Sunday, 27 May 2012

Hipkitty Oxblood Distortion

Information from the builder:

The Oxblood Distortion was designed to emulate the tone and response of an old Vox AC15 with added gain at the input stage. Unlike other Vox-like pedals which emulate the tone and response of the Vox AC30, only the Oxblood Distortion emulates a boosted AC15.

Unique to the Oxblood Distortion is it's ability to make a "large" amp sound "small" and in hyper-drive with the tone of the AC15.

Also unique to the Oxblood Distortion is it's controlled output. While other distortion pedals use greater than unity gain at output to alter the user's amplifier input stages, the Oxblood Distortion does not. This keeps the true tone and response of the effect intact throughout the initial preamp stage of the amplifier in use.

The schematic by WhiteKeyHole that I did this from (big thanks to him as usual for his great tracing) didn't include a supply filter cap, and so I did the layout above exactly as per the schematic.  If you want to include one then you can use the following layout.  I've used an axial cap because I have those to hand in that size, but you could use a radial cap if that's what you have available, and you could probably reduce the layout in width by a column if you do.

A couple of notes based on the FSB thread, if you want more volume then you could reduce the value of the 10K resistor at Q3 collector, for more bite reduce the 220n in the middle between row 1 and 4.  Maybe socket and experiment to fine tune it to your liking.

Thursday, 24 May 2012

Skreddy P19

Just to give mirosol a bigger headache deciding which Skreddy pedal to build next .... :o)

Info from Marc about the excellent original:

Specifically tuned to the sound of a block-buster 1979 album and emulates the "magic" 70's era fuzz pedal that was somehow clear and articulate on high notes while still fuzzy and aggressive on low notes, without excessive low-end muffiness or high-end fizz.  The mids are scooped just enough to keep it from sounding congested, the lows are rolled off just enough to keep it from sounding wooly or boomy, and the highs are gentle, present, and well balanced.

Its clarity will encourage you to dig in and express yourself; it's not an overwhelming "wall of fuzz" type effect.

A wide variety of aggressive and clear-sounding applications, particularly excelling in sustaining, biting, legato lead work


EHX Screaming Hog

Request.  Sounds like something from Deliverance.

After the recent Screaming Bird and Hogs Foot posts I mentioned having them both switchable in the same circuit and someone has asked me to post details so this is what I meant.  You can get a 4PDT switch cheaply on eBay, and if you were considering building both this will save you the price of a second box and footswitch, so you know it makes sense!

Rangemaster with switchable input caps

Request.  This is your standard Rangemaster, but with a 5K trimmer instead of the 3K9 to help bias the transistor, and 6 switchable input caps to go from treble boost to more of a full range boost.  It would be easy to add a 3PDT toggle to switch between a germanium or silicon transistor, but I would expect them to bias differently and so don't know how good it will sound switching to silicon when the transistor is biasd for a germanium.

As always though, have a play with the circuit and see what you like, and remember if you want to use this daisy chained with negative ground effects, you could always use the Negative Voltage Converter.

Tuesday, 22 May 2012

Austone Textone Fuzz Nutz

Manufacturer's description:

Each component is hand tested and selected in this hand- built discrete circuitry beauty. Has more crunch than the original Fuzz Nutz due to an extra gain stage and a tone control. A sustain and crunch monster! Very British sounding. The Textone control rolls off the high end for a singing woman tone, or open it up to peel the chrome off your Tele's bridge! Great for slide, lead, or crunchy rhythm. You must plug this into a wah wah and approach the tone altar!!! Radio frequency interference proof. Each hand-built unit comes standard with a red LED. True bypass switching is retained by using a 3 pole double throw switch. To preserve the battery, the 9V battery power is only available when a plug is inserted in the input jack. A 9V DC negative center tip "wall wart" power supply jack is supplied as standard on all units.

Like me, you may need to fast forward to 1 min 56 seconds! :o)

Wednesday, 16 May 2012

Maxon OD820

Klon killer?  Some people think so, but whatever it's certainly a great sounding overdrive.

Info about the original from Maxon:

While many consider the OD808 to be the greatest overdrive ever created, Maxon is not a company to rest on its laurels. Instead of basking in the glowing praise, Maxon has focused on the user's feedback to come up with an all-new overdrive circuit that addresses the key shortcomings of other units - the result is the OD-820 Overdrive Pro.

The OD-820 was designed to provide a wide range of tube-amp overdrive tones as well as a transparent, hi-gain clean boost. As the name implies, the OD-820 was intended for use by professional guitarists with advanced playing techniques. The OD-820's expressive tone reproduces fingering and picking nuances with haunting precision, making the best use of any guitar or amplifier's character. With a full-frequency response, minimal compression and zero tonal coloration, the OD-820 won't mask a player's performance weaknesses like other overdrives can.

One of the key ingredients to the OD-820's amazing sound lies in its power section. While the OD-820 accepts 9 volts coming in, it then uses a DC-DC voltage converter (#MAX1044) to bump this up to 18 volts. This higher voltage allows for a more accurate, full-frequency reproduction of the input signal than other units can provide. This higher voltage also allows for more balanced powering of the circuit, providing stabilized positive and negative DC voltage to the overdrive, blend, and tone sections of the circuit.

Overdrive and Blend? That's right ­ the other secret weapon of the OD-820 lies in it's blending of distorted and non-distorted signal to create its massive tone. The OD-820's Drive knob does double duty, controlling both the amount of gain and the balance between distorted and non-distorted signal. Note that we said non-distorted signal rather than dry signal ­ this is because this signal is still processed through the tone section of the OD-820's circuit before reaching the output. So, at the lowest Drive settings only non-distorted signal is sent to the output, providing the OD-820's stunning clean boost tone.

Like the OD808, the OD-820 distorts signal in the amplifier section of the circuit rather than having a separate clipping stage, which provides a smoother, more realistic tube-like overdrive than other methods. The higher voltage supplied to the amplifier section provides slightly more clipping than the OD808 or OD-9. The OD-820 uses only JRC4558 op amps for the warmest overdrive tone possible.

And a version using a modified gain pot arrangement (described in the comments below), using two independent pots for the gain control, now labelled Gain and Clean and put together by John.  Increasing the Gain pot to 500K will give you quite a bit more dirt out of this version.

Monday, 14 May 2012

Barber LTD Silver

Dave Barber makes some very nice effects, with high quality workanship and at reasonable prices, so as usual with this kind of builder show your support and buy something from him if and when you can.  For those who want a taster here's the LTD silver with all 6 external controls.

Info from Dave about the original:

Silver L.T.D.

The Silver LTD low gain overdrive is now available in a custom silver hammertone paint. The Silver LTD carries the sweet clear overdrive character of the Classic LTD, but with a flatter eq response. The Silver LTD continues the tradition of stellar chord clarity, with copious sweetness and harmonics.

Sweet Spot tone control, very subtle tone shift that is usable throughout the entire rotational range.

    * Precision matched components-using proprietary specifications to ensure symmetrical clipping and reduced intermodulation distortion.
    * True bypass switching with led indicator- this is achieved by using an extremely high grade switch, in addendum Solid 20 gauge copper hookup wire is used between the jacks and switching.
    * Full size pots- for durability and for easy serviceability if needed.
    * Hand made-we make the LTD one at a time and each one is signed and dated by the craftsman.
    * Volume knob response circuitry-more shades shades and textures at your fingertips than ever before,just by adjusting your volume knob.
    * Cast aluminum enclosure-our incredibly durable enclosure will last decades if not centuries!
    * Double sided pc board with plate through holes-This is the way the military does it when they want electronics to work FOREVER! all pedals should be made this way , few are....once again Barber electronics draws the line in the sand!
    * Three knob control +2 internal adjustments -The LTD uses a simple three knob control layout to keep things easy on the performer. There are two more trim adjusts inside of the LTD so the most demanding player can match bass and presence to his/her needs.
    * Ready for 18 volt operation-The LTD operates from 9 volts to 18 volts, this allows use of higher voltage converters and supplies, for players who want to try higher voltage tweaks.
    * Vintage and modern style components- Players have requested the use of carbon comp resistors, metalized polyester and silver mica caps. These components were thought to be only available on the highest priced pedals. Players asked, and we problem. In addition the Silver LTD has some modern components to get things dialed in perfectly.
    * Center EQ tone control- This Barber tuned vintage style control is meant to sound balanced at the 12 o clock position, from there going up adds treble and cuts bass, turning it down adds bottom and cuts treble. The Silver LTD makes use of the entire range of the tone adjustment with a Sweet Spot tone control.

The Story

The Silver LTD was reborn from and early LTD prototype that some of our best known beta testers and friends had fallen in love with and refused to ever return (thieves!). We took this early flatter response prototype and tuned it in to the enth degree and now we are making it available to the guitar playing masses.

The Sound

With a perfectly tuned drive and new Sweet Spot subtle tone controls you will hear terms like; clean, purring, bloom, twang, sweet, balanced, smooth, clear, sustain, harmonics etc... flying through your head and hands!

Update: I've just seen a gutshot which showed a JRC4040G opamp, which I've never even heard of.  I think most people building these effects will have their own favourite ICs that they like to use, so just try any dual opamp to get the best sound to your ears.  TL072 and NE5532 always sound good to me in almost everything I try them in.

Saturday, 12 May 2012

Rab Fuzz - modified Kay Fuzz Tone

And the other request, a slightly modified and modernised version using more common transistors.  Something to do with the second wah shell you've got lying around! :o)

Kay F1 Fuzz Tone

Request.  A nice little project here for an unused wah shell you may have lying around.  The transistors may be difficult to source so I've laid this out based on 2N5088 for Q1 & Q2, and 2N3904 for Q3 & Q4.

Thursday, 10 May 2012

Death By Audio - Harmonic Transformer

A huge pedal with a huge sound. Complete with enough alien noises to freak out your listeners. Direct crazy intermodulating distortion to make unique music with. The Harmonic Transformer is an extremely loud and intense fuzz pedal which is very interactive with the incoming signal ranging from over the top to bizzare.

Saturday, 5 May 2012

Keeley Java Boost

Info from Keeley Electronics:

The Java Boost is a germanium based Treble Booster designed to give you classic tones from the 60's and 70's. It is not a clean boost.

It must be used with a cranked amp that is overdriven or distorting a bit already. Cranking the amp and pedal will result in more creamy, beautiful, sustaining distortion with the Java Boost.

The Java Boost is most widely used with a tube amp set to a bit of overdrive or clipping which is the key to getting a great sound from this pedal. Setting the java boost in front of a very clean amp with the volume on 1-2 will surely result in a fairly weak guitar tone! Set the amp for some breakup, then click the Java on. There, you'll have a fantastic sound and see why people rave about the Java Boost.


    * Modern Dallas Rangemaster Circuit
    * 3 way Switched Treble-Booster - Locking 3 way switch so your setting is not moved.
    * Stock Vintage Rangemaster (Center), Mid-boost (Right), and Full Range (Left)
    * Metal film parts for low noise
    * The ULTRA RARE MULLARD OC44 !!!!!!!!!!!!!!!!

The Java Boost is not related to the TS9 or Blues Driver, or any other distortion or overdrive pedal. Boss and Ibanez do not make anything like it!

This product is a Treble Booster by design, not a typical overdrive or distortion pedal. That means, the higher the note played, the more it gets amplified and then, by your amp, distorted. Bass notes get cut in two modes on the Java Boost!

Some people don't have experience with treble boosters. This can make using the Java Boost difficult if you try to use it with a huge power amp that has tons of headroom or doesn't distort easily. The trick to get the Java Boost to outperform any other pedal is to have the right amp settings. The amp should be on the verge of breakup or greater. This is where the wealth of tone will is possible.

Another way to run it is before an overdrive pedal. This is the pedal to get if you want a two pedal overdrive setup. Couple this in front of a TS9 or BD-2 and the results are simply amazing. This will add sparkle and life to your solos like no other pedal can.

So what if your amp is set to super clean?!?! No problem, I've found that I love the Java Boost in front of most other overdrive pedals! Yes, simply use the Java in front of your blues driver, TS, DS, BD, SD, FF type pedal and you get similar results when the standard overdrive pedal is on.

Ampeg Scrambler

Info from the manufacturer:

The AMPEG Scrambler was designed in response to requests for a distortion device that was flexible, easy to use, and most importantly, musical. Inherent performance limitations of all designs on the market precluded one or more of the aforementioned requisites. New concepts and methods were researched and tested by leading musicians until every requirement was surpassed. The end result was enthusiasm on the part of every one who tried the unit.

Basic understanding of the unit and its operation will result in the ability to use each of the sounds that the unit can produce. Don’t be afraid to experiment with all of the controls – a little time spent with the Scrambler will enable you to use the unit to its fullest capacity.

EHX Screaming Bird

Request.  This layout is based on the schematic for the original Screaming Bird and as such some of the values are a bit unusual today.  Try 2n2 for input and output caps, and 47K and 470K for base resistors.

Friday, 4 May 2012

Devi Ever Hyperion 2

Info from Devi:

The Hyperion is a titan fuzz God in guitar geek mythology, literally translating to ‘I can’t hear anything anymore’. Imagine, if you will, a Big Muff with enough steroids in its system to kill an ox with its proverbial little finger. The new Hyperion 2 also adds oscillation to this heavy-hitter’s already impressive resumé, opening Pandora’s Box for all sorts of sonic mayhem, mischief and whimsy.  The Hyperion 2 also shares its name with a legendary British thoroughbred stallion. It’s no coincidence that it’s just as well-equipped in the trouser department. Isn’t it about time that your pedalboard got hung like a horse?


Fault Finding a Build

I thought that some sort of debugging guide would be a useful addition to the blog.  I get a lot of requests about non-working builds and always have basically the same answers, so this is a first port of call for anyone having problems.

The build I'm using in this guide for simplicity is an NPN silicon Fuzz Face I built a while ago:

and yes I know this one wouldn't work without transistors! :o)

1) Transistor Orientation

With my earlier layouts (hopefully not so many recently) I used the transistor symbol purely as a graphical representation of a transistor.  I always included the required pinouts but often people have taken the orientation as correct (understandably unless you've known what I've written about it in the past) and so if you're having problems with a transistor build (especially from an older layout) then first thing to do is check the datasheet for your own transistors to make sure the orientation matches.  I always socket transistors to allow me to experiment with different types and gains and would always suggest everyone else do the same.  You can use PCB header sockets (found on eBay) which cost me £5.55 for 20 strips of 40, which is enough to socket 266 transistors.  Not a lot of money to allow you to experiment easily with every build.  As a bonus it's also easy to turn a transistor round if the orientation is wrong.

2) Faulty components

This is really something to check before a build.  Once the components are in circuit you can't guarantee they will measure accurately and as you can get a cheap multimeter that can measure both resistors and caps for not a lot of cash, then everyone should be doing this first.  I've done a number of builds where I was tearing my hair out and as I destroyed the board in anger, measured components afterwards, usually to find a faulty electrolytic cap.  If you have the patience then do it because it can save you a lot of heartache.  If you don't have the patience, then develop some! :o)

3) Cold solder joints

If you're getting noise (or no sound at all) from your build, then a good thing to check is for cold solder joints. 

You want all soldering to be shiny and so look out for dull looking points or pitted solder, and reflow if necessary to make sure you've got a strong connection.

4) Unwanted Bridges

When you make a track cut in vero you always run the risk of leaving a burr that is making an unwanted bridge across tracks which will almost certainly stop the build from working properly.  Similarly solder can stray sometimes to cross the groove between strips and cause the same problem.

If you've got a multimeter the best way to test this is to use the audible diode test to check for continuity between consecutive tracks including points in the row which have been isolated by track cuts.  So in the Fuzz Face example this is where you would want to look for continuity.

If an unwanted bridge is found then use a sharp knife to cut between the tracks and break the bridge.  It may be worth using a magnifying glass to make sure nothing is left which could cause additional problems in the future.

If you don't have a multimeter then just score between all the tracks with a sharp knife, or better still a small hacksaw, to make sure there is complete separation.

5) Checking placement and cuts

I often come across problems with builds where a part was soldered to the wrong hole, or a cut misplaced and again in most cases this would stop the effect working.  With smaller layouts it's easy enough to go over everything and double check but I use a visual method to help me check for placement errors.  Anyone who uses a graphics editing program like Photoshop or Paint Shop Pro should be able to do this easily enough, but not everyone wants to mess around with graphics programs to fault find a build, and if that is the case then just check your placements critically against the layout, counting holes to make sure everything is where it is intended to be.  You can ignore the rest of this section and skip to number 6.

I take a front and back pic of the board and then use the layout pic to create a semi transparent layer over the top.  For the top of the board just select right round the board layout and copy and paste it as a new layer over the top of the front photo. Then you can make it semi transparent by setting the layer opacity.  Then use a deformation tool to line up the layout with the photo (it's easiest to try to lineup the vero holes as points of reference).  The results make it very clear where everything should go and highlight errors

Do the same with the reverse side (don't forget to mirror the layout before pasting over the picture so it's the correct way round.

Using a filter on the track side can make it more obvious where the photo and layout cuts are.  This was using a simple "Darken" blend mode

6)  Measurements

If the above all looks good then we need something else to give us a clue to where your problem arises.  The best way to provide this is to measure the DC voltage between all transistors, ICs, regulators etc and ground.  Any voltage that isn't in the right sort of ball park will stand out like a sore thumb, so if you want help make sure you do this first to give us something to work with.

To assist you in giving us the correct information, ICs follow the following numbering convention:


and if the circuit contains transistors be sure to identify collector, base and emitter when giving voltages. 

7)  If all else fails .....

If all of the above check out ok, then the problem must be an incompetent layout designer! :o)  In this case post a message to the board including any front and back pics you've taken, along with the pin voltages mentioned in (6) and that could really help identify the problem area.

Hopefully you have more successes from this blog than failures to make the frustrations worthwhile.

Negative Voltage Inverter

I've done a few layouts using this method, but thought it may be useful to include a little daughter board which will allow you to easily convert any existing positive ground effects to (daisy chainable) negative ground.

Just de-solder the supply and ground wire from the existing board, and solder to this board, then take a couple of new wires from the -9V output and ground connections on this back to the de-soldered pads on the effects board.

5 minute job and you can get rid of your positive ground power supply.

Thursday, 3 May 2012

ToadWorks Mr Squishy Compressor

Info about the original from the manufacturer:

ToadWorks Mr. Squishy is an analog compressor pedal that combines purity of tone with tight, punchy squeeze-on-demand. Mr. Squishy has been tested with a wide range of amplifiers, including tube, solid state and hybrid, and it delivers the goods every time.

ToadWorks Mr. Squishy provides great compression without oppression, remaining transparent enough that you never lose the original tonal qualities that made you love your axe in the first place. For years, guitarists have sought a natural sounding compression that did not diminish their tone, and ToadWorks has delivered.

Don't you just hate when you kick on the compressor, and your guitar sound changes? Compressors aren't supposed to do that. ToadWorks Mr. Squishy is the anti-compressor - your tone stays crystal clear and unblemished.

Mr. Squishy provides plenty of squish where you want it, and none where you don't. The Gain, Squish & Level controls allow you to compensate for all manner of differences between guitars, pickup types, etc. Mr. Squishy has a nice, tight attack, and a long, slow release, giving you the best of both worlds. Mr. Squishy won't distort unless you want it to; there is no buffer, the Op-Amp can be overdriven, but that's what the Gain control is for. And when you listen to the sound clips, notice that the Level is always around six... want to guess what happens if you turn off the Squish, crank the Gain, and set the Level at 10? A very serious clean boost that will overdrive your amp's input. Yes, that's right - Mr. Squishy can double as perfect clean boost, with power to spare.

Mr. Squishy is hand made, assembled and tested, by real humans with guitars. From the high quality 3PDT switches to our custom made enclosures and knobs, each component is the finest available, making ToadWorks pedals the most well-built and reliable effect units in the world. So stomp away.

Operation and Controls

ToadWorks Mr. Squishy is an Op-Amp based compression effect designed to provide clean, transparent tone even at full effect. The compression effect is more subtle than many other units, while at the same time offering cleaner, longer sustain.

The switch turns the effect on and off, the Input knob controls the level of input prior to the effect, the Squish knob controls the amount of compression, and the Level knob controls the overall output level.

Mr. Squishy features a true-bypass circuit, so un-squishing won't suck your tone dry. Each pedal is carefully manufactured by hand, using only the finest components.

Wednesday, 2 May 2012

MXR Micro Amp with tone control


Rogue Sound Hatchet Harry

I had a request forthe Blind Mary and will do that when I get a confirmed schematic, but in the meantime thought I'd post the Hatchet Harry.