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    Power Supply Questions - Reverse Voltage Over Voltage

    Hey folks. Given I design for myself and don't really have to worry about scale, I want to design things the "right way. I'm designing pedal and studio gear. I think for some stuff I will use a linear power supply that will provide +12/0/-12 using a 5 pin din connector, so not worried about the...
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    Transfer function of Diodes

    Further to my wondering whether we are analysing diodes a little deceptively, I thought I would test the transfer function, as that's what we're actually interested in at the end of the day? You can see some interesting data in this interactive plot...
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    GPT-5 Circuit Analysis

    Hey folks, thought I would give GPT-5 a go at some (?simple) circuit analysis. I'm not a circuit wizz myself so not sure how well it did but here is the analysis. You said: how is the frequency range determined in this circuit You said: yes please You said: I would like to create two...
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    Diode Testing on Breadboard

    Hey folks, I've been doing some testing with diodes using my breadboard, except I've run into an issue, no matter how I hook up the diodes, I'm always getting asymmetric clipping. It doesn't matter whether they are silicon, germanium etc. This is as measured with my oscilloscope using a 2.4v...
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    Lt1054 negative voltage grounds

    Using this schematic from AionFX to build a negative voltage supply for my bread board. I notice they have separate ground for the negative voltage compared to the input filtering. Is this necessary or just to minimise switching noise?
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    20 ГT309Б Ge Transistors Tested

    Alright, back with another round of Ge transistor testing this time the GT309B. These were quite a bit more expensive per transistor than the previous boxes I purchased. However if you want higher gain but low leakage these definitely seem worth taking a risk on. Out of 20, only 1 device is...
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    SPICE library

    This quote on an old thread discussing diode Vf and knee made me realise, in a lot of circuit analysis, a lot is mentioned of the voltage but rarely the current. It made me want to do some simulations and examine this topic further. Thing is I've only ever used LiveSpice, does any have a SPICE...
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    Are these two diode shunt configs different?

    Hey folks, just looking at this "tape simulator" schematic, the original schematic is on the left, what I'm wondering is, would there be any difference compared to the version of the right? I'm vaguely aware of the concept of diode ladders, but usually I think there are some resistors in the...
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    Are we fooling ourselves when it comes to diode softness?

    I've been reading up on diode softness and curve tracing and all that kind of stuff. 2 threads in particular have made me question some of our understanding of practicalities of measuring the softness of the clipping/conduction knee. Take this thread for instance on MOSFET clipping, in this...
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    What to make with 30-50 hFE Germaniums

    If anyone has followed my recent NOS [PNP] Gemanium transistor box adventures you would know I now own a large number of ~40 hFE, low leakage Germaniums. These are obviously not at all suited for Fuzz circuits, but that's ok, I like more subtle pre-amp like effects a lot of the time anyway. My...
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    Box of 100 1T313V Ge Transistors Tested

    Here's the results for the box of 100 1T313V, though there were 4 or 5, 1T313B sprinkled in. The data sheet suggested a hFE range of 20 - 250 so I had high hopes there would be a nice range of gains in the box. However, as you will see from the results, that was not the case. In fact I would say...
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    Box of 50 П416Б Ge Transistor Tested

    Bought a box of 50 П416Б Russian NOS Germanium Transistors from eBay. Spent the day in between working chucking them in the TC1 tester, so take the results with a grain of salt I guess. Apparently these are known for being low leakage, in fact the TC1 did not report an Iceo for most of them...
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    FNIRSI DSO-TC4

    TLDR: AVOID. Hey folks, so given that I'm sure these FNIRSI devices have popped up on people's radars I thought I would share my experience with the DSO-TC4, a combination signal generator, oscilloscope, transistor tester. I purchased this device primarily for the SigGen and Oscope abilities...
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    CMOS Switching Pots

    Hey folks, I have a question about using CMOS switching for potentiometers. (CD4053 in this case) I want to build a pedal that is a Tube Screamer and a SD-1. Both circuits will be on the same PCB, but I want each to be a "mode" with a push button (in this case because I like to build "studio"...
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    Fretting about FETs

    *Renamed the thread as it is primarily about FET designs. Hey folks, so I've been reading Merlin Blencowe's Designing Guitar Preamp book. One thing that has interested me is the effect of essentially a poor design leading to some current leaking into the grid of the follower and therefore...
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    STM32

    Has anyone here used an STM32 as a microcontroller for switching? The reason I ask is that JLC has a few as a basic part for assembly. Just wondering how easy it is to program. I'm guessing you would need pins on the pcb in order to flash the firmware onto it. ESP32 boards are cheap on...
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    Performance of Various Transformers

    Hey folks, I tested a bunch of cheap transformers for use in pedal design. I won't replicate the post here, the full thing is over at GroupDIY. I think the Hammond 142 series one are the most interesting. Despite claiming a frequency response of 200 - 15khz they actually extended all the way...
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    LiveSpice

    Does anyone here use LiveSpice? I like that you can change components and instantly hear the effect and feel by just playing your guitar, also allows useful stuff like adding power amp sim and cab IR afterwards if you use the VST version. The only problem is, the component selection is quite...
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    Create Reusable Patterns

    Hey folks! So some elements of my circuit designs get a lot of use, like this JFET buffer for instance. What I want is to be able to save this as a component so that I can just add the whole buffer circuit to a schematic and have it pre-laid out once I go to the PCB layout phase and have all...
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    Topor Lite

    Might be a weird request, but did anyone ever get a copy of ToporLite, I guess preferably v7. Seems impossible to get off the internet now as the Emerex site is really badly maintained and they've moved on to this Delta Design platform.
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