Hi, and welcome to the forum. Thanks for asking a very interesting question, interesting because from what you describe, there is nothing that you are doing wrong. It SHOULD work...

But there is a computer and USB involved, so you should first check the analog side of things. Plug in a microphone or any audio line source to channel 1 and find out where the signal goes and if you can HEAR it in the different outputs. If you hear something, then we'll probably find and solve the USB problem.

Thank you for the quick reply. Unfortunately I don't have a microphone available to plug into the back this weekend. However, I did attempt to plug in one of my small line level synths into the combo input 1 jack. This is the same synth I tested the ERIS monitors with so I know it produces output.

Frustratingly, I can't get to seem to get any level into the mixer. I turned the fader all the way up, as well as the gain on the fat channel and can't get any level LEDs to light up on either the fader channel or fat channel.

I've tried using both mono, TRS, and XLR cable inputs from my mixer on a couple random channels and the same thing happens.

I've made sure the selected fader channels were selected to analog input and assigned to the L/R mix, but seeing as I can't even get the fader channel LEDs to light up, I'm assuming that's the first problem.

It just seems like the analog I/O isn't working at this point. Is that a thing? Is there a connection in the mixer between the CPU and analog I/O that can get disconnected during shipping maybe? Just spitballing here as I am at a loss.

I just can't get any noise out of this mixer on any channel, mix, monitor, or phones no matter what I do so far. I'd be happy if I could just get a test tone out to make sure I'm not going crazy!

My guess is that the Solo Mode is still on (default) ‘Radio’. Switching it to Control Room (‘CR’) allows you to monitor Main Out when nothing is soloed.

As for the XLR main outputs there’s a little trim pot right next to them that may be turned all the way down. If so then turn it up for XLR output.

Oh, and make sure you plug you jacks in all the way.

The 64S does not have that knob. Don't search for it...

Could you check a signal in Tape In (analog, RCA ports) or Aux In 1 or 2?

wahlerstudios wroteThe 64S does not have that knob. Don't search for it...

It doesn’t? Really? No wonder there’s no sound then

OK then, skip the trim pot part. But the other two points are vald

SwitchBack wroteMy guess is that the Solo Mode is still on (default) ‘Radio’. Switching it to Control Room (‘CR’) allows you to monitor Main Out when nothing is soloed.

I did change that setting as you suggested as well as cleared the solos, but I'm still not getting any sound from any output.

wahlerstudios wroteCould you check a signal in Tape In (analog, RCA ports) or Aux In 1 or 2?

I put the same synth on the tape inputs (with 1/4 inch to RCA adapters), selected the Tape In channel, and changed to analog input. I could not see any input on the channel fader or elsewhere.

I tried plugging directly into AUX 1, selected that channel, pulled up the fader, and verified analog input. Again, no activity on the channel fader LEDs when playing the synth.

I'm thinking it's starting to look like I have a dud and may need to draft a ticket, no?

Well, you had the main meters going when sending a signal from usb to Tape In. So now, with monitor mode set to CR, you should be able to get a signal on Phones and the Monitor outputs.

SwitchBack wroteWell, you had the main meters going when sending a signal from usb to Tape In. So now, with monitor mode set to CR, you should be able to get a signal on Phones and the Monitor outputs.

I'm not getting any sound on either, that's what's driving me nuts. No matter what I do it seems that the analog ins and outs just aren't working, even if I'm getting a good USB digital signal in and ready to hear.

It is of course possible you got a faulty unit. Something silly like a loose connector inside. Happened before. With the main meters going you should get a signal on the XLRs. If not then get Customer Support or your dealer involved.

OK. Thank you all for your help in trying to solve this for me. I ended up solving my problem. After everything we've tried, I came to the conclusion there was likely a cable or some other loose or disconnected trace/connector to the analog I/O board. I was fully prepared to send my unit in to an authorized service center, but my reading of the Presonus website indicated that all repairs need to be shipped to the company in NOLA. I kind of shuddered at the cost of shipping the 64S that far so I decided I would at least first try to open it up and see if there was something simple I could fix.

So with that preface, let me do my due diligence and say:

DO NOT ATTEMPT WHAT I DID. DOING WHAT I DID IS AT YOUR OWN RISK AND IS LIKELY FROWNED UPON BY PRESONUS.

So, I flipped the unit over an removed the screws holding the bottom piece in with a small allen wrench.



To open, you will need to lift the side opposite the power adapter as that is wired to the power supply which is attached to the bottom piece.

Once removed, I could see a loose connector dangling from the power supply.



Based on the positioning and length, I was able to find the plug for it on the analog I/O board, as shown below.



After connecting it and putting it all back together, the mixer seems to work! So I'm assuming it got bumped pretty hard in shipping at some point and it came off. Well, I have to hand it to Presonus. I was pretty thrilled that this was well designed enough to be able to do a minor repair like this. The pieces inside the mixer all seem compact and well-built. I'm looking forward to getting to use this mixer now.

On the bright side of this, I got a crash course in Audio routing and I/O on the mixer!

Glad you got it working!

I hope you checked the seating of the other plugs too. Snapped into place these plugs can't work themselves free, so PreSonus' assembly site dropped the ball there.