What vst gives me the Amiga samples vibes?

[Masterofdisaster]

Just crush to 8bit @28khz

[legendCNCD]

Just crush to 8bit @28khz

Aaand thats a big nope.

[Masterofdisaster]

Just crush to 8bit @28khz

Aaand thats a big nope.

Explain

[Freaqpeak]

I had a 16bit sampler for my A500, awesome quality.
Cant remember the name of the sampler though. Mostly sampled in 8bit bc filesize. Not sure if Protracker supported 16bit back then..
To get the Amiga sound you have to use a tracker. Its how you use those 4 channels to make the music and how you can use those samples.
Think a 303 emu without a sequencer. Wont sound like a 303 until you program it like one.

[legendCNCD]

I had a 16bit sampler for my A500, awesome quality.
Cant remember the name of the sampler though. Mostly sampled in 8bit bc filesize. Not sure if Protracker supported 16bit back then..
To get the Amiga sound you have to use a tracker. Its how you use those 4 channels to make the music and how you can use those samples.
Think a 303 emu without a sequencer. Wont sound like a 303 until you program it like one.

Protracker does not support 16bit samples, but Octamed(Pro) did and Digibooster(Pro) too.
Well you can load 16bit sample to protracker... depending on format might work with one upsample round or then its just garbage to it

[legendCNCD]

Just crush to 8bit @28khz

Aaand thats a big nope.

Explain

Thats not how Paula forms samples... there are also two filters available, other is always on, other can be toggled and Amiga can output much much more than 8bit 28khz. How about 14bit? higher khz? No problem (on A1200 and later).

[mystran]

Watched a couple of Amiga tracker videos on YouTube.
Let me thinking what vst could came close to replicate that sound.

https://16-bits.org/pt2.php

Get closest to it, Amiga Protracker clone.

I looked at the source (quickly) and it looks like this one uses BLEPs (band-limited steps) to emulate the variable clock-rate zero-order hold. This is indeed the way to do it correctly (without having to render at 3.5MHz or some such silly rate). This is how you get the "Amiga sounds better than a [contemporary] PC" sound.

The way this works is basically that each voice has a separate counter and (at least effectively) it's own DAC. That counter runs at the chip clockrate of 3.5MHz [edit: I looked it up and this seems to be accurate; the maximum sampling rate is limited by how fast the DMA can fetch data, which is about 28kHz or so] and determines when the sample clock for that voice should advance. When the counter hits the threshold value (or zero if we're counting down; too lazy to figure out which way Amiga goes 'cos it makes no difference), we read the next sample, set the DAC (of that voice) to the new sample value and reset the counter. The end result is that each voice advances at different rates and this rate can change over time even for a single sample.

The thing about variable sampling rate is that unlike interpolation, it doesn't produce any aliasing. It does produce imaging where the spectrum above half the sampling rate consists of (attenuated) mirror images of the lower frequency content, but since the images are produced in continuous time (or using band-limited synthesis in the case of emulation), they never fold down to mix with the baseband.

They are audible at high frequencies for certain if below the lowpass cutoff, but it's a distinct kind of artifact different from the usual digital aliasing or quantization artifacts. It's basically the same thing you also hear with analog (BBD) delays when the delay time is long (and therefore the clockrate slow), though BBDs are much more noisy. Because this sort of scheme produces a distinct type of artifact, it's not something you can really fake except by actually emulating the process that produces it (with BLEPs being basically the most efficient approach).

ps. You can do vari-rate just fine without using a tracker and if you match the Amiga filters too, that'll get you most of the sound. I think there are some LoFi samplers that can do vari-rate (eg. TAL perhaps?), but no idea if there are any that do Amiga specifically.

[legendCNCD]

https://16-bits.org/pt2.php

Get closest to it, Amiga Protracker clone.

I looked at the source (quickly) and it looks like this one uses BLEPs (band-limited steps) to emulate the variable clock-rate zero-order hold. This is indeed the way to do it correctly (without having to render at 3.5MHz or some such silly rate). This is how you get the "Amiga sounds better than a [contemporary] PC" sound.

Thanks I had prepared to tell about BLEPs etc. but you put it so much better

[Masterofdisaster]

Just crush to 8bit @28khz

Aaand thats a big nope.

Explain

Thats not how Paula forms samples... there are also two filters available, other is always on, other can be toggled and Amiga can output much much more than 8bit 28khz. How about 14bit? higher khz? No problem (on A1200 and later).

I don't know who Paula is, is it a friend of yours?
Anyway ok i guess I read a bad page on the Internet for information.

[legendCNCD]

Just crush to 8bit @28khz

Aaand thats a big nope.

Explain

Thats not how Paula forms samples... there are also two filters available, other is always on, other can be toggled and Amiga can output much much more than 8bit 28khz. How about 14bit? higher khz? No problem (on A1200 and later).

I don't know who Paula is, is it a friend of yours?
Anyway ok i guess I read a bad page on the Internet for information.

Read this viewtopic.php?p=8709630#p8709630
Its a couple posts up.

The Paula chip, designed by Glenn Keller, from MOS Technology, is the interrupt controller, but also includes logic for audio playback, floppy disk drive control, serial port input/output and mouse/joystick buttons two and three signals. The logic remained functionally identical across all Amiga models from Commodore.

[8bitbubsy]

I looked at the source (quickly) and it looks like this one uses BLEPs (band-limited steps) to emulate the variable clock-rate zero-order hold. This is indeed the way to do it correctly (without having to render at 3.5MHz or some such silly rate). This is how you get the "Amiga sounds better than a [contemporary] PC" sound.

The way this works is basically that each voice has a separate counter and (at least effectively) it's own DAC. That counter runs at the chip clockrate of 3.5MHz [edit: I looked it up and this seems to be accurate; the maximum sampling rate is limited by how fast the DMA can fetch data, which is about 28kHz or so] and determines when the sample clock for that voice should advance. When the counter hits the threshold value (or zero if we're counting down; too lazy to figure out which way Amiga goes 'cos it makes no difference), we read the next sample, set the DAC (of that voice) to the new sample value and reset the counter. The end result is that each voice advances at different rates and this rate can change over time even for a single sample.

The thing about variable sampling rate is that unlike interpolation, it doesn't produce any aliasing. It does produce imaging where the spectrum above half the sampling rate consists of (attenuated) mirror images of the lower frequency content, but since the images are produced in continuous time (or using band-limited synthesis in the case of emulation), they never fold down to mix with the baseband.

They are audible at high frequencies for certain if below the lowpass cutoff, but it's a distinct kind of artifact different from the usual digital aliasing or quantization artifacts. It's basically the same thing you also hear with analog (BBD) delays when the delay time is long (and therefore the clockrate slow), though BBDs are much more noisy. Because this sort of scheme produces a distinct type of artifact, it's not something you can really fake except by actually emulating the process that produces it (with BLEPs being basically the most efficient approach).

ps. You can do vari-rate just fine without using a tracker and if you match the Amiga filters too, that'll get you most of the sound. I think there are some LoFi samplers that can do vari-rate (eg. TAL perhaps?), but no idea if there are any that do Amiga specifically.

Spot on. You definitely know your digital audio theory.
I got some dsp guy to code the BLEP routines for me, and man did it make a difference.

[mystran]

Spot on. You definitely know your digital audio theory.
I got some dsp guy to code the BLEP routines for me, and man did it make a difference.

For those wondering, according to source comments "some dsp guy" is aciddose so the code is probably fine.

[8bitbubsy]

Yup, that's the guy.

[Caine123]

So it seems there is no vst option yet?

Like the snes emulation vst from plogue i could imagine something like this where you drop a sample in there and adjust where the sample plays and then you go . Man i so love the amiga 500 sound..... i once downloaded a couple of amiga 500 sounds and played it in a sampler. Wonderful but i dunno if these samples are cleared i know a lot of samples used were from commercial stuff.

With the technique from plogue snes vst it would be easy to sample your own stuff and have the amiga sound. Too bad tone2 doesnt do new vsts anymore markus would have been a great guy for this i think!

[martiu]

hi, Tal Dac very good for amiga vib, buy now