Recording using PreSonus Studio 68c

[raggie]

Hi

I guess this might be an atypical question in here as I'm going to record some footage of an old gaming system that was meant for broadcast purposes back in the day. It's stored in a data museum, and it's far away from where I live but still in the same country, so it's important to have the right gear ready when I go visit the museum to capture some content.

The audio output comes from an old 90's AKAI Professional MIDI Sampler and through line levels (two 1/4" jacks - stereo).

I was going there about a week ago for a one and only test setup. I was able to record the audio using two 1/4" jacks (TRS, balanced) and it was ok. But still there was some hissing... it was noticeable when you turned up the volume... it was not much, but I was still able to pick it up while listening, and when the game was silent:
https://www.youtube.com/watch?v=N8uk-txfggU

Most of the time was spent testing the video signal, so this was all I had the time to try out.

Before visiting the museum I was told by a guy in a forum on Discord what I had to buy to get excellent audio.

So far (watch the video) I got the audio stream from the AKAI and was recording directly using my PC and a PreSonus Studio 68c:
https://www.presonus.com/products/studio-68c

According to that guy on the forum, he told me also to go buy a Radial Engineering ProD2:
https://www.radialeng.com/product/prod2

This device should be in the middle of my setup. I bought this, but I didn't try it yet. But I'd like to know a few things before I go visit the museum a final time:

By using this ProD2 I end up "converting" the cables/signal from two 1/4" jacks (TRS, balanced) to two XLR cables before it enters my PreSonus Studio 68c.

1. Will the volume change when recording the next time, or do the XLR cables only work as an "adapter" cable, as it already started out as jack cables (line level) before it entered the ProD2?

2. If the volume might change and it ends up being too low, eventually, will I then end up frying the AKAI Professional MIDI Sampler if using 48V (phantom power) on the PreSonus Studio 68c? Or does the ProD2 prevent this from happening? That actually makes me feel a little scared already, because I'm not sure, if I might end up breaking their old machine/computer.

3. By using the ProD2, and lifting the ground from the XLR conversion on the ProD2 to my PreSonus Studio 68c, might that remove the hissing totally? Or do I need another device for that to go away?

I hope someone more into all this, might know the answers and be able to help. I already bought premium cables and adapters for this.

Thanks in advance.

[James Perrett]

I don't think the hiss is excessive on that clip when you consider that the Akai may only be 12 bit to start with. A model number for the Akai would be a big help as they made a huge variety of gear.

Also try TS cables instead of TRS - I doubt that the Akai has TRS connectors which means you could be picking up extra noise through the unused connection.

[raggie]

The model is:
AKAI Professional MIDI STEREO DIGITAL SAMPLER S2000

[Hugh Robjohns]

I was able to record the audio using two 1/4" jacks (TRS, balanced) and it was ok. But still there was some hissing... it was noticeable when you turned up the volume... it was not much, but I was still able to pick it up while listening, and when the game was silent:

I suspect that noise floor is to be expected... but it's possible that it is also the result of RF interference as the Akai outputs are probably unbalanced and might no play nicely with TRS cables. In situations like this it's usually better to use unbalanced TS cables and, if that results in ground-loop problems, use a DI box with ground-lift function

I suspect an Akai product of that era is probably early 16-bit quality, but it could be 14-bit or non-linear 12-bit (or even lower)... does the file data state the quantifying resolution?

According to that guy on the forum, he told me also to go buy a Radial Engineering ProD2:

A good quality dual-channel passive DI box. I'm not sure it's strictly necessary in this application, but it won't do any harm and will solve any ground-loop problems that might arise.

By using this ProD2 I end up "converting" the cables/signal from two 1/4" jacks (TRS, balanced) to two XLR cables before it enters my PreSonus Studio 68c.

Not quite. It expects unbalanced TS inputs.

1. Will the volume change when recording the next time...

Yes! DI boxes like this take an unbalanced line-level or instrument input and convert it to a balanced microphone level output. You'll need to connect the DI box XLR outputs to the mic inputs of your interface.

2. If the volume might change and it ends up being too low, eventually, will I then end up frying the AKAI Professional MIDI Sampler if using 48V (phantom power) on the PreSonus Studio 68c? Or does the ProD2 prevent this from happening?

Well, firstly, you can switch off the phantom power on your interface, and secondly, the DI box will block it from reaching anything connected to the inputs... so your Akai will be safe even if you forget to turn off phantom.

That actually makes me feel a little scared already, because I'm not sure, if I might end up breaking their old machine/computer.

Not if you turn off phantom, and absolutely not if you use the DI box.

3. By using the ProD2, and lifting the ground from the XLR conversion on the ProD2 to my PreSonus Studio 68c, might that remove the hissing totally?

It depends on the source of the hiss. If it's due to the mis-use of TRS cables then the DI box might improve matters. But I suspect it is what it is from a 30+ year old format.

Or do I need another device for that to go away?

Broadband de-noise software is widely available, if required...

I already bought premium cables and adapters for this.

It might be worthwhile investing in some unbalanced TS instrument cables to run between the Akai and DI box.

EDIT— I've checked, and the S2000 had balanced TRS inputs, but unbalanced TS outputs. So use unbalanced TS cables into the DI box.

It's also 16-bit capable, but I can't find any specs for its noise performance.

[raggie]

Thanks a lot to both of you guys.

It means a lot to me to get those questions out of my mind... especially the one about the phantom power.

The Radial Engineering ProD2 already has -15 dB toggles. And I also have two Cloudlifters for my dynamic Shure SM7B's. So I'm also able to go up +25 dB.

Will those options do it, now the audio levels are going to change, if I end up using the Radial Engineering ProD2 and then mic levels instead of line levels?

I'll go get some premium TS cables then...

Hugh Robjohns:
In the front display it said this in one of my photos from the visit:

BY _* 12
70 prog active

I don't know if that's of any use.

[Hugh Robjohns]

The Radial Engineering ProD2 already has -15 dB toggles.

These are used to prevent transformer distortion if the input level is particularly high. It's very unlikely that you will need to use them.

And I also have two Cloudlifters for my dynamic Shure SM7B's. So I'm also able to go up +25 dB.

Again, not likely to be needed.

Just connect the DI box XLR outputs to the mic inputs of your interface and adjust the gain as necessary. You shouldn't have any difficulty.

Bear in mind the Akai has its own output level control (top right-hand corner) which you can use to optimise levels through the DI box, too.

...and actually, you may find you get perfect acceptable results using the unbalanced TS cables straight into the interface line inputs.

In the front display it said this in one of my photos from the visit:

BY _* 12
70 prog active

I don't know if that's of any use.

It's a long time since I've used an Akai sampler, but I think that just means its playing track#12 which is called BY, and there are 70 programs on the disc with the track number 12.... but others here may have a better memory than me!

[Music Wolf]

That actually makes me feel a little scared already, because I'm not sure, if I might end up breaking their old machine/computer.

You won't break it. But, speaking as someone who used to own one, no great loss to the world if you did.

I found the old review from SoS. I can't believe that I spent about £1k on one of these in the mid 90's (about £2k in today's money). It was the size of a small car and it had less memory than your average goldfish

[raggie]

Nice. Now I think I know what to do, and I soon have all the stuff I might go need.

Yeah, I guess it was top of the line back then, though not anymore, haha.

The MIDI sampler might not be worth much nowadays, but I still don't know how to replace this, if it ended up dying.

It's a custom built Amiga 4000 system with an external MIDI sampler for audio playback.

I think they no longer have the source code for the games/system, so I don't know if replacing this with another one (if it's not possible to find an exact copy anymore) would work.

https://www.abandonsocios.org/wiki/imag ... TE3000.png

You were able to dial in to a TV show and then play those games using your landline phone. And if you did great, you'd win a prize.

It was a thing in a lot of European countries, but not that much in the US. I think they made about 25 different games for it. This is the system they used for broadcasting in Sweden.