So, ground loops again...

[Drew Stephenson]

Greetings ye technical geniuses.*

I'm planning on dabbling in a bit of live streaming and my set up involves my guitar going to my pedal board, where it splits into two channels, which then go to two separate amps.
Both these amps and the pedal board plug into the same 4 way extender.
I thought I was going to be ok because one amp is traditionally earthed and the other is powered via a line lump - but it turns out this line lump is also earthed.
Which obviously then creates a ground loop.

To double check this is what's causing the problem I added an ART Studio V3 Tube pre-amp into the circuit on one side, powering an Orchid DI box.
This breaks the ground loop as you'd expect, but unfortunately my V3 is getting quite long in the tooth and is not in a very good state. It adds a lot of noise and throws in a few other issues that seem to cause my volume pedals to act as inverted switches for the other channel.

So I need to break the ground loop (which is all unbalanced TS signals) and I'm thinking an ART DTI is probably the simplest and cleanest way of doing it?
Am I missing any simpler, easier or cheaper?

* Geniei? Geniea?

[Hugh Robjohns]

The DTI is what I'd be reaching for...

[Drew Stephenson]

I guess I shall have to reach for my wallet...
It was inevitable I'd need one at some point I guess!

[Wonks]

Though if the amp PSU is one you could get a replacement class 2 PSU for, for a lot less than the ART DTI box, then that would also work.

You’d still need the normal PSU any time the amp was used on its own.

And if a replacement PSU would cost more than say 70% of the ART, then I’d go for the ART as is a very useful bit of kit.

[Drew Stephenson]

Hmm. That's a good suggestion. I shall check the specs and see what's available.

[Hugh Robjohns]

... I’d go for the ART as is a very useful bit of kit.

It is. I have five...

[Drew Stephenson]

... I’d go for the ART as is a very useful bit of kit.

It is. I have five...

Ha! Do we need to stage an intervention?

[Hugh Robjohns]

I kept lending them out, and then needed one so bought another. Eventually they all came back...

[Wonks]

I kept lending them out, and then needed one so bought another. Eventually they all came back...

So all your friends have gone and left you. Do you feel isolated?

[Hugh Robjohns]

Yeah, no friends... just being used...

[Drew Stephenson]

DTI inserted into circuit.
Loop broken.
Annoying scratchy whine gone.
...

[tacitus]

I have two, and I generally only lend stuff big enough to be in the loanee’s way. Working so far …

[ajay_m]

I will say those extremely cheap stereo isolating transformers sold on Amazon and elsewhere (they have a 3.5mm stereo jack at each end and are housed in a small, square case) work far better than I expected. They only cost a few quid and although clearly below around 70Hz you're starting to see some harmonic distortion, this isn't necessarily a concern in many applications. Well worth picking up a couple and trying them out when you have ground loops, if nothing else, they'll show whether or not a much more expensive solution is worth bothering with.

[Hugh Robjohns]

My usual approach is to plumb in a DTI box temporarily to see if that cures the suspected ground-loop problem. It's quick and easy to use because of the plethora of connector variants, both balanced and unbalanced.

If it solves the problem then I usually either modify the cable or make a replacement to break the screen connection (with suitable identifying markings).

That releases the (expensive) DTI box for use/testing elsewhere, and removes the potential source of distortion from the signal path, too.

[Drew Stephenson]

I do have a suitable (I think) box and a couple of jack sockets kicking around so I did wonder about just making my own but my attempts to google a suitable transformer were fruitless (not knowing the right questions to ask primarily I think).
But in the meantime the DTI can sit in the loop.

I'm just disappointed that no-one picked up on the obvious punchline...

[Kwackman]

I'm just disappointed that no-one picked up on the obvious punchline...

We were being polite...

[Drew Stephenson]

I'm just disappointed that no-one picked up on the obvious punchline...

We were being polite...

I felt sure that Wonks would take advantage of a set-up like that.

[Wonks]

I've been busy.

But can we now take it that Drew has given up music completely?

These DTI boxes are very useful indeed!

[Drew Stephenson]

I knew you wouldn't let me down!

[Drew Stephenson]

I do have a suitable (I think) box and a couple of jack sockets kicking around so I did wonder about just making my own but my attempts to google a suitable transformer were fruitless (not knowing the right questions to ask primarily I think).

Following on from this, if I did want to free up the DTI and make my own little box, would anyone be able to confirm if this is the kind of transformer I need: https://www.designacable.com/neutrik-nt ... ydi2rcjoI4

Gracias

[S2]

I guess I shall have to reach for my wallet...
It was inevitable I'd need one at some point I guess!

A wallet you mean?

[Drew Stephenson]

Well people tend to object if you reach for wallets that aren't yours...

[James Perrett]

Following on from this, if I did want to free up the DTI and make my own little box, would anyone be able to confirm if this is the kind of transformer I need: https://www.designacable.com/neutrik-nt ... ydi2rcjoI4

While the Neutrik one looks like it will work, I must admit that I'd be tempted to go for this

https://cpc.farnell.com/oep-oxford-elec ... dp/TF01460

mainly because it is much cheaper and they give you a much more thorough spec on the datasheet.

If you can't wait for CPC to get more stock then Farnell currently have over 2,000 of them in stock.

[Martin Walker]

While the Neutrik one looks like it will work, I must admit that I'd be tempted to go for this

https://cpc.farnell.com/oep-oxford-elec ... dp/TF01460

mainly because it is much cheaper and they give you a much more thorough spec on the datasheet.

Yes, I was surprised when I downloaded the Neutrik NT1 data sheet, only to discover that it contained no audio technical data at all

[Drew Stephenson]

Thanks James.

If you can't wait for CPC to get more stock then Farnell currently have over 2,000 of them in stock.

I thought CPC and Farnell were the same people? [EDIT - scratch that, I've found the other site. Weird set-up they have going on there.]

Also, what does pin 5 do?