I’m wondering how I can access the controls of a Presonus FP10 on a *nix system. I want to check and see if the FP10 is implementing some sort of signal attenuation on the input from the pre-amp, or at the very least to make sure all the settings that it has match the settings in JACK.
This is an attempt to solve a VERY long-running issue with my set-up: input levels are extremely low, and bringing them up to a decent level brings up the noise floor (of course). There may indeed be some secret switch somewhere I need to flip to solve this, but I’ve not had much luck. And even more odd is the fact that every now and then, sound levels are fine, and things run smoothly and I have no idea what (if anything) I did to make it so. (I’ve checked power supplies and turned off everything else in the house, fuse box included, when trying to track this down). But while I can occasionally detect electrical issues from house appliances and such, I am pretty sure this issue is internal to my signal chain.
My signal chain is pretty basic: mic (either AKG CS1000 for guitars, or Shure KSM44 for vocals) >> Vintech Dual 72 pre-amp (input = -35, output gain = max; Mogami cables) >> Presonus FP10 interface >>firewire>> DAW (U. St. Linux, Sandy Bridge i7, 16 GB memory, three drives). I generally set input track meters to around -25 / -30 to give myself some headroom. As I said - once in a while all of this works fine, but it usually doesn’t. Weirdness.
I posted a follow up in the other “notch filter” thread. Check there and decide whether you want to continue the discussion there or in this thread. By the way, I misread the FP10 manual, channels 3-8 are OK for line level input on the front panel, just channels 1 and 2 have to use the rear panel inputs for line level input.
I don’t see anything in the manual to indicate there are any internal controls. Did you have something specific in mind, or are you just grasping at straws?
I saw that other reply - thanks! Sorry for the double-posting; I wasn’t sure whether to terminate the earlier thread or continue, as the subject was morphing. I posted a long reply a few minutes ago.
It doesn’t seem that there are any internal controls; I caved and installed the drivers on a Windoze system I have and checked the clock rate and sampling rate, which was all that was accessible. I recalled seeing another discussion about an interface (not the Presonus) that discussed some sort of internal signal damping, so yah- pretty much grasping at straws.
I’ll go ahead and keep checking the other thread, as that is where most of the information lies at this point. Thanks for the time and help!!
You might have a gain staging problem somewhere in your chain.
-25 to -30 is really low. In digital -18dbfs is about where you are aiming for which should still allow you plenty of headroom.
take out the preamp and see if the noise there is an issue - having the output maxed out seems really odd and this in itself could add lots of noise. Ive never used that preamp but it looks like a decent analogue mic preamp so you can run your inputs hotter than you think and it may actually be benificiall to get those circuits heating up which means driving them into the yellow. To start of with input to zero.
if you have a quite source though at the mic then you might end up bringing in background noise.
Good signal to noise ratio is important through the entire chain, if your running things really quiet coming in you will have poor snr.
get your preamp to a good input level remember its not digital so zero is your starting point you can go higher than this. -18dbfs in digital is your anologue zero. but when working iwth anologue if your running in those really quiet ranges you have issues.
The Vintech Audio “Dual 72” is a two channel class A, all discrete, transformer balanced microphone preamplifier. It’s circuitry is based on the discrete amplifier circuits found in the Neve 1272 module. "
The Vintech Audio “Dual 72” is a two channel class A, all discrete, transformer balanced microphone preamplifier. It’s circuitry is based on the discrete amplifier circuits found in the Neve 1272 module.
its what was used in Neve consoles, and engineers would purposely drive those preamps hard to get them to produce harmonics .