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Questions tagged [synthesizer]

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2 answers
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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 ...
Dale's user avatar
  • 103
-1 votes
2 answers
72 views

What circuits do I need to make an analog synthesizer? [closed]

I want to make a simple analog synthesizer at home, please help me.
Rafli Akbar's user avatar
2 votes
2 answers
128 views

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 ...
Boldumus's user avatar
2 votes
0 answers
34 views

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 ...
user3810130's user avatar
2 votes
2 answers
103 views

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 ...
Boldumus's user avatar
1 vote
0 answers
64 views

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 ...
Organ Bender's user avatar
0 votes
2 answers
86 views

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 ...
sage_lessthan_3's user avatar
0 votes
0 answers
59 views

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 ...
Pranjal Mahajan's user avatar
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0 answers
39 views

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 ...
jc303's user avatar
  • 121
1 vote
1 answer
56 views

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 ...
Chris Zanillo's user avatar
4 votes
2 answers
262 views

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 ...
Bdrone's user avatar
  • 41
0 votes
2 answers
66 views

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 ...
DrBwts's user avatar
  • 135
1 vote
1 answer
29 views

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. ...
aaronsnoswell's user avatar
0 votes
0 answers
51 views

Info about this older transformer from my Kimball organ

I have been harvesting parts from my dying kimball "Swinger 300" and I finally got around to disassembling the power supply. It had what I assumed to be a transformer attached, as the only ...
Waboku's user avatar
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0 answers
104 views

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 (...
Ken90's user avatar
  • 176
1 vote
1 answer
310 views

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 ...
ssheep's user avatar
  • 27
3 votes
1 answer
81 views

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 ...
Aaron Kimball's user avatar
0 votes
1 answer
69 views

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; ...
jberryman's user avatar
  • 173
0 votes
0 answers
164 views

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 ...
SunnyDay's user avatar
0 votes
0 answers
33 views

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....
Purushothaman Jayaraman's user avatar
2 votes
1 answer
168 views

Verilog netlist synthesis using assign vs always [duplicate]

If you have some sort of Verilog implementation like: ...
MFerguson's user avatar
  • 209
0 votes
0 answers
40 views

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 ...
SRobison123's user avatar
1 vote
1 answer
108 views

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 ...
ohav's user avatar
  • 13
2 votes
1 answer
165 views

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 ...
MightyBeard007's user avatar
2 votes
2 answers
170 views

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 ...
Olive's user avatar
  • 21
1 vote
1 answer
646 views

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 ...
jwasch's user avatar
  • 13
3 votes
1 answer
164 views

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-...
Cerulean's user avatar
  • 135
1 vote
0 answers
56 views

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 ...
lazba's user avatar
  • 171
0 votes
0 answers
93 views

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 ...
Lucas Henry's user avatar
0 votes
1 answer
43 views

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 ...
PlugN'Play's user avatar
3 votes
1 answer
982 views

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 ...
Kenny Winker's user avatar
3 votes
1 answer
326 views

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 (...
AWESDUDE COOL's user avatar
0 votes
1 answer
301 views

~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 ...
AWESDUDE COOL's user avatar
1 vote
1 answer
206 views

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 ...
dylaneck's user avatar
3 votes
1 answer
172 views

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 ...
andowt's user avatar
  • 1,008
0 votes
0 answers
100 views

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 ...
BummBummSteffen's user avatar
2 votes
3 answers
96 views

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 ...
Paghillect's user avatar
0 votes
3 answers
2k views

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 ...
Paghillect's user avatar
0 votes
2 answers
89 views

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 ...
interstar's user avatar
  • 121
0 votes
1 answer
100 views

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 ...
interstar's user avatar
  • 121
0 votes
2 answers
93 views

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 ...
Codewell's user avatar
-1 votes
2 answers
99 views

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 ...
Jonah M's user avatar
  • 121
3 votes
2 answers
242 views

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 ...
Dieudonné's user avatar
0 votes
1 answer
669 views

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 ...
Elliott Armstrong's user avatar
0 votes
0 answers
93 views

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://...
Tobias Schulte's user avatar
0 votes
1 answer
164 views

Can I add a Sense connection to this power supply?

I have a synthesizer (Yamaha CS-50) and the power supply is broken. I don't know why but it always blows the fuse. I tried everything, changing components, testing the transformer, etc. The fault is ...
dancelwerk's user avatar
1 vote
1 answer
350 views

What is the "input" being fed into a Delta-Sigma Modulator in a Fractional-N PLL? Are bits needed for a specific resolution at the input or output?

I'm doing some reading into Fractional-N PLL design and I have a bit of conceptual confusion regarding a delta-sigma modulator used to toggle the modulus of a divider. If you're trying for a certain ...
Jack's user avatar
  • 51
1 vote
4 answers
156 views

Is an MPU capable of equal quality digital synthesis as a dedicated DSP chip? [closed]

Is there any factor which would cause a modern microprocessor ( such as an ARM Cortex A/M ) to be inferior at performing digital synthesis compared with a dedicated DSP chip of comparable speed? At a ...
ajxs's user avatar
  • 213
3 votes
0 answers
165 views

Sawtooth VCO DC offset issues

[Apologies in advance for possible misuse of terminology. I don't have any formal education in EE and am mostly self taught, so I may be lacking in some fundamentals.] I am trying to design a discrete ...
wurly's user avatar
  • 31
1 vote
4 answers
5k views

Audio output voltage range

I'm working on a synthesizer project and I'm confused on what the final audio output voltage should be. The idea is that I would send the audio to a speaker or headphone amplifier, so I don't have to ...
Australian Ostrich Farmer's user avatar