Archive for September, 2013

MXR Distortion+

Saturday, September 21st, 2013


What is it?
MXR Distrotion+, block logo and no LED. Dating back all the way to 1977.

Got this unit as an addon to one special deal. The deal was so good that i thought that someone was trying to to setup a oldschool swindle and rip me off of my money. Turned out that “too good to be true” deal was in fact true. Ended up with metal boxed SF5 and TS5 and this unit for a price that you’ll never see. Let the sum be a secret between me and the seller (Thanks Marko!), who bought this used back in 1990.


First of all, the unit was not in working condition. Opened it up and it was pretty obvious why it wasn’t working. The input jack and board input were shorted and the output jack didn’t connect to anything. I measured the switch, and while it was a bit wonky, it worked. Used some solvent to clean it and now it works almost as new. Soldered the mixed wires to their rightful places and tried again. Nothing. Seller told me that the pedal might have had an incident where it was fed a wrong polarity. Since the design doesn’t incorporate any sort of polarity protection as it’s meant to be used with battery only, one of the previous owners drilled a hole to the front panel to place a battery adapter to original battery snap. The snap was gone too. All the components measured correct, except for the UA741 opamp. The output pin was getting nearly 8 volts while both inputs measured correct near Vref voltages.  So my diagnosis was that the opamp had suffered a trauma from reverse polarity and that had burned the chip to the point where it leaked most of the supply voltage to the output of the opamp. As i don’t have notable vintage supply of 35+ year old components, i had to sub that opamp for LM741, which is the same thing – just manufactured a lot later. After those repairs the circuit fired up.


The pot codes show that the pots were manufactured in the week 21 of 1977, so it is safe to assume that the pedal was built in 1977 or early 1978 at latest.

The Alalogguru’s  schematic is simple to read. There’s one gain stage that feeds the hard clipping stage created with two 1N270 germanium diodes, which then pushes the signal to output. What i find to be the most interesting thing about this pedal is that the board isn’t fastened to anything. It just sort of floats in there with all the components bent horizontal.


The components and the topology are on spot when comparing this and the current Dunlop reissue. All the other things are not. The switching (may be better in new one), the jacks and the board itself. Jacks and switching are not bad in original, although some tone sucking may occur due to input of the board being connected all the time. My suspicion cling towards the board. On original the traces are far away from each other and there’s no ground fill at all. The sturdy box takes care of all the shielding needed. The reissues have clustered the board with massive ground fills that even go over the traces. In theory that shouldn’t affect the sound at all, but…


The bottom plate is a thing of beaty too.

How does it sound?
Astonishingly good. There’s at least three million kilometers between this and the new Dunlop made reissue. The tone really puts my praising of the OD250 reissue to the test. The output is lowish, but enough beat the clean signal fair and square. This creates the best tones with distortion knob maxed or near maxed. May be in part because of the components age, but damn it sounds good.

Warm, soft overdrive that sounds like analog heaven with both, single coils and humbuckers. Too bad that these are getting rare and the reissues aren’t helping those who want the sound. At all.

Danelectro DJ10 Grilled Cheese Distortion

Saturday, September 21st, 2013


What is it?
Danelectro DJ-10 Grilled Cheese distorion.

Had no information on the design whatsoever when i got this unit. Should probably have done some reading before paying 20€ for it. As distortions go, there is one sub-genre that i find no joy in playing with. This one sinks to that genre. Fixed wah distorion. As the ones i’ve played with, the Ibanez CD5 Cyberdrive is the least sucky in the bunch. And that too sucks quite a bit. That may be suitable for some special lead sounds usually employed by men in tights. So i may be a bit biased when judging this pedal.

Couldn’t find a schematic and to be honest, this unit does not interest me enough to even dig deeper. The comments on the internet say that there are 3 dual opamps and a inductor that make up the circuit. Bypass seems to be standard of the mini series.


One of the rare cases of complete meh. Which means i have no interest in seeing how or why this one does what it does.

How does it sound?
Like all fixed wah designs with mid scooped distortion, not completely unlike DS-1 or alike. Personally i wonder who would need or want a sound like this. It’s not my place to judge, so if you find fixed wah distortions useful, go ahead. This one will remain in mint condition in my collection.

Yamaha FL10M II Flanger

Thursday, September 19th, 2013


What is it?
Yamaha FL10M-II Flanger from the 10/Sound Device series, made in japan. Manufacture date unknown, but it seems like 80s build. Looks like a coin-op arcade machine now doesn’t it!

The brand is quite a puzzle to me. Pianos, jet skis, motorcycles, guitars and network routers. Usually i wouldn’t trust a brand that sells coffee machines and snowboards and/or something else completely unrelated. This is one exception.

One of these units that came in as defunctional. In this case, the trimpot responsible for delay time had dried up and stopped working. This time i didn’t even think of replacing the trimmer but just greased it up and the beast flanges on again. Enclosure is very sturdy. Thicker metal than usual 80s things. Black and pink! What could go wrong! Here’s another external shot of this beauty:


The box makes me feel good – by sound, and by in and out. Almost gives me goose bumps. Just like the guitar i’m using as my main instrument at the moment. It is probably the ugliest Stratocaster ever made (all strats are horribly ugly, heresy, i know). Sounds just amazing. If the sound came from some guitar that was cool looking i would probably just say, meh. But when something goes over the far end limit of being ugly, it usually turns itself around. Like in this case. The box is so ugly that it is on extreme side of beautiful. And there’s more. Didn’t know what to expect when i first opened this up. I wrote on some earlier post how i find these hand drawn acid trip-like traces pleasing. Here we have another perfect example of that – how to draw up circuit point connections with artistic point of view. I could easily live with that board image on my wall. By the way. Note the tension removing plastic addons on in/out jacks.


So not that it is beutiful on all sides, it is very well designed too. Insides are made of two individual boards stacked on top of each other and connected together with a ribbon cable.  Bottom board having the switching, jacks and LFO, upper board having the delay and controls.


Bottom of the upper board is just as beautiful as the lower one. Just simply pleasing. The boards are thick and sturdy too. The soldering is neat and looks like the person who soldered these wanted to do a good job – and he/she did. As quality of the stomp boxes come, this one needs to be touched to feel just how well it is made. I wish more modernd boxes were like this.


As one could guess, the delay is created by MN3102/MN3207 pair. The controls are Depth, Speed, Manual and Feedback. Manual and feedback can do really cool things as the modulated signal is fed back rather than trying to keep it clean. With certain low settings, this can be used as a analog delay too – Very, very short one, but still the option exists.


Even the pots are sturdier than what can be found in usual boxes from the era. Two boards are well used. The variety of controls will take a lot of board space, so i wouldn’t even call this overengineered piece of first class japanese stomp box design. So glad i got it. Thanks to Mr. M. Säisä!

How does it sound?
Great! One of the greatest flangers ever. Very wide coltrols from mild, short analog delay to massive, almost velcro-like sweeps and endless feedback. From standard guitarist flange to power electronics style noise guru sweeps. Underrated brand, underrated box and very underrated sound. Definitely a  keeper. I could sell off all the other flangers before this one. I want to hype the aesthetics one more time; Black & pink, Coin-op arcade box, acid trip traces, sturdy components and overall feel.

Danelectro D4 Fab Echo

Thursday, September 19th, 2013


What is it?
Danelectro D-4 Fab Echo. Cheapest thing made in china. Came in a trade for next to nothing.

I usually have nothing againt using plastic enclosures. And as i stated on Fab Metal post, the build quality here is astonishingly bad. This particular unit doesn’t quite reach the horrifying things inside Fab Metal, but it is still nothing i want to spend my time on. The boards are a lot neater than on the Metal distortion though. Also the components are SMD all the way, which leaves a slightly better impression.


Still i don’t find the boards eye pleasing in any way. No symmetry, nor any master plan at all. Don’t know what the designer has been thinking when doing a layouts for these. The design itself isn’t too bad. It may have looked and sounded reasonable on the designer’s breadboard before it made its way forward in the construction chain. As in all Fabs, the shilding is done with paper with foin on the other side and that piece of paper is screwed to ground. Designwise…


Yup. That’s PT2399 digital echo processor with fixed delay time. This could be modedd to full delay by just swapping one of those left hand side SMD resistors for a pot. Personally i don’t think the mod is really worth the trouble, as you can score similar sound from other china brands for pretty much the same price. That way you’ll get better shielding for your box too.

This will be my last post of the Fab series. Last weekend, i sold both of these as there was just not anything interesting in either of these and the build quality doesn’t please me. At all. While i do like Danelectro’s boxes in general, this serie will not be collected. These will continue to give a bad name to Danelectro effects. I can clearly see why.

How does it sound?
Not too horrible. Sound exactly what PT2399 chips with fixed delay time should sound like. I’d still recommend checking out china brands for a delay instead of this…

DOD Overdrive Preamp 250 (reissue)

Thursday, September 12th, 2013


What is it?
DOD Overdrive Preamp 250, 90’s reissue in yellow first series style enclosure. Made in china.

This is one of those boxes that everyone should play with at some point in their life. If for anything else, for the feel of that heavvy duty box. The base design topology is pretty much verbatim with MXR Dist+ and probably a hundred other boxes from end of the 70’s up to today.  There are differences though. And good thing there are. As in my opinion, modern Dunlop made Dist+ reissue with UA741 and Ge diodes just suck. But before anything else. Let’s just open this up and see what’s inside.


Looks quite modern with neat thin circuit traces and connector. Plus the blue jacks. Sadly, no date printed on the board. I really wish that it had a date in there. Would make the guessing process less valid. Components are often good place to start the process. So let’s see what lies underneath that board!


There is a dual opamp  in here!

Some documented units here at the internet have KA4558 chip instead of RC-branded one, so that should be a clue. Oldest Fairchild Semiconductor’s datasheet for KA4558 chip i could find is dated 2001, so i do believe that the units featuring Texas Instruments RC4558P are older than 2001. Drop a comment if you know the exact dates when these were made with KA and RC branded  chips. I’d be more than interested to know. The print on the chip is 66CRDYN, which tells me absolutely nothing. I’ve read that usual way for printing manufacture date on the chips is with four digits. Two for year in question and other two for the week of that year. Apparently not for TI chips.

The dual chip can be found only in these reissues. Original design is with UA/LM741 single opamp. Schematic for both versions (one with old single opamp and the one with dual opamp) can be found online, and checking them both out would be recommended. The dual opamp version just omits the other half of the chip completely by grounding the inverting input and shorting the output and non-inverting input. The other half is used as in original. So it is basically just wasting the other half, while staying true to the original.

The box itself is quite loyal copy of the original with the stamp on the back. But there’s also a aluminium sticker that tells us where this unit came from.


How does it sound?
Just amazing. For me, this one sounds way better than any of the single opamp versions i’ve tried. I actually cloned this version of the circuit for myself and i’m using this clone on my main pedal board. Once cloned, i can have standard 2,1mm DC jack and an indicator LED – Wouldn’t want to harm my original to incorporate those features. I use it to boost the rhythm riffs on choruses. Just a tad of boost and mild overdrive in addition to my mildly overdriven base sound. It just brings the songs alive. In my opinion, this is just the perfect overdrive/booster. Better than all the rest. I know some people will disagree. And they are welcome to disagree all they want. I just don’t see myself fastening any other design to my board as an overdrive anytime soon.

Colorless writings, part 2 – The Collector

Thursday, September 12th, 2013

Second article in this series. I’ll be asking myself questions about collecting these damn things.

Why are you collecting guitar effect pedals?

Well. I guess i’ve been sort of an addict to something for all my life. I decided that ~1250 title record shelf should be enough as a personal library. To some, that’s peanuts. But i was collecting records a few years ago. Until i started to build pedals myself. I built couple of kits that i purchased and most of them worked right off the bat. All of the sudden i noticed that i simply forgot to buy vinyls and cds and spent most of my money on components for pedals. By that time i used to have something like five to ten factory made pedals for my use. And i was building a lot. As i was building pedals for friends, i started to get some factory made stuff in trade.

I’ve been interested in pedals for a long time. For some reason that interested got a bit out of hand later on. Can’t remember my very first own pedal (TS5 or Zoom multieffect monster), but the first i bought with my own money, and really loved was Schaller tremolo. That was somewhere in the year 1999. Had to sell it later on, but many others followed. And got sold. For a very long time i only saw distortion as any distortion, tremolo as any tremolo, delay as any delay and so on. The biggest difference was the controls. I think i was the average pedal user back then. Only through building i became aware of the drastic tonal differences between designs.

I started to request pedals in exchange for pedals that i had built. Of course i had to open every last one of them open to see how these were made. To study them. If the schematic for a design was around the internet – that, in addition to hands on feel to the sound gave me good gut feeling why something on the circuit sounded the way it did. All of it started to make more and more sense. I do not know everything i want to know about electronics, but i now have these gut feelings about many things. Most of my correct assumptions are correct due to experience, not from books or studying.

Back to the question… I do value other boxes more than i value others. Through collecting pedals that i find interesting, i can get a better glimpse of the design and how it sounds. To collect pedals is to learn about them. Sort of like collecting butterflies and learning about biology – if you excuse my super lame figure of speech.

Why you chose to collect the brands you collect? 

The brands are what they are and those are selected by coincidence. I don’t care that much for brands as i do for interesting designs. Some manufacturers just tend to have more interesting stuff on their catalogue than others. Some brands are appealing, and i’ve started on few, but sold all of them quickly if the overall experience has been bad. Like Dunlop made MXRs. I had a few of those (Phase 90, Dist+, 78 Badass dist, Bluebox, Dyna Comp…). But all of them sounded just bad, even those were/are exactly the same as the old, original MXRs – at least topologically and by components. All of those felt and sounded arrogant to me. Only unit i kept is the Dist+, but that’s because i modded the hell out of it.

I’ve had some EHX boxes and still have couple. In my opinion, this is the brand that is nowadays simply overrated. Don’t get me wrong. Mr. Mathews is a genius who has developed many great original circuits. But in addition to those great circuits, he has developed a ton of crud which make up some of the most wanted effect pedals ever. The obvious ones like the Big Muff will always be part of my collection. Octave multiplexer should be mentioned here, as that’s probably the greatest down octave design i’ve had a pleasure to play with. But then.. There’s Memory Boy and Frequency analyzer to mention a few. If you don’t know what i’m talkin about, you should try to get your hands on either of those. I wasn’t the only one who thought my Memory Boy unit was broken…

Where Dunlop made MXRs feel arrogant, most of the EHX boxes feel just wrong.

I’ve always liked Danelectro pedals because of their appearance. First Dano i ever had was the Dan-Echo (unit got sold later on, and i’m looking to score one for cheap at the moment). Which led to finding interest in other Dano boxes as well.

My main collectible brands are Ibanez, Danelectro and DOD. I have mixed feelings about Boss/Roland, and my interest toward Marshall effects has peaked recently. I really don’t have a clue what my collection will be like in a few years. If get fed up with some brand, i might just sell them all.

Aren’t those cheap plastic things just bad?

Oh you mean the Ibanez Soundtanks and Dano minis+Fabs.. Well. Not necesserily. There are some that i wouldn’t call good, but the rest. You’d be surprised. 80’s cheapo will have very different price range today. If the circuit design is good, who cares about the outer shell? This may sound like some hippie “inner beuty” crap, but there is some truth to it. Besides, no matter what the quality of the enclosure may be, almost every repair job i’ve done has involved with something that isn’t caused by the enclosure. Nor the plastic jacks. Nor the “cheap” pots. Actually, most pot replacement jobs i’ve done have been with the ones that are considered to be high quality and endorsed by boutique builders world wide.

You want to get the best for a reasonable price, don’t you? Everyone does. That’s why manufacturers create series that are cheap, but offer the sound you are after – and because you buy them for the price. If no one buys certain design, that design will eventually vanish.

But generally speaking. Bad? Compared to what?

Boss TR-2 Tremolo

Monday, September 9th, 2013


What is it?
Boss TR-2 Tremolo. Unknown manufacture date. No serial, as the label has vanished at some point alolng the way. This came to me in a trade as a defunct unit. Gladly, it was just polarity protection diode and one burned resistor. No visible damage to the board itself.

Of all the tremolos i’ve played, this one just seemed solid by construction and sound. Nothing special or anything that made me go wow. Just one of those tools that are good to have. TR-2 was first released to the public in 1997. The Pb-Free label on the board suggest that this is quite new unit, maybe around 2010-11.


As the photo above shows, all the opamps are SIP-chips. The LFO and gain recovery amps are M5218/NJM4558, while the modulation amplifier is M5207 VCA. The factory schematic (found on the internet) shows how the LFO is created – and how the modulation is applied to modulation amplifier. Neat and simple. Design is pretty straightforward and does not peak my interest more. Controls offer good range, while the wavefrom control is too subtle for my taste.


Traces on the back of the board show neat soldering, but dull design. Almost machine-like autorouted feeling to it.

Some people have reported that the output level of this design is lower than unity, aka volume drop. I would mostly blame that on human brain perception or psycho acoustics, but the issue can be dealt in other ways too.  As the modulation recovery amp is wired as standard inverting amplifier, there is one resistor responsibe for the output level. That resistor being R12, the feedback resitor of IC2A in the schematic. Original value is 22K, but you could swap it for 27K or try on different values to tweak the output to your taste. You could even replacce that resistor with 50K pot to get control over the output level. Other option to try is to snip the C4 – 100nF capacitor taming the oscillator output. One more option is to lower the value of input limiting resistor of the modulation amp. This being R9, the 10K resistor. 6.8K should offer unity or slight boost. One more mod would be to remove C7. This will omit the high frequency taming at the recovery amp and let more highs through.

One could of course play with all of the above to tune it just perfect to your ears.

How does it sound?
Decent. Not too special, but nothing’s amiss or wrong. Mass tremolo with no personal character to it. LFO wave control leaves me a bit puzzled. It could be a lot better or just a bit more drastic. Not a bad thing to have. Wouldn’t buy this as a new unit, but i’m glad i got.

Danelectro D3 Fab Metal

Monday, September 9th, 2013


What is it?
Danelectro D-3 Fab Metal. Fab series, made of plastic and probably the cheapest thing you’ll ever see.

For some reason i seem to gather metal distortions even i’m not a big fan of metal music or the guitar sounds commonly affiliated with it. I do think it’s fun to play with metal distortions at home though. So while i’m gathering more of the missing Danelectro boxes that i want, these tend to arrive in the meantime. Where mini-series boxes vary in build quality, these are very consistent. Consistently bad. As new units currently sell for 15-20€, it is no wonder the build costs have been cut in every single step of the way. Not to say that these wouldn’t work. They will, probably until the end of time. But the board is shielded with a piece of paper that has a layer of tin foil on the other side. Magnet for radio frequencies and manifestation of bad business orientated thinking.


There’s flux residue all ovet the board and soldering looks astonishingly bad. I always have hard time looking at component selection that’s mixing SMD and thru-hole components. Plus the board design looks like a winner of “who can whip up a quickest PCB design” contest. Auto-router is another possibility here. Not eye pleasing at all.


I can say with certainty that Fab series isn’t designed for active guitarists, but those who are starting to learn guitar – a perfect way to kill the starting enthusiasm for tone hunting is with these pedals. It could be argued if Danelectro should have released these at all. In my opinion, they shoudn’t. These hurt the brand and spread misconception that all Danelectro boxes are made with same (lack of) integrity.


The design itself is your standard distortion with gyrators and multiple gain stages. Mr. Jones has drawn a schematin in 2006. This doesn’t have component values listed, but i suspect this may not be prime suspect for cloning or modding…

Like stated, the build quality alone make these very much undesirable boxes with no value at all. May the designs inside be how bad or good ever, you’ll be a lot better off with modern chinese cheap brands than these. These may be slightly cheaper, but still. Wouldn’t recommend this series to anyone. This may be the point where i draw the line. I have nothing against Mini series or plastic Soundtanks. These have been created to make money. If the retail prices are as low as 17-22€, you can imagine how much time, effort and quality gets in to the final product.

Danelectro. Please stop killing yourself.

How does it sound?
Awful. Didn’t have very high hopes for the unit, but as a metal distortion, it sucks. However. Once the gain is maxed, this turns into digital sounding fuzz rather than metal distortion. Which isn’t good, but it may have some use in certain situations. As a guitar effect? Avoid this like a plague. As a power electronics noise tool? Maybe.

And no. I won’t be finishing my Fab collection. Ever.

DOD FX57 Hard Rock Distortion

Friday, September 6th, 2013


What is it?
DOD FX57 Hard Rock Distortion. USA made box, dating 1987.

Bad year. 1987 i mean. According to DOD information heaven, America’s Pedal website, the basic idea for this design was already tried out on certain DigiTech double pedal, as well as on one Boss design. And what is this idea? To take a OD/Distortion and place a delay circuitry after it to “widen” or “thicken” the sound. I must say that the idea itself doesn’t sound that bad. Distortion with analog delay? How could that be bad? Well it can. For those interested, the schematic can be found online at Schematics Unlimited. It shows that the delay section is placed  after the main gain stage and to be mixed back to the distorted signal at the level control. The delay itself is created with MN3007/NM3101 pair. Level control is mixing the signal, delay included or not, with virtual ground and passing it to the presence control. The distortion control is basically just a variable resistor limiting the input signal current after the mandatory input buffer – which is needed due to basic DOD electronic switching. There are two trimmers that affect the delay functionality.


The board looks kinda cool with those yellow mylar caps.

Now what exactly makes this a bad design? Two things. The distortion and the controls. That is a lot for one design. With the soft clipping, placing four Si diodes to the feedback loop of the gain stage offers something that isn’t too far from tube screamers, but the filters and second clipping stage (the Ge diodes) before the volume control gives out texture that isn’t too desirable. And that presence control would need a huge rework to even remind me of anything reasonable.  I personally think that presence is just a wrong word for this control. It should rather be “extreme bass cut pot that we here at DOD didn’t think all the way through”.

How does it sound?
Bad. Thin, hollow and nasal. Turning the delay off doesn’t quite help you. With the distortion at minimum and delay maxed, we can get something that reminds one of usable sound. But it is pretty crappy sounding design. Not all the settings are awful, but none of them are particularly good wither. Overall experience is so crappy, that i have high hopes for this becoming a rare gem – due to low(ish) number of units manufactured in relatively short period and the fact that some people will dispose their units with their everyday garbage. Which wouldn’t be too crazy idea with this particular unit. Not all of the setting combinations are horrible, but in genereal; it sucks and it sucks hard. But it is an interesting failure.

Ibanez CP5 Compressor

Friday, September 6th, 2013


What is it?
Ibanez CP5 Compressor from Soundtank series in plastic enclosure. Serial points to somewhere around ’95-97. Date is based on a educated guess, as always with these.

First off. Ibanez compressors tend to use somewhat obscure OTA replacement in a few designs. The 9-pin  SIP-chip in question is BA6110, which is in fact a VC opamp. The datasheet doesn’t have a word about transconductance. It does talk about voltage controlled amplifiers, filters and oscillators. While the chip is way different from the obvious CA3080(A/E) found in MXR Dyna, Ross Comp and about a hundered different derivatives, it can do the same thing. Ibanez uses the same SIP-chip in only tremolo it ever produced, the TL5 – only there the VCA is harnessed to be used with LFO instead of controlling it with the input signal’s voltage. More about the tremolo once we get to it.. This post is about the compressor.


To study the schematic, you can check it out on Dirk’s page. His trace is beautiful work of art as always. All the other stuff going on with the circuit are relatively close to Dyna/Ross, so the base design is and isn’t a ripoff at the same time. I’m not quite familiar where in the Ibanez/Maxon design timeline did the BA6110 chip arrive, but it seems that the Master series CPL was the first one. Followed by CP10 and this circuit. Which are, all three of them, pretty much the same thing. In other words, an VCA adaptation of CP9, which uses more traditional LM16900 dual OTA. Which is, CP9 i mean, actually Dyna/Ross comp with dual OTA (second half unused). So the histroy behind this Soundtank CP5 is pretty clear. This time, the design revamped by the Maxon/Ibanez  team is better than the original.

I can say this with confidence. All four mentioned above do work and sound a lot better than currect Dunlop/MXR version of the Dyna.

How does it sound?
One of the great ones. Where as MXR Dyna is a lot more like shock effect with it compressing way too much even on minimum settings – This one can be used on all the time without excess noisy mushiness. Of course it can be turned to the max, which makes it quite close to Dyna. In a few words – Really good sounding compressor with classic feel to its sound. Doesn’t give you as much noisy mush as CA3080 designs, but good compression that thrives with a telecaster.