Preamp/channel strip question

Lee Douglas

Sophomore
Jan 15, 2011
183
0
16
Northwest
I've got a rack I put together for an acoustic guitarist I work with that consists of a Sennheiser EW100G2 wireless, a tuner, a Presonus Eureka for tone shaping and light compression and a Rane PE-17 for notch filters as needed. The signal comes from a variety of guitars, all loaded with Fishman piezo pickups under the bridge. It's fed through a monitors and FOH only, no stage amp. This is generally for a five to ten piece band with horns, sometimes part of the ensemble, sometimes by itself.

This is one of those instances where I should have just kept my big mouth shut, instead of correcting him when he was commenting on the nice tube sound from the preamp. As I took the signal off the unbalanced out on the wireless, it goes into the instrument input on the Presonus, thereby by passing the tube section of the preamp. You should have seen the look of horror on his face. I asked him what was wrong with the sound I was getting for him. he said absolutely nothing, but he wants to use everything he paid for. It simply has to go through the tube. Fine... I can either run it through a Radial and into the XLR on the Presonus or come directly out of the wireless XLR. Whatever.

My thought is that because a) it's going through a wireless and b) it's generally part of a band sound and not a solo guitar, that any minor gains will be negated. But I don't mind be wrong. As least as long as it's somewhat anonymously on an internet forum! ;) Am I missing something? Will this be an amazing improvement? Should I just install an orange light behind the tube (I hate when a manufacturer does that) and let him hear with his eyes? We're going to to try it anyway. What say you?
 
Re: Preamp/channel strip question

Oops. Sorry. You're right Tim, it's a Presonus Studio Channel not the Eureka. I am going to give a try for giggles. I'm just wondering what other's experiences are with a similar set up.
 
Re: Preamp/channel strip question

About ten years ago my partner at the other end of the snake for many years bought one of those "feedback eliminators" to patch into the mix that went to the unpleasable singer's mix.

After about a month he admitted "it doesn't work very well but I paid so much for it I've got to keep using it"
 
Re: Preamp/channel strip question

Oops. Sorry. You're right Tim, it's a Presonus Studio Channel not the Eureka. I am going to give a try for giggles. I'm just wondering what other's experiences are with a similar set up.
Tubes can sound very good for acoustic guitars, (and just about any instrument) whether their euphonic sound will make more than a subtle difference can only be found out by trying.
Seems to me the tube is already in use, if the tube drive is turned up.
The manual says:
“When an instrument is plugged into the instrument input, the microphone preamp is
bypassed, and the Studio Channel becomes an active instrument preamplifier.”

It then says:

“Input Gain/Trim Control. These knobs provide the following gain structure:
XLR Microphone and TS Instrument/Hi-Z Inputs. 44 dB of variable gain (+10 dB to +54 dB)
Tube Drive. The Tube Drive control increases the amount of signal routed through the 12AX7 vacuum
tube. (The gain controls overall volume, whereas the drive controls volume routed through the tube.)
The effect achieved ranges from subtle to extreme, depending on the setting being used:”

The way I read it, only the mic pre is bypassed by plugging in to the 1/4” instrument input, it would seem the input has a parallel path through the 12AX7 tube, the % of drive added is dependent on the drive pot position.
If it was set to 0, no tube is in the circuit, the higher the tube drive, the more overdrive sound is added.

Turn it up and see :^).


Art Welter
 
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Re: Preamp/channel strip question

Brian and Lee- Not exactly the first time. I can't say too much though. I've been known to buy stuff for the pretty/flashy lights!

Thanks, Art. I guess I wrongly presumed that the tube would be integral to the mic preamp circuit. Perhaps I should read the rest of the manual! I think I'll get a chance to try it on Saturday.