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GMC Forum _ GEAR & PRODUCTION _ Effects Loop Randall Amp

Posted by: Hammerhead Feb 1 2010, 05:01 PM

Aloha everyone,

I'm trying to figure out why my Tonelab doesn't seem to work through my effects loop on my Randall RG80. I have to turn up my amp volume almost half way just to hear it blink.gif All my output levels are set correctly, so when I run straight into the amp all is fine. I've read on the net "the effects loop signal level and impedance was designed for stomp boxes, not multi-effects units." regarding someone else and there issues around an effects loop not on a randall amp... but it got me thinking... Is it possible that the older amps (mine is over 20 years old... A classic almost) cannot handle the modern day multi-effects processors?

Here is the link to the discussion that i was reading if you are interested in where my quote came from. http://www.thegearpage.net/board/showthread.php?t=352321

I know the issue is not the same as mine, but it could explain why I still get a signal just not enough of one. Also I don't get any real distortion for my pedal board, with the distortion turned all the way up, and the volume on the amp up pretty high, it is quiet and clean wacko.gif

Any insight would be great... Thanks!

 

Posted by: Sollesnes Feb 1 2010, 05:59 PM

Sounds strange. Just to be sure, do you want to only use the Randall poweramp, or do you want to bypass the Vox preamp? smile.gif

Have you checked the return-level on the back of your amp? If it's set low, it could explain your problem.

Posted by: Adrian Figallo Feb 2 2010, 04:17 AM

if the tonelab is with the gain up the return shouldn't be a problem and you would hear just a very low volume sound, but distorted.
i think something is wrong with ur effects loop, it should work, never tried that amp tho.

hope you can get it fix somehow!

WAIT, i asume you are plugin your guitar on the tonelab right? they correct signal would be (if you wanna use the tonelab a pre amp too) guitar, tonelab input, and from the tonelab output directly into the effect loop return maxed. Then you can control the signal volume on the tonelab.

That would be the right thing to do, if you are connecting the guitar to the amp, and then the tonelab on the loop you will get two pre amps in a row, that can work if you use the tonelab just as modulation effects or reverb/delay effects.

Posted by: Hammerhead Feb 2 2010, 05:58 AM

QUOTE (Sollesnes @ Feb 1 2010, 06:59 AM) *
Sounds strange. Just to be sure, do you want to only use the Randall poweramp, or do you want to bypass the Vox preamp? smile.gif

Have you checked the return-level on the back of your amp? If it's set low, it could explain your problem.


Thanks for the response... this is strange! I do not have any return-level that I know of. I thought of the same thing. The back of the amp only has the 2 speaker jacks, the two effects loop jacks, a signal output jack, and a couple of jacks for re-ver and channels, and an extra power supply outlet. It is almost as though the power of the signal is lost on the effects loop dry.gif . I just don't know why there is uch a loss in signal. I've even swapped cables ph34r.gif

I'm assuming that by using that the effects loop, I will put my pedals between the Randall pre-amp, and the Randall power amp. The Vox preamp will give me all of the distortion and power the effects, so I want that too, right? But the pre-amp of the Randall seems to be the fault here? Because I can't seem to get a strong signal in the middle of the chain (effects loop) where I need it. But I really don't know what I'm doing, the problem is it's $150 USD just for someone to look under the hood...

Posted by: Hammerhead Feb 2 2010, 06:33 AM

QUOTE (Adrian Figallo @ Feb 1 2010, 05:17 PM) *
if the tonelab is with the gain up the return shouldn't be a problem and you would hear just a very low volume sound, but distorted.
i think something is wrong with ur effects loop, it should work, never tried that amp tho.

hope you can get it fix somehow!

WAIT, i asume you are plugin your guitar on the tonelab right? they correct signal would be (if you wanna use the tonelab a pre amp too) guitar, tonelab input, and from the tonelab output directly into the effect loop return maxed. Then you can control the signal volume on the tonelab.

That would be the right thing to do, if you are connecting the guitar to the amp, and then the tonelab on the loop you will get two pre amps in a row, that can work if you use the tonelab just as modulation effects or reverb/delay effects.


Thanks Adrian,
I haven't tried this yet. guitar, tonelab input, and from the tonelab output directly into the effect loop returnMy understanding is that all effects are plugged from, the send effects (out), into input of pedal, output of pedal, into effects return. This way the signal is picked up after the (Randall) pre amp, and before the (randall) power amp. This way the signal is cleaner and doesn't muddy up. So in this case I've run the effects send into the Tonelab guitar input, Tonelab output into effects return.Now the Tonelab sits in between the pre and power amps of my head... huh.gif If I runthe guitar into the Tonelab, out to effects return,... maybe that could ... could work, I would by pass the Randall pre-amp.... huh.gif I'll have to give that a try,,, just as soon as I can and I'll post the results. cool.gif

Posted by: Hammerhead Feb 2 2010, 07:15 AM

QUOTE (Hammerhead @ Feb 1 2010, 07:33 PM) *
Thanks Adrian,
I haven't tried this yet. guitar, tonelab input, and from the tonelab output directly into the effect loop returnMy understanding is that all effects are plugged from, the send effects (out), into input of pedal, output of pedal, into effects return. This way the signal is picked up after the (Randall) pre amp, and before the (randall) power amp. This way the signal is cleaner and doesn't muddy up. So in this case I've run the effects send into the Tonelab guitar input, Tonelab output into effects return.Now the Tonelab sits in between the pre and power amps of my head... huh.gif If I runthe guitar into the Tonelab, out to effects return,... maybe that could ... could work, I would by pass the Randall pre-amp.... huh.gif I'll have to give that a try,,, just as soon as I can and I'll post the results. cool.gif


OK I tried it and the Volume knob on the amp does not work... There is plenty of volume from the Tonelab ( Tiny little knob on the back of the unit)... ohmy.gif but it bypasses the controls of the amp unsure.gif

Posted by: Sollesnes Feb 2 2010, 01:07 PM

Hm.
Do you want to use the Randall preamp, or the Vox preamp? If you want to use the Randall preamp with the Vox effects, you have to use the 4 cable method. If you want to use the Vox preamp, and only the Randall poweramp, you plug your guitar into your Vox, Vox into effects return. That way you will only be using the Randall poweramp. The only knob on the Randall that will work is the master volume, because that is on the poweramp. smile.gif

Posted by: jstcrsn Feb 2 2010, 02:18 PM

[quote name='Hammerhead' date='Feb 1 2010, 05:01 PM' post='460407']
Aloha everyone,

I'm trying to figure out why my Tonelab doesn't seem to work through my effects loop on my Randall RG80. I have to turn up my amp volume almost half way just to hear it blink.gif All my output levels are set correctly, so when I run straight into the amp all is fine. I've read on the net "the effects loop signal level and impedance was designed for stomp boxes, not multi-effects units." regarding someone else and there issues around an effects loop not on a randall amp... but it got me thinking... Is it possible that the older amps (mine is over 20 years old... A classic almost) cannot handle the modern day multi-effects processors?

Here is the link to the discussion that i was reading if you are interested in where my quote came from. http://www.thegearpage.net/board/showthread.php?t=352321

just a thought , have you tried a simple peddle to see if that works?

Posted by: Adrian Figallo Feb 2 2010, 02:30 PM

QUOTE (Hammerhead @ Feb 2 2010, 01:15 AM) *
OK I tried it and the Volume knob on the amp does not work... There is plenty of volume from the Tonelab ( Tiny little knob on the back of the unit)... ohmy.gif but it bypasses the controls of the amp unsure.gif


Try the master volume on the amp, that should do it wink.gif

Posted by: MickeM Feb 2 2010, 04:02 PM

If you get almost no sound when you have it plugged into the fx loop all I can think of is that the output from the Tonelab is too low. There's usually an ouput level control knob, like someone said before probably at the back of the unit.
Also check wether the fx loop is switchable between parallell and serial. Tha'll give different sound results. There could also be a dB switch for the fx loop itself to alter it 0 to -10dB or similar to cut/boost the fx signal.

Posted by: Hammerhead Feb 3 2010, 05:08 AM



just a thought , have you tried a simple peddle to see if that works?

[/quote]
Thanks all for the responses from everyone, I am very busy and I am working on this as a check list, one item at a time... wink.gif
I have not tried one pedal yet! But I will have to... I have to dig out an old one or borrow wink.gif But this would give me the answer I'm looking for! biggrin.gif

QUOTE (Sollesnes @ Feb 2 2010, 02:07 AM) *
Hm.
Do you want to use the Randall preamp, or the Vox preamp? If you want to use the Randall preamp with the Vox effects, you have to use the 4 cable method. If you want to use the Vox preamp, and only the Randall poweramp, you plug your guitar into your Vox, Vox into effects return. That way you will only be using the Randall poweramp. The only knob on the Randall that will work is the master volume, because that is on the poweramp. smile.gif


Thanks for the help...
This may sound crazy but the master volume does not work if I run the guitar into the Vox and out to the effects return... huh.gif I can adjust the volume through the Vox... but not through the Randall master volume. blink.gif


QUOTE (MickeM @ Feb 2 2010, 05:02 AM) *
If you get almost no sound when you have it plugged into the fx loop all I can think of is that the output from the Tonelab is too low. There's usually an ouput level control knob, like someone said before probably at the back of the unit.
Also check wether the fx loop is switchable between parallell and serial. Tha'll give different sound results. There could also be a dB switch for the fx loop itself to alter it 0 to -10dB or similar to cut/boost the fx signal.


Thanks for the suggestions...
I will have to dig to see if this is parallel or series wacko.gif I'm afraid I don't have a clue...I am including a picture (not my actual amp) of the back of the Randall 80 es amp. There are no output adjustments on the back... huh.gif for the output level on the loop. It's possible that the jacks are bad? That could be the next step after trying just one pedal through the loop.


 

Posted by: Ivan Milenkovic Feb 3 2010, 11:45 PM

Cool solid wood construction, looks really vintage smile.gif


Could you please give us clear explanations how you connected the gear, like this:

GUITAR>AMP INPUT

FX LOOP: AMP SEND>TONELAB INPUT>TONELAB OUTPUT>AMP RETURN

is this how you used and got a weak signal? If so check this:


1. is the preset you are using too low?
2. is the guitar volume amplified whole way?
3. are you using correct ins/outs on the tonelab?
4. are the knobs on the amp on appropriate settings?
5. are all the cables good?




Posted by: Hammerhead Feb 4 2010, 03:59 AM

QUOTE (Ivan Milenkovic @ Feb 3 2010, 12:45 PM) *
Cool solid wood construction, looks really vintage smile.gif


Could you please give us clear explanations how you connected the gear, like this:

GUITAR>AMP INPUT

FX LOOP: AMP SEND>TONELAB INPUT>TONELAB OUTPUT>AMP RETURN

is this how you used and got a weak signal? If so check this:


1. is the preset you are using too low?
2. is the guitar volume amplified whole way?
3. are you using correct ins/outs on the tonelab?
4. are the knobs on the amp on appropriate settings?
5. are all the cables good?


Thanks for jumping in Ivan,
Here is how I've set it up...
GUITAR>AMP INPUT.
EFFECTS SEND> INPUT OF VOX TONELAB.
OUTPUT OF VOX TONELAB> EFFECTS RETURN.

That I think, is the correct way to run the cables for an effects loop. Now I have volume, and I can hear the guitar... BUT there is NO distortion from the pedal. Even when I use the Tonelab distortion cranked all the way up... it sounds like a clean channel blink.gif The effects work (delay, reverb...) but there is no real bite to the signal. Rather than distort, it begins to feedback, when I tweak either the vox output level, or the amp volume. I've tried to lower the one (amp/vox pedal) and raise the other but it seems to make no real difference dry.gif

I have swapped the cables but, that doesn't help. I've even tried to run the setup with the "output signal" from the back of the amp into the INPUT OF THE VOX TONELAB, THEN OUTPUT VOX>RETURN EFFECTS. mad.gif the signal was way too strong and it just gave me feedback.


Posted by: Rik Veldhuizen Feb 4 2010, 08:30 AM

i thought you couldn't use distortion and overdrive fx when plugged into an fx loop. In stead, you'd want to put the tonelab in front of the amp input; only effects like delay, reverb etc can work fine in the fx loop.

Btw, haven't got a board like you have (always use my amp distortion), so this is only what I've read about it...


Posted by: Sollesnes Feb 4 2010, 12:47 PM

Oh.
If you want to use Vox distortion:
Guitar -> Vox Input, Vox output -> Amp Effects Look Return

If you want to use the Amp distortion, but the Vox effects (4 cable method):

"Cable 1: Guitar OUT to ToneLab IN
Cable 2: ToneLab SEND to Amp IN
Cable 3: Amp SEND to ToneLab RETURN
Cable 4: ToneLab OUT to Amp RETURN
ToneLab settings: Pedal, Amp/Cab sims OFF, select Line2 output to use EQ."

Hope that sorts it out Because an effects processor is not an effect pedal, things are done differently. smile.gif

Edit: spelling error.

Posted by: Hammerhead Feb 5 2010, 01:23 AM

QUOTE (Sollesnes @ Feb 4 2010, 01:47 AM) *
Oh.
If you want to use Vox distortion:
Guitar -> Vox Input, Vox output -> Amp Effects Look Return

If you want to use the Amp distortion, but the Vox effects (4 cable method):

"Cable 1: Guitar OUT to ToneLab IN
Cable 2: ToneLab SEND to Amp IN
Cable 3: Amp SEND to ToneLab RETURN
Cable 4: ToneLab OUT to Amp RETURN
ToneLab settings: Pedal, Amp/Cab sims OFF, select Line2 output to use EQ."

Hope that sorts it out Because an effects processor is not an effect pedal, things are done differently. smile.gif

Edit: spelling error.


Sollesnes,

Thank you for really helping here. I will try this method as soon as I get home from work wink.gif . I'm glad to hear you say that an effects processor is NOT the same as an effects pedal... and things are done differently. I don't think I ever would have guessed to try this on my own blink.gif I just want to clarify that cable 2 & 3 will connect to the effects loop (send and return) on the Tone Lab as you've explained . This is great... again thank you for really explaining this to me. I will post the results as soon as I'm able to. cool.gif
Also you have marked the pedal,Amp/Cab sims off< and this is fine for me, but just wondering is that because it drives the signal too hard? Is this what Rik is suggesting about running distortion or overdrive on an effects loop? Thanks Rik for the heads up ohmy.gif I had not heard this. It would make sense though with all of what I've seen so far...and yes I just discovered the line 2 EQ. I've a need for some punch in the mid range and this will help.

Thanks again to everyone for helping me figure this out (I hope we've got it!). I've dug on the internet, but I could not find any answers. GMC ROCKS! cool.gif

Posted by: Ivan Milenkovic Feb 5 2010, 01:53 AM

From what you said, it may be possible that the SEND output of your amp feeds very little signal to the Tonelab. This would explain why there is no distortion and punch. On the side note, have you tried to amplify both the preamp and poweramp volume knobs?

Posted by: Sollesnes Feb 5 2010, 01:57 PM

QUOTE (Hammerhead @ Feb 5 2010, 01:23 AM) *
I just want to clarify that cable 2 & 3 will connect to the effects loop (send and return) on the Tone Lab as you've explained .
Also you have marked the pedal,Amp/Cab sims off< and this is fine for me, but just wondering is that because it drives the signal too hard? Is this what Rik is suggesting about running distortion or overdrive on an effects loop?


No problem smile.gif The 4-cable method is from google, because I believe it is done a bit differently depending on what effect processor you have.
yes, cable 2 & 3 will be connected to the effects loop of the TL. The simulations should be off because you don't need them. You will be using the preamp/tone from the amplifier by using the 4 cable method. So you do not need distortion, amp simulation, cab simulations etc from the TL, only the effects. What Rik was saying was that if you are using a distortion pedal, it can only go before the input of the amp, not in the effects loop, which is only for effects.
Let me know if it works smile.gif The 4-cable method is a lot more hassle than just using the distortion of the TL though. tongue.gif

Posted by: jstcrsn Feb 5 2010, 02:04 PM

have you ever just used a simple fx - stomp box
if it doesn't work with that it won't work with anything else

Posted by: Hammerhead Feb 6 2010, 01:13 AM

QUOTE (Sollesnes @ Feb 5 2010, 02:57 AM) *
No problem smile.gif The 4-cable method is from google, because I believe it is done a bit differently depending on what effect processor you have.
yes, cable 2 & 3 will be connected to the effects loop of the TL. The simulations should be off because you don't need them. You will be using the preamp/tone from the amplifier by using the 4 cable method. So you do not need distortion, amp simulation, cab simulations etc from the TL, only the effects. What Rik was saying was that if you are using a distortion pedal, it can only go before the input of the amp, not in the effects loop, which is only for effects.
Let me know if it works smile.gif The 4-cable method is a lot more hassle than just using the distortion of the TL though. tongue.gif


Sollesnes,
Thanks for hanging in here with me wink.gif . I tried the 4 cable method and was unable to use the Randall volume or gain knobs on either channel huh.gif All volume came from the TL. Perhaps I can move a couple of cables around and see if this (TL) processor needs a slightly different order of cables? I'm afraid I'm so busy this week that I race home after work, and don't have but a few minutes each day to figure these things out dry.gif I will also do some digging (google) this weekend. I can dedicate some time to this. The Randall amp gives a nice distortion, so I'm happy to use that, but it's nice to have choices. I will try some options and post this weekend. Thanks again for all the advice! I'm actually learning quite a bit here. Before all of this I had no idea that the effects loop sat between a pre-amp and the power amp mellow.gif of course it makes all the sense in the world... but this helps me to understand all the nuances of how to solve the current problem. WHich is still that I have no amp access, when plugged into the effects loop. I could see having an A/B switch and running through the front of the amp or the effects loop depending on what tone I was chasing. But first I think I have to sort out how to access the effects loop and still have access to the power amp. cool.gif

QUOTE (jstcrsn @ Feb 5 2010, 03:04 AM) *
have you ever just used a simple fx - stomp box
if it doesn't work with that it won't work with anything else


Jstcrsn,

You are very right! I just don't happen to have access to a pedal at the moment dry.gif . I will make a phone call or two this weekend and see if I can't borrow one though. You are right, this is the ultimate test for the effects loop of the amp. wink.gif

QUOTE (Ivan Milenkovic @ Feb 4 2010, 02:53 PM) *
From what you said, it may be possible that the SEND output of your amp feeds very little signal to the Tonelab. This would explain why there is no distortion and punch. On the side note, have you tried to amplify both the preamp and poweramp volume knobs?

Ivan,
when I plug into the effects loop...(at least so far) I loose the volume of the amp, both pre-amp (gain) and power amp (volume) for both channels wacko.gif I can only imagine that I need to try all variations of cables to find the righ way to keep access to the volume controls of the amp. Can I ask, if I run through the effects loop (and eventually it works) will I sacrifice the tone settings on the Amplifier? huh.gif

Posted by: Sollesnes Feb 6 2010, 01:13 AM

Does everything work as supposed to if you just use it like a normal effect processor (using the vox distortion)? smile.gif
You could google "4-cable method", perhaps I wrote something wrong.

Posted by: Hammerhead Feb 7 2010, 06:07 PM

QUOTE (Sollesnes @ Feb 5 2010, 02:13 PM) *
Does everything work as supposed to if you just use it like a normal effect processor (using the vox distortion)? smile.gif
You could google "4-cable method", perhaps I wrote something wrong.


Thanks Sollesnes,
I may be on to something... I'm digging around on goggle, I think what you suggested is the right way wink.gif but it may have to do with the settings within each program. Some squeal and some offer no real amp adjustment huh.gif I've got one setting that sounds halfway decent but has a lot of hissing background noise (is this a ground loop?) so I can't really adjust the volume very loud (just bedroom levels). So I will keep digging and I'll post as I uncover more. cool.gif
Everything works if I just run it through the front of the amp , when I run it through the effects loop... mad.gif I run into problems.

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