Latest Additions & Adds

Doctor Tweek is reducing his presence on eBay:

Due to the high fees and studio commitments I have decided to concentrate more effort into the web shop, continuing to provide excellent customer service and value. I will continue to sell a couple of items such as:

  • DPDT Footswitches
  • 3PDT Footswitches
  • Occasional bulk bargains

And in Doctor Tweeks Webshop:

The place in the UK for pedal parts

Parts, Components, Effects and Amps @ Doctor Tweek

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Noise Reduction NE570

If you want to improve the s/n ratio on an effect, particullarly delays, chorus and flangers, trems etc then the way to go is to include a compander into your pedal. A compander (sometimes spelt as compandor by our American cousins) is essentially a mix of two processes that are used to ‘wrap’ around an effect circuit, for example your PT2399 analogue delay.

The compander was commonly used in all the MXR and DOD pedals, in fact probably most analogue pedals from the mid 70’s through the 80’s using the NE570 or NE571 chip from Philips. The NE570 has slightly better specs than the 571 and is more forgiving in its required power suypply. Just off the top of my head without pulling up the data sheet, the NE570 is happy with anything from about 8v through to 18v. Check the datasheet first though…. I take no responsibility for you frying these.

Ah…but the NE570 is out of production… well, yes and no. Doctor Tweeks has a  good stash of these in stock, original Philips items. And there is the SA570 if you can find it.

So the two processes…

The first process is a compressor. In the case of the the un-tweeked NE570 this compression has a very high ratio, and can be likened to limiting. So, this high compression boosts the signal and then makes sure it can not increase much beyond a certain threshold or limit. The input signal to your effect becomes ‘pre-conditioned’ to be nice and loud and with a reduced dynamic range. Think of it ‘crushing’ your guitar (or bass or synth….) signal, packing as much of it as possible into your effect input.

Now normally, this heavy handed compression may give you results you don’t want…. ( or perhaps you do!). However after the signal is passed through your effect it is ‘un-compressed’ ; expanded, which aims to restore the dynamics that where removed with the compression.

Basically, it just makes everything quieter. Nuff said.

Here’s an untested layout, I’m sure it could be done better and smaller than this… the schematic with values will be posted soon when I can lay my hands on it. Meanwhile….











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Using Stripboard for your Electronic Project Builds

 Small and perfectly formed

There are a lot of ready built PCB’s available for making guitar FX. If you’ve done your web browsing you have no doubt found several sources for these, including the occasion offering from Doctor Tweek… or perhaps you could invest in all the kit and chemicals and make your own….

However, for the true ‘one off’ or a limited run of boutique creations, strip board, also known by the trade name of VeroBoard, is a great way to go. Not only is it useful for building working pedals, but it is also great for prototyping a design before committing it to a home made or commercial PCB. With stripboard you get to move your design from the test bed of a breadboard (which is great in itself) to an enclosure, so you can really check out the quality and noise issues – and of course play and gig with it!

A lot of folks are put off using stripboard because it seems complicated. What you have on a well designed stripboard often looks nothing like the schematic…but really it is simple if you go about it the right way.

Some experienced builders go straight from a schematic onto stripboard. It’s quite possible. However, I personally use a nifty piece of software called ‘LochMaster’… a free trial version is available. It allows you to place your components on a virtual board, move things around and optimise the layout. Also a lot of people just use a piece of graph paper or a printed stripboard template, along with a pencil and eraser. Nope, not for me – I’ll stick to the software!

Doctor Tweek recommends Lochmaster Vero Design Software

Super program for not much money.

The objective for most curcuit builders is:

  • Make the circuit as small and compact as possible.
  • Keep the layout neat and tidy to minimise noise.
  • Create a logical layout that is easy to modify.
  • Perhaps make the build modular so that different component boards can be used. (a modular approach also means that complex schematics can be broken down into easier to handle chunks).
  • For the boutique builder, the idea may be to be able to replicate the build easily for a small, ‘limited run’.

Here are some tips to making your own Veroboard layout:

In software, use a large oversize piece of stripboard so you do not run out of ‘space’. You can always trim the virtual board down later as you hone and tidy up the layout.

I always start by having my supply rail on the top strip and my earth as the bottom strip. You can see an example of this on the pushme pullyou octaver at the top of the page.

Start at the left of the schematic… look at the first component and place this on the vero (in software) then follow the circuit to your next component. On the vero make sure your component is going accross tracks – not along them (otherwise you will have to make a cut in the track to avoid shorting out the component!). Now follow the schematic to the next component and place… The idea here is to avoid using track cuts as much as possible – too many can get to be a real headache when you put the vero into practice. However it is doubtful that you can get away without making any cuts.

Another way to approach the task, and probably more suitable if your working with IC or Op-Amps, is to work from the center outwards. Place your chip in the middle of the stripboard and work your way around the pins, placing components as required. A note….don’t forget to cut the strips underneath the chip, other wise you will end up connecting all the pins on one side of the chip to the other side….not pretty!

The software allows you to look at the front (plain side) and the back (copper stripped side), just as you can do with the real board. It is important to get a feel for flipping the board over and relating where the componets go – as they will be ‘mirrored’ when you do this. When actually populating your vero board with components you will have to get used to this flipping over action and confirmation of where leads are in relation to the strips and cuts in the tracks.

Just to point out that the components are placed on the plain side…. generally.

If this all seems mighty confusing… well there are plenty of layouts out there already. But I reckon the satisfaction of making your own is worth the trouble.



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Custom Builds from Vachon Audio

Dave from Vachon Audio sent me some very nice pictures highlighting his custom built switcher boxes. The example below is an effects send and return pedal, allowing you to true bypass a non true bypass pedal, amongst many other uses. More details can be found by clicking on the Vachon Audio Link at Doctor Tweek Pedal Parts.

Vachon Audio Pedal in presentation case

Vachon Audio Custom Pedals come in a superb presentation case. Looking inside it all looks superb...


The switcher looks very well made...

Ready to Gig

Very industrial and solidly built, ready for gigging

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Arbiter Fuzz Face – Germanium Re-Issue

A few people have asked about this… no great shakes, but there are a few different values used in this re-issue of the classic Arbiter Fuzz Face. I found a sketch out there and have drawn it up clean and mean:

Nice clean drawing of the germanium fuzz face re-issue by Doctor Tweek
Some slight changes over the original… nice.

This is the pedal that was built into the smiley face enclosure. Can’t say I like that big round tin. The size of this circuit could probably be buit into a match box…or your guitar…mmm – there’s an idea!

Don’t forget, you can get your nice AC128’s at Doctor Tweeks UK shop, as well as all the other bits and pieces you need such as footswitches and enclosures.
Google gave:
Arbiter Fuzz Faze reissue
Type of pedal: Fuzz/distortion
Features: Classic appearance, teardrop markers on casing and controls, numbered knobs, screwed-on rubber feet, high-quality circuitboard, wiring, potentiometers, jacks, and footswitch,
Price: $185.
Build one yourself - diy fuzzface

You can build this for very little

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Get Switched On

You may need a switcher pedal for an amp or indeed any type of switcher for your pedal board, fx, keys, synths or whatever. Sometimes something is available off the shelf, sometimes not. Whatever, you can have your switch solution custom built to your specs.

Michael from Sleeping Dog FX can have a look at your needs, discuss it with you and make what you need. He uses Doctor Tweek components, so you know you are going to get a quality build both in terms of attention to detail and in the way of reliable hardware.

Custom Built Marshall Footswitch made by Sleping Dog FX @ Doctor Tweek

Custom Built Marshall Footswitch for the 9001 Pre-Amp

Recently Michael made up a now discontinued swithcher for a Marshall 9001 Pre-Amp. He tells me that this is available custom built in the states for £110. Crazy! He custom built the item for £85 which included special LED lighting as well as an extra long connection cable. So, anything is possible  – if you need a switcher or any type of routing unit please contact Doctor Tweek, or visit Sleeping Dog FX through the builders links page.

Posted in boutique effects, diystompboxes, guitar effects, recording, guitar, effects, boutique, stompbox, diystomboxes, electronics, studio, lincoln, lincoln uni, guitar pedal, | Tagged , , , , , , , , , , , , , , | Leave a comment

Silicon Fuzz Face PCB

Sleeping Dog FX have made up a really nice PCB for the Silicon Fuzz-Face (germanium coming soon!). To go with this Doctor Tweek is supplying a Silicon Fuzz-Face Parts Kit. It includes everything you need to build onto the PCB ad get it working in the box. Brilliant. The only thing you need to decide and add are which knobs you fancy – and there are plenty of choices at Doctor Tweek!

Full instructions are included in the kit:

  • Schematic (to help you tweek and modify should you wish)
  • Component Placement Diagram (explicit stuff!)
  • Top Tips Help Sheet (for the newbie to building)
  • Component List (so you can check stuff off)

Doctor Tweek's Silicon Fuzz Face PCB by Sleeping Dog FX

The board is available separately should you have your own components to use (dirty, filthy traitor!) – or you can even buy the component kit without the board so that you can vero or perf-board the build. Now that’s flexibility for you!  So have a look at   – obviously, any questions just ask at                                                                                                   Oh, Needless to say… it sounds bloody awesome, of course.                   

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Alternate Tunings

Alternate tunings are a brilliant way to breathe new life into your sound. Some are well known – some less so. I can’t take any credit for this wonderful list – originally found at

But it’s worth a copy here if it gets it out to more people 🙂

Note that some of the more radical tunings will alter the intonation of your instrument… enough to live with probably if you are only tuning for a while; but if this is going to be a permanent tuning it is probably best to check your intonation. I have one guitar tuned down a whole step and another in DADGAD… these guitars are now set up to be perfect at these tunings (the ‘drop one step’ is a Floyd Rose and took ages to get right!). Be aware also that if you are using a short scale such as a Les Paul or Jaguar then droping lower than a standard tuning may well make the whole thing too floppy…but hey, floppy strings can be fun 🙂

Alternate Guitar Tuning Chart

Standard Guitar Tuning E A D G B E
Admiral C G D G B C
All Fourths E A D G C F
Aug Fourths C F# C F# C F#
Balalaika E E A D E E A
Baritone B E A D F# B
Buzzard C F C G A# F
C 6 C G C G A E
Charango X G C E A E
Cittern (1) C F C G C D
Cittern (2) C G C G C G
Collins F C F Ab C F
Cooder Db Ab Db F Ab Db
D Minor D A D F A D
D Modal D A D D A D
Dobro G B D G B D
Dropped A A E A D G C
Drop D D A D G B E
Double Drop D D A D G B D
Face C G D G A D
Four & Twenty D A D D A D
Fourths E A D G C F
G 6 D G D G B E
G Minor D G D G Bb D
Iris B D D D D D
Half Bent F Bb Eb Ab C F
Hendrix Eb Ab Db Gb Bb Eb
High Plain D E A d G B E
Hot Type A B E F# A D
Kaki King C G D G A D
Kottke C# F# B E G# C#
Layover D A C G C E
Leadbelly B E A D F# B
Lefty E B G D A E
Lute E A D F# B E
Magic Farmer C F C G A E
Major Sixth C A F# D# C A
Major Third C E G# C E G#
Mandoguitar C G D A E B
Mayfield F# A# C# F# A# F#
Minor Sixth C G# E C G# E
Minor Third C D# F# A C# D#
Modal D D A D G A D
Modal G D G D G C D
Nashville e a d G B E
Open A E A C# E A E
Open A E A E A C# E
Open C C G C G C E
Open C C G C G C E
Open D D A D F# A
Open D D A D F# A D
Open D Minor D A D F A D
Open E E B E G# B E
Open G D G D G B D
Open G D G D G B D
Open G Minor D G D G A# d
Overtone C E G A# C D
Pelican D A D E A D
Pentatonic A C D E G A
Processional D G D F A A#
Slow Motion D G D F C D
Spirit C# A C# G# A E
Standard E A D G B E
Tarboulton C A# C F A# F
Toulouse E C D F A D
Triqueen D G D F# A B
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