Audacity Forum

I'm using Audicity 1.2.6 to record a signal (phono/LP) from my stereo. I connect the receiver to the computer using this ADC/DAC Box (http://www.adstech.com/products/RDX-150 ... _Guide.pdf), so my computer connection is via a USB 2.0 port - there is no sound card involved.

My problem is that when I record the signal is clipping and I can't figure out how to reduce the input levels. The gain control on the track has no effect - which seems really weird to me. I've tried adjusting the gain during the recording and prior to starting the recording, but it doesn't matter - no effect. And there is no way to control the output level from the receiver (the receiver volume control doesn't help, obviously). There also does not appear to be a way to adjust anything in the properties of the driver for the ADC/DAC box.

Does anyone have any suggestions for getting control of the recording input levels?

Bill

The gain control on the Track Panel only affects playback and export, not recording. Are you saying the input volume control on the Audacity Mixer Toolbar has no effect? If not, you could connect from the headphones-out of the receiver to your USB gizmo then the receiver volume control will affect the output. Or if your computer has a line-in, do without the gizmo and connect from either line-out or headphones-out of the receiver to the computer line-in. Line-out may give better quality.

USB devices are less prone to internal noise than sound devices built into the computer motherboard, but they do not necessarily have better analogue > digital converters. If you have a computer line-in I recommend you experiment and test recording from both the gizmo and the computer sound device. USB devices can also be prone to signal transport issues due to USB bandwidth limitations (even on USB 2.0).

Gale

Thanks for the info about the gain, Gale. The input volume control does have an effect - sometimes - but here is the effect that I see when it does: The recording level does retreat from the boundaries of the waveform display, but there are still parts of the signal that seem to hit a ceiling and flatten out (where the recording had peaked and clipped before); and the recording input level meter still peaks-out, exactly where those flat areas hit.

When it does not have an effect, the result can be seen in this image: http://picasaweb.google.com/Threazy/Tem ... 9349456626 The input volume control is all the way down, yet the signal is still maxing out/clipping. At times when I'm playing with controls, the input volume control will snap back to the max position, leading me to think that Audacity doesn't really pick up on my manipulations.

Does this make any sense to you?

I will try your other suggestion - run the line-out from the tape output to the input jack on the sound card on the computer (with an RCA-to-minijack cord) - and see what happens.

Bill

Gale: Okay - I swapped out the gizmo and connected the Tape Out RCA jacks directly to the Line-in mini-jack port. I can now control the input volume level with the slider and eliminate the peaks/clips, but I have to have the volume control at 0.1 - anything higher maxes it out. There must be something wrong with the USB Audio Codec/driver that the gizmo was using.

So I guess I'm good to go - except that I don't particularly having so little leeway having to set the volume control at 0.1 in order to keep the singal from clipping.

Bill

Billman wrote:connected the Tape Out RCA jacks directly to the Line-in mini-jack port. I can now control the input volume level with the slider and eliminate the peaks/clips, but I have to have the volume control at 0.1 - anything higher maxes it out.

Are you sure that it is a "Line In" socket and not a "Mic In" socket? Most PC laptops only have "Mic" inputs. Microphone inputs are much more sensitive than line inputs, so that would explain having to keep the record level so low.

Have you tried the "Spin It Again" software that is included with your product? According to the manual it is able to control the record level from the ADS gizmo.

"c) The sensitivity for the program’s automatic
track detection is also set on the “Recording”
page. See the program help for further details.
d) You can optionally run the level wizard which will aid you in correctly adjusting the amount of gain
the software imposes on the incoming audio. Note that this is software control only when used
with a USB Audio device, thus if your source is either too loud or too soft for the device itself,
volume will have to be adjusted at the source or through an amp/mixer."

Looking further, It would appear to be a limitation of the USB device that it does not allow recording software to adjust the input volume?
http://www.adstech.com/support/Faq/FaqA ... ?faqId=630

Assuming Audacity is setting the input volume correctly (check the input level in the Windows Control panel actually is low) then you are apparently stuck either with a preset high level on the tape output of the receiver, or possibly a limitation in the inbuilt sound device or its drivers.

If you don't have a gentler line output, then I can only suggest using the headphones-out as described so you can control the output level directly. Maybe worth experimenting - you may find adjusting the output volume and turning up the Audacity input level a little sounds a bit less "close".


Gale

stevethefiddle wrote:Have you tried the "Spin It Again" software that is included with your product? According to the manual it is able to control the record level from the ADS gizmo.

I did half notice that before but the confusingly written FAQ made me wonder (at least if Audacity could not control the input level). If you prefer Audacity to "Spin it Again", you could try Audacity Beta. It has a different I/O library and there is a chance it might control the USB input level better.

Gale

There's another possible solution to the overly high signal problem discussed here: http://audacityteam.org/forum/viewtopic.php?f=15&t=5080