Saturday, 28 July 2012

Greatly Improved JFET Matcher

So moving on from RG's JFET matcher which measures VGS (or more precisely, the voltage at which RDS is 10K) , this is another version by Sebastian from runoffgroove which allows you to measure VP and IDSS depending on the position of the switch.

The centre off position should be used to insert and remove the JFETs, and as long as you keep the orientation of the switch the same as shown in the layout, up measures IDSS and down measures VP.

A combination of these two layouts will allow you to match JFETs in a number of different ways, so use the appropriate one depending on what characteristic you are required to match, but if in doubt which to use, having VP and IDSS close means the JFETs are more effectively matched and so this method is probably preferable.

And an updated version which is even more simple and will allegedly give more accurate matches:

Friday, 27 July 2012

JFET Matcher

This should be a useful little circuit for a few people and will allow you to match JFETs VGS (or more precisely, the voltage at which RDS is 10K) when required in some phasers etc.  Based on the information posted by RG here which should explain how everything works. 

Compact version with onboard sockets suitable for both DSG and DGS JFETs.

This version with separately mounted sockets for JFETs.

Thursday, 26 July 2012

MXR Phase 45

I thought a small and simple phaser would be another good addition and so the Phase 45 is the automatic choice to remain 1590B friendly.  For the best results the JFETs need to be matched so you can either swap and change to select the pair that give the best sound, or measure them using a method like this one so you know they are a close match. 

Info from MXR about their currently available 75 Vintage Phase 45:

The '75 Vintage Phase 45 reissue from the MXR Custom Shop reproduces the rare little brother of the Phase 90 to exacting specifications. With two stages of phasing, the Phase 45 offers up its subtle and musical voice via hand-matched FETs and hand-wired circuit board. Authentic tried and true components and hardware such as a Carling switch, CTS pot and Switchcraft jacks. Texture your tone without over powering your sound with the limited-edition '75 Vintage Phase 45.

Geiri's video of his build:


Tuesday, 24 July 2012

Systech Harmonic Energizer

Not a lot of info on this old pedal, but it was a request so I'll let Vince tell you about it! :o)

I've omitted the reverse polarity protection part of the circuit to keep it more 1590B friendly, but if you do want to add some protection just put a 1N5817 or 1N4001 in series with the 9V supply.  The effect includes a buffered bypass and so only a SPDT latching stomp is required, or a DPDT if you want LED indication.

Monday, 23 July 2012

Seamoon Funk Machine V2 with buffered blend

After John K got better results putting a buffer before the circuit I thought it would be a useful to do a second layout incorporating a blend pot.  This almost certainly will make the effect more useful with bass, and if you want the effect 100% you can simply leave the blend pot in the extreme counter clockwise position.

For info about the effect see the original Funk Machine V2 post.


Saturday, 21 July 2012

CMAT Mods Signa Drive

Pretty much as standard TS808 with slight modification and switchable clipping diodes.  We've seen it all a thousand times but here it is in case anyone would like to build one.

Info from the manufacturer about the original:

This OD has so much tone it is unbelievable. The harmonics and note clarity just drip out of it. This is the best sounding OD that I have ever built. I would put this up against any OD at any price built by anyone. It took me along time to get this pedal where it is. I had a tone in my head and I have finally got it. This has a 3 way toggle switch that allows different clipping and gain structures.

The Signa Drive can go from a clean boost all the way to a Marshall crunch and every thing in between. If you are looking for a very versatile OD this is it. I am very proud of this pedal.

This pedal is so good, it most likely will replace both the Tubeslammer and the Tubeslammer Deluxe!

Updated 4th September 2014 - new compact layout added

Keeley 4-Knob Compressor

So close to the Ross Compressor that the 2-knob versions seems to be essentially verbatim, but I thought the 4 knob version was worth adding for the additional Clip and Attack controls.  In the original the onboard trimmer isn't used and instead two 1K resistors were used between the bottom lug of the (top left) 220K and IC pins 2 and 3.  Rather than adding fixed resistors I thought it made more sense to leave the 2K trimmer and suggest leaving it in the dead centre position for the stock setting, and so allowing the Clip pot to perform that task, which would mean that you will have some additional tweaking capability to set the base input level using the trimmer which you wouldn't get from the Keeley.  So maybe this can be the 4½-Knob Compressor! :o)

Info from RK about the original:

The Keeley Compressor is the award winning industry standard for stomp box compression. The 4 Knob adds Input Clipping and Attack controls to the top of the the original Keeley compressor for easy adjustment. Perfect for those that often switch live between single coils and humbuckers. The sound alone will inspire your creativity.

All of our Compressors are hand built in the USA. Unlike any other compressor, the Keeley Compressor was given the Editor’s Pick Award from Guitar Player’s Magazine and recently awarded Reader’s Choice for Stomp Box. It is a true audiophile and studio grade compressor with an exotic rack mount quality in a stomp box form.

After a few people mentioned wanting to use resistors instead of the trimmer and so mean that it's one less "special item" you have to get in, here's a rejigged revision with the 1K resistors.  I still think I'll build it with the trimmer because I like the idea of that fine tuning ability, but you can build whichever version you prefer.


Group Value
Resistors 1K
Resistors 10K
Resistors 15K
Resistors 27K
Resistors 56K
Resistors 150K
Resistors 220K
Resistors 470K
Resistors 1M
Resistors 4M7
Capacitors 150p
Capacitors 1n
Capacitors 2n2
Capacitors 10n
Capacitors 47n
Capacitors 1u
Capacitors 10u
Diodes 1N4148
Transistors 2N5088
IC CA3080

Friday, 20 July 2012

Ross Compressor

As predicted! :o)

Although the layouts look different, this is extremely close to the Dyna Comp, I just rejigged things around to make the best use of space.  Unfortunately I needed an extra 3 rows, but c'est la vie. Here is a summary of the differences between the Ross Compressor and the Dyna Comp:

  • 1M resistor from Q1 base to vbias changed to 2 x 470K in series with a 1u cap from the junction of the two to ground.
  • 470K resistor from trimmer 2 to supply changed to 2 x 220K in series with a 1u cap from the junction of the two to ground.
  • Direct connection of Q1 collector to supply changed to 10K resistor with 1u cap from collector to ground.
  • Sustain pot 500K reverse log
  • Output pot 100K linear
  • There was also a 1u cap from vbias to ground but I'd already included a 100u in this position in the Dyna Comp as a more effective noise filter.

Thursday, 19 July 2012

MXR Dyna Comp

No effects layout site would be complete without this one, and even if this isn't the most sought after compressor there are quite a few more fashionable ones which are based on this, and so I thought it would give a good basis for mods and tweaks, and adapting to the Dyna Comp-esque variants.  The layout is easily 1590B friendly, even with a few extra columns and rows for mods.

Info from the manufacturer about the original:

MXR Dyna Comp Compressor Guitar Pedal - One of the most popular compressors of all time, the MXR Dyna Comp is the secret weapon on many stars' pedalboards. This box will produce that percussive, clicky sound on a clean guitar that you've heard on so many pop hits. It also adds smooth sustain to lead lines.

Saturday, 14 July 2012

Wampler Ecstasy

Info about the original:

The Wampler Ecstacy uses a very simple control lay out but produces an incredible vasriety of tones that let your guitar do the talking thanks to transparency and awesome responsive gain that reacts just like a top end tube amp! Use the Ecstacy's two band EQ (high and low), Smooth/Open/Crunch switch, gain and output volume settings to set the basic distortion tone that you're after then use your guitar's volume and tone controls to choose between full on grit (both on full) choppy crunch (volume halfway tone full), singing solos (volume full, tone backed off) or even cleaner tones (volume backed right off tone full) and so on. You can even control the pedals grit with your playing dynamics and pick attack, just like a top end tube amp that costs ten times the price of this magic little pedal from Wampler!

Here's what Wampler say about the Ecstacy overdrive pedal

When Brian created the Ecstasy, he was working on creating a pedal that would go from clean tones to distorted tones while adding a bit of warmth. He wanted something for himself that would be dynamic, have a great sounding "gritty" tone to it yet be able to respond to the volume knob like a tube amp. Everything about Brian is in the dynamics of sound and if a pedal can't work with him dynamically, then he just can't use it. Out of this search, he developed the Ecstasy Drive.

The Ecstasy is his take on that elusive "dumble" tone and feel - smooth creaminess yet crunchy when you need it to be, yet the tonality is much more transparent than other "dumble sounding" pedals. Very responsive tone controls that interact with the pedal - they don't just "color" the sound. The controls actually affect the response and feel of the pedal, just like a great tube amp.

If you love the sound of your clean tone, and just wish you could have more "hair" on the note... a little bit of grit without any change in tonality, the Ecstasy will do that with ease. PLUS it's extremely flexible... with the toggle switch in the down position you'll get a hint of fuzz along with the overdrive, it's reminiscent of the tones that "Eric Johnson" may use. With the toggle in the up position the tonality is super smooth, creamy yet crunchy when you dig into the strings. This is reminiscent to the famous "dumble" tone, though it's really much, much more than that. In the center position, the toggle will give you tons of crunch, or roll the gain back a bit and push the volume up and you have a superior clean boost with a 2 band EQ that's extremely transparent, but variable so you can actually turn it into an awesome treble booster just by cranking up the treble and turning the bass down.

Thursday, 12 July 2012

Wampler Pinnacle

Many thanks to Equinox for supplying his traced PCB layout for us to create the schematic and layout from.  This is based on the current version which I think was first released in 2011. 

Info about Brian's fantastic original:

Zeke Clark, Edward Van Halen's longtime renowned guitar tech played through a pinnacle and this is what he had to say:

“I've played tons of pedals that promised that “Brown Sound”... this pedal NAILS it better than anything I've ever heard or played.” - Zeke Clark, former tech for Eddie Van Halen

Sometimes you need extreme gain, sometimes you need mild overdrive...this pedal does that with an awesome “Brown Sound”! It has an extremely tweakable EQ - from scooped mids to tons of warm mids, all with the turn of 2 knobs.

This pedal has 4 knobs -- two separate tone controls that act as a sort of parametric EQ, gain and volume. It also has a 'bright' switch that adds a ton of variety and is very handy when playing a dark sounding amp, as well as another toggle switch that will give you high gain “Brown Sound” tones.

Tuesday, 10 July 2012

True Bypass Looper - 5 loops

A couple of people have mentioned loopers to me recently, so here the wiring layout I did for someone a couple of months ago which gave 5 loops and a tuner out.  It also included a switchable buffer before the first loop which he could switch into circuit at any time.

If you're not interested in the tuner out you could just take the input straight to the bottom right hand lug of the buffer switch.  If you're not interested in the buffer either you could just take the input straight to the bottom right hand lug of the first loop switch.  And although this is for 5 loops it's totally modular so you should be able to adapt it easily for fewer or more loops as is necessary.

Monday, 9 July 2012

Seamoon Funk Machine V2

The FUNK MACHINE is a synthesizer that can be used with any amplified musical instrument. Bass Guitar ... Guitar .. . Fender Rhodes ... Harmonica ... Horns .. . Clavinet.

The FUNK MACHINE is primarily designed for use with Bass Guitar, but you will find that all other instruments will work very well. On Bass Guitar you get a sound that Is heard everywhere in recording these days. The unusual sounds coming from the Basses of Larry Graham, Sly Stone, Tower of Power, and Stanley Clarke are characteristic of the sounds of the Funk Machine.

On Guitar the FUNK MACHINE gives an effect similar to a WA WA pedal, the difference being that the FUNK MACHINE is electronically triggered by the players attack on the strings as opposed to the mechanical and foot action on the WA WA. The FUNK MACHINE gives a fender Rhodes a sound similar to a Clavinet, but because of the very low output of the Rhodes in some cases the signal generated by the piano is not strong enough to trigger the FUNK MACHINE on the extreme high notes on the piano.

Unlike most control knobs that are associated with electronic apparatus the FUNK MACHINE does not get its best effect by turning both controls to their full on position. In fact the FUNK MACHINE would get its worst effect by doing so. To get the best results read the instructions carefully.

1. Turn both controls on the FUNK MACHINE off.

2. Turn the volume control on the instrument to its full on position.

3. The FUNK MACHINE is voltage controlled meaning that the harder the note is struck the greater the FUNK EFFECT. Bear this in mind because as you adjust the controls you are as much responsible for the sound as the FUNK MACHINE.

4. Strike a low note on your instrument in a repetitive manner, (Bass Guitar "D" string, Guitar "A" string). At the same time you arc striking a low note on your instrument in a repetitive manner slowly turn the FILTER RANGE control clockwise until the FUNK EFFECT is heard. Remember that the further the FILTER RANGE control is advanced, as well as how hard the note is being struck determines the amount of effect.

5. It you play Bass Guitar the FREQUENCY SHIFT control will move the range of the FUNK MACHINE into a lower frequency range that will easily accommodate the open "E" string on a Bass Guitar. A little experimenting with the FREQUENCY SHIFT and the FILTER RANGE control will yield great results.

6. NOTE FOR BASS GUITAR: The FUNK MACHINE can be used as a sub-harmonic bass filter which will cleanly lower the bass response by two full octaves. To accomplish this simply turn the FILTER RANGE control off and use the FREQUENCY SHIFT control only.

7. Unplug the unit when not in use to increase battery life.

A helpful hint for the FUNK MACHINE as well as your other effects is to use a Y cord from your guitar into the second channel of your AMP. By splitting the signal you don't loose any of the natural response from your AMP while using effects.

Demo of the V1 Funk Machine without the Frequency Shift conrol, but should still give you a good idea of what to expect.

Saturday, 7 July 2012

Subdecay Liquid Sunshine V2

Another one for Miro because I know how much he loves JFETs! :o)

Brian Marshall of Subdecay is one of those builders who adds a lot to the DIY community.  He openly discusses the technology behind his products and has even corrected errors that have been made in schematics.  The Liquid Sunshine is out of production, but being one of the few builders now who does seem to be producing innovative products rather than rehashing the same old thing with different caps and claiming 1000 hours R&D, his other stuff is highly recommended if you're wondering what your next purchase should be.

Info from Brian about his original:

Our award winning Class A Overdrive, The Liquid Sunshine was introduced in 2004 and has been a mainstay of our stompbox lineup ever since. The Liquid Sunshine bucks the current popular trends of overdrive pedals. It is neither fully “transparent” nor “uncompressed.” It is not modeled after a specific family of amplifiers. The Liquid Sunshine adds to your tone without overwhelming it.

Low gain settings render tube power amp like compression. Add a bit more drive to gracefully ride the line between almost clean and a hint of breakup. Turn both drive controls near max for some classy sustaining rock overdrive. The all jFET design does not produce any “sharp edges” or hard clipping.

Where’s the tone control?

This pedal has two drive knobs. The top drive knob pushes the full range, while the bottom drive knob pushes the midrange and treble. Most overdrive’s tone controls have a very narrow band of useful settings. Because of the interactivity of the two drive knobs, and the jFET design we found The Liquid Sunshine did not need a dedicated tone control.

Is The Liquid Sunshine for me?

Equally well suited as an overdrive for a clean amplifier, or pushing cranked amp over the edge. This is especially important if you need an overdrive that works at many volumes. It won’t feel out of place on stage, at rehearsal or simply practicing at home.

The Liquid Sunshine absolutely loves being stacked. It’s great for pushing other drive pedals, but unlike many other low gain overdrives it excels when pushed by other dirt boxes too.

It’s also great for warming up your tone. Many modern amplifiers are biased cold. This may result in tubes lasting longer, which is especially important if the amp maker supplies the cheapest tubes available. It might even make an amp a little bit louder. Unfortunately this doesn’t always make for great tone. The Liquid Sunshine is a perfect match for amplifiers that leave you wanting more.

Many users of The Liquid Sunshine have used words like “tweedy” or “voxy” to describe its overdrive tone. This overdrive is not an “amp in a can” device. Often these designs will create a facsimile of amp tones, but often deliver unexpected depending on what amplifier is used. The design philosophy of this overdrive is to “play nice” with your tone. The Liquid Sunshine enhances what you already have.  It won’t make your amplifier sound like something it’s not.

Guild Brian May Box

This is a bit of an unusual one because I'm not even sure what it is.  It's based on a schematic done by Analogguru and is obviously a Cornish buffer in front of a booster, so what I am assuming is that the Guild Brian May is the treble booster, and the whole circuit amounts to the modifications done by Pete Cornish when putting the effect in one of his boards for Brian.

Some or all of that may be wrong as it is just my assumption, so please correct me if anyone knows more, but the thought of a Cornish buffer into a Brian May treble booster seemed too good an opportunity to miss so I thought I'd have to do the layout! :o)

The input socket should be taken directly to the board input and so only a SPDT stomp is needed for the switching because the buffer remains in circuit during bypass (the stomp is the "Sw#" connections shown in the layout).  You will of course need a DPDT stomp if you want to include an LED.  For those wanting true bypass instead of the Cornish buffer .... shame on you! :o)

Friday, 6 July 2012

ROG English Channel

Info from the Runoffgroove website:

The Vox AC-30 amp is considered by many to be the defining sound of the British Invasion during the 1960s. The Top Boost circuitry provided crisp treble-laden overdrive that perfectly complemented the rich bass content. The English Channel is a JFET-based distortion stompbox that uses the same basic architecture as that classic early '60s amp.

This circuit is based on a 1961 Vox AC-30 with Top Boost, as designed by Tom Jennings and Dick Denney. Artists such as Tom Petty, Brian May, the Rolling Stones, the Beatles and the Shadows have used the AC-30 during their careers.

The above schematic replicates the Brilliant input, but the Normal input can be simulated by changing the 470pF cap to 47nF.
(A DPDT switch to select either 470p or 47n sounds like a good idea to me for a possible mod - Mark)

To obtain 1.6v at the source of Q4, you may need to try different J201 or adjust the 4k7 resistor. During testing and development, values as high as 12k were necessary for some J201. Try to get close to 1.6v, but slightly lower values will have no audible difference.

Note that the Cut control is set up in the traditional manner, reducing treble as turned clockwise.

Philip Miller Tate (a.k.a. Ge_Whiz) found the Cut control to be quite subtle when using the stock values. He reports that substituting a 47nF capacitor and 50k-B pot provided a much more effective control.

I, mirosol, added the following: I just recently built one of these again, and noticed that couple small things could make it even better. Not that there's anything wrong with it as it is, but - i used 50K trimmers for more accurate biasing of the JFETs, linear pot for Treble, swapped the Cut pot lugs and made it 50K with 47n cap, bigger Master pot for sligtly more overall volume and the switch for Brilliant/Normal channels. The 470p felt way too thin, so 1n/47n combo on a switch sounded perfect. I also moved things slightly around to get the switch in neatly, plus i added the polarity protection diode.. Here you go. My slight mods for this, very, very nice sounding Vox in a Box.

Thursday, 5 July 2012

Barber Direct Drive

Another great sounding pedal from Dave Barber, very well made and reasonably priced if you want the original.  I have put all internal controls external with this for more flexible tweaking, and remember if you want to run this at 18V you need to select your caps appropriately.  I've also seen a schematic for this with the 10u and 4u7 caps both being shown as 1u, so if the circuit seems bass heavy consider swapping those to taste.

Info from the manufacturer about the original:

The Direct Drive provides guitar players with classic amp tones!

True to life overdrive with greatly reduced compression artifacts, this unit has it all, clarity, great guitar volume knob control, solid punchy articulate bass, gain range from a little juice to fat harmonic overdrive. Give your guitar playing a vintage voice with this stellar performer!

    Internal bass control- The Direct Drive can dial in a stronger deeper bass response to perfectly match amplifiers.

    Adjustable presence circuit- The internal presence circuit allows the Direct Drive excellent clarity while limiting fizzy artifacts.

    Volume knob response circuitry-more shades and textures at your fingertips just by adjusting your volume knob.

    Low compression artifacts!-By carefully tuning the Direct Drive compression has been reduced to the most amp like response to date!!

    Three knob control for tonal versatility-The Direct drive uses a simple three knob control layout with a push/pull tone knob for a second Fat Harmonics voice. With the Tone control pushed in the Direct Drive brings the classic tones of the past to veteran players then simply pull the tone knob for modern fat harmonic tones...KILLER! High quality components- Players have requested the use of carbon resistors, metalized polyester caps Elna silk particulate audio caps. These components were thought to be only available on the highest priced pedals. Players asked, and we problem, no exaggerated "boutique builder" pricing.

    Ready for 18 volt operation-The Direct Drive 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.

    Barber adjustable phono style recovery stage- Most of our op-amp based overdrive pedals use a cool old style phonograph circuit to recover the frequencies lost in the overdrive stage, this worked great for vinyl and now works great for guitar overdrive!

Monday, 2 July 2012

Danelectro Pastrami

Short and sweet:

The Pastrami Overdrive is well seasoned overdrive with great sustain. Delicious tone!

FYA Electronics Moldy Meat Drive
 by mirosol

Thanks mirosol for the first cheapy pedal mod, it sounds like this offers real improvements.

Sunday, 1 July 2012

Ibanez SP5 Slam Punk

One for Miro:

Crunchy distortion. The sound of the Slam Punk is what you would get from a contemporary British hi-gain stack.