Archive for January, 2015

EHX The Mole Nano

Friday, January 30th, 2015


What is it?
Electro-Harmonix The Mole Bass Booster from Nano series. Made in NYC in 2013.

As the one transistor, simple boosters in the EHX family go, here we have the “Bass Booster”. Circuit has pretty much the same topology as all the other simple boosters (LPB-1 and Screaming Bird). The component values are the ones that determine the frequency response and thus, determine if the circuit boost full-range, bass or treble. On full-range, we cut nothing out. On bass, we cut out the high. On treble we cut out the bass. Simple, isn’t it. I was expecting to see the same board as for LPB-1, but no. The Mole has its own design, even though the circuit is still simple, one transistor booster.


Here we have our modern EHX board with most of the design laid out in SMD, while couple of the caps are through hole. And the transistor is a classic TO-92 packaged device too. BC550C. I think EHX has bought those to last a lifetime. At least this type seems to be the weapon of choice for most EHX pedals calling for NPN transistors. Overall, simple and useful. Why?

How does it sound?
Useful due to how it sounds. Want to cut the high end off and give some volume for the lows? For very cheap nano series pedal, this is the way to go. While i don’t see myself using this on my main board anytime soon, i think of the unit as a tool to shape the tones in studio sessions. While it is very good unit, the lows tend to need a lot more power to get amplified. You know, your 50W all tube guitar amp will be louder than your 100W all tube bass amp. In reality, this isn’t exactly true, but due to how we humans perceive frequencies, it might as well be. Due to this, the Mole seems a bit sluggish for its output level, when compared to LPB-1 and Screaming Bird. It could be louder, but still. This one gives you decent kick for your lows while cutting the top end. Usable. Tool.

MI Audio Blues Pro V3

Tuesday, January 27th, 2015


What is it?
MI Audio Blues Pro V3. Made in australia around 2013 or so.

Smaller brands with good reputation in the tweaker community? The vast number of brands vs. the reputation leave quite a few out of the equation. There are these smaller brands that may have had one of theirs as a flavour of the month on certain guitar forums. Usually when that happens, the hype lasts just as long as someone finally opens the unit up and finds the circuit to be nothing more but a tweaked tubescreamer with questionable build quality. Mostly for that reason some of those new and exciting brands seem to vanish as fast as they appeared. But MI Audio has kept its status. And mostly for a reason. Decent build quality on all units and noticeable amount of effort to stand out with the tones. Not to mention the well developed sense of humour. I’ll admit that my first reaction was a wide smile when i opened this unit up.


I think i don’t need to say anything more. The gut shot tells you everything you need to know. If i was to say something negative about the build, the excessive flux residue makes me think the unit was put together in a hurry. Plus i’ve never been a fan of board mounted DC jack that is simply placed behind a hole in the box. That seems just a little cheap. But that’s all of the downs i can think of. Everything else is pretty solid. My guess is that the circuit is pretty much the same as for previous versions of the Blues Pro.

We have out basic three knob arrangement with Volume, Tone and Gain. The toggle switches between “OD” and “Fuzz” modes. Which both are still a lot more overdrivish tones than anything resembling a fuzz. I’d rather call those modes “standard OD” and “Slightly Fuzzier OD”. That’ll give a better idea what to expect.

How does it sound?
Open, semi-transparent mid-gain overdrive. Clear as summer sky. Clipping textures for both modes sound open and whole without compressing too much. I felt there was something familiar about this tone, so i A/B’d this with Barber LTD Silver. There are a lot of similar points for these two, mainly the openness and transparency. Both are miles away from any current mass produced big brand pedals. In a good way. I do prefer these types of clear boutique-like tone way over the tasteless big brand stuff, although MI Audio isn’t that small brand and hasn’t been for years. Good all-around overdrive pedal. Possibly not the greatest choice for soaring lead work, but as an overdrive, very good.

Australia is pretty far away from here, but i’m hoping to be able to try out their amplifiers some time in the future.

Digitech XDV Digiverb

Sunday, January 25th, 2015


What is it?
Digitech XDV Digiverb from X-series. Made in china around mid-00’s.

Hmm. Something familiar? Digitech X-series doesn’t fail to disappoint. At the top of the price list for the series, the reverb and the delay are usable units with decent set of features. Actually, these units take on Boss and other mass produced units for a tight match while still being a lot lower on the price tag. But here’s the thing. While other big brands have designed their units from ground up, solely for the purpose they serve, the Digitech units are, well. Digitech units. Once we open up the bottom plate we’ll see what’s going on. Yup. The board is the same we saw on previous X-series posts.


And it doesn’t change once we flip the board over. The circuit is the same, with inclusion of that ISSI-chip which isn’t present on most units. But the rest of the layout and electronic design is the same.  I just noticed the cutouts on the bottom right. If you look closely, you’ll see the connctors there. That must be a connection that reminds me of PCI connections found in computers. I’m fairly certain that is used to send in the data to determine which effect the pedals will be. So in general, the effect is made with AudioDNA DSP, an Atmel chip and an ISSI-chip.


I said earlier that the effect is feature packed. It is. With mix control to dime in the desired wet/dry level, EQ control to set the amount of highs and decay time control, the these three would offer decent basic setup for any reverb. But then we have seven modes that all have their own reverb tone. The modes are like straight from your standard rack mount reverb units, room, plate, hall, church, gated, reverse and spring. I’d call that a decent set of features. And these modes do resemble what they are trying to model. Quite well too.

How does it sound?
Not bad. Like any pristine sounding rack mount reverb in a small form factor. And since you can get these used for reasonable prices, the bang for buck ratio is very nice indeed. The quality of the tone is also on par with the rack mount units. And thus, the lack of personality and notable level of boringness steps in. Works fine and sounds decent. Usable for your home recordings. This could even be used as a master reverb through mixer send/return loops. I doubt that many would notice any tonal difference between this unit and any low to mid priced Lexicon rack unit. Good sounds in from a boring digital circuit. You bet the article for XDD Digidelay will be shorter than this. After all these two are in fact the same pedal with different code burned in them.

Catalinbread Merkin Fuzz

Friday, January 23rd, 2015


What is it?
Catalinbread Merkin Fuzz. Made in USA in 2010.

One of the first more “boutique” pedals i sourced and deemed as a keeper. Before getting  the unit, i had already played around with the circuit as the traced schematic has been floating around for years. You should be able to find at DIY forums. Due to this, there wasn’t anything completely new to me when i first fired this original up. When this unit reached me it had its LED burned out and i swapped it for a new one back then. Sad thing is that i didn’t snap any photos then. Call it laziness, but i just didn’t find the enthusiasm to open it all the way again for this article. If we start by looking at the guts, we’ll see two sided board that is looking very professional, but at the same time, rather dull.


Sometimes it’s great to find that circuits that have very little to do with each other on the topology have similar sounds coming out of them. I’m certain that some people thought this to be just modernized and treble cut Mosrite Fuzzrite due to it’s spongy, wild sounds. But designwise this isn’t even relatively close to Fuzzrite. In general, there are three transistor stages, which all take every single bit of gain out of their semiconductors. The texture pot is mixing the output of first and second stage, which is then pushed to the third stage. Somehow this arrangement reminds me more of the Baldwin-Burns Buzzaround, while still being nothing too close. In other words, the circuit design is pretty cool and has some out of the box thinking in it. Sure, there isn’t anything completely profound and anyone with deep experience and understanding in fuzzes could have created something that takes bits and pieces from the Fuzzrite and Buzzaround to combine them in a modern circuit. I’m not sure if this is the case. But if this design is created on a breadboard without following the two schematics mentioned, i’ll take my hat off and raise my glass.

Catalinbread is one of the companies that have grown from single person boutique operation to respectable scale and very respected reputation. There is a reason for this. First off, they know where they are coming from. Second, the quality. Professional and modern boards which are then hand crafted. Boards may look dull, but all the joints look like person with the iron has a real interest in the finished product. Next Catalinbread pedal i’m getting may very well be a new one.

How does it sound?
Ingenious. From that “satisfaction” to killer mushroom clouds. There is definitely that vintage sputter in the tone and texture maxed will give you massive single note lead tones that will work great on those doom/stoner leads too. While the two-knob configuration is the way to go with vintage-like fuzzes, there are tons of different sounds. The pedals reacts to guitar’s volume knob as a gain, and the guitar tone can be used to transform the sound. You’ll get up octaves and down octavish craziness in there too. Not to the degree of MXR Bluebox, of course, but still the overtones are something quite different from Fuzzrites and derivatives. If i had to describe this pedal with a one word. The word would be a “keeper”. Sure. It may not fit to everyone’s taste as it is quite wild. But to me. A keeper.

Digitech XSW Synth Wah

Wednesday, January 21st, 2015


What is it?
Digitech XSW Sythn Wah envelope filter from X-series. Made in china around late 00’s

Deeper green on the color than the bass version, the Synth Wah Envelope Filter takes on the battle for autowahs with slight synth features for a guitar. Decent set of features will let you play around for hours. Some of the modes are usable and may even come handy in some situations. Once again, there is nothing close to a schematic available, but once we open the torx screws and check the PCB we notice something that we didn’t want to see. Sea of vias and the auto-routed footprint that is nothing more or less than the same board we’ll see in the bass version.


This continues when we flip the board over. Yes. It is exactly the same effect as the XBW Bass Synth Wah. Only things that are different are the print on box and some lines of code inside the ROM. I did know to expect this, but it still made me feel stumped. This makes me think that all the X-series boxes have just two different boards inside them. The first are the ones which have a rotary switch as a fourth pot and the second, there are boards with a standard pot in that position. It is just me, but i’m still an analog electronics enthusiast first and thus, not too thrilled about all digital designs such as these.


I had a conversation over the social media some time ago. One talented guitarist (who uses Boss GT-100 multi effect, by the way) noted that all the effects are just resistors and capacitors, so it doesn’t matter if the design is digital or analog. I just had to correct him. You know, when there is someone wrong on the internet.. No, these two methods are not the same and cannot be compared head to head. Analog designs rely on electronics engineering, while digital designs rely on processing power, code and A/D-D/A signal conversion. Some modern pedals nowadays can easily hold a power of Nintendo64 inside them (some modern multi effects are even more like desktop computers). But the question is like comparing locally hand forged steel gate on your driveway with one that’s been moulded in chinese steel ovens. Yes. These both do the same thing. And yes. To the laymen it doesn’t matter. But for hand forging enthusiast the different is huge. Then comes the question which is “better”. Neither. Or both. Beauty is in the eye of the beholder.

How does it sound?
Not bad. The modes have good and usable wobbles in them. The synth-like sweeps are pretty wild and since there isn’t too many guitar envelope filters with similar modes available, this unit is rather desirable. Whether it is the same effect from electronics design point of view as the Bass Synth Wah is irrelevant. Sure it matters to me, but it doesn’t affect the sound. My personal opinions rarely affect the sounds… Again, the low price point and big user value will make this effect tempting to many. Not to analog enthusiasts, but for everyone else. Not a bad unit. Good and cheap thing to get. Not a bad investment, if you don’t care about the analog/digital aspect.

Boss FZ-5 Fuzz

Sunday, January 18th, 2015


What is it?
Boss FZ-5 Fuzz. Made in taiwan, may 2007.

Since we are on a roll with sounds coming out of digital circuitry, here’s one to add. Some may have wondered why there isn’t a schematic or any hint of a DIY project for a pedal with this reputation. The answer is simple. The code inside the pedal is the thing that makes up the effect. The electronic circuitry is once more nothing else but input buffer -> electronic switching -> A/D conversion -> digital signal processor -> D/A conversion -> electronic switching -> output buffer. There is a Boss branded signal processor that takes care of creating “that vintage up octave sounds”. Sure. The idea of having a Fuzz Face, Maestro FZ-1 Fuzz Tone and an Octavia in a single box is not that bad. Actually i’d call it very tempting.


But there is a “but”. The label on the cover says “COSM”, so at least the digital design isn’t being covered or pushed aside like it wasn’t there. I’m not sure when digital stopped being a selling point in pedals. In the 80’s and early 90’s it was respected to have everything digital. To be honest, i’m not sure if i’m ever going to get interested in DSP. The DSP is very useful and can do great things. For example, think of all the reverb units around. And what about those multi effects that are nothing short of great for bedroom practice sessions. Here’s the “but”. We are talking about digitally modeling three circuits that would have been doable with cheaper set of components as an analog unit. To me, this seems like one of the in-house competitions Boss engineers might have had. Say, who can turn three simple, a few transistor circuits into a current hogging digital design?


These three modeled circuits have been classics for decades and for a reason. The different transistors in Fuzz Face (and same goes for the rest of the trio..) make a noticeable difference and there have been several main versions over the years, since late 1960’s. Nevertheless, these classic effects have their status due to driving the semiconductors to the point where they shouldn’t be driven. What boss did, was to model these digitally and put it on the market. And then there are the results…

How does it sound?
Fz-5 isn’t the worst sounding pedal in Boss catalog. Hell, it isn’t even their worst sounding fuzz. But it is like playing chess with a friend on Nintendo. The three modes are surprisingly close to their idols, but still not close enough. The main difference with vintage analog circuits is the “unreliability”. The one factor that makes a Fuzz Face what it is. Even the best digital modeling can’t calculate the semiconductor behavior close enough to reality. Maybe in decade or two, but not yet. These modelers are not that bad sounding things and someone who’s not married to the analog electronics won’t be able to tell a difference. To sum it up, the pedal offers “close enough” models of three widely used and recognized fuzz circuits. For garage punk guitarists, this is not an option. But for those who want to use a little of fuzz in their home recordings, why not. The fuzzes from this box are a lot better than the ones on most multi effect units of the era. At the same time, it is good and it is bad.

Digitech XBW Bass Synth Wah

Thursday, January 15th, 2015


What is it?
Digitech XBW Bass Synth Wah, Bass envelope filter from X-series. Made in china around mid-00’s.

Ok. I’ve had some of the X-series boxes lying around for quite some time. Just didn’t find it in me to open them up until now. All them sounded and felt reasonable good on initial tests, so i just took the stance of “decent, not great, but decent” and left them be. Now i figured i would finally start checking them through. XBW is a good unit to start with. Good features and there is some notable usability in there. Sure this isn’t meant to compete with Boss SYB-3/SYB-5 with its lower price point and slightly smaller feature set. I haven’t seen schematics for any of the X-series boxes around. Opening the bottom plate gives a clue for why. There are vias like drops in the ocean.


For starters, super dull, auto-routed board design is quite off-putting. Next, the brand is called Digitech. Which made me slightly cautious and suspicious, since the Distortion series is all analog and has roots deep in the old DOD catalogue. Flipping the board over shows what’s really going on. Harman (the mother company of Digitech) branded AudioDNA digital signal processor with crystal oscillator and a ROM. Now this is what the digital effects are made of. Don’t have to see the schematic to tell you that there is analog signal path with buffers ann switching, followed by AD/DA conversion and another set of buffers and switching components. The effect is in the slash between AD/DA.


This made me worry a little. Could it be that Digitech X-series is as boring designwise as post-2005 Boss pedals? This meaning that the circuitry is exactly the same on all boxes, just with different digital control for each and different code in the ROM chips. Nothing too wrong with that. It’s just that my interest about the X-series boxes just got stomped even deeper in to the ground.

How does it sound?
Like a working “bass synthesizer” pedal. To get a picture, we need to compare it to something we already know. Boss SYB-3 is well more feature packed and wilder in its sounds. Same thing goes for Ibanez SB7. I’d say the synth sweeps here are duller than the competition, but there isn’t that much negative to the sound. More boring than the competition, but still a decent entry level bass synth/autowah unit. For the price and your home recording applications – i’d say this will suffice. Works and sounds pretty good on guitar too. Leaves me baffled, but still trusting.

Carlsbro AC1160 Wah Wah

Tuesday, January 13th, 2015


What is it?
Carlsbro AC1160 Wah Wah. Made in china around mid 00’s.

A wah in a standard Cry Baby sized enclosure, but instead of the basic black, the surface is cool looking chrome. By starters, i must confess that i’m not a big user of wahs. Since i taught myself to user choruses, i still noticed that those can’t be used in as many applications as one might have thought. Same goes with wahs. Some folks will love them and use them a lot. For myself, i just don’t see it. I’ve tried to keep and use one on my main board a few times, but no. For me, the wah use is for studio sessions and mainly just doubling the overly fuzzed lead parts to get more lively overall tone. But that’s it. I just don’t use them. I think i do know how to use them (short, quick sweeps to accent the notes and/or long slower sweeps for the funkier parts). Still. No.


Got this one from a friend with bottom screws, battery door and rubber mat from the top missing. All those parts are quite easily available, but they do not come that cheap. Since i though i’d like to have this in my collection in as pristine condition as possible, i restored it to it’s original state. It’s in decent condition, and yes. It is very nice thing to have in the world of hundreds of different wahs. The enclosure and the board have the same footprint as most other commercial wah pedals. Meaning that one could very easily swap the board for standard Cry Baby or Vox board. The board layout does look different from those two mentioned, but the inductor has the same spot as in Cry Baby. What comes to the enclosure, this model for the box has been around since the late 60’s with only a few revisions. Since it ain’t broken, why try to fix it?


Must admit it. Simply due to lack of interest i haven’t dug any deeper.  But taking the Carlsbro track record in to account, i highly doubt the circuit is anything out of the ordinary. The interwebs tells a story of the early Carlsbro wahs being just OEM’d Colorsound pedals. Since this is the 00’s (or 10’s), this may not be the same thing as it was 40 years ago. After all, this pedal is recent production and made in china. At one point i may try to get a hang of myself and just trace it. But for right now.. Nah. Once and if i get around to that, we will then know how this differs from other wahs. This post might get an update at one point.

How does it sound?
Not that different from standard GCB95 Cry Baby, currently manufactured by Dunlop. Well sweeping unit with solid overall feel to the construction and to the sound as well. Not much negative to say. But on the other hand, not that much positive either. Good solid sounding standard wah pedal. The same caveats that bother me with standard Cry Baby are in place. Annoying switching and no status LED. So in other words, this is decent vintage-like unit with nice amount of user value. Nothing special, but not bad. Nice and cool looking thing to have.

Boss OS-2 Overdrive/Distortion

Thursday, January 8th, 2015


What is it?
Boss OS-2 OverDrive/Distortion. Made in taiwan, january 1996.

I was rather keen on trying this one out. I find the idea of OD and Dist made blendable in a single unit intriguing. This, among with other basic or classic hits as DS-1 and SD-1 are probably the cheapest and most common boss pedals around (sure the number of Metal Zones sold may top everything, but still..), so the money spent versus the fun had was nicely in balance. Before digging any deeper, let’s take a look at the board.


Just as one would expect from a boss pedal that was released in 1990. All the japanese hand craft pointers are already gone and CAD software with auto-routing feature has been in use. Nothing even resembling a visual beauty has not been a part of the board designing process (yes, you can argue that it doesn’t have to be as much as you want).  So no matter what way we look at this, it is just dull looking, but well functioning board. There would have been room on the board to place things differently, but why bother. It’s not like anyone else than some pedal freak/enthusiast will ever be looking at the board from a visual perspective. But let’s look forward. There’s a traced schematic up at FIS. This is where things get a lot more interesting.


The switching and input buffering are per most analog Boss boxes, so nothing of interest in there. After the input buffer the incoming signal is split in two ways. The upper part in the FIS schematic resembles a ProCo Rat with its dual high pass filters and hard clipping. The WTF points go to post clipping filtering. After this filter network, that sort of mimics the filter control on Rats, there’s an buffer stage, followed by a mixer amp that takes care of the mode mixing with a pot called “color”. But we’ll need to back up a bit. The second path from the input buffering was sent to an overdrive stage. This stage isn’t a lot different from SD-1 clipping amp with its asymmetrical clipping diodes in the feedback loop. There is more gain coming out of it and the high pass filter is set lower than in Tubescreamers or Super OverDrives. The output of this clipping amp is then fed to the other side the color pot. The gain setting is the most peculiar thing in this design. It’s a dual (or as some folks like to call it – a stereo) pot with value of 270K that sets the feedback resistor for both sides simultaneously. Rest is just the tone control not completely unlike the one in SD-1 and the output buffering.

So yes. There is some effort in the design. I’d even go to lengths to call some parts of it interesting. Simple, but convincing. Nice design in a cheap package. But then comes the issue.

How does it sound?
Not that great. If we start with the OD side of the color pot, the biggest thing that the sound does is raise eyebrows. Maybe even shoulders. It mid honks its way to the drive-in and leaves you with warm cup of soda and cold fries. But the distortion side of the color pot is the burger. Double cheesed and not bad at all. It sure does remind me of a Rat, but not to the degree where it would be “something alike”. Nope. It’s sleeker in its tone and does not go as mushy. Not a Rat, but not a DS-1 either. Good sounding distortion that goes closer to DS-2 Turbo Distortion range. So overall sound of the pedal isn’t too impressive. But it isn’t bad. These do come cheap, so you might as well get one. Hope you like your soda warm, fries cold and burger delicious.

Rolls RFX970 Vibraflange

Tuesday, January 6th, 2015


What is it?
Rolls RFX970 Vibraflange. Made in USA, 1993.

For some reason i wasn’t aware the amount of stuff in the back catalog of this company called Rolls. The reasonably priced headphone amplifiers and patch bays i did know. But then again, the main reason might also be that the bigger part of  Rolls catalog has been paraded in the US a lot more then here in europe. This thing caught my eye on auction listings. The price was cheap and the shipping plus taxes weren’t too high either so i thought i’d give it a go. Once the parcel arrived i felt pretty enthusiastic. Had to try it out right away. But there were a slight problem in the paradise that day. Effect turned on an everything seemed to be in order, but the LFO didn’t seem to pulse correctly. After a short debugging session, i was aware of the issue’s nature. The speed pot didn’t connect properly inside the pot. And during this investigation, i got pretty certain why. The original board mounted pots were the worst pots i’ve ever seen in a production pedal. Ever. Cheapest things with tendency of disconnecting the sweeper if the pot were bent a fraction of a millimetre to suitable direction. Sure, i contacted the US seller, asked and got a partial refund, since the issue was most likely present when he shipped it out. It couldn’t have appeared during the shipping since the broken pot was one of the middle ones. So i got my partial refund (thanks to the seller, if you happen to read  this) and went on to replace those crappy parts for something that works. I had to widen the pot holes a bit to get the industry standard Alpha brand pot shafts to fit through the panel, but otherwise the task wasn’t too massive. Instead of original board mounted cheapos, i now have hand wired, panel mounted, sturdy pots in there. And the unit works as it was originally intended to. I had to replace the knobs though. Originals were flying high on the standard 17mm shafted pots i normally use. Black knobs, so the visual difference isn’t too remarkable.

While the unit was open i could straight away see how, when and with what the unit was made. My first surprise was the date codes on the electrolytics. Year 1993. I was aware of the fact that David Oreste Di Francesco formed DOD in 1973 and that he went on to build Rolls electronics afterwards, but i had no idea Di Francesco had started Rolls that early, at the time DOD was still its prime. (Please do correct me if i have any of this information wrong.) Anyway, the board design looks very familiar to those who have been inside any DOD FX series pedal. The feel and look of the design doesn’t differ much.


Of course i was assuming this would be an analog design with BBD involved instead of seeing anything digital, but the use of MN3207 and a MN3102 for its driver was still a pleasant surprise. Like i just said, the board design looks and feels a lot like most circuits we find in DOD FX series. This is not  a bad thing at all. It feels more warm, fuzzy and home-like to see this design method elsewhere.

For the features and controls we have two stomp switches, one for bypass and second for activation of “Mode 1”. I currently have no idea what this “mode” actually  does, but the overall tone of the pedal gets softer once it’s on. For the knobs, we have Depth, which controls the intensity of the flanging, Speed, which controls the rate of the LFO pulse, Manual, which affects the LFO’s intensity and a Peak, which controls how high the Q will get on the highest part of the LFO sweep. Quite a pack of controls for a flanger that, at first, seems pretty basic.

How does it sound?
Nothing like a basic flanger or the image of a basic flanger you currently have in your mind. I was blown away once started to play around with this.With zero speed setting, the tone of the pedal is like mild, shimmering octave up with nice glassy feel to it. The controls allow setting the tone from that to a vibrato, that i can call a vibrato (in reality not too many phasers or flangers get to this area). And this can also stretch to that classic velcro’ed airplane flange. Versatile modulation sounds with all the good and bad that comes with the use of analog BBD chips. This thing sounds just amazing.

One can always change the bad pots to something else if needed. But if the design sounds awesome… I may need to keep my eye out if i happen to come across some other units from this RFX pedal series with reasonable price tags.