SOUND ON SOUND

[BobTheDog]

Hi Guys,

I posted this on the Line6 forum but have not had a reply so I thought I would ask here:

I want to integrate my Orange TH30 Combo with my Helix for recording. I am thinking of doing this via a torpedo captor as a load box.

Here's what I have come up with, does it make sense?

helix fx send 1 -> amp input

amp fx send to helix fx return 1

helix fx send 2 -> amp fx return

amp speaker output -> captor amp in

captor line out -> helix fx return 2


so then I can mix and match helix pre amp with TH30 power amp and TH30 pre amp with helix power amp.

Does this sound about right?

Thanks

Andy

[BigRedX]

That will get you everything except the speaker breakup of the combo speakers.

The only thing I'd be wary off is the amount of latency generated by 3 stages of AD DA conversion.

[BobTheDog]

Hi,

Thanks very much for the reply, most appreciated.

Good to know I am not going to blow anything up!

I just had a look for the A/D->D/A figured for the FX loops on the Helix and they seem to be 1.8ms combined, so engaging both would add 3.6ms.

I guess there is also anther 1.8ms for the A/D from guitar and D/A to audio outs.

So 5.4ms in total.

It seems it cleverly adjusts the timing of other audio signal if you are using parallel loops as well, very neat.

[BobTheDog]

Actually I have one more question:

Im guessing the Amp in and AMP FX loop are at instrument level, while the Captor out is at Line level.

The Helix fx loops can be switched between Instrument and Line levels.

So I think I may need 3 FX loops?

1. Instrument level
helix fx send 1 -> amp input
amp fx send to helix fx return 1

2. Instrument level
helix fx send 2 -> amp fx return

3. Line level
captor line out -> helix fx return 3

Does that make sense, or could I get away with using instrument level on the helix input from the Captor and turning down the return gain?

[BigRedX]

That latency finger sounds OK so long as you don't have any other digital devices in your signal chain.

As for the level matching, you'll just have to try it. It will depend if the output from the Captor is overloading any circuitry before the input level control.

[BobTheDog]

Thanks for the reply.

It definitely seemed to need the Line level return.

Something is still iffy with the Helix though, it just sounds bad with the Captor.

Just a simple test with send to amp in and return from the Captor sounds bad, noise and hum, loss of high end and a general sort of compressed sound. Not good at all.


Testing with guitar into amp and the Captor into Apollo interface sounds amazing, no noise and no hum, sounds really good.

So I need to spend some time tracking down where the issue is with the Helix...

[Wonks]

Cab models still on?

[BobTheDog]

Cab models on and off when testing.

I just tested Guitar directly into Amp and Captor return into Helix.

Sounds absolutely perfect, no hum, no noise, no loss of high frequencies.

So It seems it is something to do with Helix send to the amp.

[BobTheDog]

Some more tests with guitar->helix->send to amp->return from captor.

Turn off send block, hum and noise still there

Disconnect guitar from back of Helix, hum and noise still there.

Removed USB cable, hum and noise still there.

Use different sends, hum and noise still there.

Ground lift on on both Captor and Helix, hum and noise still there.

So it looks like it is coming from the helix.

[Wonks]

The spikes are at 50, 100, 150 etc so look to be mains noise. The rest is down at very low levels (though there's no audio signal level to compare it to).

[BobTheDog]

Here is the same plot with guitar into amp return to helix.

Both are set so there was a -6db reading when strumming a chord hard.

[BobTheDog]

I will do a plot tomorrow where the helix is totally removed, I am guessing it will be pretty near the second one though.

[blinddrew]

Any chance of a couple of sound files? Looks like it might be ground-loop related?

[BigRedX]

I'd be looking at ground loops and phase.

Are you sure that your effects loops are 100% in series and none of the direct signal is mixed in?

[BobTheDog]

Thanks for the interest guys.

Yep definitely in series.

Everything is powered from same master socket via a ups and then a furman power distributer.

I’ll do some more testing tomorrow and post the results...

[BigRedX]

Are you in the UK? If so I'd try it without the Furman as they are designed for places with more "interesting" mains supplies and can cause problems with the better regulated ones.

[BobTheDog]

Hi Guys,

Sorry for the delay, first chance to try things today.

Guitar into amp and captor into audio interface is about the same as guitar into amp and return to helix, a bit less noise.

So the Send is adding in most of the hum and a lot of high frequency noise.

I just tried an Ebtech Hum Eliminator in the send from the helix to the amp and it gets much better, basically knocks out the > 100hz hum and reduces 50hz by 6db and 100hz by 9db and also around 9db reduction in high frequency noise.

I will try it without the Furman, might be a bit difficult to get everything off of it so I will test with headphones with just the Helix and the Amp...

[BobTheDog]

Just tried without the Furman, still the same issue.

I have found out the Helix has about the noisiest headphone out ever though!

So I guess the Ebtech is the way to go, I will wire up both sends through it to see if it works ok...

[BobTheDog]

Ok, wired it all up with the multiple send returns and guess what.

The Amp send introduces hum into the Helix.

One dual Hum Eliminator is not enough.

I may rethink this!

[blinddrew]

Might help to draw it all out and see if there's a loop being formed somewhere non-obvious that you could break with a transformer isolator.