Noisy Effect Loop Orange Dark Terror

spev11

As pleased as I am with Dark Terror mine has quite a noise effects loop, I've got two pedals in the loop, a Behringer DR600 reverb and an Ibanez analogue delay. Off they seem quite as soon as one is on (either one) its gets a low level white noise. I've tried the amp clean so the gain isn't causing it. Changed the send/return cables and tried one or other of the pedals only. I haven't tried anything else yet as I need to have a little read up and ask here etc.
 Can I jumper the loop to see if it still does the noise or will that cause problems of its own? ( i'd imagine its fine as thats what the loop is with pedals off isnt it? )
Possibly the valve ? Its a ECC81 buffered loop , at 22 quid for a JJ , whilst not that expensive I thought i'd check first.

nero1701

Tried the pedals I'm the front to see if the noise is there? 

ICBM

If it’s only noisy when the pedals are on, the noise is coming from the pedals, not the amp. From the schematic, the loop is after the master volume, so at low volume levels the signal-to-noise ratio in the loop will be poor. In fact the whole loop circuit looks quite oddly designed and as if it will maximise noise…

Jumpering the loop with a cable won’t do anything, since the loop is switched directly via the jacks anyway.

spev11

I'll give it a try in front tomorrow, I've not had much time to swap stuff about today as I've been dicking about repairing the car. 
I don't recall either pedal being noisy when I ran into the quilter but then I only ran them into the front.

spev11

Ta both, I just did a quick swap of the pedals about (still in the loop) ran each pedal on its own in the loop and its the DR600 reverb by the looks of it. The delay is silent. Still can't remember the Behringer being noisy through the quilter but something in the Orange may be accentuating it possibly?
 An excuse to search for a reverb then (as if I needed an excuse)

steamabacus

spev11 said:

its the DR600 reverb by the looks of it.

I remember a couple of those Behringer plastic pedals I had once (a bass limiter and a graphic eq) being noisy in a similar way, a low level hiss whenever switched on.

Alex2678

spev11 said:

Ta both, I just did a quick swap of the pedals about (still in the loop) ran each pedal on its own in the loop and its the DR600 reverb by the looks of it. The delay is silent. Still can't remember the Behringer being noisy through the quilter but something in the Orange may be accentuating it possibly?
 An excuse to search for a reverb then (as if I needed an excuse)

Like ICBM says if the loop comes back in after the master volume then the hiss from the pedal is going into the power amp wide open whereas the guitar signal is going through all the controls. If it went into the front of the quilter the noise would’ve been attenuated by any volume and EQ controls along with the guitar signal

ICBM

It really baffles me how amp designers by and large don’t seem to be able to get FX loops right. It isn’t rocket science…

Having the loop after the final master volume causes three problems - it’s difficult to get the signal level right without causing potential clipping issues with low-headroom FX because it’s dependent on the master volume setting; at low settings the signal is weak compared to any noise from the FX; and you have no volume control on the amp if you’re using the FX return as a power amp input.

A quick fix for this would be to put a passive volume box in the loop after the pedals, turn the master volume up, and control the volume with the volume box.

InactiveX

ICBM said:

Having the loop after the final master volume <SNIP>

What...?

I've never owned an amp with send/return, and I'm really suprised to hear this. Is it very common ICBM? I can't see why it would be done like this instead of having the loop before the master volume.

ICBM

InactiveX said:

I've never owned an amp with send/return, and I'm really suprised to hear this. Is it very common ICBM? I can't see why it would be done like this instead of having the loop before the master volume.

Yes, very common or even the normal way. Part of the problem is that many 2-channel amps don’t actually have an overall master volume at all. (Which is then an issue when you have to turn up or down, and have to re-match the channels.) Some seem to be OK - the Fender Hotrod for example - but this one looks from the schematic like the level is intentionally reduced too far, then reamplified too much.

spev11

So this is what ive tried so far
Ibanez in front on its own - fine
behringer in front on its own - fine
ibanez in loop on its own - noisy
behringer in loop on its own - noisy
 i tried minimal gain and max volume on both the 15 and 7 watt settings and its humming like my grandad in church on a sunday
to conclude , the loop is a noisy bugger. I like the loop though so has anybody else got a Dark Terror that does or doesnt do the same? Or is there a simple fix for this? Other than not running the pedals in the loop (seems a shame)

Alex2678

ICBMs suggestion of a volume box after the pedals should help

spev11

Right oh, i'll knock one up tomorrow and wack it in and see how it goes

noisepolluter

OP, did you manage to resolve this? I recently got a Rocker 15 Terror which I’m absolutely loving, and I could also be tempted by a Dark Terror at some point if I knew it had exactly the same fx loop design, as I know the R15T one works perfectly for me. 

spev11

I did yeah, it was the 17ay7 valve, bit of a pain removing the cage but easy enough

noisepolluter

spev11 said:

I did yeah, it was the 17ay7 valve, bit of a pain removing the cage but easy enough

Nice one, so the loop noise has gone?

spev11

it has ( and I sold the amp so its gone even further)