OT throughput mixer audio quality?

avantronica · 2016-09-14T19:09:26.733Z

secretmusic:

Thank you for pointing out that posts can be flagged, i was not aware of that and will make good use of that feature, if necessary

Okay - I see you flagged a post from 20months ago - as i mentioned, that’s the user that had left (dramatically), had since returned, had further discussions with the current mods concerning language etc - to be fair, we can’t go back through the years of postings (nor know what contemporaneous Moderation happened), but we can take down anything obviously offensive that wasn’t swept up and deal with any current postings

Things are different now we have migrated to a better platform for Elektronauts 2.0, the more active Moderation isn’t for all, but we do our best and we represent a broad range of views and try to be balanced and keep things genial, positive and on topic

nfim · 2016-09-14T19:09:50.273Z

We might as well. I’m happy to do some tests but my only interface other than the OT is a focusrite saffire 24, clean but not really pro-grade.

Stickhit, I was just thinking the same thing. Probably folks just care more about preserving the signal quality of something like a voyager or tempest more than volcas, which are potentially providing less ‘crucial’ elements of the track.

Secretmusic, keep in mind all the bickering in this thread was posted over a year ago and lots has changed since then.

stutech · 2016-09-14T22:23:59.989Z

Good point. Isn’t the OT recording @ 44.1kHz? I’d imagine a Moog Voyager to produce frequencies way above 22kHz which, while not being “heard” that much, can change our perception of the sounds.

Stickhit · 2016-09-15T11:21:26.864Z

There are many things that can affect our perception of sound (e.g. visual stimulus, age, health, mood, fatigue, personal biases etc.). I suspect that frequencies outside the human audio range are the least likely to affect sound perception, though they may upset your cat.

stutech · 2016-09-15T11:25:53.128Z

I respectfully disagree. Human hearing doesn’t just cut off @ 20k, it gradually rolls off (also the exact cutoff point and slope vary from person to person). Depending on the bandwidth and implementation of the filters in a converter, 44kHz can sound somewhat “smeared” compared to even 48kHz.

secretmusic · 2016-09-15T12:39:04.372Z

Hi ! You’re right, and this is what i meant. The volca is just as much an analog signal before it hits the OT, however, its frequency range is different, it lacks the massive present low end of the Voyager, and complex subharmonics. I’ve found that the OT will fare better with that kind of signal (almost bandpassed) than with full range, complex signals. Hope this makes it clearer

secretmusic · 2016-09-15T12:46:12.895Z

Hi Josker !
Yes you’re absolutely right. However, you’re forgetting one vital component in the A/B process, and this is why I always make a point in reminding people who think that this would settle anything : the OT has no way to ensure proper gain staging.
There are no meters, except from a LED that goes from green to red (!?)

So, there is no way to correctly ensure that we’re hitting the converters at the “proper” level (whatever that may be )
Also, there are a few more stages of gain on the playback chain, from sample level to track level to Master level. Which combination of those levels ensures limiting free playback of the sample ? We don’t know, and quite frankly, without Elektron’s insight (which they won’t give), there is no way to know.

Without clear and repeatable gain staging through metering, any A/B test is futile. It leaves too much to the ear, feelings, and user “error”.

Cheers !!

secretmusic · 2016-09-15T13:10:50.723Z

Hi ! Apologies again, i must admit that I didn’t check the date of the post I flagged !
Appreciate the help

secretmusic · 2016-09-15T13:13:18.654Z

Precisely ! Some instruments have a more intricate, delicate and wide ranging signal than others. Such signals benefit greatly from hi - end conversion, which the OT is not quite suited for, if only because of its lack of proper metering Cheers !

Stickhit · 2016-09-15T14:00:22.930Z

You are correct, human hearing does not just cut off at specific upper and lower frequencies and the cut off points and associated roll off slopes do indeed vary from person to person. However, this does not alter the fact that there are audio frequencies which you have never been able to hear and there are audio frequencies which you will no longer be able to hear as you get older.
The point I was trying to make in my initial post was that there are other things which I believe are more likely to affect your sound perception, on a day to day basis, than frequencies at the edge of your audible hearing range.

bolandross · 2016-09-15T14:42:28.266Z

I assert, that in a blind test, nobody would be able to distinguish a signal that went through the Octatrack from a signal that did not.

(using proper gain staging, since driving a converter too hot or digitally clipping a signal will -of course- be audible)

In other words: If you do it right, you won’t hear any “quality loss”.

By the way: A great song will still sound great, even after capturing it with a 8 bit sampler at 11khz … but that’s not what this discussion here is about.

Best regards,
bolandross

josker · 2016-09-15T14:47:47.520Z

Heh, well put.

I try to ignore things I can’t at all hear.

But yes, this is purely out of curiosity

Stickhit · 2016-09-15T15:10:16.975Z

A null test would be more accurate, takes the human being out of the equation

JuanSOLO · 2016-09-15T15:18:29.334Z

When I had a Tempest, I had it plugged into the OT for a long while, one day I decided to bypass the OT, and I was like “WOW, that sounds much better, so full and rich”
I got curious and did the same with my SlimPhatty, same reaction really.
For a while I got wacky obsessed about it, and it would bother me that I was loosing something.
Then I realized that I enjoy crushing my music with effects more than I like a super clean sound.
Haven’t looked back since.
All things flow through the OT.

LyingDalai · 2016-09-15T15:37:00.195Z

Still, have you tried to spend some time to get the cleanest sound from your gear plugged in OT ?

There are many way to change the gain, each must affect the incoming sound in a way… Correct me if I’m wrong :

input gain : I would think this guy should be brought as high as possible until the led is yellowing for the highest volume (I would even lower it a bit)
vol input of the thru track
amp volume
track level

I would expect VOL to affect the sound less, so I would use this one to get a proper volume.
Track level would be used only for lowering the sound temporarily, like for slowly muting the track, I guess.

Another way to get some volume up is using FX, but either COMP GAIN or FILTER DRIVE would alter the signal.

Best way to iron such thing out would be with a synth with stereo output, I guess… One direct in the mixer, the other in the OT.

Even if OT has not the best A/D converters in the universe, I feel like it’s important to identify the best way to handle the gain staging.

JuanSOLO · 2016-09-15T15:54:07.825Z

My OT sounds great, along with the other machines running thru it.
I got no complaints, my music sounds better to me than it ever has.
Granted I have been doing lots of dialing in compression, and gain staging on my machines over the last year.
I’m over being obsessed about loosing something.
Even though I notice quite a difference when not running things into the OT, I just ceased to care that much, it still sounds great to me, but more importantly, it so much more fun.

It’s funny to watch kids get into 4 track cassettes these days, etc.
That’s how I started out.
Back then I didn’t care if my gear was high end, I needed something workable for like $100.
I listen to those tapes and I like they way it comes off with all this lo-fi character, but I don’t like it enough to start recording to cassette.
It does put things into perspective though.
I think my 20 year old self would think I was spoiled, prone to high maintenance, and would rather me worry about crafting music than if I had the most high end sounding shit.

avantronica · 2016-09-15T16:46:09.377Z

bolandross:

I assert, that in a blind test, nobody would be able to distinguish a signal that went through the Octatrack from a signal that did not.

I ran a blind test here a while back

I sourced a ‘reference’ high fidelity classical recording and ran it through the OT headphone out to a budget field recorder and sampled it into the OT

I presented the three files and pretty much the jury was split three ways about what was what, there was no consensus, there was little to hear in the projected sounds - what I found (for OT rec), it may even be discussed above or linked, was that the noise floor, the space around the sound, had less ‘space/openess’ to it compared to the source, the field recording was only a little deteriorated (if at all, and also in the same areas) - essentially - the journey through -12db drop at OT ins and following a 12db recovery boost the rendered file was essentially fine, and trivial to the impact the source would undergo if run through time stretching etc

what nobody can offer, unless you meet in the same room is a comparison between direct to amp and fed through OT - I occasionally put the prophet 08 direct to the amp and there is presence of sound which i’d be astonished if a soft synth could deliver or a recording could portray (i must try an A/B soon, but i’d prefer to do it blind)

I’m also not yet convinced about this chase for the last % of gain pre clipping … how big a difference does chasing the highest level make when the recording is immediately subject to a 12db cut internally (reduce by 3/4 or so) … maybe I’m missing something ? This may be good mixing housekeeping on Elektron’s part, but i’d sooner have had the option to bypass that

on the occasional browse of discussion on this, it becomes clear that people mix and match good practice from the old pre-digital days unhelpfully with current kit - clipping is just about the only thing you need to avoid 100% digitally, low recording level is less of an issue compared to capturing on tape was the gyst iirc … too much of the debate is subjective too, a bit like my comment on the prophet presence !

Edit : Inputs not attenuated (as per comment above) on OT, see here

Gain aGain Octatrack

Ah, i think i have discovered that there’s been a bit of a prior misunderstanding, possibly on my part and it’s been perpetuated … I tried Setting the Gain to 0 on the mixer to see how far i could push the DE, it could go way beyond the 1/4 scale captures you’d see if the inputs were categorically being lowered by -12dB … but not far enough, the VCA seemed to level off after about 7>8 and it was maybe 2/3rds or more full-scale on the OT and the shape was good/clean (red inputs) So i stacked up…

nunocardoso · 2021-09-22T19:18:05.917Z

Hi all,
Im new to the octatrack and recently noticed the following.
I have a synth going into inputs A/B and mix it in via DIR, GAIN is set at 0.
When i increase or decrease the DIR level, i can hear significant stepping/aliasing on the synth audio as the volume increases/decreases.
Is this normal, does it happen for you guys as well?

Thanks

randy909 · 2021-09-22T19:53:24.890Z

DIR has 128 values it can be set to. Sometimes you can hear the jump from one step to the next just like you can with many values controlled via MIDI CC (also 128 steps). Is this what you are talking about? Is this a problem for you in your setup? If so I would adjust the output side of the synth as a workaround. If your synth is very hot you will probably notice a bigger jump from one DIR value to the next.

nunocardoso · 2021-09-22T20:10:30.282Z

Thanks for the reply.
Yes it is in a way, if using DIR to mix in out when jamming/playing live it makes noticeable artefacts.
It curious because other devices i used with audio inputs and digital control dont make this sort of stepping artefacts.