Tuesday, 29 April 2014

Acoustic Piezo Preamp

Request for a simple opamp piezo preamp based on this circuit:

Monday, 28 April 2014

Bearfoot Emerald Green Distortion Machine

Today is Bearfoot day.  Info about the original

For the Vox lover in all of us, Bearfoot FX has created the Emerald Green Distortion Machine- a pedal which captures the chimey, crunchy essence of the AC series amps and provides a faithful simulation of the Vox tone through a variety of amps. Used through a Vox, this pedal acts as a booster driver to really push your amp into sonic heaven.  The EGDM Distortion and Voice controls are interactive and used together will take you from the low, clean tones of an AC all the way up to the screaming tone of a cranked Vox. The EGDM is extremely responsive to picking dynamics and your guitar’s volume knob.  

Bearfoot FX is the brainchild of Bjorn Juhl of BJF Design and Donner Rusk of Donnerbox. Every pedal is handpainted and no two are exactly alike. The pedals now ship with a plain, unpainted bottom plate to help ensure the most secure contact with adhesive Velcro for use on pedalboards. Bearfoot FX pedals are handmade in St. Louis, Missouri, USA. 


Bearfoot Candy Apple Fuzz Gold

There was a resistor missing from the schematic so the layout has now been fixed. If anyone has already built this then if you can add a 2K resistor somewhere between the germ transistor emitters and ground that should sort it out.  Or you can use then fix layout John did at the bottom of this page.  The main layout has been fixed with an extra column being added to accommodate the resistor

As usual with Bjorn designed stompboxes, a great sounding fuzz.  2N1308s should be available on eBay but if you can't find them, just throw any NPN germaniums in there.

Info about the original:
The Candy Apple Fuzz is one of Bjorns first BJFe circuits (along with the BBOD and DRD) ... it was made to cover the nastier side of vintage fuzzes and it does just that and more … over the years the one recurring request was to make it a bit smoother and more musically manageable ... when it came time for the BearFoot version he did just that by adding a treble control to reign in the rasp as needed… and he also adjusted the circuit to germanium transitors, which are smoother and more musical to most ears ... BUT silicon has its own musicality and many just like the full on unruliness and extra rip of silicon ... now you have a choice as we introduce the original silicon formula CAF ... Silver/Silicon ... Gold/Germanium

And the quick fix for anyone who built using the original layout, the resistor value should be 2K.

Saturday, 26 April 2014

Frantone Vibutron

Great sounding tremolo here from Fran, and something for me to finally build with the batch of ICL8038 ICs I bought a couple of years ago! :o)  To keep the size down and make it 1590B friendly I've done away with the rotary switch used in the original, and instead I've used a DPDT on/on/on toggle to select the waveforms.  Functionally they remain identical and you will be able to select sine, triangle or square wave in exactly the same way, but remember to add the link noted.  I've also added an optional "Fast" switch which isn't in the original, but will do what it says on the tin and so some people may like the extra effect.  Thanks to KindaFuzzy on FSB for his schematic.

Info about the original:

Good Vibrations!
All of the warm, soothing tone you'd expect from a great vintage amp trem with the added versatility of selectable waveform.  Designed with the single coil player in mind, this variable amplitude modulator is a favorite among those that want the highest fidelity and smooth performance combined.  The Depth control allows you to dial in as much effect as you like, from the slightest hint of mellow sine wave smoothness to fully gated square wave effects.  The added benefit of a wide Speed range makes this a very powerful tool for the serious musician.  The Vibutron's lemon-lime motif is highlighted by the custom made cherry red Bakelite knobs.
Bon appetit!

Friday, 25 April 2014

Son of Screamer

OK we already have this here essentially with the Lovepedal Eternity, but this was a request and using the Eternity as a template meant it took 2 minutes to do.  This is Jack Orman's circuit which pre-dates the Eternity and so the design that Sean was "inspired" by.  Anyway I suppose it's nice to keep filling the library so we have everything,

Not verified in this guise, but it is really of course :o)

and an 18V charge pump version as requested

Thursday, 24 April 2014

New US based kit supplier

This has been requested by lots of people in the US.  Bitsbox are a fantastic resource for this site supplying kits and other parts to many destinations around the world, but unfortunately the insurance requirement for shipping goods to the US became prohibitively expensive for some businesses over here and so they had to make the decision to stop shipments to the US.  Many of the visitors to this blog, in fact the majority of visitors to this blog are US based and I have been asked about kits for a couple of years now by many people, and now you can get them.

MKLEC is a small independent retailer located in Columbus, Mississippi and they have been working hard for a couple of months now to get their stocks up on the components required for the kits, and have now started putting them together.  At the moment only the Deep Blue Delay kit is up on their site, but it will be followed by the Klon very shortly and lots more to follow.  The kits will be posted on this page:


The business is run by husband and wife David and Amanda who are lovely people, and I would encourage anyone who is interested in buying kits in the US to contact them to give them feedback of what kits you would like to see first, then they can give some kits priority in putting them together.

As I said they have been putting a lot of work in getting the parts together and David was adamant that he use high quality components throughout, so the kits use Xicon 1% metal film resistors, Nichicon and Panasonic polyester film capacitors, WIMA and Cornell Dubilier for the polybox cap and audio grade electrolytics so even if you are indifferent about component types, you can be assured of quality and longevity of the popular branded components chosen.

If you have any questions then get in contact with us, or even better MKLEC directly so you can hear straight from the horses mouth.

David has sent me a kit to build and when completed this will be given away in a free draw to new customers signing up for an account with MKLEC via this blog, so when you do sign up make sure you note tagboardeffects somewhere in the registration form so you can be included in the draw.  Just pop it in one of the unused form boxes like Fax, Company or Company ID or alternatively send him an email so you're added to the list.

Wednesday, 23 April 2014

Fulltone Fatboost V1

Request for vero version.  Info about Fulltone's slightly modified copy of Jack's Mini-Booster circuit:

This magic little box (the size of an MXR phase 45) is for the Purist, whether you're a Guitarist, a Bassist, whether your thing is Jazz, Rock, Acoustic/Electric, or Heavy Rock.

Not a distortion box, the Fat-Boost is a Class A Discrete design offering up to up to 30db of Clean Boost without ANY change to your EQ.... and at the same time it makes your sound Bigger, with more even order harmonics! You Blues players with the vintage-type tube amps will never turn this thing off... and it works great in front of Master-Volume amps to kick them up a notch as well.           

The Fat-Boost gives you the feeling that your amp is cranked at living room volumes so clean playing is more dynamic, notes hold on longer without being distorted! 

Jerry Garcia Tiger Preamp

Request. Info about Jerry's original guitar with inbuilt electronics

Tiger was Jerry Garcia's main guitar from 1979 to 1989. It was built by Sonoma County luthier Doug Irwin. The Tiger is named after the tiger inlaid on the preamp cover located on the guitar's top, just behind the tailpiece.

The electronics of Garcia's Irwin guitars are unique, and feature an onboard preamp and effects loop. Much like a Stratocaster, the three pickups are selected with a five-way switch. Signal from the pickups passes through the tone controls, followed by an op-amp based buffer preamp, or Unity Gain Buffer, which is designed to prevent signal loss due to capacitance when long cables are used.

Tuesday, 22 April 2014

Fulltone Bassdrive Mosfet

And the bass version.  This is based on the guitar version but with the passive changes to match the filters in the bass version.  The diodes seem to have changed often in this, some with symmetrical mosfet/germanium combinations with a 1N34A in both directions and some with asymmetrical as shown here.  Some with more than one 1N4001 (or 4005) or asymmetrical on the silicon side with 2 x 1N4001 and 1 x 1N914.  So I'm just leaving the clipping as per the guitar version, and you can put your favourite combination in there if you choose.

Info about the discontinued original:

Bassists need dirt too! But no one, until now, has given you something that works, with all the full, rich bottom-end that you deserve, damn-it! BTW, many guitarists use and prefer the Bassdrive for Guitar!

The Bass-Drive is a lot like its cousin the Full-Drive2, but voiced with an extra octave of bass coverage... still giving a natural, uncolored FATNESS to your thang.

From just adding a little grind, to replicating a raging SVT, to sounding like Jack Bruce in Cream. (He's got one already!)


Here is another version seen in one schematic and confirmed by John K based on values noted in ones he repaired.  This one based on symmetrical clipping with the mosfets using 2 x 1N4001 in that section.  If you prefer to use the asymmetrical mosfet clipping with a germanium diode shown in the first layout, then just use the V1 layout as a base and change the capacitors to the alternative values mentioned in John's post:

1) 100n input coupling cap is 22n
2) 10p input cap to ground is 51p
3) 51p cap between pins 1 and 2 is 100p
4) 220n at pin 2 is 330n
5) 220n at pin 5 is 68n

Fulltone Fulldrive II Mosfet

Requested by a few people. Even at 22 columns wide it could still fit in a 1590B if you wanted, and the first person to do it wins the TagboardEffects Awesome Builder of the Week award! :o)  But I wasn't too bothered about the board size because I suspect most people will want to put this in a 1590BB with two stomp switches.  The layout is based on this schematic on FSB posted by mozwell.

Info from Fuller about his original souped up Tubescreamer:

Housed in a beautiful powder coated Blue 16ga. steel enclosure, the dual-channel FullDrive2 gives you the best of both worlds. The first channel is the "Overdrive Mode" capable of clean boost or non-compressed overdrive or choose light to medium softer overdrives all while retaining your guitar's original tone. The Tone knob is a very effective presence control that can smooth out or add upper harmonics. The second channel is the "Boost Mode" with its own separate distortion control for medium to higher gains with a more singing violin-like sustain!

In 2007, the FullDrive2, the most popular boutique overdrive ever made, and staple on many pedalboards for years, became the FullDrive2-Mosfet, sounding better than ever before.

One mini-toggle lets you choose between a "Vintage" FD2 sound with mid-heavy tones that cut through the mix and "FM (flat-mids)" for a more natural, transparent sound that works awesome with a Strat's neck pickup.

The other mini-toggle lets you choose between Mosfet and Normal clipping modes. Normal mode is even more asymmetrical, sweeter and more open, with no "blanket" over the sound.

And, of course, the FD2-Mosfet features super-bright LEDs (borrowed from the OCD) and Fulltone's exclusive "no-thump/no-pop" True Bypass switches. We are the first to offer a switchable "Boost" Channel in an overdrive and manufacture our own Super-Duty 3PDT footswitch allowing True-Bypass plus LED.

Chosen by Guitar Player Magazine as "Best Stompbox of 2006" and as one of the all-time top 50 effects ever!

I wasn't a great fan of the asymmetrical mosfet and 1N34A diode configuration in an OCD version 4, which quite frankly I thought sounded like ass.  So I've done an alternate version based on symmetrical clipping with 2 x 1N4001 instead of the germanium diode.  This has been noted in some versions of this pedal and was definitely used in the Bassdrive so I think I personally would opt for this version.


Friday, 18 April 2014

ValveWizard Equinox II

Request, and also for those who want another PT2399 based reverb pedal.  Not one for the faint hearted with that many links and cuts! :o)

One thing you will notice straight away is that this doesn't have the usual 3PDT stomp switching to bypass the effect.  Because it has tails, the stomp will just turn the effect (and LED) off and not mechanically bypass the circuit, so in bypassed mode IC1 will just act as a buffer.  So the input and output wires go straight to the sockets, and only a SPDT stomp is required.

With this being a dual PT2399 build I don't think anyone will want to run it off a battery because if they do it really won't last very long, so this should fit fairly comfortably in a 1590B without making allowances for battery space, and especially with a single pot.

Info from Merlin about his project:

Equinox II: Reverb with Tails
This project came about because I wanted to roll my own reverb. A common way to do this is to use a tapped delay line, but no such chips exist any more. No matter; the result is the same as using multiple delay lines in series and/or parallel. Several DIY reverb effects use the excellent accutronics Belton Digi-Log reverb module, and the associated patent, US8204240, shows that it uses three PT2399 delay chips, one of which is modulated at a slow rate to give a more realistic spring reverb sound. The Accutronics module is not commonly avalable in Britain (also it's cheating to use a ready made effect module!), but I did have a tube full of PT2399s (I absolutely love these chips). I also wondered whether just two could do the job, and it turns out that for guitar use you can indeed get a primitive but usable effect this way. I think this makes the Equinox II the simplest DIY reverb project on the net at the moment!

In the Equinox II the reverb effect is acheived by passing the audio through two delay lines in parallel. One is arranged for a short delay (about 80ms), and the other a long delay (about 250ms). The outputs from each are summed and fed back to the input of the delay lines, and also mixed with the original audio via a mix pot- that's it. (I have an affection for one-knob effects.)

In detail, after passing through the input buffer the guitar signal is sent both to the output mixer and to the JFET analog switch. This switch allows the input to the delay line to be muted, creating bypass with tails (this is exactly the same as my Small Time delay).
Following the JFET the signal then passes through a 15nF capacitor which provides a little bass cut, to stop the reverb getting too muddy, and it then feeds into a second-order high-cut filter. This is also where the output of the delays lines is fed back in.
The output of this filter feeds the short delay line, and also the long delay line (via an unavoidable inverting buffer).
After the signals emerge from the two delay lines they are both summed and filtered again. All this filtering is necessary to reduce noise from the analog-digital-analog conversion inside the ICs.

I spent a long time tweaking the delay times, filtering, feedback, and mixing ratios, to get what I think is the most usable reverb sound using standard component values and the simplest architecture. My first Equinox prototype also had adjustable delay time on the long delay line, and a fat/bright switch. But I didn't find these to be very useful (at anything but the optimum delay time all you get are 'metallic bathroom' type sounds), so I trimmed the circuit down to the bare essentials, creating the Equinox II shown here.

To see more information including the schematic and a PCB for those who want an easier life, check out Merlin's page here, and a clip can be heard here which sounds pretty damn good to me!

And after discussions below, a version which omits the JFET and instead uses the second pole of the stomp to turn the reverb on and off.  This will also keep tails intact as per the original but because of the parts omitted has removed a link and a couple of cuts and is one column smaller.

Tuesday, 15 April 2014

Madbean Cave Dweller II Dub Edition

As requested, version 2 of the Cave Dweller with all noted mods included.
Info from Brian which can be found in the PDF linked in the version 1 thread

Cave Dweller II (“Dub Ed.”) expands upon the underlying design of CDI , but adds an additional PT2399 for roughly twice the delay time. It also combines the two feedback controls into one. An additional mod has been included if you wish to add a true Mix control to Cave Dweller II.

Cave Dweller II Controls

Time – This sets the delay time.
Dwell – This control is a combined version of the Dwell and Echo controls of CD1 (thanks, Alex!)


Cave Dweller II - Dub. Edition - is for those really cavernous delay needs. It utilizes the current mirror set-up of the “DM-5” delay project to achieve roughly twice the delay time of CD1. The max delay time should yield about 1 sec, although a mod has been included to artificially reduce this, if desired.

In this version, Dwell and Echo are combined into one. The control works slightly differently than CD1. At minimum, the repeats are filtered on the opposite end of the spectrum, meaning they are more “telephonic”. This setting sounds very similar to the Deep Blue Delay. At max, the repeats are dark and ambient similar to the CD1.

One caveat with the combined control is that there is minimal influence on the number of repeats produced by the effect. For those builders who wish to add an additional Mix control to limit the number of repeats, a simple mod has been included. Please see the illustration below on how to implement the Mix control mod.

Additionally, the dark repeats have been limited to non-oscillating by using a larger value for R12 . If you do implement the Mix mod, you can lower the value of this resistor from 750k to a value between 470k and 560k to re-introduce oscillation. This is not recommended when not using the Mix mod.

One other mod has been included with R20 . This resistor resides in parallel with the Time control and allows you to reduce the max delay time of effect. This mod was included for those who prefer a cleaner delay (max delay times with PT2399s tend to introduce some digital artifacts and noise). The value can be selected to taste, and a 200k is suggested. This results in roughly 20% less delay. A 150k resistor yields approximately 25% less delay. 

Working voltages as posted by ξεναγός νεκρόπολης:

volt.reg. q1 q2
i.9.22 e.0.05 e.0.06
g.0 b.0.62 b.0.62
o.5.01 c.2.43 c.2.44

pt2399 (both same)

1.5,01 16.2,44
2.2,43 15.2,44
3.0 14.2,44
4.0 13.2,44
5.2,88 12.2,44
6.2,43 11.2,44
7.0,77 10.2,44
8.0,89 9.2,44

Madbean Cave Dweller

Nice sounding mini delay, designed by Madbean to fit in a 1590A box, and after checking with Javi this layout should fit in one too :o).  Tantalum caps or mini electros may be needed to keep things as compact as possible, and maybe a multi layer ceramic for the 1u.

Info from Brian about his original project:

The Cave Dweller I is a low parts count delay comprised of a single PT2399 chip and fitted for a 1590A enclosure. This ranks as a “mediumi-fi” type circuit, meaning that filtering of the PT2399 is kept at a minimum in favor of a small footprint. While you won’t get quite the fidelity of the Echo Base, for example, it still sounds very, very good and offers a somewhat unique flavor of delay. The effect takes advantage of the two on-board amps of the PT2399 for use as input and output mixers. The feedback and filtering are combined in a unique way which produces a slightly different set of controls than the typical PT2399 delay. This leads to some really “haunting” and musical repeats at long delay times.

You can read more about it in the project documents here, and if you prefer, the PCBs can of course be purchased at http://www.madbeanpedals.com/projects/index.html.  Check out some of his other boards while you're there.  I just bought a Pork Barrel, Collosalus and StageFright from him which are fantastic quality, and are builds that I would always prefer to opt for PCB over vero.

Monday, 14 April 2014

EHX Satisfaction Fuzz

Note that the C7 and the D2-D3 are not present on the original pedal. There are holes ready for those components. Adding C7 as 4n7-100nF cap will increase bass response and adding diode clipping to the place of D2 & D3... Well. That will make this an different animal.

Grind Customs Electric Boogaloo Optical Tremolo

Another project collaboration between Rej at Grind Customs and CultureJam, similar to the Shoot the Moon but with a couple of subtle differences including a shape switch instead of the wave pot (similar to the 2 knob version we did).  If you don't want to roll your own with the LDR and LED, the Vactec VTL5C3 is the recommended vactrol.

I can't find a video anywhere, so if anyone can make one that I can post with the layout that would be great.

Black Arts Toneworks Black Forest

A modern upgrade on the Colorsound Overdriver.  I have included a 6 position 2 pole rotary switch and you can do it one of two ways.  Use the cap daughterboard I have shown in the layout (which will only actually uses one of the poles), or if you prefer you can just solder the caps straight to the switch like this:

Input > Sw A
8n2 between lugs 1 and 7
10n between lugs 2 and 8
22n between lugs 3and 9
47n between lugs 4 and 10
220n between lugs 5 and 11
470n between lugs 6 and 12
Sw B > out to Q1 base on board

If you do solder straight to the switch then I'd recommend putting a 1M resistor between the input wire and ground in a convenient place to avoid those switch pops.

Info about the original:

Black Arts Toneworks unleashes their latest pedal, the Black Forest overdrive. Based on the legendary Colorsound Overdriver, the Black Forest provides that classic tone in spadeswith a difference. Not only is the classic Overdriver tone there but the Black Arts Toneworks Black Forest adds more grit and gain as well as a bit fatter tone than the original while at the same time decreasing the noise floor to astounding quietness. When the gain is maxed out, the sound is very fat with harmonic-laden overtones and a classic sound that no guitarist can deny. In addition to this, the Black Forest also features more tonal control with the addition of a six way Depth control. This allows the user to cycle through six different capacitor configurations that alter the voice and gain structure of the unit offering an array of sounds not available in the original circuit. The additional gain on tap allows the Black Arts Toneworks Black Forest to achieve anything from a gritty boost to a classic overdrive to a vintage fuzz tone and will keep the inspiration coming for even the most seasoned players.

Sunday, 13 April 2014

CultureJam Neptune Delay

Another PT2399 delay from CJ.  An LDR with greater than 1M dark resistance and preferably less than 100K light resistance is recommended.  I put the resistors in between LDR and LED to add a bit of separation so you can get them facing each other more easily.  As usual with these, it's recommended that you tape LED and LDR together or use some heat shrink tubing so you can test the circuit without it needing to be boxed.

Info from CJ about his project

Here is my two cents thrown in to the bucket of PT2399-based delay circuits. It features aggressive low-pass filtering on the delay line to virtually eliminate the nasty artifacts that often plague PT2399 delays; and it also sports a momentary footswitch that modulates the delay time, allowing for some cool pitch-bending sounds and really funky detune effects. It can also be made to sound sort of like a lap steel (in a way).

The base of the circuit is derived from madbean's "Sea Urchin" circuit. Then cranked up the filtering and added the modulation footswitch.

More info can be read in the project PDF posted here.

Saturday, 12 April 2014

NPN Fuzz Face with BMP Tone Stack

This was a request but thought I may as well share it here in case anyone else wants something similar.  It's just a Fuzz Face with Big Muff tone stack which some may find useful, and can easily be adapted for a germanium build if you prefer.  I included a graph of the tone pot rotation frequency response thanks to the excellent Duncan Amps Tone Stack Calculator which I would recommend everyone use when working with the included tone stacks to fine tune the build to your own taste/gear.

I've put the 8K2 resistor to the far left hand side so if someone wants to add a trimmer to bias Q2, they can omit the resistor and add it in this position.  The trimmer legs may need a little fettling to span 4 rows but it should be easy enough to do.

And a second version with added base/collector Miller effect filter caps which cuts some high frequencies and makes it sound smoother and more like a germanium version.  Similar to the DAM Meathead.

Friday, 11 April 2014

Little Angel Chorus - NYE Edition (AMZ modified)

Jack Orman's modifications to the Little Angel Chorus, which will hopefully help us get a bit more consistency with the builds.  Information about the mods and a schematic can be found on Jack's blog here:


Currently unverified but based on the verified original layout so should be good to go.

Death By Audio Sound Saw

I would advise caution before you proceed :o)

This has been put together after a request, but it's based on a schematic of unknown origin so I don't know whether the scheme even works never mind the layout.

A couple of things do make me think it could be a good trace though.  The volume pots are wired in an unusual way which I have seen from DBA before, although for this layout I have changed them to the more usual volume pot configuration that we are used to, purely to remove unnecessary daisy chaining and so make connections simpler - their functionality in the circuit remains identical.  It also looks like a mish mash rats nest of a circuit, which again points to authentic Death By Audio :o) (just joking guys).

As this is a gamble at this stage, it may be one to do with pots in a breadboard first rather than soldering them, but as long as you know the score from the outset, if it's something you want then please let us know so we can verify the scheme and layout or bin the post entirely.

Update 12th April: Now corrected and verified so no longer a gamble :o)

Here is the schematic it is based on for those who may want to follow it

The pot numbering shown in the schematic is the reverse of the convention and so I have swapped lugs 1 and 3 where necessary.  As noted above the volume pot connections have been altered to our usual:

Volume 1 ground
Volume 2 output
Volume 3 input

Only the second stomp switch connections are shown in the layout.  The main bypass stomp switch is wired as per usual, and with a separate LED to show when bypassed.  Then the LED mentioned in the layout (assuming using bi-colour) displays the selected channel.

One of the LED resistors was shown as 100K which seems huge to me even for a ultra bright LED, so I've just included a single 3K3 resistor for current limiting, which can be used for a common anode bi-colour LEDs with stomp 2 switching the ground connections.

Anyway, enough waffle, here's the info about the original:

trash the system. make your fuzz pedal kill, kill, kill. everyone will scream in terror. here is the SOUND SAW. 2 unique channels of huge thick quasi-eq filters to intensify your wall of sound. blast your way out of the mix and sound enormous. the one channel of the SOUND SAW cuts a selectable frequency and boosts the hell out of the frequencies around it while the other is an active bass to treble blaster. LED of selected engaged filter dims when bypassed to let you know which channel is active. the SOUND SAW is capable of nice creamy tones or huge amounts of boosting, feedback insanity, cutting, sub woofing, room shaking, glass breaking frequencies to make you have the most intense sound possible.

Sound Samples:

Thursday, 10 April 2014

Dice Works Muff Diver

Info from Kit Rae about the discontinued but much sought after original:

DICE WORKS MUFF DIVER modified Triangle Big Muff clone - A discontinued boutique clone made by Eric Holden, circa 2005, of the an original Electro-Harmonix V1 Big Muff circuit shown on page 1 (PNP Triangle 72 #2), with the addition of switchable coupling caps at C4 and C5 to make it sound more like the custom Big Muff known as the P-1 that Pete Cornish made for David Gilmour (of Pink Floyd) in the late 1970's. In reality, it sounds nothing like the P-1, but resembles something in between the Cornish P-2 and G-2 tone. It makes for a very versatile Big Muff. One of my favorites. Another version of the Muff Diver included a switchable input cap setup identical to the Cornish/Original switch in the standard version, switchable Ge diodes in the first clipping stage, and a switch to remove the Si diodes from the second clipping stage. 

More info can be found at Kit Rae's bigmuffpage.com.

Like the original I have used BC327-40 PNP transistors here and have included the voltage inverter daughterboard so it can have a negative ground.  I'm not sure whether the same was true in the original or whether it had a positive ground, but either way, it makes sense to have a home built version as compatible as possible with most of your other effects.  I have included two clipping switches though which will allow you to have silicon or germanium diodes in either/both stages, or lifted in the centre off position for a maximum range of sounds.

Like some other Big Muff's and variants, the base sound with this is scooped, but if you would prefer flatter mids then increase the 3n9 cap at Q3 collector to 10n which will make the frequency response very flat.  Or you could always add another switch if you want both options available to you.

Tuesday, 8 April 2014

Grind Customs FX Tenebrion Reverb

Another project from Rej in conjunction with another great DIY personality CultureJam, this time the Grind Customs FX Tenebrion Reverb which requires one of the smaller Belton BTDR2 bricks which are available with short, medium or long decay.

Saturday, 5 April 2014

Grind Customs FX DeProfundis Delay

Rej at Grind Customs FX is well known in the DIY community.  He designs some great effects, shares a lot of projects with us all and also sells some really excellent PCBs, the Chimaera in particular is extremely popular with those who want to build a Klon in a small box.  See the projects on his forum at http://www.grindcustomsfx.com/forum and check out his PCBs at http://www.grindcustomsfx.com.

This one in a very nice sounding delay based on the PT2399 IC and is definitely a recommended build.
Info from Rej about his effect:

The DeProfundis Delay is a PT2399 based digital delay with aggressively filtered repeats and the possibility of very long delay times (and minimal delay line noise). There is also a tone control trimmer to adjust the high pass cutoff frequency on the repeats. The stock values yield a max delay time of approximately 550ms - 600ms. With a minor modifications (see below), max delay time can be extended to almost 900ms.  

Tweaks & Modifications  

“Love You Long Time” - Extend the max delay time

This is a very easy modification. Change the Time pot to A100K and then add a 270K resistor in parallel with Time. You can add the resistor either to the pot pads on the board, or you can use the pads marked “M1” and “M2” (see below for more info on these). Adding the 270K resistor brings the Time pot’s total resistance value down to about 75K, which is about the limit of what this circuit can handle without getting noisy and producing synth like repeats (more resistance = more delay time). If you don’t have 270K on hand, try 220K, but be aware that this will give you less max delay time. Or you could put multiple resistors in series to get close to 270K.  

Even Darker Repeats 
If the dark and murky tone of the stock circuit does not satisfy your black heart, try increasing the value of C7 (Mark's note: 10n cap to ground under IC2) to taste.

Video of Rej's build with modulation added.  And before you ask, yes I am :o)

This version is based on Rej's notes for increasing the maximum delay time.  Instead of putting a resistor in parallel with the Time pot I've used a multi-turn trimmer so you can set the maximum delay time exactly, to the point just before things starts getting a bit noisy. 

Here is the modulation daughterboard for those wanting to add it to the effect.  It is based on Rej's Portable LFO schematic and although it is designed for the DeProfundis, it would work equally well to add delay to other PT2399 based delay pedals such as the Deep Blue Delay.

The main modulation switch will be centre off, in one position you'll have modulated delay, in the other position you'll have modulation only.

The Shape switch will let you select a sin or square wave, and could if you prefer be swapped for a 500K linear pot which will sweep between the two waves and then give you the in between settings too.

The LED and LDR need to face each other, ideally tape them together or use heat shrink around them so you can try the circuit without it needing to be boxed first.  You'll need to experiment with LED type and colour etc and LDR type to see how it works for you, or maybe use a Vactrol for an integrated unit.

Barber Gain Changer

Another versatile overdrive here from Dave Barber, and as usual at a very fair price.  If you want to fine tune the mids and bass content to suit your own style or gear, consider socketing the 7K5 resistor on the right for mids, and the 22K resistor at the top for bass.

Info about the original:

Measuring only 2.3” wide, the NEW Barber Gain-Changer harnesses a vast spectrum of EQ and gain. Flick the toggle one way and you have sweet very low-gain overdrive, flick it the other way and you get wildly charged harmonic content of our much praised unLimiTeD distortion. Pop over to the other toggle-switch and you can volley between the flat sweet-EQ of the LTD SR , the vintage snarling-fat-EQ of our classic LTD v2 or a new voice that combines flat EQ with a little added fatness. Combine all these different options together and you have a super-versatile harmonic beast. Our goal was to shrink the size of our pedals and retain all the ultra-high quality electronics and build quality that we are world famous for. In the end, it’s almost impossible to miss the target if you are shopping for a new overdrive for your rig, “it’s like shooting fish in a barrel Jethro.”

The Gain-Changer has real honest solder lugs for jacks, True-bypass footswitch, toggles and pots. There are no worries about PCB mounted thru-panel parts that can’t be serviced on the road, or that lead to high cost repairs. Nothing but the best tried and true hand-built methods adorn the interior of the Barber Electronics Gain-Changer. The Gain-Changer has a generous 2 1/2” of clearance between the front edge of the footswitch and the back edge of the knobs, no more worries about changing your settings with each click of your footswitch. Buy a hand-built Barber Gain-Changer, and enter a world of immense overdrive possibilities.

BJFE Folk Fuzz 3.5%

Another one of John's here, this time for Bjorn's DIY project, the Folk Fuzz.  I can't find the original post with Bjorn describing this but I think most people know what it is.

Friday, 4 April 2014

Frantone The Sweet

Although this isn't your usual muff clone, you can certainly tell where the inspiration came from.  This pre-dates the EQD Hoof, but like that pedal this uses NPN germanium transistors for Q2 and Q3 but with schottky diodes here instead of LEDs.  I can't find any information at all about the FS25444 838 Q4 transistor, but it is definitely NPN bipolar, and looking at a gut shot on the Frantone web site it's an old style TO106 style case like the 2N5133 that are much sought after for Big Muffs, or the ME4003 that I know a few people on here use.  Anyway just try anything for that and let us know your results.

Info about the great sounding original:

Truly insane fuzztone!
 Over the top in every way using the classic tone of germanium transistors.  This is the longest sustaining and smoothest sounding all-transistor fuzztone you will ever own.  I have designed many fuzztones, including the 2000 New York City Big Muff for Electro-Harmonix, so believe me when I say that this is the most extreme one I have ever made.  It's tone is indescribable.  The full bottom and crisp highs will astound you, and the endless sustain will make you cry like a baby.   But don't take my word for it.. try one for yourself!

All new Frantone effects come with full signal bypass and status light!

Each one of The Sweet fuzztones is hand-made in
the USA by Frantone and features:

    Tough cast aluminum case
    Black Epoxy Enamel finish
    True bypass switching
    Green indicator LED
    Steel LED bezel
    Switchcraft jacks
    Custom White Bakelite knobs
    Hard mounted PCB
    External power jack
    All teflon hook-up wire
    Really cute clear feet

Wednesday, 2 April 2014

Moosapotamus Skippy Tremolo / Ring Mod

Based on the Vox Repeat Percussion but with greater control options, and another advantage is this version uses the 2N6027 Programmable Unijunction Transistor which is still available cheaply and in quantity, so you don't have to search around for 2N2646's and pay top dollar for them. 

I haven't included the connections required for external expression pedal rate control, opting to keep it self contained, but if you do want to include one, make the connections to the control socket to where the rate pot currently connects to the board, as shown in the scheme on the Moosapotamus site.

Info from Moosapotamus about their pedal:

The SKIPPY tremolo is based on the vintage Vox Repeat Percussion. The original VRP is well known for it’s very hard, percussive tremolo sound, or chop. Certain combinations of speed settings and playing style can almost trick your ears into thinking that you are playing through a delay instead of a tremolo. For these reasons, the sound of this tremolo effect is often described as synth-like.

Originally, the VRP had only one control, Rate, to adjust the speed of the effect. In addition, the version that was built into the Vox Beatle Super Reverb amplifier also had an input jack for a foot pedal that enabled you to control the speed of the effect with your foot.

With additional controls and features, SKIPPY covers a much wider sonic range while still retaining all the character and bravado of the original VRP. Check out the video…

Depth - Adjust effect depth from subtle throb to hard chop.
Rate - Adjust effect speed.
Level - Adjust output volume to compensate for perceived volume loss with certain extreme settings.
Tone - Switch original Vox low-cut filter on or off. When on, output has a lot of treble and very little bass.
Mode - Switch between hi and low speed ranges. Low speed is normal tremolo range. Hi speed is pseudo ring-modulator range.

Plug CV pedal into control jack to vary speed with foot while playing.
Capable of ultra-wide range of speeds, up to pseudo ring-modulator speeds.

Tuesday, 1 April 2014

Catalinbread SFT

One of the layouts that is frequently mentioned so I thought I'd do a tagboardeffects version of it.  There's a couple of axial electrolytics in there, simply because I have them in that size and to me they suit the layout as it is better than radial, but as usual, use whatever you have.

Info about the original:

When we originally set out on our quest to make the best Bass overdrive ever, we never imagined that it could also sound so amazing with guitar – but then we got to thinking about some of the classic late ‘60s/early ‘70s ‘Ya-Yas’ era tones and thought we should take a stab at them. And heck while we’re at it, it would be really cool if it worked for the more modern drop tuned heavy stuff too. Made sense since those tones were due in large part to guitars being played through amps designed for bass, right?

And what about the Bass tones? We wanted a pedal that FINALLY let you control the amount of grind solely based on your finger attack. You know the feeling - full and rich and clean when you brush lightly and some nice wooly edge when you dig in. At the other end of the sonic spectrum we wanted a drive pedal that could deliver bone-crunching grind and still hold together without sounding thin or turning into a sludgy mess no matter how hard you hit it.

So we did a LOT of listening – listening for the dynamics, how the pedal responds to pick or finger attack. The cornerstone of those particular amps is their dynamic sensitivity – the feeling that you plugged directly into the power amp, that there is always more potential on tap. It’s a big, lively, responsive tone – you feel completely connected to it and control it all through your hands, nothing gets in the way. So we worked on the input sensitivity until it turned our rather sterile solid-state test subject into a warm and responsive vintage-sounding tube amp.

We also listened for that classic EQ voicing – the ‘right’ midrange was crucial and it was absolutely critical that we got it right. So we scoped it out and found it, and it was good. Then we added some really flexible Treble and Bass controls so you can dial in the right amount of feel - if you wanted a more edgy grind or a looser bottom it was super easy to dial it in with a minimum of tweaking. And those were good too.

We had to get the drive character right as well – meaning that it had so be clean but really full sounding when you picked lightly, and blossom into that huge rich grind when you hit it harder. It had to decay in a certain way, no fizzy stuff as the notes or chords die off. It needed to respond in a very dynamic way just like the amps do – no generic smothering of the transients, it needed to breathe.

So after months of listening, testing, listening some more, and fine-tuning these are the results. The SFT was a real labor of love for us – we wanted a killer, super-versatile bass pedal the likes of which nobody has heard before, and for guitar we wanted a faithful recreation of those classic Taylor-era tones with the ability to morph into more modern heavy sounds and we finally feel we’ve nailed it.

Cornish G2

I was surprised I hadn't already posted this one since we've had the schematic for a while.  Iconic and much admired builder to the stars, popular on TGP and everywhere that guitarists want the size of their gear budgets to be known by all.  It sounds pretty good to me.  This includes the famous Cornish Buffer at the input as per the original, but omits the bypass buffer for the usual true bypass switching.   If you do want to make it buffered bypass then you could use the standalone buffer layout as a bypass daughterboard.

For those who do want the bypass done in the same way as Cornish, the input socket connects directly to the input of the bypass buffer.  The output of the bypass buffer then goes to G2 input and daisy chains to the 3PDT stomp switch, lugs 1 and 4.  The output from Volume 2 of the G2 will go to 3PDT lugs 3 and 6, and the output socket connects to 3PDT lugs 2 and 5. 

The third pole of the 3PDT is used for LED switching.

You could do this with a DPDT stomp just making single connections, but Pete did this using two separate poles to add some redundancy in should one of the contacts fail.

Info from Pete about his original bomb proof effect:

The PETE CORNISH G-2™ has been hailed as the most original sounding distortion unit available to guitarists in the Rock Arena. It features a four stage overdriven discrete transistor Class A circuit with additional Germanium components that generate much warmer sounding harmonics than anything else on the market. Within the huge tone generated by this unit, the original guitar sound and dynamics are present creating a much more musical effect than any other distortion pedal.

The G-2™ gives a higher level of overdrive for that classic cranked up Marshall sound found on most British rock records of the 70s (Led Zeppelin, Free, Bad Company etc.). The G-2™ with its warm Germanium qualities and higher gain starts at around the rhythmic crunch stage of the SS-3™ and continues through in controllable degrees to a rounded but dynamic lead.

The input to this unique device is our universally acclaimed High Impedance, Unity Gain, Class A, Buffer Preamp with it's superior RFI rejecting capability (to eliminate Radio Station interference) and Low Impedance output, allowing the use of extended cable runs from the G-2™ in bypass mode. The fixed High Impedance load presented to the Guitar allows the pickups to operate at their optimum, even when several effects units are connected after the G-2™. The Unity Gain Buffer also prevents "Ghost Distortion" being audible in Bypass Mode. This effect unit gets the most benefit from being fed into a clean, full frequency response amplifier and I recommend that when you receive your pedal you connect it up without anything else in line, just Guitar/Pedal/Amp, and discover the way the controls interact, both with themselves and the guitar/amp controls. Then adding the rest of your effects, you may find that you need to make slight adjustments to these as they are now being fed with a constant signal when the G-2™ is in Bypass Mode.

[updated 15th July 2014]

And the wiring diagram for buffered bypass with all the peripheral wiring removed to simplify it.  You can see the first two poles are linked meaning that if a contact on one of the poles fails, then the switching will still work, and so it's adding redundancy.  But you really don't need to do that if you prefer not to, you can just use a DPDT and use a single pole instead of the linked pair.



Runoffgroove Ginger

Info about the great ROG Ampeg emulation project:

The Flipster, runoffgroove.com's only circuit primarily intended for use with a bass guitar, was released in June 2004. It was another adaptation of a vintage tube amp for use as a distortion pedal, namely the Ampeg SB-12 Portaflex introduced in 1965. Several bass players in the DIY-fx community acted as beta testers during its development, and while the resulting circuit captured a good deal of the target sound, it had higher gain and the overall frequency response was inaccurate due to impedance differences.

In this "next generation" version named Ginger, the tonestack impedance has been scaled down 10x to reduce noise and overall frequency response has been further adjusted to cover a more suitable range with reduced insertion loss, as seen in this graph from Duncan's Tonestack Calculator.

Also, each stage has a pair of clipping diodes at the gate to avoid hard clipping in the JFET stages. Additionally, each stage has been adjusted to provide overall circuit gain more faithful to the Ampeg SB-12 Portaflex. While the circuit does not follow the original amp schematic, it has been tuned to approach the target sound. Finally, the low-pass filter at the output has been upgraded for improved attenuation of frequencies outside the original speaker range.

While the circuit is intended for use with a bass, it also provides excellent overdrive for a guitar and the flexible tone controls allow a great deal of fine-tuning.

The drain voltage of Q1 and Q2 should be adjusted close to 6.0V by tuning the corresponding trimpot. Once the optimum resistor value is determined, each trimpot may be optionally replaced by a fixed resistor for best noise performance.

More info can be seen here.