School me on FX loop levels...

[MattACaster]

So I know there is the -10 and +4 levels.

 

But I've also heard the terms..

Line level

Guitar level

Consumer level

Professional level

Rack level

Pedal level

 

Which is which?

[EdMan57]

From what I understand,the +4dB effects loop is basically "line","professional" and "rack" levels.Some refer to it as "effects loop" level,though many fx loops are designed for instrument level use.The -10dB is "instrument","guitar" and "pedal" levels.Some pedals [usually time-based fx] and lots of rack gear offer the choice of both,usually via an internal switch and/or separate inputs for each level.


Ed

[MattACaster]

 

and lots of rack gear offer the choice of both,usually via an internal switch and/or separate inputs for each level. Ed

 

 

Great, thanks!

 

I'm wanting to run my Line6 DL4 through the loop on my RM100 but when I flip it on all the high end disappears from the amp. I'm told that it because it's the wrong level. I guess the DL4 is -10 and the amp is +4. Does that make sense?

[Seano Porno]

marked

[diocide]

 

Great, thanks! I'm wanting to run my Line6 DL4 through the loop on my RM100 but when I flip it on all the high end disappears from the amp. I'm told that it because it's the wrong level. I guess the DL4 is -10 and the amp is +4. Does that make sense?

 

Usually when your fx loop is +4 and you use a -8 or whatever effect, it effects the volume severely. This is because the amp is expecting a higher signal to come back than the pedal is provding. I'm not sure if this would effect the tone in the way you're describing, but it's definitely possible.

 

EbTech makes a box called the Line Level Shifter that can fix problems like this. I've never used one, but I learned about it when I bought my last amp, which I thought had a +6 loop, when it really had a -8 loop.

[teemuk]

Line level

 

 

The problem comes from there being several "line levels". For instance there are:

ARD of Germany +6dBu, USA professional audio +4dBu, and consumer audio -10dBV.

 

The reference voltage of dBu and dBV is different because each is derived from producing a certain power across a certain load resistance. The reference of dBu is approximately 0.78 VRMS while the reference of dBV is 1VRMS.

 

Thus, nominal signal levels are

ARD: 1.55VRMS

USA professional audio: 1.228VRMS

Consumer audio: 0.316VRMS

 

The professional line levels have higher nominal amplitude because that ensures a better signal to noise-ratio.

 

 

Guitar level

 

This would refer to nominal signal levels of a guitar's output, which vary a lot. Basically you could expect them to be in the order of several millivolts. However, peak voltages can be in order of several volts with "hot" pickups. Pickups vary a lot so there really can be no universal standard for this.

 

 

Rack level

 

This is most likely one of the line levels (either professional or consumer) but it really depends on the rack unit and there are no universal rules. Refer to manual, it should state on which kinds of input and output levels the unit operates on optimally.

 

 

Pedal level

 

Pedals normally operate on signal levels close to those produced by a guitar. Higher input signal amplitudes (such as line level signals) would easily overdrive them. Again, depends a lot on the pedal and anything universal can't be really said about this.

[MattACaster]

 

Usually when your fx loop is +4 and you use a -8 or whatever effect, it effects the volume severely. This is because the amp is expecting a higher signal to come back than the pedal is provding. I'm not sure if this would effect the tone in the way you're describing, but it's definitely possible. EbTech makes a box called the Line Level Shifter that can fix problems like this. I've never used one, but I learned about it when I bought my last amp, which I thought had a +6 loop, when it really had a -8 loop.

 

 

I'm actually looking at picking one of those up for the DL4. I wonder if the high end loss could be a bad FX loop tube?

[MattACaster]

 

The problem comes from there being several "line levels". For instance there are: ARD of Germany +6dBu, USA professional audio +4dBu, and consumer audio -10dBV. The reference voltage of dBu and dBV is different because each is derived from producing a certain power across a certain load resistance. The reference of dBu is approximately 0.78 VRMS while the reference of dBV is 1VRMS. Thus, nominal signal levels are ARD: 1.55VRMS USA professional audio: 1.228VRMS Consumer audio: 0.316VRMS The professional line levels have higher nominal amplitude because that ensures a better signal to noise-ratio. This would refer to nominal signal levels of a guitar's output, which vary a lot. Basically you could expect them to be in the order of several millivolts. However, peak voltages can be in order of several volts with "hot" pickups. Pickups vary a lot so there really can be no universal standard for this. This is most likely one of the line levels (either professional or consumer) but it really depends on the rack unit and there are no universal rules. Refer to manual, it should state on which kinds of input and output levels the unit operates on optimally. Pedals normally operate on signal levels close to those produced by a guitar. Higher input signal amplitudes (such as line level signals) would easily overdrive them. Again, depends a lot on the pedal and anything universal can't be really said about this.

 

 

Every time I see you post I know it's going to be wicked technical, and I love it! Thanks for the info!!