Self Noise

[grappa]

All,

Not strictly Scope related this but looking for some real world info as I'm driving myself a bit nuts...

My environment is a mix of the new (Scope XITE) and some of my faithful old buddies (PCM80, Reflex, Proteus 1/2, Akai S3000, D550, Drawmer '69) into two A16 Ultra's. I know times have moved on but it's what I know..

I'm on a bug hunt on the moment as my recent move introduced some ground loop issues (arghh) however being critical there's a fair bit of self noise from all of this outboard kit. It's running on balanced where appropriate but I'm still getting circa -80db on the individual inputs, adding up to -60db at the master meter.

Is there anything that can be done about this or do I just need to live with it if I want to continue in this way?

Regards,

Simon

[garyb]

balanced connections don't guarantee a groundloop or background radiation-free signal. the noise level seems high, but it's so hard to say why without being there. the noise level is without anything connected?

[grappa]

That's the noise level with everything connected and the outboard turned on.

Just the Xite and 2 A16's running with everything turned off (but connected) gives me circa -80db at the individual inputs and -70db at the master..

I'm going to strip the whole thing again over the next few days and put it back together piece by piece..

Simon

[grappa]

Actually I've just rechecked this and the noise is predominately coming from the two Lexicons..

Some of the other inputs see slightly more noise when the kit is powered on (change of 3db on one of the Proteus units) however the aux return for the Reflex increases to -61db and the PCM to -73db..

Simon

[garyb]

that's probably normal. the older Lexicons sound great, but they're pretty noisy by modern standards.

[Bud Weiser]

that's probably normal. the older Lexicons sound great, but they're pretty noisy by modern standards.

Well yeah, using the older hardware gear because of sound means living w/ some noise and hum.
Let´s say it´s part of their charme.

Characterful tube guitar amps and stomp boxes are noisy too and pro guitar players prefer and use ´em up today.
Recording enginneers deal w/ that.
Gates, single ended NR and finding the right balance of noisefloor and wanted signal in the mix is the workaround.

Bud

[grappa]

Thanks all..

I did some further exploration late last night and let's say the gain structure accross the Lexicon's wasn't optimal leading to SNR issues.. I've tweaked this now and things are certainly much improved although as you say I'll have to live with some of the vintage 'charm'.

I've done the same with my other key source of unwanted noise (one of the Proteus units) and I'll just have to look to gating where i can and live with the rest!

Thanks again,

Si