| Author |
Topic: Placement of pedals in the chain... |
Steve Wood
From:
Kitchener, Ontario, Canada
|
Posted 4 Aug 2011 10:53 pm |
|
I want to experiment with my effect pedal (Boss RV1 and DD3) placement.
Right now I have them coming from my volume pedal to delay, to reverb to amp input.
What are the benefits of using them in the pre/post effects jacks on the amp itself?
thanks!
steve |
|
|
 |
Dave Grafe
From:
Hudson River Valley NY
|
Posted 5 Aug 2011 9:14 am
|
|
I would not change anything, Steve, you've got it right already.
Amp effects loops will generally work best with rack-mount, line-level devices, while your stomp-boxes are instrument-level units. They may work there but most likely you will get more noise and possibly a skewed frequency response as well. |
|
|
|
Steve Wood
From:
Kitchener, Ontario, Canada
|
Posted 5 Aug 2011 9:25 am
|
|
Thanks, Dave.
What makes something line-level vs. instrument level? Because it has not 'entered' the amp yet?
cheers,
s. |
|
|
|
Brad Sarno
From:
St. Louis, MO USA
|
Posted 5 Aug 2011 12:12 pm
|
|
| Steve Wood wrote: |
Thanks, Dave.
What makes something line-level vs. instrument level? Because it has not 'entered' the amp yet?
cheers,
s. |
Instrument level is a range of signal level (voltage) that relates to the fairly soft or low levels that come from guitars. Guitar pedals and amplifier inputs are designed for a sensitivity and headroom (headroom is the max signal before distortion happens) that best handles these low levels.
Line-level is much higher voltage, like what comes out of a preamp's output on its way to a power amp, or maybe like the levels seen in an effects unit used with a mixing console. These levels are MUCH hotter than instrument level. The problem some people find when trying to use a guitar pedal in an amplifier's loop is that the loop is "line level" and the signal is SO hot that it distorts the guitar pedal that was never designed to see such hot levels.
The other issue some people find is that they try to use a rack-mount line-level effects unit as a guitar effect, right after the guitar and before their amplifier. They find that the guitar signal level isn't nearly strong enough to get the effect unit to respond well.
Instrument/guitar devices belong in instrument level positions, before an amplifier or preamplifier. Line level effects belong in amplifier effects loops or after preamplifiers.
That's a simplified rundown.
Brad |
|
|
|
Ken Fox
From:
Nashville GA USA
|
Posted 5 Aug 2011 12:22 pm
|
|
Some old info I posted a while back:
Often amps are designed with effects loops that actually do not work well with standard pedals. The problem can seen in this example of the N-400 loops (not so unlike many amps out there). Using a pre amp out to drive an effects unit is a bad idea, as it is a line level signal!
This was an earlier reply I made on the N-400 amp itself:
After 30 years of experience and training with the design of audio systems I know a bit about overloading devices.
Let's take a Boss RV-5 pedal for example:
nominal input level rated for -20dbu (0.21 volts)
Nominal level is the normal operating signal that allows 10db of headroom in live music or 20db of headroom in recording application to allow for volume dynamics associated with playing or recording music. That from my old Yamaha manuals of years ago!!!
The preamp output of the N-400 is 1 volt nominal and can go much higher when psuhed! That is 5 times the nominal voltage the Boss RV-5 want to see for it normal operating range and best signal to noise ratio.
The RV-5's nominal output is also -20dbu, 5 times to weak to properly drive the power amp of the N-400 amp.
The pre EQ patch output of the N-400 is amazingly a nominal of 0.2 volts, same as the effects pedal requires!
The patch EQ input of the Nashville 400 is 0.2 volts, the same as the nominal output of the effects pedal.
There is no supporting argument for using the preamp to drive a common effects pedal. Those pedal are designed for unity gain and a guitar level signal at their input.
So in layman's terms. using the pre-amp out to feed a common effect pedal is like trying to shove 5 lbs of stuff in a 1 lb bag.
Your choice, do it either way. I just believe in the things I learned while I studied and trained in the Pro Audio field to preserve proper signal to noise ratio and prevent gain overlap (that leads to distortion)
I could go on further into gain overlap, impedance matching and a ream of other subject matter but I do not think it necessary for this application!!
A bit more from the net about operating levels:
Nominal level is the operating level at which an electronic signal processing device is designed to operate. The electronic circuits that make up such equipment are limited in the maximum signal they can output and the low-level internally-generated electronic noise they add to the signal. The difference between the internal noise and the maximum output level is the device's dynamic range. When a signal is chained improperly through many devices, the dynamic range of the signal is reduced. The nominal level is the level that these devices were designed to operate at, for best dynamic range.
In audio, a related measurement, signal-to-noise ratio, is usually defined as the difference between the nominal level and the noise floor, leaving the headroom as the difference between nominal and maximum output.[1][2] It is important to realize that the measured level is a time average, meaning that the peaks of audio signals regularly exceed the measured average level. The headroom measurement defines how far the peak levels can stray from the nominal measured level before clipping. The difference between the peaks and the average for a given signal is the crest factor.
There is some confusion over the use of the term "nominal", which is often used incorrectly to mean "average or typical". The relevant definition in this case is "as per design"; gain is applied to make the average signal level correspond to the designed, or nominal, level.[/quote]
_________________ |
|
|
|
Steve Wood
From:
Kitchener, Ontario, Canada
|
Posted 6 Aug 2011 11:13 pm
|
|
Ken, Brad and Dave, thank you so much for your input and help. This is a lot to digest, but it makes sense, for sure. What a fortunate group we are to have pros willing to help out the novice.
thanks again,
steve |
|
|
|
Ray Anderson
From:
Jenkins, Kentucky USA
|
Posted 7 Aug 2011 4:59 am Placement of pedals
|
|
Now I am confused, I have mine as follows,Guitar to Vp....Vp to Amp input....EQ Out to Stomp boxes.....Stomp boxesback to EQ. Is this the proper hookup?  |
|
|
|
Dave Grafe
From:
Hudson River Valley NY
|
Posted 7 Aug 2011 10:45 am
|
|
You don't necessarily have it wrong, Ray, if your current hookup sounds fine and doesn't make a lot of extra noise from impedance and level mis-matches you may as well stick with it. As detailed here already, guitar stomp-boxes are designed to operate at instrument pickup levels and impedances, while most amplifier effects loops are designed for the higher levels and lower impedances of rack mountable, line-level devices. Every amp manufacturer has a different idea of how to hook things up so results can vary wildly in the real world.
If you are uncertain or curious, try connecting your stompboxes between the VP and the amp. Whichever way sounds better and/or is less noisy, you will know for certain what works best for your particular collection of gear  |
|
|
|
Ray Anderson
From:
Jenkins, Kentucky USA
|
Posted 7 Aug 2011 12:44 pm Pedal placement
|
|
When I hook up my stomp boxes into line with VP to amp input they make humming noises and such, when I go into EQ it stops. I using a N 400 with a Carbon Copy and Holy Grail. I certainly don't want to damage my amp. Thanks a heap. Ray  |
|
|
|
Dave Grafe
From:
Hudson River Valley NY
|
Posted 7 Aug 2011 3:07 pm
|
|
| You won't hurt a thing either way, Ray, and if it sounds better the way you are doing it then you are doing it right |
|
|
|
Dave Hopping
From:
Aurora, Colorado
|
Posted 7 Aug 2011 4:42 pm
|
|
| I've been running gain-based effects (compression/limiting,distortion if I used it) before the pre-amp,and time-based effects(delay/reverb/chorus,etc) in the FX loop.This is with my Peaveys,where I also use the "volume pedal patch". |
|
|
|
Ray Anderson
From:
Jenkins, Kentucky USA
|
Posted 7 Aug 2011 6:31 pm pedal chain
|
|
| Now I,m really confused, where is the VP patch? Using a N400 and don,t know where that is on it. Elaborate further please. |
|
|
|
Kevin Mincke
From:
Farmington, MN (Twin Cities-South Metro) USA
|
|
|
|
