Recording volume problem

[JackFerguson]

Setup: Audacity 1.3.9(beta), Cabled from tape deck line-out to computer line-in.
- When record-level slide is set to 0.0 there is no recording (OK)
- Move the slide to 0.1 and I get indications of max recording level (not good)
- Move the slide anywhere above 0.1 and I get too high recording level (not good)

Why doesn't the slide give me a gradual increase and decrease? The Windows line-in volume control is coupled to the Audacity record-slide --- move one, and the other moves (seems OK). The Windows record volume device controls only the line-in (no master level function).

[bat]

turn down the volume on the tape deck...

[kozikowski]

<<<Cabled from tape deck line-out to computer line-in.>>>

I bet not. I bet it's plugged into the computer Mic-In (sometimes pink). The microphone input on a Windows machine is terrifically sensitive and there are no good volume control settings to do what you want. It's either nothing or Fire Hose. If you're on a deskside machine, look around back at the sound card and try to find the actual Line-In -- sometimes blue.

If you're on a laptop, you may need to add one of the fine USB sound cards.

http://forum.audacityteam.org/viewtopic.php?f=27&t=9477

Koz

[JackFerguson]

I had already carefully checked that I am plugged into line-in and not mic-in. The volume control on the tape deck is for the built-in speakers (on tape deck) and does not affect the line-out signal. I had this same problem with Audacity 1.2.6. My sound card is "C-Media AC97 Audio Device" (if that has any bearing on the problem). I even built a resistor voltage divider circuit to reduce the signal strength to the computer line-in --- still did not have a gradual level control with the recording volume slide.

[kozikowski]

Has it ever worked? Does it work with Windows Sound Recorder?

Windows Sound Recorder
Start -> Programs -> Accessories -> Entertainment

What happens if you plug into the Mic-In and select that in all the appropriate panels?

Does this sound card have a 20dB Boost Option and is it turned on?

Koz

[JackFerguson]

I've not tried the Windows Sound Recorder. Good idea. I'll do that tomorrow. I'll also try the microphone input.

I just checked the Audio/Sound Devices in the Control Panel. I see no 20dB boost feature.

Thanks, Jack

[kozikowski]

Some of the better sound cards have that 20dB boost feature and it's frequently the difference between getting a microphone to work and not. Of course, if it's running at the wrong time...

Koz

[JackFerguson]

I tried recording thru Windows Sound Recorder. It was difficult to see exactly what was happening with the small spectograph (correct name?), but the volume control didn't seem to be generating much response. Didn't try the mic-in --- afraid I might damage something.

I just found a wikipedia article that said line-out impedance is about 100 ohms and line-in is about 10K ohms. The article says that very unmatched out-to-in impedances is desirable to avoid loading down the line-out.

Based on that information I might do some more experimenting with my resistor voltage divider circuits. I'm not optimistic that will solve the problem. My previous attempts have reduced the audio level, but still did not result is a gradual record-level control. My present impression is that Audacity has a "bug" in the record-level logic.

[kozikowski]

The output impedance of the average cassette machine is around 1000 ohms. There is a 10 to 1 intentional mismatch between that and the average line-in. It's cheap and it works as long as you don't need sound cables much over about ten feet.

This also allows you to get "mono" by jamming Left and Right together in a "Y" cable with no appreciable damage.

<<<My present impression is that Audacity has a "bug" in the record-level logic.>>>

But only for you. If you couldn't get Windows Sound Recorder volume to go up and down, either, then the sound card is broken.

Koz

[JackFerguson]

I guess I need to get a new sound card. I dread having to open the computer, installing a new card, hoping that I have enough resourses to make it work, and going thru all the install procedures.

You mentioned something about USB sound cards. That would seem to be a simpler installation. I have a desktop machine. Would that work for me? Any brand recommendations?

Jack