Posts Tagged ‘Overdrive’

EHX Hot Tubes Nano

Sunday, February 8th, 2015


What is it?
Electro-Harmonix Hot Tubes Nano. Made in NYC, 2013.

Some time ago i stumbled on to a schematic of this CD4049 hex inverter based OD/Dist unit. Played around with the design and noticed it had some real potential. There are numerous drive designs with hex inverters on the wild and while the CD4049 distortion is quite distinct in its tone, most of the circuits still have their own kind of face. Since i had played around with the old version of the circuit and loved it, i had no choice but to get the modern original. Rare occasion, but since the new EHX nanos are priced very reasonably, i got this one as a new unit. For all you DIY’ers out there – get the original. It will be cheaper than building your own from the schematic.


Quick eyeballin’ of the board shows that the circuit is the same as for the old, big boxed Hot Tubes units, just executed with SMD components. Everything from board design to the box scream “EHX” from miles away. Nothing special in the insides. There is a schematic up at Gauss Markov’s site. Plus a documentation for you to build your own. Like i said above, it may not be economically viable, but still. If we recap the design, there is JRC4558 after the input. Both channels of this chip are used to drive the first gain stage of the hex inverter. The gain of the design is set by simply placing a variable resistor between the dual opamp output and the first inverter input. This is followed by a second stage and next up is the switch for bypassing the tone stack. Both option outputs are driven by hex inverter stages, which means we have two of the inverters not in use. The tone control itself is pretty close to the variable high pass/low pass filter we see in all the Big Muffs and derivatives. It’s always a pleasure to look at an electronic design that makes sense.

How does it sound?
Vintage-like. Not too trebly in any way, but focusing on the lower frequencies for the overtones. It does sound very powerful. From mild boost to soaring distortion. I think some of the bass players will enjoy this more than average guitarist due to its relatively dark tone. Like stated, the tone focuses on lower frequencies, but i find this very usable nevertheless. The tone bypass is a novel idea too and will add to already high usability. Very good sounding unit. And since these come cheap, i can’t help myself but to recommend it to you all. It may not suit to everyone’s taste for a main overdrive, but it will have its use.

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.

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.

Nux AS3 Modern Amp Simulator

Monday, November 17th, 2014


What is it?
Nux AS3 Modern Amp Simulator. Made in china around mid to late 00’s

I don’t know what it is. I really can’t point my finger to one particular thing on these and say; “this is why i like Nux Effects!”. But i do. Or least i did. I recall talking to people about how Nux is the solid brand that can turn the low brand value, cheap chinese pedals around. Unless they decide to start OEM’ng their designs to other brands that have low brand value to begin with. This, one of my mildest nightmares came into reality in mid october 2014. I noticed that at least one chinese retailer was offering the Force and Core series effects with another brand name. No. Please don’t do that. Nux was the only modern chinese brand that didn’t have a six year old graphic designer and they didn’t save money on all the wrong places (just on few key places, but not on all). That day was very sad day for me. But what can i do? Nothing. So let’s just forget that misfortune for now and focus on the unit on hand.

This Cherub/Nux series that i like to call “The First Series” hasn’t let me down yet. The overall feel of the boxes is solid and firm. The cheapest feel comes from the battery compartment lid, which in my opinion is placed rather geniously. The user can change the battery without lifting or even tilting the pedal. Not that i know a lot of people using batteries, but still. I think this is just the kind of ingenuity these factory built pedals need today. More on the feel, the pots in this series are not the cheapest kind and they feel solid too. Now, to open this puppy up.. Modern autorouted look. But still neater and more solid looking than current Bosses. And the rest of the manufacturing methods leave no bad word in my mouth.


And once the board is flipped over.. Awww. It reminds me of US made DOD FX series board. Warm and fuzzy feeling with its all analog, all through hole construction. The pots are mounted on their own daughter board.


I’m not aware of the exact topology of the circuit and thus, can’t analyze it much further at the moment. Looks like this has two TL072s and one 4558 for opamps. The D2-D3 silicon diodes look like they might be clippers. I’m not going much further in this guessing game, but even the design looks rather solid. While i do like this box like a young man likes his date, there is one caveat.

How does it sound?
And it is the sound. This is most likely a predecessor of the black AS-4 from the later series and the circuit has been revamped for that release. This earlier one works nicely as a light dirt driver, but it’s hollowness and mids leave a lot to wish for. While this pedal is way greater than its follower on the outside, the better version made its way to the cheaper feeling later version. The bright side is that the EQ section is powerful and working well (i’m guessing gyrators). So i’m left with mixed feelings. As an overdrive effect, this is a lot better than many Tubescreamer derivatives, but as a full blown preamp, not so much. I believe these have out of manufacturing line for a while now. So if you can score one for ridiculously cheap, i’d suggest you go for it. It may not sound like much, but there is some usability in there.

Plus this unit reminds us all what potential Nux had before they changed to cheapest parts and resorted in OEM manufacturing for even lower end brands. World is a cold place.

Ibanez MSL Metal Screamer

Monday, November 10th, 2014


What is it?
Ibanez MSL Metal Screamer from Master series. Made in japan around 1986.

These seem to be rather rare these days. And with rarity, or scarcity, come a price tag that’s not for everyone. I happened to score this unit with some nicks and dents from Mr. Lindén in a batch deal for a good price. Needless to say i’m not parting my way with this one anytime soon. Somehow i wish Ibanez should have manufactured these commercial flops in greater numbers. Mainly because people are simply stupid. Number of SML Super Metals available today is high, since people bought them a lot. It’s not a great pedal, but still it apparently sold better than the Metal Screamer. One wise man on the internet once said, this is the one design in all Tubescreamer family that’s usually just forgotten from the TS canon. The truth is that MSL is more of of a TS than TS10. Before going deeper in to the circuit, let’s open it up.


Opening the bottom plate shows your standard Ibanez board with similar traces as most pedals of the series. The boards (controls have their own board, as  all the other boxes in the series) are thick and overall feel of the electronics is just solid. Not a beauty, but all solid. Black silk screening also looks very pleasing with thick lines.


Chip here is JRC4558D and it is socketed. So i’m fairly certain that’s not original part. Schematic up at Tonegeek page shows the chip as 4558, but knowing Ibanez, there may have been another chip in there when this left the factory. And Maxon/Ibanez boxes never used sockets, so this part replacement assumption is based on well educated guess. Now. If we take a look at the schematic, we see standard Ibanez electronic switching and input/output buffers are also per many other Ibanez boxes. Reference voltage for input buffer has its own network, separate from all the rest reference voltage points.


Tone control and rest of the topology is is per TS9. So yeah. It is more of a TS9 than anything else. Since we’ve now established that the circuit is pretty much TS9, let’s focus on the differences. There is only one.


And this one difference makes a world of difference. Notice the C6 capacitor coming from non-inverting input to R9, 4K7 resistor. This cap is 47nF in every other TS. This capacitor determines the roll-off frequency for the high pass filter created in the clipping amp. Value of 82nF lets a noticeable amount more bass through than the stock TS9 configuration. This means that one could easily just swap that capacitor for 47nF and voilá, instant TS9. Doing this wouldn’t make any sense though. This is the cap that gets its value up in every possible mod know to TS***/SD-1 world. 82nF is a lot better choice instead of TS9 stock value.

How does it sound?
Like a Tubescreamer with slightly added bass content. As Tubescreamers come, this is simply better sounding than any other version. Ok, maybe not better than Super Tubescreamer from 9-series or TS7 with its hot mode. But as a vintage styled TS.. This takes the cake. Added bass takes a bit of the worst honking away, while the overall tone still feels like a TS. This is good. Highly recommended pedal. Especially if you don’t have to pay massive amounts of money for one.

EHX Germanium OD

Saturday, November 1st, 2014


What is it?
Electro-Harmonix Germanium OD, “Vintage Overdrive” from XO series. Made in USA around late 00’s.

Creativity. A threat or a possibility? Sometimes it manifests itself as both. And at the same time. I got mine as used for a fair price with velcro on the bottom. By the way, you can use the detached strip to get the residue glue off the metal. Anyway. The internet had only a few guesses of how this circuit was made. This was one of motivators in play when i decided to buy one. Opened it up as usual.


And traced it. If you take my drawing and mirror it vertically, there are some similarities with Arbiter Rangemaster – but not much. The point of the design is PNP transistors reversed with negative ground and odd controls that affect resistance on both, emitter and collector side of the main transistor. Which looks a lot like remake of NKT275. Or possibly even a re-branded NKT275.


Everything about the circuit and the build quality is more or less on par with all the other modern new york manufactured EHXs. No handwiring involved and most of the circuit is made with SMD components. I brought up the creativity in the first paragraph, because this design falls easily into “drunk or genius” category.

How does it sound?
Unusual. Wouldn’t call it good, but it offers that broken 60’s tone when applied in front of a decent tube amplifier. But folks looking for an overdrive.. This may feel like an awful mistake if you are not exactly sure you know what you are getting into. OD may not be a perfect description for the sound this produces, in my opinion. I’d rather call this Germanium Warmer. If considered as a “warmer” instead of an overdrive, this might be a useful tool to nail that sixties teenage garage punk clean tones. Think of this as a Rangemaster style treble booster with full frequency range and less boost. With rather senseless controls, of course. That should land you in the correct park.

Not bad at all. But i still wouldn’t call this an OD.

Tone Freak Effects Abunai

Saturday, October 25th, 2014


What is it?
Tone Freak Effects Abunai. Made in USA,2008.

More like a boutique brand, the Tone Freak Effects apparently gained some recognition in the latter half of the 00’s. However, the little respect from the diy community turned into a frown pretty quickly. For those who do not see it, i can point out already – it is obvious why. For this particular unit, i got it in a trade as a defunct pedal. The interest for the brand and designs marketed on it did not exactly warrant the purchase of a new unit which is considered higher shelf boutique thing and is priced accordingly.

As always with broken pedals i get, the first thing was to debug the issue and find a cure for it. Opening this one up revealed somewhat ugly PCB design and all handcrafted board. Board design does not look very appealing and the plastic plate, in credit card thickness, says it all. Abunai 808.


Found the issue pretty quickly. A burned out polarity protection diode. Swapped that and the pedal was rocking again. You got your socketed opamp and switchable clipping configurations. Otherwise, the topology is pretty much a Tubescreamer. Now, those who didn’t understand why the brand’s profile isn’t as high as it could be. This is the reason.


Do we really need a new, slightly modified Tubescreamer derivative every month? Do these really sell well enough to warrant their existence? No matter what way you look at it, it is still nothing more but a slightly modified Tubescreamer. These modifications may, and usually will, make the unit sound better than the TS9 reissue you can buy from just about anywhere. This unit incorporates the modifications that are quite usual, clipping options, more bass and more gain. Main reason that  makes this dull is that you can go out and get yourself a TS7 for less than 1/4 price and get the same “TS on steroids” sound. It wasn’t just this model on the Tone Freak Effects catalog that made the brand look far from great. It seems that most of the brand’s designs are slightly modified versions of known designs. If the board design looked even a bit more interesting, the hand made part would appeal a lot more to me.

How does it sound?
Like all the other “TS on steroids” boxes out there. Definite TS sound, including tamed mid honk, but with clipping options on a switch, added bass and gain content. Boxes with same tonal results are out there in numbers, so what makes the Abunai stand out? Nothing. Soundwise, this is just another souped up Tubescreamer. In fact i find the TS7’s Hot mode  to sound pretty close, if not better.

Danelectro CTO-2 Transparent Overdrive V2

Wednesday, October 22nd, 2014


What is it?
Danelectro CTO-2 Transparent Overdrive V2 from Danelectro Cool Cat series. Made in china around late 00’s to early 10’s.

This unit was the very first of Cool Cat series pedal i ever bought. Got it as used unit from one great local guitarist who had just tried it  out. The price was right so i grabbed it. For the pedals in this series it’s usual to see number of upgrades in V2 or just later versions of the pedals. For this particular unit, there are added DIP switch under the battery door. This switch lets you to change the clipping options added to the second version.


Construction, board quality and design decisions are very close to all the other units in the series. The special usage of two sides, that’s not something i’ve seen too often. The board is otherwise SMD, but there is one transistor and a couple of capacitors on the other side of the board. Apparently the board is designed in a manner that it can handle these components in either through hole, or surface mount components. Idea or reasoning behind this method is unknown to me.


While i can’t be sure at the moment, the design seems like slightly modified version of CTO-1, the renowned Danelectro Timmy. With added clipping options of course. These options seem to switch between four LEDs (red and blue) and four MOSFETs. The switching can also take them all of, which leaves us with opamp clipping only. And tons of output level. I must point out that while i may seem like a fan of Danelectro boxes, their board designs have not made me feel at home since  late 90’s. There is something in the looks that make it look forced somehow.


Otherwise the controls are quite standard. You got your volume control, bass/treble EQ section and your gain control. Once again, the treble/bass controls as a concentric pot isn’t the best of ideas (as the knobs tend to touch each other when turning). Sufficient controls and sufficient levels of volume and gain. All this in small, thick aluminium box and armed with 3PDT true bypass. And for the price? How could this go wrong?

How does it sound?
This time it doesn’t. Very nice sounding Timmy-derivative with good controls and a sound that is very much usable. The tweakable clipping take the sound from all out booster via compressed to open distortion. Nice sounding overdrive. And for this price range, i suggest you try it out. You won’t lose much is you decide you don’t like it.

EHX OD Glove

Friday, October 10th, 2014


What is it?
Electro-Harmonix OD Glove from EHX nano series. Made in NYC in 2013.

An overdrive that sounds like nothing else on EHX catalog. That’s the catchphrase from the marketing material. Sure enough. It isn’t close to anything from current or past EHX catalog. But it is rather familiar from somewhere else. Take a look.


The chip on the right is ICL7660S, a DC-DC converter, which doubles the incoming 9V to 18V(ish). There’s a slide switch for selecting the use of standard 9V or doubled. I suspect the 18V doubled mode will eat your battery a lot faster than the standard voltage mode, so a switch may have been a nice idea. How does it affect the operation or sound.. That’s another story. But let me say – not that much. There is a distinctive difference, but t actually hear it, you’ll need to be somewhere else than your rehearsal room with the rest of your band.

The main circuit looked pretty simple when the function of the other chip was established. Couldn’t help myself but to trace the whole thing. Here are the results. Does it look familiar to you? Non-inverting gain stage with gain control, hard clipping done with two MOSFETs (shunt to VRef instead of ground), a recovery stage and a two mode switchable, simple tone control. All that followed by a standard level control.

If you haven’t seen this before, i guess it’s time for you to get yourself a 18V running, MOSFET clipped, tone control added derivative of a Voodoo Lab Overdrive. Or in other words, a very nice and super cheap derivative of something related to an obsessive compulsion disorder.

How does it sound?
Fat and distortion-like overdrive. Very nice sound that sits well in somewhere between a Voodoo Lab OD and a MI Audio Crunchbox. High gain overdrive that’ll suit many occasions with its good controls and good range from near clean to overwhelming drive. The 18V switch adds some headroom, which lets the pedal to live a bit more than it does running on 9V. Treble cutting the tone knob does may be useful to most as well. I’ll keep this short. It sounds good.

EHX Holy Stain

Saturday, September 13th, 2014


What is it?
Electro Harmonix Holy Stain from XO series.Made in united states in 2010(ish).

Once again. Put a pedal, any pedal, for sale with a broken switch and a price tag around 20% of a new unit. You bet i’ll be there, bombing your email and throwing the little money i have against the computer screen. This was one of those. Simply swapped the defected 3PDT bypass switch and did a little cleaning. Unit works as it should. Or at least close to it.

Checking out the insides shows a DSP based big board. All done in current, dull EHX manner. I’m guessing the drive/fuzz/distortion is done with transistors and the rest is digital. It’s sort of like a modern hybrid.


Let’s talk about the features a bit. To begin with, the Holy Stain looks like a cross breed between a Muff and a Holy Grail Reverb, with a few added extras. The main stomp switch is our bypass that sets the overall effect on and off. The basic side is controlled by two rotary switches, a tone control and a volume control. The first rotary selects between clean, fuzz or drive modes. The second selects overall tone color between bright, dark and warm. Tone control acts pretty much like the one on big muff pedals and volume is rather self-explanatory. All that is used to set the base tone.

Then we have the rest. Foot switch selects the digital effect mode between room reverb, hall reverb, a pitch shifter and a tremolo. These four modes share the two controls for all of them, the mix and amount. Mix sets the blend of this extra effect against the clean/fuzz/drive tone coming from the first part. The amount acts as a decay time setting for both reverbs. It also sets the frequency of the pitch shifter mode and the rate of the tremolo. Amount can be rocked with a external expression pedal, which makes the tremolo mode a lot more interesting and the pitch shifter to have similar features to a Whammy.

Limited, but still quite a set of features. These usually come pretty cheap, even as new. But if you think about the features and compare them to what you actually use – or want to use. For me, i would probably gone for separate drive and effects sections with a stomp to engage/disengage the effects other than the drive side. Sure there is notable amount of outside the box thinking when the designer has set the features, but…

How does it sound?
I’ll start with the good and go on about the bad a bit later. The Fuzz mode is actually good with its crisp lead sounds. On fuzz mode, the color settings are usable too, even though i tend to leave it on warm. Both reverbs are ok too, with a slight note explained further…

Off to the bad. First off, to me (yup, may be heresy, but i’m talking about my taste) the clean and drive modes are just bad. First thing that comes to mind is the horrible distortion section found in Digitech RP6 multi-effect. Color and tone controls won’t save those, no matter what. Other reason why the RP6 pops up to mind is the latency. All the digital effect modes are fine if you have your mix control below 35% mark. Higher than that, the guitar signal has already gone out of the speakers before the verbs/shifter/tremolo even think about touching the signal. Similar digital lag as heard on RP6.

One very good mode with almost usable multi-effect section – if you keep the mix down enough for it to work right. Otherwise… no.