Boss chorus that needs an ACA and a newer Boss compressor that wants a PSA. I am currently going through the exercise of building a multi-output isolated power supply with a non-regulated ACA output for that chorus, a bunch of regulated 9V outputs for most others and a variable output for experimenting with things that might care...
Thanks for the info. Are you designing your own circuits, or are you following a schematic? I've got 3 or 4 Boss ACA pedals, and they're a pain in the ass. Am I okay sending them 12v from a regulated power supply? What is a regulated powersupply, really, though? Okay so it is regulated, how is that actually achieved at the circuit level? And do you have any links for pedal power supply tech information? I'm searching for 9v dc wall wart powersupplies with really low ripple readings. Also, what is the deal with those transformerless 9v dc pedal powersupplies? How do they work? Are they noisier? Do they work better or worse for use with pedal powersupply daisy chains? AND one last, if you've hung in there. I recently purchased a EHX 9.6v DC powersupply (several) to power a couple JHS inspired Behringer pedals I finally got, like actually got, after ordering them 15 blood moons ago, actually still waiting on the Super Fuzz, it's supposed to be in the mail... tracking, it is one state over, supposed to be delivered today. Fedex has been sucking lately, like in the last couple years, just blowing past their delivery deadlines like they don't exist. Holy cow, I think all the prescription drugs are fighting it out in my swiss cheese brain. Okay, so here is the actual question, if you've somehow hung in there: When I plug the Behringer Ultra Vibrato into it's own EHX 9.6vdc powersupply, into a "powerstrip" and I plug the B-ringer Ultra Chorus into its own EHX 9.6vdc powersupply plugged into the same powerstrip, I hear the craziest sounds. One of the two pedals, or both, I haven't been able to isolate the issue to which pedal, it could be either or both, but they make these occasional zipper noises, and they're not discrete, they're only like a second long, and they go zzzziiiip-ererer-piiiiizzzz. I have an old Alpha Juno synth and something in the BBD of the chorus is going bad, either a timing component, or one of the buckets itself, and it "kind of", loosely speaking here, kind of makes the same sound when the chorus comes around to that particular bucket in its chorus cycle. Unfortunately, both B-ringer's Vibrato and Chorus, I imagine, use similar signal delay components. Anyway, if I remove one of the pedals, the remaining pedal will not zipper. Any help for what is causing this, and why removing one stops the other from making this sound? I assume it is a grounding issue? But I don't know enough and can't imagine how some component of one of the pedals is periodically creating this audible signal, that is going backwards, down the ground into the shared ground of the powerstrip, and then from that common ground, up through the other powersupply into the other pedal, and that zipper signal is then making it into the actual audio signal? Or is some signal just coming into the common ground, coming up through both powersupplies, making it into the And if I may, Chinese gang pedal power supply sellers, like the Caline CP-4, or whatever, always say their power outputs are isolated, sometimes they're even printed on the box itself, but they're not really isolated, right? Again, what does it mean to actually isolate a powersupply in such a way that it won't cause noise issues, I think it means that each individual ground is isolated, but I can't imagine how you can isolate a ground, when all the different power outputs from a gang box have to all share the same ultimate ground, I mean, they are all only connected, and have access to one ground wire. So, however it is, these Behringers need to be isolated, STAT, as I'm LOVING the Vibrato, thanks Josh (though just saw a video from him made in June, he fell into and participated in the anti-white agitprop, so that's fun), the Vibrato really is great.
i bought an HM2 for £65 the other day thinking i'd scored a bargain but I plugged it into 9v and it was weak, crapped-out and glitchy. I really thought I'd bought a dud and lost my money. Then I found this video and the pedal has transformed into a harbinger of the apocalypse! It would never have occurred to me to use 12v, so thank you!
I thought the same thing. I was like I know my first one didn't sound this bad 35 years ago. The led didn't work either. So I unplugged it, and put a battery in it and there it was the sound of my youth, the sound of the first pedal I ever bought. Couple hours later I find this, finally I have a use for this rando 12v adapter layin' around, cool thanks Ryan.
These pedals actually are powered by 9V, but there is a resistor and a diode taking 12V down to 9V inside. If you put a 9V supply in then you actually end up with about 6V. There's an article if you look up "boss 12 to 9 volt conversion" showing the component numbers. You can solder the two connections together on each component to bypass them, and it's a 9V pedal now. Takes away the option of the starved sound, but some of the other distortions didn't sound too good on the lower power. I think I left this comment on the last video, awesome that you posted a new video on it. It's weird how many people don't know this, given how popular Boss pedals have always been. I guess most people just ran them on the battery, which bypassed the internal voltage limiting. As for why it's an EQ thing instead of a gain thing, I'm fairly certain it's because the tone stacks in both pedals are both somewhat active and are driven by an opamp (three opamps in the HM2). Both the tone stacks interfere heavily with the mids too, which is probably why that shifts the most. Anyone else who knows more please tell me, as I'd like to know too.
Hi I will try to help you here!!! Before i start,i will ask sorry for my bad english :) First thing the gain of an op-amp depents on the passive components and mainly from the resistors between the input and output of the op-amp... so that's why more voltage doesn't change the gain ... what more voltage do is giving the op-amp more bandwidth. What i mean? Real op-amps have frequency response like a low pass filter and the higher the voltage the higher the cutoff frequency . So that's the reason behind the eq thing ... more voltage means higher frequencies can be amplified.
@@spirosmexias950 That's what I was thinking! Good to know I was on the right track. Also don't bother about your english, you already know more about language than most english people.
I LOVE the HM-2. I lost mine many moons ago, then I got an Arion Metal Master which is a direct clone. I use it all the time. Check out Arion, affordable but legendary!
My HM2 got stolen decades ago and I bought the Arion because I had a show that night... freaking LOVED it. I traded it for something somewhere along the line, still have my Arion SOD1 though. That is a great pedal as well if you can find one cheap. Mine currently is in the shop because after 30 years the output Jack got rattled loose and it loses signal randomly. Not bad for "plastic junk"😉
HM-2 was my first pedal ever, bought new in 1987. Still have it... though my son has adopted it onto his board. Love that pedal. Mine was always operated voltage starved, because I ran it on a 9V battery for the first 10 years I had it, and on a 9V adapter after that.
I got an HM-2 years ago to get that Swedish death metal tone. I had no clue about the 12V power and sure enough, mine says Boss ACA power only. I'll have to try this too!
Interesting. I have an old HM-2 that wasn't working, so I gave it to a friend (who builds/fixes pedals) to take a look at. He said it needs to run on 12V and when he did that it works fine. 9V, nothing. Odd...
Thanks for the vid. I was wondering why my HM2 was behaving the same way when using the Ispot pro PS. Toggled from 9V to 12V and bingo, the led lights up nice and bright! Have an 80s Tokai Delay pedal and that did not need the 12V boost.
Check for my comment if you can. Basically there was a diode and a resistor taking the 12V down to 9V internally, but the battery wasn't connected to that circuitry, and was allowed to run it's full 9V.
This video demonstrates why I run my self-built rat at 18 volts and with LED clipping. The sound is just clearer, bigger, and less "crushed". I also feel like the pedal is more responsive with pick attack.
I've currently begun a series on my channel with an ALL BOSS 'Affordaboard' keeping it $100 or less per pedal on (primarily) the used market. Been very exciting learning about so many different offerings (and power requirements, BF-2 Flanger is also 12v). The HM-2 is very cool, but unlikely I will find one at 100 or less. That being said I've got some vintage circuits coming that fall under that $100. Check it out! Love your vids Ryan and this is uber fun learning about the differences in power/sounds on the HM-2.
Definitely, on 9v there are larger "grains" of distortion, you know, like in Rat. 12v sounds noticeable smoother. I like both options and curious is it possible to do the trick on modern hm2's? Should you lower voltage to make it sound more raw?
Seems like you could get the 9v sound with the 12v power supply, just by tweaking the gain and eq. If so, that would be the best of both worlds solution, would it not?
So many players chased the starved amps with EVH's attenuator ... now the chase is on for boss starved pedals started by Ryan. Actually, there always was the 'worn out 9v battery' chase. The problem is going to be all those players that get 12v power supplies and end up burning out all their boutique 9v pedals that were never designed to handle more voltage.
Well, poker-style, I'll see you 'I wish not to lose anonymity', and I raise you a double switching affair that relies on two - YES TWO! - LEDs of different colours which indicate the mode! One mode is the face value of the knobs, the other is a STRAIGHT LINE TO SWEDISH CHAINSAW!. And what you do to switch between is a Taylor Swift double-tap to change between rhythm and solo.
"only" a chsinsaw if you run it into an overdriven amp.thats yh whole chainsaw tone...into an overdriven amp.there us NO chsinsaw if you run it into a clean amp.none at all.zilch.
NOW I see WHY the HM2 sounded like crap back in the day! 9V battery! 12V just opened it up! I can hear it now! It's not just brighter, the clipping is better, not as ratty/sputtery! It's smoother! The OD2 was the same, better clipping character! Seems they were built with some W I D E power tolerance!
@@DMSProduktions But when you plug 9v into the jack the pedal gets 6v and if you plug in 12v it ends up at 9v. 12v is therefore the same as with a battery.
i've never really liked the SD-1 but i thought that sounded super dope when you had everything dimed, i swear all Boss gain pedals sound the best (to me anyway) with everything up full
Is this why your stuff was squeeling when you unplugged things the video you compared everything to the HM-2 My power supply has a 12v in between the row of 9v and the 18v I always wondered why.. Hiree with a bunch of LED and AC plugs on top. So I guess I need a BOSS pedal now.
It would be kind of awesome if, along with the Waza HM-2s, Boss also reissued the non-Waza HM-2s Also, idk if u have a Marshall amp there, but, you an HM-2, you have an SD-1, and I see a Cherry Sunburst Les Paul in the background...you have a Euronymous setup (at least according to Circle of Tone)
My Chorus pedal of choice was always the CE-3..Sorry CE-2 fans, I know it’s just me. Anyways, it runs on 9V through a daisy chain cable from other pedal(led is on)..However, it doesn’t sound as crisp and it makes some noise if you put it before a looper(which needs more current). My conclusion:ACA pedals sound best with either 9V battery, or 12v center negative adapter. Thank you for this video-you are awesome.
I think I like it more with the 9v power supply. More muddy/fuzzy sound. Does anyone know if the sound of the HM-2 with daisy chain at 9v is the same as HM-2 with 12v power supply?
I am surprised the ACA PSA difference was so misunderstood. The pedals clearly say what they need. If you are reading this you have the internet at your disposal to learn the difference. There is sufficient information available to learn how to convert an ACA pedal to effectively have a PSA power input. EHX 9.6V choice is interesting. A brand new 9V alkaline battery is typically 9.6V. I broke down a couple of years ago go and got one of these expensive multiple output power adapters when I got tired of replacing batteries. Some pedals draw enough current that a brand new battery is only good for a couple of hours. The one I got happens to have a bunch of the outputs that are switchable between 9V and 12V. Honestly, I have not looked back since. One thing to note is that some brands of power cables that go from the power supply to the pedal are better than others. I found that some pedals generate noise even when disengaged unless the better cables are used.
Boss Metal Zone pedal was the first pedal I bought and eventually one of the channels burnt out. I don't know why I didn't try and fix it but I was a teenager so, I guess I answered my own question
They all run off 9V batteries. ACA pedals have internal voltage divider to lower the 12V from the ACA adapter to 9, so from a 9V PSA adapter you only get ~6V to the pedal.
RYAN, I think your Boss HM-2 sounded differently because the vintage DC needs 12vdc to convert DOWN to 9vdc but you used 9vdc so it "down converted" to 6vdc which the ChainSaw EQ sounded more Midrange because the pedal only was operating at 6vdc instead? let me know
@@60CycleHumcast When using a 9vdc power supply with a vintage ACA 12vdc Boss HM-2 pedal it should sound more fuzzy because its down converting the 9vdc to 6vdc so the operating point has shifted down causing the HM-2 to be starving voltage fuzzing out.
i always like the 5-6v sound. Lol I couldnt afford the power adapter so i had lots of half dead 9v batteries laying around back in 85'. Though when i got an adapter i ran 12v thru it. Their is a noticeable difference between the 80s and 90s HM2's IMO.
Might be a dumb question but I want to use the 12v on my power supply but don't have any vintage pedals like this HM-2. Are there any adapters or splitters I can use to make it work on standard modern 9v pedals? Thanks, and awesome video!!
Back in the 80s, I bought a Boss PSM 5, which used a Boss PSA 9 volt power supply. I don't think the PSM 5 increased the voltage. Before that, I used 9 volt batteries for all my Boss pedals, including my DDS2. They all ran just fine on 9 volts, though they did suggest the ACA 12 volt adapter for the inividual pedals. Doesn't make sense the PSM 5 would only take 9 volts when the pedals it was feeding ran on 12 volts.
Voltage starving a distortion, fuzz and overdrive for flat battery type sounds is always fun. A 12v pedal might work with 9v and won't be damaged. A 9v pedal might work with 12v, but it might be damaged, so don't risk it with anything rare or expensive.
The old pedals while they use 9v they take in 12v from the supply and drop the voltage to 9v from a resistor inside the pedal, you can remove it and bridge the connections with a peice of wire. But you'll devaule you're pedal if its vintage but also *fry* it by feeding it the old 12v ACA power. I always ran my ACA pedals seperatley and my PSA on my first board in the 00s. For years I just had them on a oiece of wood and velcro with a daisy chain cable. I might rebuild that for laugh i got my old BF2 flanger back and my hm2 and ds1 are the only pedals i have with velcro years later. The velcro on my heavy metal is so old it doesn't even stick to anything anymore, all the dog and cat hair over those years.
Rule of thumb with the hm-2 is to only use it with the settings dimed out. It’s a sacrilege to do anything different.... Ryan needs to read Swedish Viking manuscripts. I believe it’s on chapter 2
Hey Ryan long time subscriber first time commenting... If you still have the HX Stomp how about a comparison hm-2 v Swedish chain saw model that has been added to helix v3.0 firmware???
Btw I’m not a Heavy metal sort of guy, I’m interested as it is a main pedal for Belinda from My Bloody Valentine, so has applications for shoegaze. While on the subject of MBV how about you and Steve doing an album review of their seminal album “Loveless” on the podcast?
Hi I have a question do you use a 9v or a 12v power supply for the Boss HM-2? I will buy one this week but I only have a Strymon Ojai wich is a 9v with 5 slots... The other option that I have is to power supply it through my TU-3 will that work?? and is it much difference between a 9v and a 12v in the HM-2? greetings from Chile
That's interesting. I have an old Japanese SD1 with the 12v supply. It sounds like crap if I try to run it off my generic Donner 9v supply- all noisy and blah.
What about starving the voltage down to 6 volts? I bet it would make for an interesting fuzz pedal. It's definitely "better" sounding at 12V, but sometimes crappier sounding is the desired result.
@@Tommy712rus It's complicated. There are many pedals that would happily take 12V. I'd argue most analog drive/fuzz/distortion/boost pedals can handle 12v. The problem is, you won't know for sure unless you know the specs of the parts they used. Some chips and capacitors may only have a 10V rating. Usually, they're way higher at 20V-50V though. Some fuzzes I built can probably take 35 volts! 12V is a small step above 9V. Obviously, never do this to digital pedals. Probably not worth messing with analog modulation pedal voltages either. I know some expensive chips have a 10v limit. This is different from the vintage Boss 12V vs 9V thing though, since at 12V, the pedal circuit is only receiving 9V (and at 9V it's receiving something like 6V).
Yeah the gain is slightly less saturated and it is far more clear with 12 volts maybe you cant hear it in the room but the sound quality is far better with 12 volt.
whats good people! i have a boss ft-2. currently powering with 9v batteries. I have a un-isolated power supply similar to the joyo that's on the video. Is there a risk if i connect that boss pedal to the 12v output of my power supply?
You may be mistaken. 4.5V is often used as Vcc/2 for offset or bias for a 9V circuit since the signal cannot go negative in most pedals. There are a few exceptions where pnp transistors were used where the positive terminal of the battery or power supply was tied to GND and the circuit runs off of a negative potential.
i think the reason the light gets brighter if you daisy chain the HM-2 is that the circuit is running in a series with the other pedal so the current gets multiplied. not sure though been a while since applied science, can anyone either confirm or bust my theory?
Seems more like a ground issue with a non isolated pedal power system. It seems hilarious that you can feed power into this pedal from up the signal chain, but here we be.
Love my HM-2, traded an Ibanez DS7 for it and an Ibanez SC10 Super Chorus. I got the better end of the deal. Slight EQ difference on 12v. And I've never really noticed the difference because I'm always daisy chaining mine with other, modern Boss pedals!
Yes, Boss PSA mod, according to my tech easy to do and vintage Boss pedals anyway drop power internally from 12V to 9V (you know, they work fully ok with 9V battery).
My absolute favorite guitar at the moment is my"MATTE BLACK Q BLACK HARDWARE 7 STRING SG COPY"it's,a no-name brand beast from the east.uts hellish and breathes fire..chainsaws th shit outta everything when running the HM-2 into an overdriven amp.the saw IS the law...lol.horns up and saw on....
oh and your not supposed to pliug oit into a 12 volt adapter.it could damage it i imagine...because when you use the correct boss adapter the pedal itself has a charge pump that bumps it up already to 12 volts from the 9 volts supplied.
Coming into the end jam, this is the worst guitar playing I've ever heard on youtube! That is a distinction! But then, you actually dialed it in, and it sounded pretty good. And to clarify, not the worst guitar playing I've ever heard... I'm a former bassist losing his mind in waves to dementia so constantly forget the line I've written, and am playing. I even forget what scale and key I'm in, so every second note or so is a sour note. Anybody wanna jam? Lol, no.
Your death metal setting is wrong if you don't run it into a distorted amp....the distorted amp with a hm-2 ran into it is what makes the chainsaw.for real...run it into a slightly distorted amp and it transforms completely into a death metal beast...
I owned two of these over the years. It was my first pedal ever. Then after getting rid of it long ago, I got one for nostalgia sake. Horrible buzzy sounding thing. Got rid of it again.
Folks are correct saying that the "ACA" pedal works on 9V internally. The Boss "ACA" supply has a higher voltage and the "ACA" pedals reduce that higher power input to ~9V internally. Those pedals work about the same on a (fresh) 9V battery as they do on an ACA power supply.
The old Boss ACA power supply is NOT regulated and can be anything from about 10V to 14V depending on how much current the pedal draws, variations in the mains voltage, etc., etc. The ACA pedals were specifically designed to handle that variation in the voltage. The later Boss PSA power supply is a regulated 9V (or actually 9.6V...) that hardly varies at all with changes in load current or mains voltage.
Old "ACA" pedals usually work reasonably on a regulated 9V supply, but are running on something below 9V internally: The dim LED is the clue to this. Pedals that were designed for 9V might or might not "be happy" when run at higher voltages. Some won't care, some will sound different, some will decide you aren't their friend and will never work for you again.
If you plug an ACA pedal and a PSA pedal together into the same 9V supply, the patch cable between the pedals basically bypasses the circuitry in the ACA pedal that drops the power voltage from ACA level to 9V, which is why that seems to work... but it means you are also transferring a little bit of power through the patch cable between the pedals, which isn't a great idea for good sound. Each pedal really should have its own isolated power supply, with the vintage ACA pedals given about 12V and newer PSA pedals (and other brands) given 9V.
And then there is the whole argument about vintage fuzz pedals and dying batteries and driving them at even lower voltages from a supply with a "high" impedance... For some pedals this may sound better to some people, but I get the impression that it varies with each individual pedal in the same kind of way that those old pedals each sounded a little different. You need to experiment with each pedal individually to find the sweet spot that sounds the way you like. And that is a whole different discussion.
I have a few pedals, including a vintage Boss chorus that needs an ACA and a newer Boss compressor that wants a PSA. I am currently going through the exercise of building a multi-output isolated power supply with a non-regulated ACA output for that chorus, a bunch of regulated 9V outputs for most others and a variable output for experimenting with things that might care...
Thanks for the info. Are you designing your own circuits, or are you following a schematic? I've got 3 or 4 Boss ACA pedals, and they're a pain in the ass. Am I okay sending them 12v from a regulated power supply? What is a regulated powersupply, really, though? Okay so it is regulated, how is that actually achieved at the circuit level?
And do you have any links for pedal power supply tech information? I'm searching for 9v dc wall wart powersupplies with really low ripple readings.
Also, what is the deal with those transformerless 9v dc pedal powersupplies? How do they work? Are they noisier? Do they work better or worse for use with pedal powersupply daisy chains?
AND one last, if you've hung in there. I recently purchased a EHX 9.6v DC powersupply (several) to power a couple JHS inspired Behringer pedals I finally got, like actually got, after ordering them 15 blood moons ago, actually still waiting on the Super Fuzz, it's supposed to be in the mail... tracking, it is one state over, supposed to be delivered today. Fedex has been sucking lately, like in the last couple years, just blowing past their delivery deadlines like they don't exist.
Holy cow, I think all the prescription drugs are fighting it out in my swiss cheese brain. Okay, so here is the actual question, if you've somehow hung in there: When I plug the Behringer Ultra Vibrato into it's own EHX 9.6vdc powersupply, into a "powerstrip" and I plug the B-ringer Ultra Chorus into its own EHX 9.6vdc powersupply plugged into the same powerstrip, I hear the craziest sounds. One of the two pedals, or both, I haven't been able to isolate the issue to which pedal, it could be either or both, but they make these occasional zipper noises, and they're not discrete, they're only like a second long, and they go zzzziiiip-ererer-piiiiizzzz. I have an old Alpha Juno synth and something in the BBD of the chorus is going bad, either a timing component, or one of the buckets itself, and it "kind of", loosely speaking here, kind of makes the same sound when the chorus comes around to that particular bucket in its chorus cycle. Unfortunately, both B-ringer's Vibrato and Chorus, I imagine, use similar signal delay components.
Anyway, if I remove one of the pedals, the remaining pedal will not zipper. Any help for what is causing this, and why removing one stops the other from making this sound? I assume it is a grounding issue? But I don't know enough and can't imagine how some component of one of the pedals is periodically creating this audible signal, that is going backwards, down the ground into the shared ground of the powerstrip, and then from that common ground, up through the other powersupply into the other pedal, and that zipper signal is then making it into the actual audio signal? Or is some signal just coming into the common ground, coming up through both powersupplies, making it into the
And if I may, Chinese gang pedal power supply sellers, like the Caline CP-4, or whatever, always say their power outputs are isolated, sometimes they're even printed on the box itself, but they're not really isolated, right? Again, what does it mean to actually isolate a powersupply in such a way that it won't cause noise issues, I think it means that each individual ground is isolated, but I can't imagine how you can isolate a ground, when all the different power outputs from a gang box have to all share the same ultimate ground, I mean, they are all only connected, and have access to one ground wire. So, however it is, these Behringers need to be isolated, STAT, as I'm LOVING the Vibrato, thanks Josh (though just saw a video from him made in June, he fell into and participated in the anti-white agitprop, so that's fun), the Vibrato really is great.
i bought an HM2 for £65 the other day thinking i'd scored a bargain but I plugged it into 9v and it was weak, crapped-out and glitchy. I really thought I'd bought a dud and lost my money. Then I found this video and the pedal has transformed into a harbinger of the apocalypse! It would never have occurred to me to use 12v, so thank you!
I thought the same thing. I was like I know my first one didn't sound this bad 35 years ago. The led didn't work either. So I unplugged it, and put a battery in it and there it was the sound of my youth, the sound of the first pedal I ever bought. Couple hours later I find this, finally I have a use for this rando 12v adapter layin' around, cool thanks Ryan.
These pedals actually are powered by 9V, but there is a resistor and a diode taking 12V down to 9V inside. If you put a 9V supply in then you actually end up with about 6V.
There's an article if you look up "boss 12 to 9 volt conversion" showing the component numbers. You can solder the two connections together on each component to bypass them, and it's a 9V pedal now. Takes away the option of the starved sound, but some of the other distortions didn't sound too good on the lower power. I think I left this comment on the last video, awesome that you posted a new video on it.
It's weird how many people don't know this, given how popular Boss pedals have always been. I guess most people just ran them on the battery, which bypassed the internal voltage limiting.
As for why it's an EQ thing instead of a gain thing, I'm fairly certain it's because the tone stacks in both pedals are both somewhat active and are driven by an opamp (three opamps in the HM2). Both the tone stacks interfere heavily with the mids too, which is probably why that shifts the most. Anyone else who knows more please tell me, as I'd like to know too.
Hi
I will try to help you here!!!
Before i start,i will ask sorry for my bad english :)
First thing the gain of an op-amp depents on the passive components and mainly from the resistors between the input and output of the op-amp... so that's why more voltage doesn't change the gain ... what more voltage do is giving the op-amp more bandwidth.
What i mean?
Real op-amps have frequency response like a low pass filter and the higher the voltage the higher the cutoff frequency .
So that's the reason behind the eq thing ... more voltage means higher frequencies can be amplified.
@@spirosmexias950 That's what I was thinking! Good to know I was on the right track.
Also don't bother about your english, you already know more about language than most english people.
@@leylandpedals3893 thanks you !!!
I always run my Heavy Metal at 12V. It sounds as if it's not on/broken if I run it at 9V.
I LOVE the HM-2. I lost mine many moons ago, then I got an Arion Metal Master which is a direct clone. I use it all the time. Check out Arion, affordable but legendary!
My HM2 got stolen decades ago and I bought the Arion because I had a show that night... freaking LOVED it. I traded it for something somewhere along the line, still have my Arion SOD1 though. That is a great pedal as well if you can find one cheap. Mine currently is in the shop because after 30 years the output Jack got rattled loose and it loses signal randomly. Not bad for "plastic junk"😉
I love mine too.it seems a bit more aggressive than th hm-2 but that's why I love it...lol
Boss pedals from the 80's run on 12 volts solo but when you chain them with other pedals they get a common ground and runs perfectly on 9 volts.
HM-2 was my first pedal ever, bought new in 1987. Still have it... though my son has adopted it onto his board. Love that pedal. Mine was always operated voltage starved, because I ran it on a 9V battery for the first 10 years I had it, and on a 9V adapter after that.
I had to buy my son his own MT-2 because he kept borrowing mine. 😂
Should do a Klon Clone afford aboard shoot out soon. I know you have most of the good ones already.
I liked the "starved" sound as well.
I got an HM-2 years ago to get that Swedish death metal tone. I had no clue about the 12V power and sure enough, mine says Boss ACA power only. I'll have to try this too!
That sg is pretty rad my dude!
It sounds better on the 12 volt power supply. It's a little louder but noticeably clearer.
All the flub/mud went away
With 12 volts
I agree with you. I like the sound of it better starved @9V. Rock On!
Interesting. I have an old HM-2 that wasn't working, so I gave it to a friend (who builds/fixes pedals) to take a look at. He said it needs to run on 12V and when he did that it works fine. 9V, nothing. Odd...
Thanks for the vid. I was wondering why my HM2 was behaving the same way when using the Ispot pro PS. Toggled from 9V to 12V and bingo, the led lights up nice and bright! Have an 80s Tokai Delay pedal and that did not need the 12V boost.
It seemed to me that I could hear more string noise on the SD-1 when you were plugged into 12v. it all sounded good
Did the same mistake for 25 something years!! Time flies....
My old Boss pedals were all ACA. Never understood why they had 12v power supplies but still ran off 9v batteries.
Check for my comment if you can. Basically there was a diode and a resistor taking the 12V down to 9V internally, but the battery wasn't connected to that circuitry, and was allowed to run it's full 9V.
@@leylandpedals3893 Saw that after I posted. Thanks!
The switch on my Metal Zone has never worked correctly. I’d love to be able to fix it inexpensively like you did. I will have to look into that.
This video demonstrates why I run my self-built rat at 18 volts and with LED clipping. The sound is just clearer, bigger, and less "crushed". I also feel like the pedal is more responsive with pick attack.
Damn, Ryan with the Euronymous setup
Cool video...those older Boss pedals are great, for modding. You should just take an ON/OFF mini toggle switch... and make that jumper, switchable. 😉
I wish you would have tried 9v vs 12 vs battery power. I had one in the 80s and I don't think I ever used a power supply, just the 9v battery.
They run "right" on a 9v battery, the same as they do on 12v external supply.
I looked up a scan of the original '83 user manual and it said 9V Battery or AC Adaptor. Didn't find anything about 12V.
I've currently begun a series on my channel with an ALL BOSS 'Affordaboard' keeping it $100 or less per pedal on (primarily) the used market. Been very exciting learning about so many different offerings (and power requirements, BF-2 Flanger is also 12v). The HM-2 is very cool, but unlikely I will find one at 100 or less. That being said I've got some vintage circuits coming that fall under that $100. Check it out!
Love your vids Ryan and this is uber fun learning about the differences in power/sounds on the HM-2.
WHEN inputs are higher, the circuit is quicker, stressed I guess. It reminds me of a tube setup when more voltage is applied to the circuit.
Definitely, on 9v there are larger "grains" of distortion, you know, like in Rat. 12v sounds noticeable smoother. I like both options and curious is it possible to do the trick on modern hm2's? Should you lower voltage to make it sound more raw?
Seems like you could get the 9v sound with the 12v power supply, just by tweaking the gain and eq. If so, that would be the best of both worlds solution, would it not?
So many players chased the starved amps with EVH's attenuator ... now the chase is on for boss starved pedals started by Ryan. Actually, there always was the 'worn out 9v battery' chase. The problem is going to be all those players that get 12v power supplies and end up burning out all their boutique 9v pedals that were never designed to handle more voltage.
The only thing the switch on the Waza version should do is just max all the knobs so it's instant Swedish chainsaw. Normal and SC mode.
Well, poker-style, I'll see you 'I wish not to lose anonymity', and I raise you a double switching affair that relies on two - YES TWO! - LEDs of different colours which indicate the mode! One mode is the face value of the knobs, the other is a STRAIGHT LINE TO SWEDISH CHAINSAW!.
And what you do to switch between is a Taylor Swift double-tap to change between rhythm and solo.
"only" a chsinsaw if you run it into an overdriven amp.thats yh whole chainsaw tone...into an overdriven amp.there us NO chsinsaw if you run it into a clean amp.none at all.zilch.
What is the Gold Offset with white knobs above your right shoulder on the wall.
NOW I see WHY the HM2 sounded like crap back in the day! 9V battery! 12V just opened it up! I can hear it now! It's not just brighter, the clipping is better, not as ratty/sputtery! It's smoother! The OD2 was the same, better clipping character! Seems they were built with some W I D E power tolerance!
9V battery is the same as 12V powerbrick for the pedal.
@@visualdarkness HOW is that possible?
@@DMSProduktions Because of a resistor at the jack input that lowers the voltage by 3V. The battery bypass that stage.
@@visualdarkness Ahh, I C! That doesn't make a lot of sense, when it sounds so much BETTER @ 12V!
@@DMSProduktions But when you plug 9v into the jack the pedal gets 6v and if you plug in 12v it ends up at 9v. 12v is therefore the same as with a battery.
That ending was beatiful
What about 18v?
i've never really liked the SD-1 but i thought that sounded super dope when you had everything dimed, i swear all Boss gain pedals sound the best (to me anyway) with everything up full
I have an SD-1 and from my experience it only sounds good through Marshall 2203/2204. It seems like there are pairings that bring out the magic.
actually love that SD1 paint job
Is this why your stuff was squeeling when you unplugged things the video you compared everything to the HM-2
My power supply has a 12v in between the row of 9v and the 18v I always wondered why..
Hiree with a bunch of LED and AC plugs on top. So I guess I need a BOSS pedal now.
Any chance you'd do a video of you poking around and shorting things out in the HM-2 kind of like what you did with the flashback fuzz?
Nope!
I with you on the voltage starved sound mate👍 Same way that I prefer the sound of a dying battery in a fuzz.
It would be kind of awesome if, along with the Waza HM-2s, Boss also reissued the non-Waza HM-2s
Also, idk if u have a Marshall amp there, but, you an HM-2, you have an SD-1, and I see a Cherry Sunburst Les Paul in the background...you have a Euronymous setup (at least according to Circle of Tone)
The Waza HM-2 is the original hm2 reissue, just with an extra mode you can switch to if you want.
My Chorus pedal of choice was always the CE-3..Sorry CE-2 fans, I know it’s just me. Anyways, it runs on 9V through a daisy chain cable from other pedal(led is on)..However, it doesn’t sound as crisp and it makes some noise if you put it before a looper(which needs more current). My conclusion:ACA pedals sound best with either 9V battery, or 12v center negative adapter.
Thank you for this video-you are awesome.
Never should have sold mine.
I think I like it more with the 9v power supply. More muddy/fuzzy sound.
Does anyone know if the sound of the HM-2 with daisy chain at 9v is the same as HM-2 with 12v power supply?
You need to max the volume too for a death metal sound. It does affect the sound.
I am surprised the ACA PSA difference was so misunderstood. The pedals clearly say what they need. If you are reading this you have the internet at your disposal to learn the difference. There is sufficient information available to learn how to convert an ACA pedal to effectively have a PSA power input. EHX 9.6V choice is interesting. A brand new 9V alkaline battery is typically 9.6V. I broke down a couple of years ago go and got one of these expensive multiple output power adapters when I got tired of replacing batteries. Some pedals draw enough current that a brand new battery is only good for a couple of hours. The one I got happens to have a bunch of the outputs that are switchable between 9V and 12V. Honestly, I have not looked back since. One thing to note is that some brands of power cables that go from the power supply to the pedal are better than others. I found that some pedals generate noise even when disengaged unless the better cables are used.
Boss Metal Zone pedal was the first pedal I bought and eventually one of the channels burnt out. I don't know why I didn't try and fix it but I was a teenager so, I guess I answered my own question
They all run off 9V batteries. ACA pedals have internal voltage divider to lower the 12V from the ACA adapter to 9, so from a 9V PSA adapter you only get ~6V to the pedal.
can you use a waza hm2 at 12v?
RYAN, I think your Boss HM-2 sounded differently because the vintage DC needs 12vdc to convert DOWN to 9vdc but you used 9vdc so it "down converted" to 6vdc which the ChainSaw EQ sounded more Midrange because the pedal only was operating at 6vdc instead? let me know
I’ve explored that situation and the sound does change but not so dramatically that it sounds like a different pedal
@@60CycleHumcast When using a 9vdc power supply with a vintage ACA 12vdc Boss HM-2 pedal it should sound more fuzzy because its down converting the 9vdc to 6vdc so the operating point has shifted down causing the HM-2 to be starving voltage fuzzing out.
i always like the 5-6v sound. Lol I couldnt afford the power adapter so i had lots of half dead 9v batteries laying around back in 85'. Though when i got an adapter i ran 12v thru it. Their is a noticeable difference between the 80s and 90s HM2's IMO.
Might be a dumb question but I want to use the 12v on my power supply but don't have any vintage pedals like this HM-2. Are there any adapters or splitters I can use to make it work on standard modern 9v pedals? Thanks, and awesome video!!
I’m not aware of any. Some pedals can take up to 18v, you might something on your board that can handle 12v and free up a 9v slot for something else.
I think the hm2 sounded a little more fuzzy/crunchy with 9v.
What does the little silver oval sticker say you should put in the power input?
I went for several months using a Boss CE3 on 9v thinking the led was blown I also have a GE7 that wants 12v
My catalinbread SFT says 9V-18V. I think most of their pedals are like this. I've only ever used a 9V supply with it
Good video great playing and I heard a little more strength with the 12
Back in the 80s, I bought a Boss PSM 5, which used a Boss PSA 9 volt power supply. I don't think the PSM 5 increased the voltage. Before that, I used 9 volt batteries for all my Boss pedals, including my DDS2. They all ran just fine on 9 volts, though they did suggest the ACA 12 volt adapter for the inividual pedals. Doesn't make sense the PSM 5 would only take 9 volts when the pedals it was feeding ran on 12 volts.
Voltage starving a distortion, fuzz and overdrive for flat battery type sounds is always fun. A 12v pedal might work with 9v and won't be damaged. A 9v pedal might work with 12v, but it might be damaged, so don't risk it with anything rare or expensive.
The old pedals while they use 9v they take in 12v from the supply and drop the voltage to 9v from a resistor inside the pedal, you can remove it and bridge the connections with a peice of wire. But you'll devaule you're pedal if its vintage but also *fry* it by feeding it the old 12v ACA power. I always ran my ACA pedals seperatley and my PSA on my first board in the 00s. For years I just had them on a oiece of wood and velcro with a daisy chain cable. I might rebuild that for laugh i got my old BF2 flanger back and my hm2 and ds1 are the only pedals i have with velcro years later. The velcro on my heavy metal is so old it doesn't even stick to anything anymore, all the dog and cat hair over those years.
If you daisy chain it ,it takes care of the voltage problem.mine lights up bright in a daisy chain
Oops...jus seen that you figured that out too.sorry
I started using a line 6 Uber metal and now I don't use much else. Ever tried one?
Rule of thumb with the hm-2 is to only use it with the settings dimed out. It’s a sacrilege to do anything different.... Ryan needs to read Swedish Viking manuscripts. I believe it’s on chapter 2
The Vikings were mostly illiterate.
@@60CycleHumcast truth haha
ACA has been my bane, or is it bain, or whatever it is?
I had no idea
I run mine on 18v because there's an out on my DC brick. Capacity's either 20 or 24v I believe. Nothing's been fried yet.
Hey Ryan long time subscriber first time commenting...
If you still have the HX Stomp how about a comparison hm-2 v Swedish chain saw model that has been added to helix v3.0 firmware???
Btw I’m not a Heavy metal sort of guy, I’m interested as it is a main pedal for Belinda from My Bloody Valentine, so has applications for shoegaze.
While on the subject of MBV how about you and Steve doing an album review of their seminal album “Loveless” on the podcast?
im planning a video on the new update. especially with the princeton amp model
Painting pedals - will that be your next project?
mayyyyyybe
I have a 79' silver screw Boss OD-1 that loves 11-12 volts.
I did not know that. I been runing my 82 od1 on 9v and I almost cant see the led when its on. Thanks for the tip 👍
Hi I have a question do you use a 9v or a 12v power supply for the Boss HM-2? I will buy one this week but I only have a Strymon Ojai wich is a 9v with 5 slots... The other option that I have is to power supply it through my TU-3 will that work?? and is it much difference between a 9v and a 12v in the HM-2? greetings from Chile
Vintage hm-2s need 12v but newer ones take 9v
That's interesting. I have an old Japanese SD1 with the 12v supply. It sounds like crap if I try to run it off my generic Donner 9v supply- all noisy and blah.
“It’s all a great big sad mistake,” same
Does this apply to the HM300 from Behringer?
nope, hm300 only 9v
@@SefaPrasetia Booooo
What about starving the voltage down to 6 volts? I bet it would make for an interesting fuzz pedal. It's definitely "better" sounding at 12V, but sometimes crappier sounding is the desired result.
Is it safe to use 12v on 9v pedals?
Only sometimes.
@@60CycleHumcast which times?
When the manufacturer says it is - steve
@@Tommy712rus It's complicated. There are many pedals that would happily take 12V. I'd argue most analog drive/fuzz/distortion/boost pedals can handle 12v.
The problem is, you won't know for sure unless you know the specs of the parts they used. Some chips and capacitors may only have a 10V rating. Usually, they're way higher at 20V-50V though. Some fuzzes I built can probably take 35 volts! 12V is a small step above 9V.
Obviously, never do this to digital pedals. Probably not worth messing with analog modulation pedal voltages either. I know some expensive chips have a 10v limit.
This is different from the vintage Boss 12V vs 9V thing though, since at 12V, the pedal circuit is only receiving 9V (and at 9V it's receiving something like 6V).
What’s the guitar???
Yeah the gain is slightly less saturated and it is far more clear with 12 volts maybe you cant hear it in the room but the sound quality is far better with 12 volt.
There’s a pretty simple mod you can do on the old boss pedals to solve this.
That SG is so so so nice...
whats good people! i have a boss ft-2. currently powering with 9v batteries. I have a un-isolated power supply similar to the joyo that's on the video. Is there a risk if i connect that boss pedal to the 12v output of my power supply?
Because at the beginning of the circuit it splits the voltage to 4-5 . So using 12v it's still only running at 6v.
You may be mistaken. 4.5V is often used as Vcc/2 for offset or bias for a 9V circuit since the signal cannot go negative in most pedals. There are a few exceptions where pnp transistors were used where the positive terminal of the battery or power supply was tied to GND and the circuit runs off of a negative potential.
Ok this is insane. Why have I been using all my Boss pedals wrong? I need a smoke.
This is only the early ones. They will have an aca power sticker on them.
@@60CycleHumcast Good to know my dude.
Weird? I always though HM2’s sounded good at half a volt.
Ive hm2'd plenty with dieing 9v's
i think the reason the light gets brighter if you daisy chain the HM-2 is that the circuit is running in a series with the other pedal so the current gets multiplied. not sure though been a while since applied science, can anyone either confirm or bust my theory?
Seems more like a ground issue with a non isolated pedal power system.
It seems hilarious that you can feed power into this pedal from up the signal chain, but here we be.
12 volts give this pedal some sort of fuller 3d kinda sound.
Love my HM-2, traded an Ibanez DS7 for it and an Ibanez SC10 Super Chorus. I got the better end of the deal.
Slight EQ difference on 12v. And I've never really noticed the difference because I'm always daisy chaining mine with other, modern Boss pedals!
High Gain Ryan is Best Ryan
Best thumb ever haha
Some HM-2s (and other vintage boss pedals) have been modded to take standard 9v power supplies by their previous owners.
Yes, Boss PSA mod, according to my tech easy to do and vintage Boss pedals anyway drop power internally from 12V to 9V (you know, they work fully ok with 9V battery).
Correct
Best voltage for an HM2: Either 18 volts, or 6 volts (for a super sputtery fuzz).
My absolute favorite guitar at the moment is my"MATTE BLACK Q BLACK HARDWARE 7 STRING SG COPY"it's,a no-name brand beast from the east.uts hellish and breathes fire..chainsaws th shit outta everything when running the HM-2 into an overdriven amp.the saw IS the law...lol.horns up and saw on....
oh and your not supposed to pliug oit into a 12 volt adapter.it could damage it i imagine...because when you use the correct boss adapter the pedal itself has a charge pump that bumps it up already to 12 volts from the 9 volts supplied.
Coming into the end jam, this is the worst guitar playing I've ever heard on youtube! That is a distinction! But then, you actually dialed it in, and it sounded pretty good. And to clarify, not the worst guitar playing I've ever heard... I'm a former bassist losing his mind in waves to dementia so constantly forget the line I've written, and am playing. I even forget what scale and key I'm in, so every second note or so is a sour note. Anybody wanna jam? Lol, no.
On 9 volt it got a hint of fuzz
Who wants a MIT? I have half a dozen. The MIJs are staying
We giving out pedals? Sign me up, I don't have an HM-2 and I'd love any Boss pedal no matter where it comes from
Starve that HM2 🤣. This is why fancy nice pedal power units have the option to send lower voltages 🥳
Your SD-1 looks like it was saved from a burning building. 😢
Your death metal setting is wrong if you don't run it into a distorted amp....the distorted amp with a hm-2 ran into it is what makes the chainsaw.for real...run it into a slightly distorted amp and it transforms completely into a death metal beast...
Old boss pedals, I invested in rechargeable 9 v battery's and charger on Amazon, problem solved forever. No more buying battery's 😅😅
I owned two of these over the years. It was my first pedal ever. Then after getting rid of it long ago, I got one for nostalgia sake. Horrible buzzy sounding thing. Got rid of it again.