Level matching tips anyone?

N

neverwind

New member
Hello,

Something has been bothering me for quite some time and I hope there's someone here who can make things more clear :)
How do I know I have the correct level at my amp's input?
I've been using rack gear for quite a while and I swear, each peace of gear has its own output level controls and they are all different:
There's 0 dBv, +10 dBv, 0 dB, -10 dB, -20 dB, +4 dB...

How does one tell if the signal going to an amp's input is not too hot or too cold?
Is there a piece of equipment that can measure that? Like a VU meter to go in between?
 
Re: Level matching tips anyone?

neverwind said:
Hello,

Something has been bothering me for quite some time and I hope there's someone here who can make things more clear :)
How do I know I have the correct level at my amp's input?
I've been using rack gear for quite a while and I swear, each peace of gear has its own output level controls and they are all different:
There's 0 dBv, +10 dBv, 0 dB, -10 dB, -20 dB, +4 dB...

How does one tell if the signal going to an amp's input is not too hot or too cold?
Is there a piece of equipment that can measure that? Like a VU meter to go in between?
Click to expand...
Hi, I believe most guitar amp inputs are set at instrument level...meaning the amp expects a signal at around -10dB..."line level"
The higher outputs +4dB and above are meant to be connected to devices that really need a big input OR an fx loop with variable input level like a Blackstar fx loop which has the +4dB -10dB thing as a switchable option.
Most pedal fx are at instrument level. Some Preamp fx are at +4dB, which means they eliminate the need of a preamp circuit to boost the signal, as they effectively take over that job.
So in the guitarist' world if your fx rack is +4 dB you need to plug into the loop and not the front of the amp.
Sorry, I don't have enough experience to know if higher output stuff still works by simply turning down the output or if it overdrives the loop altogether. I am guessing having multiple output levels is far from ideal?
Hope this helps a little.

Sent from my SM-G920V using Tapatalk
 
Re: Level matching tips anyone?

-10dB is instrument level, +4dB is line level which most rack processors expect. Some pedals can handle line level signals, some (like Boss single pedals) can't. If you put a Boss DD-3/5/6/7 in a line level loop, it will distort the buffers so the signal will be distorted even when the pedal is off.

A power amp also usually expects a line level as well, but if the level is lower you can always just turn the amp up more.
 
Re: Level matching tips anyone?

Thanks johnthomas, devastone. I appreciate the feedback.
As a matter of fact, I'm perfectly aware of the definitions of 'Instrument', 'Line', 'Mic' and 'Pro Line' level signals :)
The thing is, when an output has a certain level, be it -10 dB, 0 dB, +4 dB, etc, this still doesn't mean the signal coming out of the device is always at 'that' level. It rather puts you around it and most of the time you still have an output level knob to play with.

I was wondering if there was a way to measure the signal coming out from a JMP-1 preamp for example.
 
Re: Level matching tips anyone?

Doh, sorry about that. You're right and I'm not sure if the "level" rating is when the volume is full or how they decide that. I can't think of a good/simple way to measure the output, maybe a load and an oscilloscope, but that seems like a lot of trouble. The output is also going to be dependent on the input, so it will also depend on what is plugged into it.

The manual says the JMP-1 has a switch on the back to set the master and emulated output levels, so I would go with that and set it to the appropriate level for what you are interfacing with.

https://www.zikinf.com/manuels/marshall-jmp-1-manuel-utilisateur-en-32796.pdf
 
Re: Level matching tips anyone?

neverwind said:
..............I was wondering if there was a way to measure the signal coming out from a JMP-1 preamp for example.
Click to expand...
Other than curiosity, what does it matter. To me, the end sound is the important issue....does it appear clean or unnecessarily distorted based on the expected character of the amp.
 
Re: Level matching tips anyone?

@devastone
Thanks again. I just gave the JMP-1 as an example, but I really appreciate the effort :)
Unfortunately, the output level is again affected by other controls as well.
And I've got 7 more preamps and besides having such a switch, each has at least one other way to refine the output level further.

@IM4Tone
Curiosity is close :)
I'd like to find out what a certain preamp and a poweramp would sound like at the 'expected' level if I may put it like this.
I've got a couple of preamps to play with alongside 3 power amps.
 
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