Behringer 204HD help

[Majik]

I may have asked this (and had this answered) before: does it still hum if the guitar cable is unplugged from the amp?

If it does, it points to some sort of ground loop or a noisy USB interface (I’ve come across these before, especially on laptops). On a lot of computers, the USB sockets are not well grounded and they pick up, and transmit, digital noise. I have this on my laptop when the power supply is connected (if I disconnect the power supply, it goes away).

There are USB isolators available ranging from about £8 upwards, with varying reviews. In theory, these devices may help in some cases and it may be worth trying one of the cheaper ones to see if they help. I’ve never tried any myself, so I can’t say if they work or not.

Cheers,

Keith

[Stuartw]

@Majik

I may have asked this (and had this answered) before: does it still hum if the guitar cable is unplugged from the amp?

It does. The only time it doesn’t hum if is when the amp is off which obviously is not much use!

@Majik

There are USB isolators available ranging from about £8 upwards,

It’s worth a try.

[Majik]

Something like this might do the trick:

SubZero Hum Destroyer at Gear4music

You’ll need an extra cable.

Again, I’ve not used one, so it’s a bit suck-it-and-see.

Cheers,

Keith

[Stuartw]

@Majik

Something like this might do the trick:

Thanks. Is this positioned before the AI, so Guitar > Boss DS-1 > amp > SubZero>204HD? Can’t quite work this out!

[Majik]

Yes, between the guitar amp output and AI input. Basically to provide isolation between the two.

Cheers,

Keith

[Stuartw]

@Majik So I bought one of the Hum Destroyer but it has not helped, in fact it has made it worse. I now have hum even when the amp is off!!

I’m guessing that something is not right and will be having a word word with Gear4music!

The cable from the amp that went into the AI I put in the ‘input’ on the hum destroyer, with a cable in the ‘output’ to the AI.

[Majik]

Sorry to hear that, and sorry for suggesting it if it doesn’t work.

If you can, send it back and get a refund.

Cheers,

Keith

[Stuartw]

@Majik

Sorry to hear that, and sorry for suggesting it if it doesn’t work.

Not a problem and worth a try, although a bit frustrating, and taken the shine of home recording a bit to be honest.

@Majik

If you can, send it back and get a refund.

I’ve sent them an email about the problem. Let’s see what they say before I send it back.

[Stuartw]

@Stuartw

I’ve sent them an email about the problem. Let’s see what they say before I send it back.

So I’ve sent an email to Gear4music and received this standard response. Bottom line they couldn’t help and have been trying to send the unit back. They have refunded the money but don’t seem that bothered in have the item back!!

Anyway this still leaves me with an AI that hums, which even I can hear and moderate volumes!

I have been doing some testing to find out what may be causing this and have determined:

1. The hum only happens when the amp is on.
2. It’s not the amp power supply as far as I can tell as I have tested with the power coming from a completely different socket.
3. If I remove the cable from the ‘recording out’ socket on the amp the hum disappears. I know that this is obvious but wanted to check! The hum comes back if I touch jack of the cable. I have tested with different cables but makes no difference.
4. The hum disappears if I set the 204 to ‘line’ not ‘inst’ but that means I can’t hear the guitar in my headphones.

At this point I’ve no idea what is causing the issue and don’t know what to test further.

As an aside I have noticed that the 204 clips even with the gain really low. Volume on the amp is about 2.5 and about half way on the guitar.