Questions tagged [synthesizer]
The synthesizer tag has no usage guidance.
124 questions
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Understanding DC versus AC in synthesizers
Can someone please explain the difference between DC and AC?
Especially in these scenarios:
Envelope that goes from 0 V to 5 V over time and back to 0 V
Square wave that oscillates between -5 V and +...
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Does it make sense to separate an analog and digital ground plane in the Eurorack modules?
Eurorack synthesizer is quite a specific standard.
centralized power supply unit,
modules are connected to the backplane using IDC ribbons - that means parasitics,
they are patched with external ...
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Create an Attack-Release Envelope for a 555 Synth
So I am designing a synthesizer based on the 555 chip, and I'm having trouble incorporating an AR (attack-release) envelope without changing the oscillator frequency. In more detail:
I have the ...
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Variable RC high pass filter problem [closed]
I'm having an issue with a simple RC HPF. I calculated what max cutoff frequency I want and picked up components accordingly (10kΩ potentiometer and 1nF capacitor). When I feed the signal through it ...
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'inverting' an LFO output
I want to 'invert' the output of an LFO I built. This is for use in a CV Synthesizer environment where all signals are 0V to 5V. By inverting I mean if for example I have a ramp going from 0V to 5V, I ...
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Buffer changes pitch of the oscilator
I'm in the process of building my first synthesizer (super simple design as I'm new to all of this.) After the output of the oscillator, I put a buffer (using UA741CP) before going into the RC filter. ...
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84
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Where to find/learn standard meaning of ω or φ, etc., in RF circuit design
I am retired from a long career in Electronic Warfare (EW) in the US Navy, followed by decades in communications in two-way radio engineering, cellular system technical management, etc, and then a ...
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What circuits do I need to make an analog synthesizer? [closed]
I want to make a simple analog synthesizer at home, please help me.
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195
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Circuit simulation is not functioning properly
I am a college level electrical physics student (and so I do not have a lot of knowledge on the topic of electronics) and I am in the midst of writing a report on a project that was done throughout ...
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46
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How do I solve DC offset GND between 2 power supplies 220V to 12V/GND? [closed]
The setup:
Two modular synths (lets call them A and B) with each their own power supply making 220V AC into DC +12V, GND, -12V.
I measure a DC offset (like 6.5V) between the GND's of synths A+B (no ...
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Improving the waveshape and amplitude of a saw-tooth generator
I am a student in in college level physics and so I do not have a lot of knowledge when it comes to circuits and the different electrical components. Still, as a project, I decided to try to build an ...
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Help me make this switching transistor circuit is right
I'd like some insight to make sure my circuit's design is at its best. At the moment the circuit is working, but since this is my first time designing a circuit from scratch with transistors, I ...
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138
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Using a square and/or sine wave generator through a speaker [closed]
I have recently undergone some university study which introduced square and sine wave generators, I was wondering if there's a specific speaker I could use (its inputs would be a power supply and the ...
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Delta Sigma Modulator for 2/3 Multi modulus divider used in FracN PLL
I have been trying to implement a Delta Sigma modulator for a 2/3 Multi Modulus divider. I am referring to Riley's paper: https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=229400
I have designed ...
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Using multiple bench PSU for three outputs +/-18V, +11V for old synth
I am trying to power a vintage synthesizer (Roland MKS-30) on my bench without having to have the transformer and raw AC parts out near where I will be working.
The PSU of the synth has two rectifiers ...
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59
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Swapping a number pad from telephone to synth [closed]
I’ve recently acquired from the trash a toy synth keyboard piano.
It works, but I wanted to create a stand-alone number pad from an old telephone.
I’d like to know if it’s possible and how to do it if ...
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Amplitude inversion circuit
I am a beginner in electric circuit building and I am trying to build a specific circuit aimed for audio transformation (guitar efx pedal, euro rack etc). I have built a number of implementations of ...
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Is it possible to access the data stored on a HN62304BPC99 ROM?
The HN62304BPC99 appears in a number of Roland synths.
Whilst I can find service manuals & the odd reference to dumping ROM contents, what I cant find as of yet is a way to wire up this chip in a ...
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Help IDing a high-power IC - OODOW 836 T57
I'm fault finding for a Korg M50 Synthesizer.
Symptoms: on every boot a message appears saying the device is updating the left/right control panel firmware, after which it requests a re-boot. ...
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124
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How to synthetize a 10 kHz signal from 1 Hz analogically
I would like to synthesize a 1 Hz signal to a 10 kHz one without using MCU or related DPLLs.
Anyone has a schematic example? I found this reference schematic on Art of Electronics.
Would that suit (...
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How to properly connect oscillator circuit to amplifier?
edit v2:
Schematics:
The ic on the left is a 40106, and the thing inside is a Schmitt trigger with inverting output.
In 'edit v1' below you can see a wiring diagram.
edit v1:
Rough schematics and ...
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91
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How to debug unexpected behavior on voltage-controlled oscillator PCBA?
I designed a circuit for a voltage-controlled oscillator (VCO) for use in a synth and had it fabricated and assembled as a PCBA. I got three assemblies back and while two behave exactly to spec (and ...
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Replacing a linear softpot (ribbon sensor) with a regular potentiometer
I'm a beginner with electronics. I'm trying to replace a softpot on a cheap synthesizer with a regular potentiometer. As far as I can tell this component (pictured below) behaves just like a 10K pot; ...
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213
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Modern temperature compensation of 1 V/oct VCOs
With Akaneohm Tempco resistors going out of production, I have been searching for alternative ways to reliably build a VCO that does not drift with temperature. I have been searching around, but I can ...
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How to get freq stability with constant offset for PLL synthesizer?
I used ADF5356 PLL synthesizer. And i use reference oscillator freq is 10MHz with initially offset 0.1ppm and stability is 10 ppb. I need to output freq is 3750 MHz.
Expected output result:
10MHz × 0....
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200
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Verilog netlist synthesis using assign vs always
If you have some sort of Verilog implementation like:
...
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43
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Conditioning inputs and outputs when using virtual ground
I am using a 120 VAC to 30 VDC single-sided supply to power a synthesizer that requires double ended power supplies, +/-15 V.
I am using a TLE2426 rail splitter to create a virtual ground, then ...
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124
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Diode voltage drop characteristics in an envelope generator design for audio synthesis
I have no actual EE knowledge, I have just been fiddling around with audio circuits for a while.
I built an attack-decay envelope generator for audio synthesis purposes following a design by Ray ...
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Reliability issue of HMC833 PLL
We are using an HMC833LP6GE PLL in our design for generating 122.88 MHz from a reference of 100 MHz.
We are feeding a reference signal of >5 dBm. What we are observing is that out of 10 times, if ...
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DAC to quad op-amp for Arduino FM synthesizer
I'm working on a little Arduino digital synthesizer powered by an old Yamaha sound chip (YM2151).
I have a fairly good understanding of how to connect the YM2151 to the Arduino and the YM2151 to the ...
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How to set LMX2820 MUXOUT for SPI readback
I am controlling an LMX2820 synthesizer over SPI. I want to perform SPI register reads and need to use the chip's MUXOUT signal as SDO pin as SPI MISO.
I expect to have to set MUXOUT_SEL to assign ...
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Is there any way to tell the current used by a particular SD Card?
I need to replace an SD card that came with a piece of electronic equipment (specifically, a sequencer for a Eurorack modular synthesizer). The SD card that came with the module is 1GB, and is a no-...
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LMX2820 readback operation [duplicate]
How can a readback operation be done on LMX2820?
I've looked through over it's datasheet, register map and AN documents and there is no information about that. In LMX2594 read and write operations are ...
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Analog step sequencer schematic help
I'm currently working on an analog step sequencer for a synthesizer I'm making. It has a split rail 24 V supply (so +12V, GND, -12V) and follows the Kosmo specification. The features I want are:
8 ...
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How should I go about overriding or switching between an internal control voltage source when an external source gets connected?
For example, I'm using a potentiometer to modulate an internally generated +5v audio signal, and I'm sending the output signal down to the next part of my circuit. If I were to add an external input ...
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Headphone output - what is the function of these resistors going to ground between the decoupling capacitors and headphones
The Korg Monotron Duo synth uses the TPA6111A2 headphone amp. The circuit they use is largely the same as the one from the datasheet - except for R78, the 470ohm resistor going to ground right after ...
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362
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Analog synthesizer- Add second VCO
I am working on reviving an old synth design (Transcendent 2000), but I would like to add a second oscillator. I was thinking of doubling the circuit highlighted below, and sharing the pitch control (...
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~3400 ppm/C resistor replacement/substitute?
I am working on reviving an old synth design (Transcendent 2000 for those interested) and the VCO and VCF both rely on high ppm/C resistors to compensate for temperature changes. I can include the ...
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Purpose of PNP transistors connected base to base in 1V/Octave synthesizer keyboard circuit
The circuit below (found here) is designed to be used in a 1V/octave keyboard used to control a synthesizer. When the potentiometer is adjusted properly, pressing the buttons produces output voltages ...
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How can this 74 series Inverter circuit be analyzed?
I'm trying to analyze the keymech scanning / sampling circuit in the WASP synthesizer
So far I understand that the keymech is sampled one key at a time by the 74 series logic driven by the dual ...
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How to stabilize this CV triggered toggle (555 timer latching switch) when fed with two gates?
I created the prototype for a modular synthesizer module. The project goal is an AND gate that is fed with two control voltage inputs (A and B with an Vpp around 5V). There will be two outputs: the ...
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How do different octaves sound different in the presence of a low-pass filter in a synthesizer?
Per my understanding, when playing a certain pitch, say 440 Hz (middle C), the VCOs will produce their corresponding waveforms (say sawtooth) at that frequency. Because of the characteristics of the ...
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Understanding sawtooth wave harmonics
I've been playing synthesizers for a while and I'm trying to understand their math and electronics better.
The sawtooth is one of the three common waveforms on most subtractive synths. The waves are ...
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Could an analog synthesiser be made to run on USB power 2.5W?
5V USB is now standard and very convenient.
But I see a lot of synths and audio projects working with higher voltages ... from 9V to 12V to 22V etc.
Are there physics reasons for this? In that ...
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Custom breadboard manufacturers [closed]
I'm not sure if this is the right StackExchange for this, but I'm interested in whether it's possible to get some custom breadboards made. That is some solderless prototyping breadboards with a couple ...
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Help identifying circuitry diagram
Now first and foremost, I know absolutely nothing about circuitry - joined an computer science chatroom and they couldn't help, I have cross referenced the symbols to the internet to try and ...
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Identifying missing component from vintage synthesizer [closed]
I acquired a Hillwood C-1A synthesizer with a burnt circuit board with 3 empty holes where a part needs to go. I'd like to repair the board but I don't know what component to look for... Help?
The ...
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A triple voltage supply from a dual supply
I have build a dual power supply for an analog synth (see image below).
The input source is a 12 VAC - 1.7A adapter. It is based on the Wall Wart power supply from Music from Outer Space.
Now I would ...
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Difference between a frequency synthesizer and a frequency mixer
I have tried looking a couple different places but cannot find a concise explanation on the difference between a frequency synthesizer and a frequency mixer. My goal is to take a signal at 915 MHz and ...
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Connect multiple bipolar PSUs to one torroidal transformer with center tapped secondary winding
I'm currently starting my ventures into building a modular synthesizer in eurorack format and am currently using a single power supply like this with a 12V AC wall wart:
Source:
http://...
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