PC > preamp > powered monitors gain staging question.

[viivo]

I assume it's 100% PC and speaker amps and use the preamp for adjusting level, but I'm asking because there is quite a bit of audible noise from the speakers when their gains are set to maximum that isn't there at lower settings. Is this a separate issue or is there a different way to set the gains?

 

[ProtegeManiac]

I assume it's 100% PC and speaker amps and use the preamp for adjusting level, but I'm asking because there is quite a bit of audible noise from the speakers when their gains are set to maximum that isn't there at lower settings. Is this a separate issue or is there a different way to set the gains?

In the first place, you're not really supposed to max out the gain, it's an extremely rare case to do so. If that was the case they'd just nix the gain control and set them all to +4dB or +6dB.

One way to set the gain is to set your unity gain preamp to roughly 1:00 on the dial (just under 3/4 if I'm using a digital control, like in a car), then slowly raise the gain on one speaker amp. When you hit noise, pull back until it's barely audible. Do the same on the other side. Lower the unity gain preamp knob setting to around 10:00 on the dial (1/4 on digital knobs). Too loud? Reduce the speaker amp gain. Too soft? Crank it up to 12:00. Still too soft? Go back to 10:00 and crank up the speaker amps' gain bit by bit, making sure you at least don't hear any noise when music is playing. If you have a USB mic and RTA software, do this for just one side then match the output on the other side (mic has to be where your head is; when I do this in cars it inevitably configures the passenger side speaker gain to be set louder using the receiver's/DSP's balance control if I'm not using separate amps per side).

 

[viivo]

Thank you for the detailed reply.

I have a question now about the same setup arranged a little differently. I removed the preamp and am instead using the onboard's optical out to a very basic DAC and out to the monitors. This seems to have removed most of the noise, but now the only volume control I have is Windows Master Volume. Should I try to incorporate the preamp for physical gain control or is it no neccessary?

 

[PurpleAngel]

I assume it's 100% PC and speaker amps and use the preamp for adjusting level, but I'm asking because there is quite a bit of audible noise from the speakers when their gains are set to maximum that isn't there at lower settings. Is this a separate issue or is there a different way to set the gains?

When you say speaker amps, can we assume your talking about the amplifier(s) built into the speakers (studio monitors)?
Or are you using a speaker amplifier with un-powered speakers?
What is the make and model of the pre-amp and the studio monitors?
How is the PC connected to the pre-amp and how is the pre-amp connected to the studio monitors?

You might be getting a feedback loop, might be caused by all the power cords plugged into the same surge protector.

 

[PurpleAngel]

Thank you for the detailed reply.
I have a question now about the same setup arranged a little differently. I removed the preamp and am instead using the on-board's optical out to a very basic DAC and out to the monitors. This seems to have removed most of the noise, but now the only volume control I have is Windows Master Volume. Should I try to incorporate the preamp for physical gain control or is it no necessary?

Using an optical connection will help prevent noise caused by a feedback loop.
Seem like not using the pre-amp is a plus.

 

[viivo]

Yes, the amps are mounted on each speaker. They are the MP/SR 8-inch powered monitors, preamp is Schiit Magni 2 Uber. I don't think it's just a ground loop because the noise is still there with a cheater plug.

 

[PurpleAngel]

Yes, the amps are mounted on each speaker. They are the MP/SR 8-inch powered monitors, preamp is Schiit Magni 2 Uber. I don't think it's just a ground loop because the noise is still there with a cheater plug.

Ok, so you have a PC, connected (analog connection) to a Schiit Magni 2, functioning as a pre-amp, connected to Monoprice 8-inch studio monitors.
The Magni to monoprice connection is using a cable that uses an RCA plug on one end and a 1/4" mono TS plug on the other end (not a 1/4" TRS plug?).
When you remove the Magni and use a low cost optical DAC, you get less noise.
What is the make and model of the low end DAC?

I'm not sure a cheater plug would solve a ground loop issue?

I'm thinking you should set the Monoprice to lower gain settings, if that helps with the noise issue and just use the PC (or magni) for volume control.

 

[ProtegeManiac]

Thank you for the detailed reply.

I have a question now about the same setup arranged a little differently. I removed the preamp and am instead using the onboard's optical out to a very basic DAC and out to the monitors. This seems to have removed most of the noise, but now the only volume control I have is Windows Master Volume. Should I try to incorporate the preamp for physical gain control or is it no neccessary?

It could be a ground loop if it's still there, and using a preamp might not solve it since there is now a different link back to the computer.

That said...do you still have it maxed out? Lower it and use the Windows control at a lower level.

You can still try a DAC with preamp output to control it but if it's a ground loop there's no telling how much better or worse that can be.