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Advice needed re. peaking levels
Posted: Sat Feb 13, 2010 7:44 pm
by PhilR
So I have just started out on Audacity and have just done my first needledrop. Problem is that the levels seem to be too high and are tripping into the red. The Wiki site suggests manually setting them, but I don't seem to be able to follow their instructions. I'm running it via a macbook pro connected to my Bryston amp with RGB cables.
So here is where I am - you can see where the red bars are 'holding' at the top.

- decals.jpg (146.75 KiB) Viewed 1849 times

- decals3.jpg (19.86 KiB) Viewed 1849 times
So you can see that is tripping into the red. The waveform itself looks fine, but at certain points it is clipping.
Here are the settings on my Mac -

- Mac pref.jpg (60.64 KiB) Viewed 1848 times
Any thoughts advice on how I can do things better?
Re: Advice needed re. peaking levels
Posted: Sat Feb 13, 2010 8:45 pm
by billw58
Select View > Show Clipping to make sure that the clip indicators on the meters weren't triggered by the needle drop.
Are you using the "Tape" outputs on the Bryston? Does the Bryston have a pre-amp output? If you can, try connecting to the pre-amp outputs which will allow you to adjust the levels before they get into your MacBook.
-- Bill
Re: Advice needed re. peaking levels
Posted: Sun Feb 14, 2010 12:00 am
by kozikowski
<<<with RGB cables. >>>
Another red flag.
With.... what? In general you can't use component video cables to do this. You need one of these...
http://www.belkin.com/IWCatProductPage. ... t_Id=23690
...or shorter. It's pretty hard to overload a Mac Stereo Line-In, so something is very wrong. It does get a lot worse if you turn the Mac controls up, right? If it doesn't change, then we got a whole different problem.
Koz
Re: Advice needed re. peaking levels
Posted: Sun Feb 14, 2010 12:56 pm
by PhilR
Sorry, not RGB, but I have a replica of the cables you posted.
When you say 'turn the mac controls' up, what do you mean?
Re: Advice needed re. peaking levels
Posted: Sun Feb 14, 2010 1:23 pm
by kozikowski
In your bottom illustration, you posted the Mac Hardware > Input panel with the volume control all the way down. Those blue dots under the panel are a wide-range volume meter. Where do the dots bounce when you play the music (the last one to the right is overload) and can you make it worse with the volume control?
Leave Audacity closed.
Koz
Re: Advice needed re. peaking levels
Posted: Mon Feb 15, 2010 1:12 pm
by waxcylinder
Re: Advice needed re. peaking levels
Posted: Sat Feb 20, 2010 8:37 am
by PhilR
kozikowski wrote:In your bottom illustration, you posted the Mac Hardware > Input panel with the volume control all the way down. Those blue dots under the panel are a wide-range volume meter. Where do the dots bounce when you play the music (the last one to the right is overload) and can you make it worse with the volume control?
Leave Audacity closed.
Koz
Thanks for the help Koz.
The blue dots under the panel bounce about 3 or 4 from the right hand side, and that is with the input volume set to zero. If I move the volume up even a little, then it goes immediately hard right.
Same on Audacity - if I move the input volume up from zero at all it instantly starts clipping.
Is there something I can do to prevent this - I'm presuming everything else is set up OK. The recordings I do sound fine, but I can see the clipping on there and it bugs me (and there MUST be something I am doing wrong here).
Re: Advice needed re. peaking levels
Posted: Sat Feb 20, 2010 3:13 pm
by billw58
How are you connecting from the Bryston to the MacBook? Tape out or pre-amp out?
-- Bill
Re: Advice needed re. peaking levels
Posted: Sat Feb 20, 2010 3:17 pm
by PhilR
billw58 wrote:How are you connecting from the Bryston to the MacBook? Tape out or pre-amp out?
-- Bill
On the back of the Bryston I am going from the sockets marked 'Tape Loop - To' (the other option is 'Tape Loop - From' which doesn't generate anything into the Mac).
Re: Advice needed re. peaking levels
Posted: Sat Feb 20, 2010 3:31 pm
by billw58
We've determined that the problem is that the Bryston tape outs are sending a very strong signal to your MacBook. So there's nothing that Audacity itself can do about it. Do you have pre-amp outs available on the Bryston? Perhaps a set of "pre-amp out" and "pre-amp in" jacks? If so, you could connect to the MacBook using the pre-amp out jacks, and control the volume into the MacBook using the volume control on the Bryston. Do you have a cassette deck? What kind of recording levels do you see on the cassette deck if you connect it to the tape outs on the Bryston?
-- Bill