US-16x08 pre gain knob problem

[Miguelzero]

Hello to all!
I register on this forum to find out if anyone already had this issue with Tascam US-16x08.
I configured mine yesterday, but realized that, even with the gain knob completely turned to the left side, i still have sound on that input.
When i start to raise the gain of the pre, i quickly hit peak volume.
Gave a look at the tascam control panel and i saw that, even with the knob completely "off", the sound hit more than half on that meter, so i excluded DAW.
This happens at least on the 8 XLR front inputs.
i upgraded from a Tascam US-16-41, wich did not had this issue.
Can anyone help?

Thanks to all once again
Miguel

 

[Miguelzero]

Any ideas?

 

[Miguelzero]

?

 

[Miguelzero]

up

 

[Mark Richards]

even with the gain knob completely turned to the left side, i still have sound on that input...i upgraded from a Tascam US-16-41, wich did not had this issue.

@Miguelzero, The gain knob isn't a volume control. A signal is always present, ranging in power between -68 dBu to -12 dBu according to the spec sheet in the US-16x08 owner manual.

 

[Miguelzero]

Thanks A LOT for your reply Mark!
I asked because i had the previous version and did not have this issue.
Do you own a US-1608 also Mark?
I'm trying to get the feedback from another owner to see if they face the same issue.
Anyway i'm already recording with it !

Thanks once again
Miguel

 

[Mark Richards]

@Miguelzero
I don't own this particular product, but glad you're on your way making music with it.

According to the TASCAM US-1641 owner manual spec sheet, the gain knob for that unit ranges in power between -58 dBu and -2 dBu. The US-1641 gain is in fact 10 dB more than the newer US-16x08: -58 dBu vs -68 dBu and -2 dBu vs -12 dBu; while the gain range remains the same at 56 dB.

So for both units, there's no "infinity/off/100%" signal attenuation. That's not how a gain circuit works in a mic pre-amp.

Think of it like this:
* The purpose of the pre-amp is to raise the mic level to a usable level.

*The purpose of the gain knob is control of the incoming mic signal to the pre-amp so the mic signal doesn't distort the circuit.

* A very strong mic signal (e.g., a vocalist who eats the mic) will call for reducing the level of the incoming signal (turning the gain down). A weaker mic signal (e.g., an acoustic guitar playing a classical piece, with the mic three feet away) may call for keeping the gain up.

* The goal is to balance the mic signal using the gain knob so that you achieve a good signal level without peak distortion.

I always start with gain full up (in your case full right - clockwise); and reduce the gain (turn the knob counter clockwise) until I have a strong signal without peak clipping. Sometimes it becomes necessary to reposition the mic if the gain knob can't do its job effectively.

I suspect what you recall about the US-1641 may have been due to the signal level produced by the microphone and thus its relative interaction with the 1641 vs how that mic interacts with the US-16x08.