I have an 80's SM9 Ibanez version and am curious about everyone's thoughts on it's inner workings with all the gyrators and such. I think it sounds really good but it seems to be one of those misunderstood pedals because of the complex obscure eq. Also, It only dips below unity gain when the eq controls are dimed. It's not an overly loud pedal but I get a boost at most settings. Everybody loves pays a lot of money for the Boss HM-2 and it seems to be fairly similar circuit.
I don't have any experience with the Maxon reissue or the new mini pedal but I have read that they are a different circuit.
I haven't been able to find any pcb's for it out there... Why no diy love?
Edit:
From https://www.diystompboxes.com/smfforum/index.php?topic=35451.0
"The Per Cederholm SM9 schematic contains errors (around the punch control. It took me 3 hours to find out why that control did not work. (it's the connection to the + input of that opamp)"
The 10K resistor leading to the 10K volume pot forms a voltage divider. You could jumper the 10k resistor and change the pot to a 20K for increased volume with the same response.
I think that this...
Quote from: Aentons on December 25, 2018, 06:23:38 PM
Everybody loves the Boss HM-2 and it seems to be fairly similar circuit.
...is a controversial statement at best ;)
I DO love the records that the thing was/is used on, but that's not in the pedal that's in the songs.
Quote from: Rockhorst on December 27, 2018, 03:54:05 PM
I think that this...
Quote from: Aentons on December 25, 2018, 06:23:38 PM
Everybody loves the Boss HM-2 and it seems to be fairly similar circuit.
...is a controversial statement at best ;)
I DO love the records that the thing was/is used on, but that's not in the pedal that's in the songs.
Statement corrected...
Also, to clarify... I don't think they sound the same, I was just commenting on the similarities of the circuit. The SM9 is much more of a JCM800 Marshall in a box type thing that has a lot of the character and sparkle of a tubescreamer.
The tone control is interesting for sure. And it's nice to see Ibanez/Maxon used a buffered output on the pedal. It definitely has a few things going for it looking at the schematic. I also saw Maxon has a 4-knob metal distortion that seems a derivative of this thing (called the SM-9 Pro +).
I might whip up a PCB in the coming week if there's any interest in it, how about that :) Let me know below
Quote from: Rockhorst on December 28, 2018, 09:11:15 AM
I also saw Maxon has a 4-knob metal distortion that seems a derivative of this thing (called the SM-9 Pro +).
Yep, that's the reissue that I was referring to above. I haven't seen a schematic for it, but to my ears it sounds like a fairly different pedal. The new Ibanez mini pedal sounds much closer but still slightly different.
Quote
I might whip up a PCB in the coming week if there's any interest in it, how about that :) Let me know below
Count me in!
I'm not sure where I pulled that schematic from and I can't vouch for it's accuracy. I thought I had the Ibanez service manual but I can't seem to find it at the moment... I'll see if I can dig it up. BTW, It has been stated elsewhere that the Ibanez SML and MS10 are the same circuit.
The actual drive section is less like an HM-2 and a li'l bit more like a Shredmaster with frequency shaping up front.
It had been a while so I decided to open it up and have a look... behold
Here is a MS10 Metal Charger schematic that someone drew. The internet says it's likely the same as the SML and at least very close to the SM9.
Edit: supposedly this schematic does not contain the errors that the Cederholm sm9 schematic has
I think everybody was on break, so... bump
Well mostly I've been swamped with work for the day job and will be so until mid February. Any spare time goes into staying sane, taking care of my kiddo and (hopefully) finalizing some new Nucleon projects that where supposed to come out past November. But this is still on my radar :) I'm actually more curious about that 4 knob Maxon. From the demos I've heard it seems a bit more my cup of tea. Might buy one to attempt a trace.
Tiny update: I've bought a second hand Maxon 4-knobber for some real life testing. Will keep you posted :)
The SML , SM9 is not the same as a Metal Charger it has a transistor output buffer. It is the same as a SM7 and there's a schematic http://www.freeinfosociety.com/media.php?id=4071 (http://www.freeinfosociety.com/media.php?id=4071) I know it's an old topic but some people do search like me. ;)
Quote from: Rockhorst on January 28, 2019, 01:53:09 PM
Tiny update: I've bought a second hand Maxon 4-knobber for some real life testing. Will keep you posted :)
Now that the Sandstorm (SD-9) project has been released (and ordered), it reminded me of this.
I'm curious if you have explored your 4 knobber enough to enlighten us as to the differences between it and the old 5 knobber?
https://www.freestompboxes.org/viewtopic.php?f=1&t=9005&start=20
Interesting, from the pics above it looks like the SM9 has the disguised black band LEDs for D1 and D3 as well. I'll have to see if they light up.
First stage is J-FET buffer, preparing stronger, lower impedantion signal to second stage - preamp with max. gain cca 5. This first ATTACK opamp "heats" and equalizing (slight high pass) signal for overdrive stages with clipping diodes in feedback. There are LED and normal Si diode paralelly, which will give unsymetrical clipping, closing sound to valve clipping. After those clipping stages is distortion segment - two diodes and capacitor to ground. Again, clipping signal, giving to it more even harmonics, typical for valve distortion. Then are correctors opamps. First PUNCH is typical Baxandall corrector, which you can find in common audio amplifiers as TONE knobs. Here is used for freqs around LOW-MID, giving "body" to signal. Another stage is EDGE EQ. Typical EQ circuit with two freqs, enhanced or muted with pot. Gyrators and their functions are fairly described here:
http://www.muzique.com/lab/gyrator.htm
At the end is output buffer giving strong power output, to kick up your power amp. Volume pot and serial resistor 10k is described upper by Space Monkey.
Quote from: mojah63 on July 20, 2019, 02:01:05 PM
The SML , SM9 is not the same as a Metal Charger it has a transistor output buffer. It is the same as a SM7 and there's a schematic http://www.freeinfosociety.com/media.php?id=4071 (http://www.freeinfosociety.com/media.php?id=4071) I know it's an old topic but some people do search like me. ;)
Btw, this is super-duper not true. The SM7 has nothing to do with the earlier Super Metal pedals. The SM-9, SML, MS-10 are all the same circuit, although IC3 and IC4 are sometimes different (either 4558 or 1458 depending on the model). The MS-10 may use a BJT instead of JFET for the input buffer, but this could be a tracing error. Otherwise—notwithstanding that some of the traces have obvious errors that are easily corrected when comparing other schematics—the three pedals are identical inside, even the part values.
The Maxon SM-01 appears to be the same as well, same PCB layout as the Ibanez SM-9. I can't confirm the values but there's no reason to think it's any different.
The Maxon SM-9 reissue from a few years ago is different, however. It only has 4 knobs, replacing "Attack" and "Punch" with one called "Scoop", and it has an optional 18V charge pump. I haven't seen a trace of this one, but just from appearance we can tell it's not an accurate reissue.
There is an etchable layout and build doc here if anyone is interested. It's the only project for the SM that I have been able to find. It is very likey following the schematics above. Alas, I am not an etcher.
http://www.zeta-sound.se/clipping/
http://zeta-sound.se/wp-content/uploads/zeta-sound/distortion/Ibanez_SM-9/Ibanez_SM-9.pdf
Quote from: Zerro on October 08, 2021, 06:35:31 AM
First stage is J-FET buffer, preparing stronger, lower impedantion signal to second stage - preamp with max. gain cca 5. This first ATTACK opamp "heats" and equalizing (slight high pass) signal for overdrive stages with clipping diodes in feedback. There are LED and normal Si diode paralelly, which will give unsymetrical clipping, closing sound to valve clipping. After those clipping stages is distortion segment - two diodes and capacitor to ground. Again, clipping signal, giving to it more even harmonics, typical for valve distortion. Then are correctors opamps. First PUNCH is typical Baxandall corrector, which you can find in common audio amplifiers as TONE knobs. Here is used for freqs around MID, giving "body" to signal. Another stage is EDGE EQ. Typical EQ circuit with two freqs, enhanced or muted with pot. Gyrators and their functions are fairly described here:
http://www.muzique.com/lab/gyrator.htm
At the end is output buffer giving strong power output, to kick up your power amp. Volume pot and serial resistor 10k is described upper by Space Monkey.
Thanks for the description and analysis.
My low-tech interpretation the schematics is that the SM seems to be as if you squezzed two asymmetrical tubscreamers and an SD9 together, moved the regular tone control (attack) to the front and replaced it with a couple of graphic eq active tone controls for bass and high-mid (punch and edge)
Quote from: Aentons on October 08, 2021, 07:48:52 AM
Quote from: Zerro on October 08, 2021, 06:35:31 AM
First stage is J-FET buffer, preparing stronger, lower impedantion signal to second stage - preamp with max. gain cca 5. This first ATTACK opamp "heats" and equalizing (slight high pass) signal for overdrive stages with clipping diodes in feedback. There are LED and normal Si diode paralelly, which will give unsymetrical clipping, closing sound to valve clipping. After those clipping stages is distortion segment - two diodes and capacitor to ground. Again, clipping signal, giving to it more even harmonics, typical for valve distortion. Then are correctors opamps. First PUNCH is typical Baxandall corrector, which you can find in common audio amplifiers as TONE knobs. Here is used for freqs around MID, giving "body" to signal. Another stage is EDGE EQ. Typical EQ circuit with two freqs, enhanced or muted with pot. Gyrators and their functions are fairly described here:
http://www.muzique.com/lab/gyrator.htm
At the end is output buffer giving strong power output, to kick up your power amp. Volume pot and serial resistor 10k is described upper by Space Monkey.
Thanks for the description and analysis.
My low-tech interpretation the schematics is that the SM seems to be as if you squezzed two asymmetrical tubscteamers and an SD9 together, moved the regular tone control (attack) to the front and replaced it with a couple of graphic eq active tone controls for bass and high-mid (punch and edge)
There is also a nice write-up of the functions by 11gauge here.
From:
https://www.tdpri.com/threads/ibanez-mt10-awesome.260198/
"
- The Attack control is basically a "pre gain" variation of the tone control in a TS.
- The first gain stage is sort of like a TS (soft clipping), and this is where the Distortion control is.
- The second gain stage is also TS-like, but uses a LED with a traditional TS diode, and it isn't adjustable.
- You then get the hard clipping diodes to ground just like a DS-1/Rat/D+, but the extra gain is going to make this thing more on par with the DOD and Boss pedals of the time (HM-2, American Metal, etc.).
- Next is the Punch circuitry - it's an active EQ that adjusts bass.
- Next is the Edge circuitry, which is an active EQ "blender," with a "band" for treble and a "band" for midrange.
...Compared to it's contemporaries, it's a smarter design, IMO. The HM-2 "hardwired" the mid and treble "EQ bands," making them non-adjustable. The DOD copies of the HM-2 were even worse - they blended the bass EQ boost with the fixed mid/treble EQ boost!
And - the pre-gain tone control predates the Boss MT-2. The MT-2 is also not adjustable and is responsible for that big honking upper mid boost that you can't dial out at any setting.
Ibanez was WAY ahead of the curve with this one, too. I can see a lot of elements that other companies "borrowed" and implemented in their "metal pedals."
Luckily for those who like them, the MS10 is much cheaper!
"
Quote from: Aentons on October 07, 2021, 11:06:45 PM
https://www.freestompboxes.org/viewtopic.php?f=1&t=9005&start=20
Interesting, from the pics above it looks like the SM9 has the disguised black band LEDs for D1 and D3 as well. I'll have to see if they light up.
Yep, they light up. I made a quick video that shows it.
https://youtube.com/shorts/kDq5eK8v_qw?
Edit: I measured d1 and d3 at 1.4v forward voltage and just out of curiousity the others measure at 0.6v
While I had the SM9 open I decided to document the pot values and tapers.
Level = 10kA
Drive = 100kB
Attack = 20kG
Edge = 20kG
Punch = 100kB
For those who search or who may have missed it. aion has a board for the Super Metal now.
https://aionfx.com/project/sentinel-metal-distortion/
Thank you, thank you, thank you, aion
I'd change the 10k output pot to 50k or 100k for gobs more output myself.
Quote from: WonkoTheSane on July 08, 2023, 03:06:13 PM
I'd change the 10k output pot to 50k or 100k for gobs more output myself.
There is a different fix in the build notes of the aion project. It also adds a charge pump for an 18v switch
"Increased volume
The stock SM-9 is known for having low volume. There are two confusing and easily-remedied design
decisions causing this.
• R19, the 4.7k bias resistor for IC3A, cuts the signal in half when combined with R18.
• R27, the 10k resistor in series with the volume control, halves the maximum volume again.
We have corrected both of these in the default parts list for this project, raising R19 to 100k and
recommending to jumper R27. With these two changes, the maximum volume is comparable to other
distortion effects."
Hrm I dunno if any of the schematics are accurate, I'll trace mine.
Quote from: WonkoTheSane on July 09, 2023, 11:17:55 PM
Hrm I dunno if any of the schematics are accurate, I'll trace mine.
That would be awesome of you!