Thermionic Culture Vulture noise

[J_Naylor4]

Hi All! Sorry if I'm driving down newbie street with this, but I am very much a newbie to the recording side of things, coming from being a musician first!

Long story short: I've borrowed a Thermionic Culture Vulture (2x unbalanced out) from a friend and have hooked it up to my RME UC interface (2x balanced in). Seems ok, other than this constant interference in the background. Here is a sample of it below, which I've boosted very slightly so it's more audible:

http://vocaroo.com/i/s09SUOxt9sAD

I know there's loads on the internet about balanced/ unbalanced, ground hums, valves, connecting analogue hardware to computers, but I'm slightly overwhelmed by all the information and hoped someone here could point me in the best direction to clean things up!

Cheers,
J

[Billum]

It sounds to me like the sort of noise generated by computers & monitors, being picked up by the unbalanced cables.

Does the noise go away if you switch off your computer monitor? Can you move the RME interface further from the computer so that less noise is picked up on the unbalanced cables? Are you using the higher level outputs from the Vulture so that the picked-up noise is relatively low compared to the signal? You could also try a DI box connected close to the vulture (ie. on a short cable) so that the longer run of cabling is balanced.

Strange that on a high-end bit of kit like that the only outputs are unbalanced

[Hugh Robjohns]

Strange that on a high-end bit of kit like that the only outputs are unbalanced

There is nothing fundamentally wrong with unbalanced line level connections, but it does require a properly sorted technical grounding scheme to work effectively.

Vic, who designs the Thermionic gear, believes that unbalanced outputs sound better than balanced outputs, and there's no arguing that it is a less expensive option!

In suspect the issue here will be ground-loop related rather than direct electrostatic/electromagnetic interference.

I'd make sure that the Therminic box is plugged into the adjacent mains outlet to the interface, to minimise any ground loop possibility. If that doesn't cure the problem, then I'd use a pseudo-balanced cable to connect the Thermionic's outputs to the balanced interface inputs.

You can buy high-quality custom pseudo-balanced cables (with TRS or XLRs at the balanced end) from the SOS shop, or you can make your own if you have soldering skills.

H

[J_Naylor4]

Brilliant, thanks very much for the replies. I'll try the suggestions and let you know how I get on. Cheers!

Interesting to hear that Thermionic Culture think unbalanced sounds better. Though that then raises the question why they put balanced outputs on the 'Mastering Plus' version of the Culture Vulture...

[Hugh Robjohns]

Interesting to hear that Thermionic Culture think unbalanced sounds better. Though that then raises the question why they put balanced outputs on the 'Mastering Plus' version of the Culture Vulture...

I didn't say it made any sense, just reporting their reasoning as explained to me when I queried it!

H