Archive for December, 2013

Boss MT-2 Metal Zone

Monday, December 30th, 2013


What is it?
Boss MT-2 Metal Zone Distortion. Made in Taiwan in january 1999.

While the design seems to be quite a standard for metal players, it doesn’t move me that much. The eq section with half parametric mids is well designed and definitely the best part of this pedal. The schematic shows that the design is probably one of the biggest analog distortions around. Several gyrators in addition to several gain stages and fairly complex EQ. These are the things your Metal Zone is made of.


SIP opmaps on a crowded board with modern style techical looking traces. The board material makes me wonder if this unit is in fact older than i originally thought. When i hadn’t checked the serial number decoder to confirm…


Due to the price of used units this will probably never make it to DIY favourites. Maybe it is just a good thing. Too much of gain may not always be an advantage when the goal is to keep the sound reminding you of a guitar. Besides the EQ, the controls are Distortion and Level. Latter is good to have as this one can reach the unity level in early part of the sweep. For distortion control.. I have no clue why it is there. There’s basically 269 degrees of unusable area on the sweep.

To me it seems like this design has been sort of an competition. How much distortion and gain can you get out of 9V operated pedal without oscillation or massive noise content?

How does it sound?
As your standard ultra high-gain distortion with reasonably loud output should. This sound has been more or less the standard for ripping death metal since its inital release in 1992. EQ section adds a lot of usability, while the distortion control is completely useless. Or have you ever heard or seen someone to use MT-2 with minimal or even moderate distortion setting? I sure haven’t.

Ibanez OT10 Octave

Thursday, December 26th, 2013


What is it?
Ibanez OT10 Octave from Power series. Made in taiwan around late 80’s.

The most interesting Ibanez boxes are the couple of designs that only occur once. There are more examples where the designs have lived on in different series with slightly different names or very slight differences. For example, all the different Tube Screamers and metal distortions. Where as TL5 Tremolo from the Sounstank series is the only tremolo effect Ibanez ever produced, the OT10 Octave is the only octave effect offered by Ibanez. These are bound to gather some noticeable collectors value. Box offers up and down octaves that can be mixed with the clean signal. The clean is the same as bypassed signal. Trace design isn’t looking too beautiful, but there’s nothing wrong with it. Just your standard modern style traces.


Like all 10-series boxes, there are two circuit boards. One with the controls and one as the main board. Boards are connected with 10 stranded ribbon cable. All three pots are 100K Ohm linear taper PCB mounted carbon ptos. The ouput buffering  and part of the electronic switching network is also placed on the control board. The schematic is up online. Once again, it’s Dirk’s beautiful trace, which is simply amazing work.


The buffering aside, the signal is splitted into three and fed to down octave divider, up octave circuit and a clean channel. Down octave is created by standard method of driving the s*it out of 4013 CMOS chip by one quad opamp. Upper octave is done by two diodes and wonderful looking inverting/non-inverting amplifier pile. Clean comes through with single unity amplifier.


All this is is mixed with three pots and passed on to last filtering buffering stage. I think the design is quite elegant and still far off from the circuits considered standard, like Boss OC-2. The design clearly has potential, so it makes me wonder why Ibanez (or Maxon) didn’t pursuit the idea further..

How does it sound?
This might be the main contributing factor why OT10 remains the only octave effect in Maxon/Ibanez back catalog. Up and Down octaves are both relatively clean, with the low one being just as unstable in frequency tracking as it usually is with octave dividing designs. The box does get way better if driven by some angry fuzz or distortion. While both octaves have their own personalities and the box sounds generally good, i see why this wasn’t as big of a hit OC-2 for example. Good thing is that those who have the box usually know why they have it – it has more than just collectors value. It’s quite usable. It has more going for it than just plain two different octaves. Character. Wouldn’t use this on my board as everyday octave box, but it’ll be with me in the studio. Every time.

Monkee Music Satan Distortion

Saturday, December 21st, 2013


What is it?
Monkee Music Satan Distortion, made in japan in 1989.

Ok. It has super cool font saying “Satan” on it. It is made of plastic and it is apparently japanese 1:1 clone of  Rocktek DIR-1 Distortion. When i say it’s made of plastic, i do mean that. Even that the outer shell is made of cheapest materials possible, the insides are not that bad. There are couple other pros in it too.


The board mounted jacks are held in palce with plastic holders, not completely unlike the older Yamaha box jack’s pull relief solution.  Which in my opinion is a nice method. This keeps the strongest pull/strain away from the jacks. As some of you may know, the plastic on plastic is better than metal on plastic. Traces have that japanese  clang to them and the soldering is solid and professional looking.


Components, excluding the momentary bypass switch seem to be all good. Even the switch doesn’t have any issues, but i do believe this unit has not seen much use in its existance. As the unit is 1:1 with Rocktek DIR-1 Distortion, there is a traced schematic up at Freestompboxes forum. Although you need to be logged in to see it.


The main driver is 6458D, which is old Sanyo chip with some similarities to JRC4558. Sanyo model however is quite more high-end audio product. The datasheet is available online. I’m tagging this as “Other Brands”, as this unit is apparently only Monkee Music brand box ever manufactured.

How does it sound?
I’ve heard this type of distortions before. Below unity and basically just one tone you can get out of it. It’s not that bad of a distortion, but all the controls are pretty much unnesessary. You’ll need to have everything maxed to have a reasonable result out of  this box.  It’s that classic 80’s/90’s distortion sound that everyone is familiar. Relatively high gain. The lower than unity output level is the worst culprit in addition to weak plastic enclosure. Prime suspect for modding and /or rehousing. But for that – i’d suggest to get Rocktek DIR-01 as this Satan Distortion seems to be quite rare specimen.

DOD FX69 Grunge

Thursday, December 19th, 2013


What is it?
DOD FX69 Grunge, made in USA around 1995. Board revision is “B”, but the box is per 1993 version.

The DOD engineers were probaly after the sound of Kurt Cobain’s Boss DS-1/DS-2 and the Mudhoney fuzzes that were taken over the top. Or then it was just a plan to make a lot of money out of the genre that hadn’t too much to do with the pedal’s sound. There are conflicts between the sources about mr. Cobains use of this make. I personally feel that the most accurate version of the truth is told at Kurt’s Equipment website, stating the Nirvana’s guitar tech as a source for the information. So the throwing the pedal at the audience is probably just a myth. May it be what ever. Let’s check the pedal itself out and not focus on who did what 20 years ago.


There’s standard DOD electronic swithching and lots of gain stages and filters. Schematic is available online and it shows the signal path to be buffer -> filtering gain stage -> passive filter -> main gain stage -> hard clipping -> dual gyrator filter stage -> tone control (active lows and passive highs) -> one last driver for tone control -> output buffering. Yeah. Simple. But all that is needed to create horrid amount of gain and keep the audible oscillation and too much excess noise from completely ruining your sound.

So it’s a fairly complicated super high gain distortion with reasonably good eq section. Does it really depict the sound of the genre? Probably not. DOD already had numerous “metal” pedals in its lineup. What makes this all special is the fact that marketing is completely in reverse. Most of he ones that are branded as metal distortions are lower gain devices and FX69 Grunge is definitely at its best when used for metal distortion tones. Now, who of you metalheads want to use pedal with “Grunge” written on it for your lead sounds? How come i see no hands raised…

How does it sound?
Weird. At the same time amazingly good and utterly bad. Very few “standard” designs leave you feeling this baffled. Maybe it’s a good thing to get feelings out of a pedal. At least it does raise an opinion out of almost everyone. You’ll either love it or hate it. There’s no meh-factor on this one.

If you are after that buzzsaw sound, then the Grunge may be just the right pedal for you. It’s even underrated and highly praised at the same time. DOD grunge – the paradox of all well selling pedals. I’m basing the sales argument on the fact that Digitech is still selling the same circuit on its D-series, which makes the design over 20 years old and it has apparently been on the market since the initial release in 1993.

Ibanez SP5 Slam Punk

Sunday, December 15th, 2013


What is it?
Ibanez SP5 Slam Punk distortion from later Soundtank series. Made in taiwan, mid to late 90’s.

One of the soundtanks that i had a pleasure of being in contact with before acquiring one. I did a rehousing job with true bypass for a friend and played with the circuit before letting it go. I knew then already that i may need to clone this circuit for myself, and maybe mod it slightly to lose some of the low cut that the original pedal had. Not much, but still the original had slightly clinical bottom end. After building couple of clones, to no surprise, i found another healthy original for reasonable price. This puppy is that one and i’m not letting it go.


The board has standard taiwan modern traces. Take a note of the empty, unmarked holes. The board has SP5 printed on it, so the exactly same board hasn’t been used for another desing in this series. But i do believe the layout without the silk screening has been.

However. The schematic is up at 8bitsindgenug. It shows some similarities to ProCo Rat and other Ibanez designs based on it. The board has a lot of room on it.


Even though the Soundtanks aren’t getting the appreciation they should in general, this one is one of the most underrated pedals in the series with Black Noise and a few others. Nevermind the plastic housing. The sound is there, regardless of the box.

How does it sound?
High gain accuracy and definition, but still usable as a very nice overdrive. Think of Social Distortion’s “When the angels sing”. This pedal pretty much nails that overdriven/distorted base sound. No doubt this pedal wasn’t used on the recording, but the sound is close. Anyone mocking this one as a plastic cheap crap should play with one and say that again.

Danelectro DDS-1 Sitar Swami

Friday, December 13th, 2013


What is it?
Danelectro DDS-1 Sitar Swami “Sitar Emulator” from 60’s series, made in china in late 90’s.

I noticed one for sale for a very good price, and the Danelectro enthusiast i am, i just couldn’t let the opportunity slide. These are quite rare and special too. Forget the “Sitar Emulation” part. If you’re judging this one as a sitar emulation, you’re going to hate it. I’ve played with a real sitar and this does not have any resemblance in its sound. But just by listening to  this box gave me an understanding of what’s going on.

Opening the box up made it very clear why there’s no traced schematic available. Two sided circuit boards filled with the tiniest SMD components around. And the size issue doesn’t end there. In addition to standard two board setup these enclosures normally house, there are two daughter boards soldered in 90 degree angle to the motherboard.


If you are interested about this pedal, you should definitely read the Electrosmash’s article on the issue. The article doesn’t analyze the design itself, but it gives you good clue what’s goin on with its semiconductor listing. First of all, the pedal sounds like there’s low octave CMOS divider, an echo circuit and continuous set flange sweeping in the background all the time. All this with a mild upper octave cleanish fuzz that isn’t too far off from the Green Ringer.  Sadly the only controls are level and EQ. This would be something very desirable with more controls (for flange speed, low octave mix and time/feedback parameters for the delay) – but then again, it’s Dano’s interpretation of a sitar emulation. It’s still sick and i can already think of things to use this with. Would have been super to see the breadboard this one was developed on. Must have been a sick mess.


“The droning, resonating tones of the 60’s!”. Now that’s more than correct.

I did notice one thing when tying the pedal out. The flange stays on all the time with noisy power supply. When using a slightly dead battery, the flange comes on only when strings are hit. This is probably good thing to keep in mind when trying to fit this to any sound your after. Another thing. Try placing a fuzz in front of the unit. Instant 60’s psyche lead sounds.

How does it sound?
Sick and good. Like i said, one should not judge this as sitar emulation as it doesn’t do that well at all. To be honest, it doesn’t do that at all. It does it’s own 60’s style sick fuzzed lead sound with special spices in it. And it does that very well. That’s basically nothing you can’t achieve with Boss OC-2, any PT2399 based delay, a Green Ringer and a flanger. But you can get that same droning psychedelia with a single box with no controls. I’m loving it, but the at the same time i think it’s a monster that should not be alive.

Without a further due, the award for sickest multieffect with zero controls go to Dano Sitar Swami.

Boss SD-1 Super Overdrive

Wednesday, December 11th, 2013


What is it?
Boss SD-1 Super Overdrive. Made in taiwan, january 2010.

One of these boxes that i knew i had to have, no matter if i like or not. And the answer is not. Must be one of the most sold Roland Boss pedals ever. The design has been on the market since 1981. As the box has already reached 30 years of age without any changes to the design, it must be popular product. If it wasn’t, it wuold have been axed and/or replaced by some other design a long ago. Cool thing about the circuit is that it still looks and feels pretty much like the original japan made SD-1s, even though it’s taiwanese and nearly 30 years younger.


One of my friends has an early 80’s japanese version of the SD-1. According to him, the current production versions sound exactly the same, if not better. Haven’t had a pleasure of trying out really old unit myself. Value of those early 80s versions are through the roof. So i’m kinda hoping that 25000 of these units suddenly break up beyond repair and that 25 years passes very quickly. Maybe then my unit will have more value than twenty european dollars.

The board traces are the same as the photos of old units found on the web. Let’s then take a look at the schematic (from Doesn’t that look a bit similar to something we’ve seen before? With just a couple of component changes (a few values, a 1M pot for gain and asymmetric clipper diodes), and it surely does seem like something really familiar.


Funny. I thought it sounded and felt pretty familiar too. So in fact, it is a slightly modified Tubescreamer with added gain and asymmetric clipping. The pedal is so common that modding it is very popular. No one will ever cry after an original SD-1 because of the mods. One can simply use the mod sheets found on the internet that apply to TS-family.

With just couple of component swaps and one could easily mod this to TS808 specs. Sounds so bad as an idea, that i may have to aqcuire another cheap used unit and mod it to 808.

UPDATE. I did get another from around 2005 in a trade (thanks Kasperi!). And i did mod it to TS808. All it takes is removal of one cap, swapping the places of one resistor and a cap, swapping 25 components to different values (including two pots) and making a few slight modifications to the circuit board. In all, about 30 components need some attention. Doable, but it’ll take couple of hours to perform. I A/B’d the result with my TS9 (as i don’t have TS808, yet), and i really couldn’t tell which one of the pedals was on at a time. So yes. It can be done. Do i recommend it, or is it really worth the trouble? Can’t say for sure, but it feels pretty damn weird to have TS808 sound coming from SD-1 box. After trying the result out, i sanded the SD-1 text off from the label and used permanent marker to tag it as “SD-808”.

How does it sound?
Like a Tubescreamer with slightly more harmonics on the clipping due to asymmetrical clipping configuration. Oh. And lots more gain.  Does it sound better than TSs? No. But it doesn’t sound any worse either. Mid-humping overdrive that keeps slapping you on the top of your head. Doesn’t take good pickups well, jsut slaps you even harder. For P90s with  moderately low output, this shines. As do all the TSs. A classic, but not that great. I do get why some people do like this and keep using it. To me, it’s just another cheap TS alternative in yellow box. Swap the diodes for two silicon ones for symmetrical clipping and you’ll have something that’s close to a Tubescreamer. that’ll cost you a lot less than current reissue of TS9.

After the mods, it is a TS808. I think i want to keep them both.

Colorless writings, part 5 – The Bypass Surgery

Wednesday, December 11th, 2013

Bypass surgery? Are you referring to bypass systems found in pedals?

You got that right. True-bypass seems to many as a something that will make them play better. I thought i’d like open up and let you know what i think about different bypass and switching methods. From outside, sort of generalizing, there are just couple of ways to create bypass switching on a effect pedal. We all do want to have bypass option on our pedals, right? At least i do. The unusable options are mechanical switches that have input of the circuit connected all the time. This method always results is this mythical “tone sucking” that so many of you are talking about around the internet. I haven’t come accross any modern pedal, boutique or factory made, that would use this method as main bypass switching, so we can safely leave that be. The usual two ways are magical “true bypass” that will set you free and save the world from certain death and the “buffered bypass” that is demon’s work and will *always* suck your signal dry before it hits the amplifier’s high impedance input. Or that’s exactly how i’ve seem people act on this issue.

Let’s start with the myths about true bypass. It will not make you play better, nor will it save the world. It’s just a method that will let your signal travel through the pedal without touching any part of the circuit. Yes, there are things that are good with this method. First of all, it doesn’t change the impedance of your signal when effect is not engaged. This means that your signal will travel happily in tact from your guitar to your amplifier. In addition, i can quickly think of two things that are not so good.

  1. Switches may be and are unreliable
  2. The lack of buffering will have your signal travel through 6 metres of guitar cable -> pedalboard with about 20 connections -> another 6 metres of guitar cable

No matter what you say. The standard 3PDT stomp switch used in almost every single boutique pedal will at least once or twice in its life span leave one or more of the poles unconnected. This usually fixes itself on the next stomp, but it is still very annoying.  It’s not the matter of build quality of these switches, but a simple fault in a way switches work. Many modern factory pedals are also using 3PDTs or 4PDTs as stomp switches – because it is hip to have this mythical thing called “True-Bypass”. Old school 2PDTs are known to be more reliable, but they limit switching options and usually leave the LED indicator out. Or address the issue in some other manner.

The example above leaves you with approx. 15 metres of guitar cable between your guitar and your amplifier. There are many jack/plug connections on the way too. Do you really think your signal generated by the guitar is strong enough to travel that many connections and that much cable without being degraded? Didn’t think so. This is what makes true bypass bad. You’ll have to rely on your cable quality and the connections on pedals.

So you’re saying that true bypass is a bad thing?!?

Oh yes i am. The impedance is the key. Guitar output impedance (or Z, or AC resistance) is always low in Ohms. Usually around a few thousand Ohms, less than 10K. The next item that takes the signal in will need to have a high impedance to catch the signal and pass it on. Usual amplifiers and pedals have input impedance from around 500K (which is lowish) to 1M Ohms (which is good) and up. Longer the cable, higher the output impedance for your guitar’s signal. Two six meter cables and and a pedalboard seems like quite standard setup for many. In this setup your signal can be degraded before hitting the amp due to long cables and lots of connections in the way.

Now let’s think about putting a simple buffer in there, middle of the pedal board. Buffers are just very simple semiconductor devices that transform the impedance back to low value and still keeping the signal in tact. If we have one of those in the middle of the chain, we’ve basically cut the cable lenght in half. The guitar “sees” the high impedance input of a buffer after first six meters of cable. The amp “sees” the low output impedance coming from the buffer’s output and percieves that as only 6 metres of cable. Good buffers can push you through even considerably longer cables without a problem.

So you’re saying buffered bypass is a good thing?

Yes and no. Like most things in life, it is just not that simple. Well designed bufferes are always more than welcome to my pedal board. Bad designs with even worse electronics switching.. Not that much.

The other reason for buffered bypass (or buffered pedals in general) is the electronic switching. As the JFET switching will need at least reference voltage of ~4.5V to work, the designers can’t just take the input to JFET switching “buffer” – that would take the voltage to the pickups, and that’s not what we ordered. So there needs to be a buffer to separate (or decouple) the input, JFET electronic switching and the next phase, which is either output buffer or the effects circuit. On the other view, some otherwise perfectly working circuits will need an input buffering to get the incoming signal just right. If there isn’t input buffering, the too low input impedance will cause something called “pickup loading”. In essence, it means that the guitar pickups are giving out too hign output impedance and the signal doesn’t get picked up by the circuit input well enough. Result will sound bad. Effects with too low input impedance do exist. And in numbers.

This brings us to the real issue and real practice. I don’t think that having true bypass in every single pedal in my board is good practice. Í also don’t think it’s a good idea to have in/out & bypass buffers in every pedal. Some sort of middle ground should be sufficient.

Does one exist?

Yeah. I think so. If you put your mind to it and think about how you want to build your pedal board.. You’ll get the hang of it.

Oh. There’s one more thing that popped in to my mind. Some people will probably remember when everyone wanted to modify their cheap pedals for true bypass? I have one question regarding that.. Did it make any of those pedals better than they were? I suppose there could be a case here and there where the TB’ing a pedal will help with the mythical tone sucking, but in general? Does it really help you to sound better?

I’ve had couple of pedals where i’ve heard the highs die when the effect was disengaged. I do think there is some psychoaural symptoms going on with that one too. What if the effect slightly boosts your highs? Then the buffered/bypasses signal would sound dull when disengaged. Have you used a/b testing to see if you can hear a difference between true bypassed signal and a buffered bypass?

In my opinion, the greatest solution to this age old, highly puzzling and opinion raising subject is the one we can today find in BJF Designed Mad Professor brand pedal, the Ruby Red Booster. This pedal has true bypass and buffered bypass switchable inside the enclosure. Ingenious. There should be more pedals with this option. Would be a big help for those who are designing or redesigning their pedal boards.

Pearl OD-05 Overdrive

Sunday, December 8th, 2013


What is it?
Pearl OD-05 Overdrive. Made in japan, early eighties.

This must be one of most desired overdrives on the planet. And for good reason i might add. I don’t know how many units were made, but the amount must be a lot. There’s almost always one for sale on eBay, so this ain’t exactly a rarity but the prices these go for do tell us something.

Opening the unit’s six screws show peaceful board with strong, solid traces and neat, professionally made solder joints. Just what one would expect from japanese early eighties pedal.


There  is an factory schematic available online (plus numerous DIY projects), which opens up what this design is made of. There’s a buffer first, then a slight boosting gain stage to drive the  semi-parametric EQ. Couple of filters follow, and then the main gain stage. This has symmetrical clipping diodes in feedback loop of non-inverting amplifier. Something that we see quite often in overdrives that try to emulate tube saturation. And of course, an output buffer. All this with electronic JFET switching and well designed ins and outs.

Pearl-OD05-guts3There’s two JRC4558D dual opamp and a handful of transistors in the signal path. The output level is sufficient as the main gain stage is there just before the output buffer. This way the tone control or filters won’t affect the output.

Well made boxes indeed. I think the prices are going to slightly rise on these units in next ten to twenty years. It is a classic without massively marketed reissues – actually, no reissues exist at all.

How does it sound?
Natural sounding overdrive with great addition of semi-parametric EQ to tune it to suit your guitar better than most other classic overdrives. The sound has some same characteristics as your Tubescreamers, but the EQ lets you control the hump point. It sounds very good and usable. Recommended pedal. Strongly recommended.

Ibanez TS10 Tube Screamer Classic

Wednesday, December 4th, 2013

Ah. Back to the old tricks with yet another Tube Screamer.


What is it?
Ibanez TS10 Tube Screamer Classic. Later version, made in Taiwan late 80s or early 90s.

So it is TS9 with one resistor added before the inverting input of the opamp. These taiwanese units tend to sell for less than current TS9 reissues, so modding one might not be such a bad idea. Personally i’m happy that this post leaves me only with TS7 to cover from the standard tubescreamers – as it gets quite boring to try to find something to write about a box that one has written about twice already. TS7 has something more to offer than just one added 220R resistor.


Dull as expected. In more ways than one. The enclosure may not be as sturdy as 9-series boxes, but for some reason i find this type of box soothing. Featurewise, placing of the jacks is the biggest difference between this and the nine series TS.


The photo above is taken after i modded other one of my taiwanese units. One with a keen eye should be able to catch all the components that have been swapped. Hint: original unit has 5% carbon film resistors and transparent mylar caps. Okay. I’ll let you know everything there is to know. The one resistor in the middle of the board is swapped from 220R to 0R. The inverting input components have been replaced – minimum drive setting up, more bass and more overall gain. Also the 51p ceramic cap is swapped for multilayer type. The two resistors on the bottom left are the two resistors that make this a TS9. Swapping all the mentioned values will result the circuit being transformed from TS10 to TS808 on steroids.

How does it sound?
As all the rest of the Tubescreamers. Without the mods it sounds pretty much 1:1 with TS9 and TS5. It can (and probably should) be modded into something that simply sounds way better. But still. In its heart it will always be just a tubescreamer. The sound i personally won’t ever be using for anything.