But, like the fabulous Apple products I use now, it feels like we get new and amazing features from Steinberg – that we may or may not want – but certain underlying issues never get fixed…

Case in point – there’s still a nasty and unacceptable bug – still as of Cubase 15 Pro. I’m posting this both to help others, and remind myself of the fix, for next time it happens…
And yes I have reported this to Steinberg years ago…

As far as I can tell, when Cubase crashes, or somehow gets disconnected from the audio sub-system, it overwrites the External Plugins.xml file.

On a mac, you can find this here – /Users/Username/Library/Preferences/Cubase 15/External Plugins.xml

How annoying?
I have three external ADAT racks, with mono and stereo assignments stored in this file, and it is a big F**KING pain when this file gets corrupted and I have to re-assign the IO for 24 effects units..
The fix, I think (but defer to the experts who know the software arch) is to add this external FX panel settings – and maybe the same for the external instruments(?) to a preset – simple.

My workaround, is simply to configure my system and copy this .xml file to a backup location for WHEN the next crash happens.
Painful. Hope this helps someone else out there!

But I was inspired by this recent SOS magazine podcast – on just this very topic – to build some super simple passive attenuators.
They are literally a 250k dual-gang log pot wired in a box. Segway – I hate hand wiring cables and connectors – but it’s a useful skill. Kudos to the amazing fuzz box builders out there!!

Anyway, the idea is to use these directly on the hot outputs of synths and drum machines.
Really simple, and a quick custom enclosure and print job (well why not!?) makes for a useful studio tool…

My original solution is detailed in this older blog post. I basically created the bare-bones of a pedal utilizing all the parts that would give me a robust platform. This DIY version proved to be very useful, and I made several that I am still using.
Yes, I’m an engineer who knows all about feature creep(!), and considered adding a myriad of additional switches, pots, LEDs, MCU and display to measure power yadda yadda… but restrained myself and kept it to the essential minimum!

So why the update!? I started building and selling these dev boards, and the demand was gratifying, but took a long time to hand assemble, so I decided to refresh the design and productize what I could to minimize build time and make them more cost-effective.

Enter the Stomp Box Developer!

The main attraction is still the highest quality breadboard, now bigger – a massive BusBoard Prototype Systems (BPS) 2930 point board with 6 power rail pairs. It’s easy to use, high quality, reliable and if damaged, the design allows the breadboard, or a board-part, to be replaced.

I improved the plug-in power PCB to add power rail options – every positive rail can be either 9V or 4.5V or isolated to use for your own biased or negative rails… And there are secure test points (loops) to reliably connect probes to grounds, power rails and signal in and out. DC input voltage can be up to 18V – the split rail will track at a simple half of the input voltage.

The main 1590B enclosure now holds a PCB so there’s no hand-wiring at all in the build – with a nine way ribbon cable connecting the two PCBs.

Inside the enclosure is a typical true-bypass switching circuit using a quality Alpha 3PDT switch, with a filtered cap circuit for the LED indicator (won’t pop!) plus a PFET circuit to provide reverse polarity protection, with minimal voltage drop.
KISS and clean were the overriding goals, and I’m pleased with the result.

I’m working on a video and blog about how I use the Stomp Box Developer to perform audio tests, and A/B tests of my circuits against prototypes and production units – my own and others – just like a professional mixer references commercial tracks when mixing!

The boards are available to buy in the store, as are these 3PDT true bypass switch kits I created using the same switch and cable, to assemble prototypes faster, with minimal hand wiring.

My aim is to build light-weight acoustic panels to cover a couple of walls. Something along the lines of this custom one I have in my workshop…

This was printed and made by ATS Acoustics (no affiliate links)

Acoustic panels will absorb different frequencies at different rates, dependent on the material and thickness of the material – and any air space to the wall. What I am building here are modest absorbers, that will make the room sound much better overall (I’ve done this before!) but won’t act as well on the lower bass frequencies – the panels would need to be much thicker… But I can handle that tradeoff…

So where to begin!? As luck would have it, we found a set of four large square canvas prints in a budget store and decided to kickstart the build with those.
My wife also had some plain framed canvases (she is an artist!), which she painted to work with the budget prints.

For an absorber, I used 1″ thick Owens Corning 703 rigid fiberglass board. I got a box of 12 1″ panels at 24″ x 48″ for about $130, delivered.
These have to be cut to fit the back of the prints. Wear gloves, mask and long sleeves to avoid irritation from the fibers. I used a long metal ruler, and cuts easily with a couple of passes with a box cutter.
Use a generous coasting of 3M Super 77 on the canvas and board to fix in place. (I hate this glue – it seems to get everywhere, so keep covered up!)

You could stop here and have functional absorbers, but I have DIY tools, and will use them!

First, I built a wooden frame around the canvases, using coated MDF door trim. Easy to work with and smooth finish for painting… These were epoxied and pin-nailed in place, then painted.

Finally, I cut ¼” plywood back panels, again using epoxy and pin nails to assemble, before finally adding a couple of hooks to hang.

Some comments on other options… First, my panels ended up being about 1 1/4″ deep. There’s nothing stopping you using similar 1″ canvas prints, and building a deeper frame, and filling that with thicker fiberboard, for more bass absorption. Also, you can use something called mass loaded vinyl as well as the ply. It’s meant for construction, but heh…
And finally, you can buy Z hooks to mount these more cleanly to walls, rather than the low cost hooks I used.
And having a wife who is an artist might help!

Here’s the main wall, with the modified and home made panels – the studio is starting to come together

The Concept: Reviving the Dead
Guitarists have long known the charm of plugging in a pedal with a dying battery. The fluctuating and lower voltage can lead to a sagging, spluttering, and compressed sound that’s hard to replicate with a fully charged battery or power supply. It’s like your pedal is fighting to keep going, adding an element of unpredictability and texture to your tone. The Undead captures this phenomenon perfectly, providing a reliable way to achieve those tones without constantly hunting for half-dead batteries.

How It Works
The Undead circuit simulates the declining voltage of a dying 9V battery, but with control. The output can be set from around 8V down to about 5.4V (the voltage that a 9V battery literally dies at!) – or use the bypass switch to pass through the clean 9V from your power supply. The lower voltage allows you to explore a range of tones from slightly underpowered warmth to all-out fuzz chaos – plus you can still switch in full 9V power – so it’s two power supplies (or tones) in one!
It’s like having a volume knob for your power supply—turn down the voltage, and watch your pedal come to life in new and unexpected ways. It maintains a consistent lower voltage, unlike real batteries that can be unpredictable, ensuring your fuzz always performs at its gritty best.

The Benefits: More Than Just a Dying Battery
Consistent Sag: Unlike real batteries, which can suddenly die out or behave inconsistently, the Undead offers a stable output at lower voltages, so your tone stays reliably ‘dead’ in the sweet spot.

Versatility in Tone: Experiment with different voltage levels to discover unique sounds. From smooth, mellow fuzz to raspy, glitchy tones that sound like your pedal is on its last breath, the Undead lets you dial in exactly the right amount of ‘sag.’

Long-Lasting Performance: No more swapping out batteries mid-performance or dealing with the frustration of a pedal that suddenly dies. With the Undead, your pedal’s ‘dying battery’ sound is always on tap.

Preserve Your Gear: Using real dying batteries can sometimes harm your pedals or lead to inconsistent performance. The Undead provides a safer, more reliable alternative that doesn’t compromise your gear.

The Undead features a bomb-proof, clean, quiet electronic design, that protects against input reverse polarity, output short circuit and thermal overloads. If you do overload it, it will come back to life! Don’t feed it after midnight…

Why You Need The Undead
Whether you’re looking to add new textures to your fuzz tones, experiment with lo-fi sounds, or just want to capture that elusive ‘dying battery’ feel without the hassle, the Undead is your ticket to sonic experimentation. It’s perfect for studio settings where consistency is key, or on stage when you want to wow the audience with tones that stand out from the usual fuzz fare.

Give your fuzz pedal a taste of the afterlife. Let it become the Undead, and discover the wild, untamed potential of your sound. Are you ready to go beyond the grave? Plug in, turn down the voltage, and unleash a whole new realm of fuzzy, distorted bliss.

Available no in our online store.

The second member of our Art Series of pedals, a boutique-like Klon clone, offering very complimentary tones to our first pedal – the Hi Scream.
Re-inventing lost or rare vintage tech – with a modern twist – is one of our product development aims.

Klone Ranger is more like a posse with its three clipping diode options, labeled S, D and A.

The S setting features a symmetrical pair of Germanium 1N34A diodes.
The D setting switches in two symmetrical silicon diode pairs – two diodes in each direction, giving a huge clipping overhead.
Finally, the A setting tweaks the silicon diode circuit into an asymmetrical clipper with two diodes in one direction, and one in the other.
It’s like having three overdrive pedals in one.

Wanted – Great Tone!
All settings offer wonderful warm tonal ranges from boost thru cutting, biting drive. Each clipping circuit offering its own unique character.

Klone Ranger features the original buffered bypass, with a pop-free, clean, modern design, and incorporates rare vintage 1N34A Germanium diodes.
Every pedal is hand assembled and thoroughly tested in the USA.

You can find more details on the Klone Ranger product page, and in our online store. Pedals will ship at the end of July, and more quickly thereafter.

Customizations
Klone Ranger utilizes an innovative clipping circuit with six germanium / silicon diodes, and as such is hugely customizable. We are open to modification requests!

Reviewers wanted!
If you would like to review one of our products on social media, we would be delighted. Please get in touch for more details.

Developed as a fast and reliable way to add an ON-ON stomp switch to a guitar or synth module build for true bypass and LED switching – or whatever else can make use of the 3PDT functionality!

A huge value for rapid prototyping, the 9-way (0.1″ pitch) 2″ long flexible cable brings out each of the three switches in grouped ways. The wiring is uncommitted, but I chose to make pin 4 (on the middle switch) a ground connection, which connects to a solid, uninterrupted ground plane on the upper side of the board. This is done for two reasons – it’s typical to use the middle switch for LED switching, so pin 4 can be utilized for the ground return for the LED. Clearly, also having a ground plane above all audio signals helps prevent electrical interference / return paths also.

Here’s the schematic –

This ground plane also has two 1mm holes for additional ground connections or test points.

The switch posts and cable ways are clearly labeled on the screen silk. The cable itself has a color coded strip indicating a pin 1.

Made with only quality parts, the kit comprises an Alpha 3PDT switch, a 2-layer PCB, and a 2″ 9-way 0.1″ pitch flexible ribbon cable. (The 2″ dimension is just less than the length of the plastic carrier – as shown in the pics.)

The flexible cable enables a short connection to your own PCB or Veroboard, which can sit at a different level than the footswitch PCB. It is very flexible – but note it is not intended for moving applications!

I’m thrilled to announce our first pedal is finally available for sale, and we called it Hi Scream.
Inspired by the legendary TS-9 Tubescreamer overdrive – originals of which are now selling for crazy prices, if you can find one at all!
Re-inventing lost or rare vintage tech – with a modern twist – is one of our product development aims.

Hi Scream has an amazing range of tone. With three clipping diode options, and a huge range of gain, it’s like having three overdrive pedals in one – and boutique ones at that!

At low levels, with the single pair of symmetrical diode clippers (S setting), it creates sublime warm tones. Add more gain, and push the output level, and the pedal and your amp can create sizzling sound – great for solos and plucking.

The second diode clipping option (D setting) switches in two symmetrical diode pairs. You will hear a leap in clean tone being passed, which again plays well with the output level control – and can either drive an external amp harder, and / or push the extended gain into clipping, and really stand out in a crowded band sound.

Finally, switching to the third diode clipping option (A setting) turns the circuit into an asymmetrical clipper with two diodes in one direction, and one in the other. This again creates a new range of tones (maybe with slightly lower gain settings, can we suggest!?) that again plays very well with the output level.

High gain settings can create insane crunch and dirt, especially if you play chords!

Setting up an overdrive is all about interplay between drive and level – and what amp you are driving – Hi Scream gives you lots of options to play and find tone you like.

Originally designed for guitars, the clipping circuit adds wonderful harmonic richness to any sound source. Definitely worth trying in a recording / production setup – try it on snares, claps, and ‘found sounds’ to create new / altered sounds from loops and samples.

Hi Scream features true bypass, with a pop-free, clean, modern design, but incorporates some of the same components found in the hard-to-find, expensive 1970s original. Power can be stand-alone with a 9V battery, or via the DC jack.
Every pedal is hand assembled and thoroughly tested in the USA.

You can find more details on the Hi Scream product page, and in our online store. Pedals will ship at the end of July, and more quickly thereafter.

Customizations
Hi Scream utilizes an innovative clipping circuit with six silicon diodes, and as such is hugely customizable. We have a limited run version in development with our own diode concoction, but we are open to modification requests and ideas. Definitely a topic for upcoming blogs and videos!

Reviewers wanted!
If you would like to review one of our products on social media, we would be delighted. Please get in touch for more details.

Debug
To debug this, or any other pedal issue, you have to simplify and isolate – build on known good stuff. Since I’m an engineer, I think of building like layers of an onion, or working forward or backward, depending on how complex your effects setup / rig is – let me explain…

Working forward. If you have a fairly simple setup with a handful of pedals, it might be easier to start from the simplest setup – guitar – cable – amp, and confirm these all work fine first. Then, swap out all the cables you are using and again confirm these are all OK – now you know the basics and all interconnects are good. If there is an issue, it’s not in the effect, it’s a bad jack solder connection, or grunge on the jack itself.

Working backward. Suitable if you have the mother of all loaded pedal boards and suddenly have an issue. This is a slightly different problem beast, but again start with the basics, check cables in / out of the board, and then test each pedal individually – ideally removing other connectors. A cable tester can be useful here – pull each cable and check.

Useful tip – clean stuff! I had a friend back in the UK whose idea of bike maintenance was to ride his bike, store it in a damp shed until the next ride, and then douse the rusty monstrosity with WD40 until it worked again! Back to guitars and effects (!) – waiting til something breaks is one approach we can all relate to, but some minimal maintenance of cables and connectors can really avoid a shitty gig experience… I can recommend Dioxit G – but you can likely get decent results using good old Isopropyl Alcohol. Not WD40. (I just know someone will tell me they do!!)

OK, so we’ve got a good guitar to amp connection, and a bunch of clean / solid patch cables…
Now we add one pedal in at a time and test at low and (carefully) high amp levels. If the option exists, use a battery – so we aren’t introducing two variables. However, if you normally use a power supply, add that next – one pedal and one PSU connection. I am assuming the PSU is a decent brand with isolated outputs. If not, there can be all sorts of loops and issues… Another article maybe?

I would test each pedal individually – it’s the fastest way to find most issues. We are looking to isolate the one thing.
Gently wiggle the jacks on each side of the pedal if it doesn’t show up immediately. Once you find the offending pedal, we can get to work. But! Since you are already doing this, test the rest of your kit just in case…

Open the bad pedal and have a look inside. Trace the jacks and wiring on them. It’s unlikely you will see anything wrong, but just maybe there’s an identifiable wire barely touching, or very definite dry solder joint etc.
More likely one or more of the solder joints will have gone bad, and you can’t see it, at least not usually without a microscope.

One other test – with the bad pedal on its back, with its legs in the air (!?) try loosening the jacks (if they are case mounted) and do more wiggling. Do this carefully at lower amp volumes – this might identify the bad joint.
If PCB mounted, we need to move to re-solder the jacks, even if the connections look good. You can either desolder the jack terminals one at a time and re-solder, or use a liquid flux and re-solder over the old soldered connection – especially if you have panel mounted jacks. Since you are committed to do this, do ALL connector joints, not just the ones you suspect.

These dry joints are a common problem – they can develop over time from a badly soldered joint, and / or joints can fail due to mechanical stresses on them. For DIYers, who, let’s be honest, buy many parts from low-cost sources, I have another warning or bit of advice. Be aware that jacks you purchase may simply not be properly solderable. Be aware that cheap / fake / corroded new jacks may give you these symptoms in a brand new build on your bench – and can be soul destroying, especially after completing all that elegant looking wiring! If you get this issue, replace the connectors with known quality parts / good sources, OR just flux-solder-flux-solder until you cure it – at least for now!
I have used ultrasonic cleaners to clean corrosion from old connectors, but it was for a repair – but can be a useful trick. I spent years in the maker community for Arm, and I have seen far too many fake and nasty parts ruin a build. Being aware, you can debug if an issue arises!

Scratchy / noisy pots
Whilst I’m on the topic of noise issues, let’s look at scratchy pots. Noisy pots are ones that can crackle when moved – or not. It indicates there’s dust and grime on the track breaking the wiper connection.
99% of the time (a statistic with no backup!), it can be fixed with a generous application of Deoxit F (F for fader) or similar. Find an access to the pot internals, and spray, and rotate the wiper to apply the cleaner.
If you have an open pedal to fix a bad connector, I’d do this as matter of course anyway.
If several applications of the cleaner don’t fix the crackle, it may be new pot time.

Bypass switching noise
Now I’m going off on one, as this next topic isn’t a repair as such, but you may find this issue as you add a new pedal to your setup, or change the positions, and mix buffered / non-buffered pedals for instance. That is pedal pops when turned on (most likely) or off.
This is a mod, rather than a maintenance or repair, but again, you can diagnose and fix this one fairly quickly and cheaply.

Typically the pop comes from having an input capacitor in the input circuit that can hold a small DC charge (maybe leaky, lower cost part also) and exhibits itself as a click when switched into the audio path. Typical remedy is to add a 1M resistor on the input. This gives the cap a route to discharge. To test this, try placing a resistor on the input jack – or even in the input jack plug outside the pedal. Below are some test boxes I made to access signals, and I added a 1M resistor on one of these for future testing.

Hope that was useful – an impromptu blog post caused by a noisy pedal, and I got into rant mode! Let me know if there are other topics I can usefully rant about.

Applying power to pedals should be a simple thing, but as designers we have to understand that if something can go wrong, it absolutely will. Or said another way, if a user can do something stupid, they will…

So I thought I’d dig in on what reverse polarity protection options are out there and / or make sense to protect pedal circuits from mis-applied power.

Let’s start with the typical power switching circuit for a pedal that has a battery and power jack, to understand how it works.

So quick run-through of what happens and when.

Battery powered (no DC power) – battery is actually isolated until the input jack completes the connection to circuit ground. This is really key to understand – the screen and ring connections of a stereo jack are used like a switch on the barrel of the (mono) input jack to complete the ground circuit connection. This is done to save battery power – the circuit is powered on only when you put the input jack in.
Two things are of note immediately – changing a battery and connecting it backwards will do no damage if there is no input jack in place. But! If the jack is present, we need a reverse polarity protection mechanism… Second, when designing PCBs, we need to remember that the input jack is our ground input…
Note the DC jack has a switching function here also – this time on the positive side. With no DC power jack inserted, the battery 9V connects to the circuit via the shorted ring connector on the DC jack.

DC powered – when a DC jack is inserted, it isolates the battery, and feeds the input voltage to the circuit instead. If a battery is in the case, it is isolated. Again, anther useful observation is that if you only power your pedals with external power supplies, and never use batteries, then you don’t need to worry about the battery terminals rattling against the case metal. You don’t need to wrap it in tape or anything else – it can’t do any damage. Obvious caveat – the ground connection on the battery clip should be kept away from components on the circuit board!

Another observation about the DC power jack on (almost all) guitar pedals – they have an odd polarity! The center pin is negative (0V or GND) – and that is the opposite of almost all other power connectors on consumer appliances. It would seem way more sensible to have a DC jack with the outer connection and possibly shell be ground, since we would likely want the case to be grounded for screening purposes… So, if you try to use a household jack, it will be the wrong way round. Thankfully most consumer power bricks are 2.5mm and center-positive, whereas guitar pedals are 2.1mm and center-negative.

However, there are guitar pedals made the ‘other or ‘right’ way round – and any good pedal power supply unit comes with cables for these opposite / legacy connections – so be careful!

Anyway, applying power to a DC jack, or via the battery clip, the wrong way round will cause damage if the circuit is not protected.
So with my observations and opinions out of the way, let’s look at circuits…

1. Silicon Diode across power rails

I’ve done this. It’s bad, but I’ve done it… There I feel better already…

Probably the most popular method of polarity protection (sort of) is to apply a beefy silicon diode (1N4001 or similar) across the rails to protect the circuit. So yes, with a reverse voltage applied, this will protect the circuit, but makes your 9V battery into a nice heater. Try it
A fresh alkaline can source 1A or more, but the voltage will sag rapidly – say to 4V or less, but still an amp is an amp… So we will get lots of heat in the battery.
(Don’t ever think you can do this with LiPos – they will literally blow up…)

1a. Silicon Diode across power rails, with added fuse series resistor

So to limit the reverse current, we can add a series resistor. The upside is we no longer get huge fault currents, but the downside is the voltage drop across this resistor – which is in circuit at all times – and the power dissipated in the resistor.

ProCo Rat has such a circuit. A 1/4W 47R or 100R resistor. If we consider the 1A current capability of a 9V battery, or that most power supplies will provide 500mA, then these resistors are really just fuses, and eat useful power at all times the circuit operates… Caveats again – yes they might survive short duration ‘doh’ moments of battery wrong connections, but it’s a bad engineering choice.

And yes you can use much larger power resistors, but really – think of all that sad lost power we are turning into heat instead of delicious tone

Quick side thought on fuses. Resettable fuses do exist – I’ve used them in motor-related products. Their downsides are the very high (proportionally) trip currents, and relative slow response times. They do however, interrupt a fault current, and reset after it has been removed. It’s worth surveying new devices to see if the specs could work for this protection scenario…

2. Silicon or Schottky on input rail

Another obvious and widely used technique is to place the protection diode in circuit. A silicon diode (Vf around 0.6V) or better Schottky (Vf around 0.45V) can be used.

This approach does provide protection, but the obvious downside is that always present voltage drop.

That said, even before I talk about more complex circuit topologies, I think a Schottky diode used like this is likely the best bang for the buck protection for most pedals – it’s simple, low cost and loses only a small amount of input voltage to the protection.

3. MOSFETs

MOSFETs are the last option I will examine. These circuits are more complex (at least to design correctly), more expensive, use more board (real estate) area, can be very difficult to find for through-hole options, requires care in selection, but technically the best solution. I say technically best as we get reverse polarity protection, with only a tiny voltage (in the realms of tens mV??) loss to the FET device during operation. Ideally we’d like the protection to be ‘invisible’, but heh, engineering is all about compromise!

We can use PFETs or NFETs. Let’s start by looking at PFETs and how to select one.

When we apply the correct polarity, the PFET operates by virtue of the body diode passing input voltage and biasing the gate such that the device turns on – and when it is on, the resistance of the device is so low, the diode is no longer in play. When reverse voltage is applied, this biasing cannot happen, so the device is off.

I have shown the circuit with an additional zener and resistor, but these may not be required as we will see as we select a device…

To select a device for our circuit, we need to consider the following parameters – maybe in this order –
VDS – drain to source voltage. This must be higher (I’d say much higher) than the battery or PSU voltage. If we are using 9V battery, I’d look for say 30V VDS, but some pedals can also use an 18V PSU – so consider the worst case.

Drain current and power. We need to make sure the device can sustain the worst case operating circuit current, and also (see next parameter) that the package can withstand that power level – in conjunction with RDS(ON). As above, I’d look for something way above what we expect / worst case – so that we are designing for longevity (good word!) and not stressing the power components.

RDS(ON) – drain source resistance. This is a huge one! Power loss is I2R, and Voltage drop is IR, so we need that R to be tiny – ideally tens of milli ohms – so we reap the benefit we are paying for…

VGS – gate to source voltage. If you can find a device that meets the above specs and has a VGS max greater than the input supply voltage, then we don’t need that zener and resistor (tie the gate to ground). The zener is literally there to clamp the VGS voltage to a safe level (see the datasheet). Eg if VGS is 8V, I might clamp it with a zener at 6 or 7V.
The resistor value is not critical – say 10k to 100k – protects the zener and limits current.
Quick note – RDS(ON) is a function of VGS, so check the datasheet for the typical applied VGS vs what max RDS(ON) you can expect! Ah, engineering circles of fun..

Some personal observations on selecting MOSFETs for this application: I found that very large (TO220 packages) had RDS(ON) in the right range – like the IRF5305 that I use on my development boards. I also found that there were quite a few nice PFETs in smaller surface mount packages that met the specs, but very few in something like a TO92 package or similar for my all through-hole builds. If you find something, post a comment or drop me a mail!

However, help may be at hand using an NFET as shown in the diagram below, and indeed NFETs can have very attractive features such as lower RDS(ON), might be lower cost and with more availability of devices.

Hope this is useful. Happy to answer questions, and take feedback.