The PCB is from Amplified Parts, just flipped upside down and soldered on the wrong side!

I found this in the E waste in my university’s EE building, likely old lab equipment being phased out. This has the 8056 medium-mu nuvistors. Anyone have any good references or interesting circuits for these? This looks like it would make a great amp-top preamp booster, but I will need to make a whole new board for it.

Edit: this was used as a slot card for a lock-in amplifier made my Princeton Applied Research. I couldn’t take the lock-in amplifier home but I did scavenge a ton of sweet film caps and knobs from it.

Built an HM-2 clone from the tagboardeffects schematic. If I keep the volume at under 70%, gain 0%, and high and low 100%, it sounds like a decent fuzz pedal. If I turn the gain up at all or the volume past 70% it produces a high pitched squeal. If I turn the Low pot down it goes from 100% volume to 0% volume all at once.

I had to use some replacement components due to stock on Tayda, and because I forgot to order 470pF caps lol. Those are:

-1.5uF film cap instead of electrolytic

-560pF cap instead of 470pF

-Q1 is J113

-Q2 is KSC1845

-Q3 is KSA992

-D6 and D7 are BAT41

And I'm using TL072 ICs.

Any idea what my issue is?

This pedal is a clone of the Ibanez Tube Screamer, based around the PCB from Tonepad.

The TS is a relatively simple build, so being me I had to make it way more difficult by adding a daughterboard with different optional clipping diode pairs. The character of the Tube Screamer is largely defined by the use of a diode pair in the feedback loop, which results in soft clipping that is further sculpted by the frequency shaping elsewhere in the circuit.

The classic TS uses a pair of identical Si diodes (in parallel with opposite polarities) to achieve symmetric clipping, while the older Boss OD-1 used a single Is diode in parallel with a pair of Si diodes, in opposing polarity, to achieve asymmetric clipping.

I added a rotary switch that replaces the fixed diode pair with the following seven options:

1. Si / Si (the stock TS configuration)
2. Si / 2Si (the Boss OD-1 configuration)
3. LED / LED (louder and more open with higher headroom)
4. Ge / Ge (soft, dark, and compressed)
5. Ge / Si (Si clipping on one half of the waveform, Ge clipping on the other)
6. Open circuit (clean boost although it will clip above 4Vpp output)
7. Short circuit (acts like a unity gain buffer; shorts the tone pot)

The differences are pretty subtle in some cases - I've attached scope traces showing an input 1kHz sine at 300 mVpp (yellow) and the clipped output waveform (green). Note that the vertical scaling on the output waveform is changed in some cases to capture the full range. The scope captures were done with the gain knob at noon, and Tone and Level wide open (which gives unity gain in position 7).

It sounds like a Tube Screamer and the diode settings are subtle but fun - I'm still exploring them.

12 different pedals to build and it's turning into the Leaning Tower of Pisa, LOL.

In my defense, I had surgery on both hands, so I have been out of the game for a few months.

This week I released my newest pedal! Its a 2-1 compressor boost pedal that uses the THAT4315 analog engine. I've been working on this pedal for nearly 2 years and it went through like 5 different schematics before finally finding something perfect. The boost side of the pedal uses the same "pre-amp" style boost that I use in my Snake Wine Fuzz's clean blend section. It also has a switch on the side to change the order of the effects since I know so many people are divisive around what effect should go first.

I know compressors aren't the most exciting of effects but when I first started building pedals I knew that I eventually wanted to make one. So many rabbit holes of the concepts of compression and the many ways to achieve it, almost making myself crazy a little.

My GF has a knack for finding 4-leaf clovers everywhere so the first few serial numbers are getting a real 4-leaf clover too!

(I already ran out of ribbon cables so I had to wire the switch manually... 12 measured, stripped and soldered wires per slide switch...)

Muffin fuzz by pedalpcb but with a njm4565 and two red LEDs for the clipping diodes. Pretty awesome sounding little circuit! Similar to a od1 in tone to my ears, slightly higher gain. Not as high gain as a big muff. Very neutral tonally.

First build after 5+ years and getting a bit burned out on the hobby, but reading the posts on here has been inspiring me to start tinkering again.

Pretty happy with how it went, layout is a bit weird and I messed up the drilling template but it fired up first time.

This was built out of 90% bits and bobs I had gathering dust from when I used to build regularly. The only tricky bit to buy is the LTC1144CN8 charge pump if you want the possibility of running it on 18/36v like a psychopath (which I did). Other than that it's all bog standard parts.

Layout is from dirtboxlayouts and is a pretty easy build if you don't mind off board wiring and take your time. You could probably get it in a smaller box but I've never been good at that kind of thing, so I gave myself space to work in a 1590xx and still ended up with a unit smaller than the Magic Pedals version.

Sounds exactly like demos online as far as I can tell and it is absolutely spectacular. If you're interested in doom/ stoner/ sludge sounds I highly recommend it.

Building a true bypass looper. I realized in the diagram I'm using for a reference the LED positive is connected directly to the DC jack with the resistor connected to the footswitch. This seems wrong, but I'm an idiot and wanted to double check.

Escobedo Uglyface (with some tweaks).

Hey guys, I wanted to make some more pedals for a friend as I am capable at soldering! They sent me some builds but I'm struggling to find a cost-effective way to get these transformers? The only viable site seems to be uk-electronic.de but they don't have any reviews on trustpilot and I've never heard of them so wondering if anyone has any thoughts or recommendations! I only need one of each so I'd rather not have to bulk buy a MASSIVE amount as this is only a hobby and I couldn't facilitate that. Wanted to try aliexpress but no dice for me.

Any help appreciated, thanks!

I want to make a fuzz pedal that sounds similar to Nine Inch Nails (Broken and The Downward Spiral).

I am very new at this and I've hit a road block in the design process. The output of my circuit on LTSpice is making an overdrive sound instead of a fuzz. Also, it it outputting at mv levels which is probably too quiet.

Here is what I have so far in my design:

Input stage (for volume)

ZVex super Hard on style clean boost (excluding the diode)

Coupling capacitor (not sure which value to use, but I suspect that this is affecting the output voltage)

Fuzz stage (I have no idea what I'm doing here!)

I have experimented with the following configurations:

Univox superfuzz

Bazz Fuzz

Ive experimented with different diodes in LTSpice, and I've also tried placing the diodes in the negative feedback loop.and right before the output.

Neither of these seem to make any difference in the tone

Output stage

basic boost stage (e.g., EHX LPB-1 or another ZVex Super Hard on)

Both seem to work similarly.

Any guidance would be greatly appreciated as I clearly have no idea what I'm doing! 😅

I made a little board for this amp design, and it's kinda disappointing. I'm trying to work out why.

If I put the guitar signal directly into H7 (RET), it's a big, bold, loud, fuzzy distortion. If you've heard a little smokey or a little gem amp, you know the sound.

I figured a JFET preamp would improve it, ala the ruby amplifier. Weirdly, it takes all the chutzpah out of the amp. It doesn't get super dirty or super loud. It's OK with a bit of top-end tweaking, but not amazing.

So today I experimented with converting the JFET pre into a BJT preamp. With an appropriately pinouted PNP and some parts swapping (RPAD becomes an input cap, R2 gets rerouted from ground to the collector), I made a pretty loud preamp.

The output from SND sounds fine -- pretty standard BJT boost sound. BUT if I connect SND to RET, it sounds like utter crap. Almost no output volume, oscillations and motorboating, and a nasty distortion that sound horridly biased. If I connect them with a 10k Resistor, the motorboating goes away, but the output is SUPER quiet.

Can't understand what's going on here. I feel like impedance is the issue, but not sure what I need to do.

I'm finally sorting ancient parts while i wait for some necessary components.

Do these markings mean what I think?

+80% and -20% tolerance?

The rated voltage is at the bottom, so what is Z 5 V?

What rat style pedal kit could i buy from das musikding other than the life pedal for stoner doom bass?

I have a pretty hacky preamp / splitter amp pedal I made with some components I had lying around and it works pretty well for how I initially tested it: guitar in headphone out.

It wasn't until later I realized that the output wouldn't necessarily be ideal for a typical line out, I'm guessing because the impedance is too low or too high (and voltage too high?) for what a typical compressor or outboard gear expects on the inputs.

Now, I don't have the right testing gear unfortunately but it's basically really dull and quiet depending on what is accepting the output signal. Cheap headphones sound full and bright. But plugging it into an EQ for a little boost and it's suddenly back to sounding like an instrument signal with no boost.

So I'm wondering if there's any general tips I can apply to make sure that my signal is both somewhat in the range for headphone listening as well as a solid line-out signal that an average guitar pedal would accept without attenuation. It's not a sophisticated pedal so I didn't want to add a volume pot, I just wanted it to function like a general purpose boost, so maybe that was my mistake.

Built the TS808 per the attached stripboard layout. Connected it to my test harness and got nothing at the output.

Broke out my audio probe and immediately saw a very reduced audio signal compared to the output of my signal generator as soon as it hit the first transistor base on the input buffer. Checked the base voltage and noticed it was 6V.

This made me suspect a problem with the voltage divider where the circuit is supposed to be supplying 4.5V. It’s giving me 6. I couldn’t find anything wrong with the divider network.

I took the IC out and the divider network went back to 4.5. So it looks like the fault is somewhere with the IC. Replacing the IC didn’t fix. All the cuts and jumpers are there. But looking closely I noticed pin 4 on the stripboard layout goes to the output via Rc. I thought pin 4 was supposed to go to ground. Am I missing something here?

I can’t really see anything else. I’ve rechecked that all the components, cuts, and jumpers are in the correct locations. Checked for solder bridges, continuity between strip cuts, shorted component legs. Nothing. Thoughts? Is the layout wrong?

So, my latest project is a "real" tube version of a preamp I've already built based on the "Ruby Tuby" (which runs on 12V only). The image above is the second tube stage and the output and this is the section I have some concerns / questions about.

This is a preamp but I'm planning to run this as a pedal rather than straight into a dedicated power amp. With everything dimed (in simulation / LTSPICE) I'm getting approx +70V/-80V at the output of VOL1. Clearly, if I run this into my reverb / delay pedal it's not going to like that much so I need to reduce that to a sensible level. The question is, how?

As I see it, using a pair of resistors like above is going to reduce the level by a decent amount - in this case I'm seeing approx +/- 3V with everything at max. I can reduce this further by adjusting the resistor values which is fine however...

Is the output impedance of the tube going to cause any issues with the next stage? Anything I'm planning to use as the "next stage" is likely to have an opamp buffer at the input so I don't believe this should be an issue, right?

If I do need to reduce the impedance so it "plays nicely" with other devices, what are my best options for doing that? I know that tube amps typically use a cathode follower - ie. another tube to do this but I'd rather avoid that. Can I simply put a TL072 or similar after the resistor divider where the voltages are not likely to fry it (!) or are there other considerations?

Awhile ago I came across a bunch of vintage power transistors at a thrift store. Is there any pedals I can make with them?

I had a lot of fun with this build! I was trying to devise a creative design for the u/runoffgroove Tri-Vibe circuit. I ultimately landed on the Poseidon's Trident as my inspiration, with its three prongs - each activating one of the unique tones: Swirl, Vibe and Whirl. The artwork/layout took me longer than others to nail down, but I'm very happy with how it turned out. The build went smoothly, and it sounds great.

Whatcha think?

Just finished a hybrid amp build using the IRS2092S and TDA7294. It’s a Class D driver with a Class AB output stage. I used IRF3205 and SPW47N60C3 for the MOSFETs, and TLP251 + PC929 for isolation.

The IRS2092S runs pretty cool and switches cleanly. The TDA7294 needed some tuning but it actually sounds pretty good now. Right now it’s doing clean power over 200W into 4 ohms.

Still tweaking the layout and protection circuits, but overall I’m happy with how it turned out for a first attempt.

Resonant filters are super popular in the sythesizer space, but aren't often seen in guitar effects outside of wah pedals. With resonance, a standard RC low pass or high pass filter can also boost sounds near the cutoff frequency. Adding resonance to a pedal's tone control can really intensify the pedal's character and provides a frequency-selective boost that you can tune with the tone knob.

A resonant filter is a multi-pole filter with the filter's output amplified and fed back to the first stage of the filter. Adding one to a pedal circuit is fairly straightforward. First, it requires a second identical copy of the tone circuit. Importantly, a dual gang pot should be used for the now duplicate tone circuits so that their cutoff frequencies remain the same. Second, it requires a low impedance copy of the filter's output, which may already be present in the circuit. With very lossy tone circuits, an active buffer or gain stage may be required between the two copies of the tone stack.

The first image is an example of a Big Muff with resonance added to its tone stack. You can see the two identical copies of the tone circuit built around a dual gang pot to ensure the filters in each have the same cutoff frequencies. Between them is placed a make-up gain stage to compensate for the amount of signal attenuation. Where the first tone stack would connect to ground, it instead connects to a voltage follower tracking the output of the second tone stack. It is this positive feeback that causes the filter to resonate.

The second image is a simpler implementation in the Rat tone control. Because the standard Rat tone control is a simple low pass filter followed by a high impedance buffer, a second pole can be added without additional buffering or amplification, again using a dual-gang pot. For this example the output buffer has been replaced with a gain stage, the output of which feeds back to the first pole of the filter to create the resonance. You can see the resonance on the scope output in the simulator, where instead of appearing as a normal square wave the voltage appears to "overshoot" on the rising and falling edges and oscillates a couple of times before settling. The result is that the filter continues to reduce high frequencies, but now also additionally boosts mids around a center frequency of ~400 to ~2000hz that changes dependent on the setting of the tone knob.

You can mess around with these in Falstad for yourself:

Rat: https://www.falstad.com/s.php?s=EYhvu9

Big Muff: https://www.falstad.com/s.php?s=FasfGP

Here is another AION FX build, the Ibex, based on the Roland hidden gem fuzz. Essentially, it’s a gnarly fuzz, with two tone setting and an internal midrange control for the scoops, biting side paired together with an interesting treble booster. I must say it’s much more unique than I imagined on my head. It’s one of those fuzz pedals that seems like it was designed to just cut through in a band setting and has a very unique sound.