ISD1820 Sampler Chip - How it works and easy Mods
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- Опубліковано 4 жов 2024
- Link to ISD1820 Sampler Part 2 - Adding Automation with Control Voltage
• ISD1820 Sampler Part 2...
Link to ISD1820 Sampler Part 3 - Complete Schematic with Sequencer and DJ scratch demo
• ISD1820 Sampler Part ...
ERROR CORRECTION in video: the audio output goes to the other pin labelled SP not the one where i put the asterisk
First looks at the ISD1820 Sampler chip as a possible addition of looped audio samples into a triggerable rhythm circuit.
The chip can be used as standalone or on a module which comes faster when ordered. The chip can be removed from the module as it isnt soldered in but in a socket.
I made some modifications to it in order to improve how it sounds and adding various features like playback speed control and a line in.
Will add additional features soon including integration with a sequencer and adding control voltage. Thanks for watching!
#audiosignal #analog #circuitrhythm #drummachine #isd1820 #samplers #sampler - Розваги
I'm surprised that thing is still in production, i renember when that chip went out in late 90's we received 1 sample of it and did same fun like you with at the lab. Some guys used it to have speech response on commands in their products. What's interesting is that you can command addresses to play only certain parts of the recording and with a record of short words using wav file from a computer, it makes a kind of speaking machine.
My mistake the one that is addressable with a microcontroller is the ISD2560.
Information Storage Devices (now Nuvoton) don't make the ISD1820, these are knock-offs. Very similar in function, but the ones from Nuvoton have higher sound quality and lower noise. They have many models with various features including addressability.
@@bobblick7963 do you know what the bit rate of the genuine one is?
Max sample rate is 12000 samples per second for the one I used(part number escapes me, bought at Radio Shack in the last century). A search for ISD ChipCorder should get some results. Put a power supply cap very close to the chip, keep grounds short for least jitter. Clock jitter shows up as noise in your recordings
If I recall correctly, the ISD1800 series are not digital samplers, the sound is stored as analog levels in the non-volatile storage array.
For what is primarily intended to be voice recorders, this makes a lot of sense, you don't need an ADC and a DAC, and more importantly, the storage array can be a lot smaller, as you store one sample point per cell while for digital one cell can only hold one bit.
It would technically be possible to save space by using a multilevel cell approach for digital samples, too, like how modern SSDs store several bits worth of data per cell, but that would just be pointless additional complexity for this application.
Yes. Easiest way is just to chain several of them together to get rid of any lag time between played samples. I want to do that but haven’t gotten around to it yet
Right. Engineers, years ago, discovered you could store analogue values in, I think, EPROM cells, by very quickly writing a pulse, and testing what level the memory cell returned. Keep feeding it pulses til it's up to the voltage you wanted, then move on to the next cell. You've got analogue recording! I presume these chips use EEPROM.
It's possible DRAM could do the same, since it uses capacitors, but the refresh circuit would be a bit hard, and these are non-volatile AFAIK.
You could perhaps rig up multi-level digital storage with this, a DAC to this chip to an ADC. Of course you'd need an ADC at the front to actually record the sound, and another DAC at the end to play your recovered digital data. So a DAC -> ADC -> this chip -> ADC -> DAC. That way you could get arbitrary sound quality at the expense of recording length. You just wouldn't, though! The crappy sound quality is part of the charm I think here, synth freaks with their love of analogue and "analogue" synths, drum machine collectors. They love things that sound terrible! I'm sure there's a thousand filters for DAWs you can find under "enshittening".
@@greenaum THAT"S THE MOST CURSED THING! LMFAO gonna have to remember that one! It honestly reminds me a lot of the levels of storage used in SSDs today! SLC stores 1 bit per cell, but MLC can store 2 bits (4 voltage levels) and we are up to QLC and beyond now, storing 4 bits or 16 descrete voltage levels per cell. This is like what, 8 bits per cell of storage? quite cool tbh!
That is correct...they are not digital.
this was very informative dropping a like
Glad you liked it
That is an interesting module! Thanks for the vid, I need to source one.
Thanks. Its easier to get the module than the individual chip and actually cheaper. About $1.50 to $2 and comes overnight. I got 4 of them for 7 bucks and you can take the chip out of it as its just in a socket so no complex desoldering required.
Nice video, thanks :)
Thanks
Fun module to mess with. I built a 7 channel parallel sampler using 7 of these modules wired in parallel, and hooking up photo resistors to each one to independently control their pitch with light, for crazy, modulating playback chaos!
Here's a demo of it:
ua-cam.com/video/Wi3nscocne8/v-deo.html&ab_channel=Already%2CStill%2CAgain
that looks pretty cool,
I wonder what the internals of that IC look like
I guess it's probably relatively simple containing mainly these parts:
RAM - for storing audio samples
adc, dac - for analog input and output
2x 555-timer + digital counter - for computing the adress for sample recording and playback
digital comparator - for testing if the playback adress reached the recording length
some buffer flip-flops - for saving the end of recording adress, and maybe buffering some sample data
Its an eeprom in there
@@igorbrichkov3632 ok cool persistent memory, thx :)
Vary the potentiometer while you're recording, and/or during playback for more effects.
Good idea
Does it remember the sample when it is turned off?
Yes. The chip has a built in eeprom
A guitar amp isn't full range. Play it through a stereo system.
Yes. Using the guitar amp for testing the audio output. Plan to hook everything up to a real amplifier. I built a small one based on the lm386 but I ultimately want to build my own based off of the lm3886 down the road.
the first speaker sounded damaged
No. I tested it with lower volume on something else and it was just weak. The module turning off and on in between playing samples makes a click that gets distorted with the tiny speaker
Really Great Work! We'd love to offer you some boards if you might need them in the upcoming content. (PCBWayDaisy) 😄
That would be cool!
@@igorbrichkov3632 sure thing!