Analog to computer - humming sound

K

kollontai77

New member
Hello everyone,

I've finally done some test recordings on my Uher 4000 report (mono portable reel to reel) and loaded them up into the computer, using Goldwave software and leads.

However, I'm having some problems.

1. There's a weird humming noise on the recording. I've hooked the Uher to the hifi, and that humming isn't there. So it's something to do with the computer and/or leads.

2. Crackles and dropout in the digitised recordings. (Could be the leads.)

3. I'm none too pleased with the sound quality either. Thin + cold, regardless on what quality settings I select on Goldwave.

What can I do? :confused:
 
Try a fresh, new, known to work patch cord or set of leads, as you call them, and also ensure that the two devices are on the same electrical outlet box or power bar strip in the same room.

If you don't follow that last part about the power connection, you can create a ground loop because of the different ground potential points in the electrical system of the premises and a hum will be the result.

Good luck! :)

Cheers! :)
 
So you mean that both computer and Reel to Reel should be plugged in from the same power point?

What if my reel to reel is battery powered?
 
kollontai77 said:
So you mean that both computer and Reel to Reel should be plugged in from the same power point?

What if my reel to reel is battery powered?
Click to expand...

An earth loop is about the most common reason for humming, but if one unit is battery powered it shouldn't happen.

Make sure that you are plugging the output of the reel to reel into the 'line in' on your computer, not the 'mic in'. Also check your leads as Ghost has suggested - a faulty earth could also be the cause of your problems.

Cya
Andrew

EDIT: Note - if you're in the US you probably call earth "ground" instead....
 
Some questions:

1. What's a "faulty earth?" or "ground?" Don't know much about electronics.

2. What's an audio interface?

I'm plugging it into the "line in", so that's not the problem.
 
kollontai77 said:
1. What's a "faulty earth?" or "ground?" Don't know much about electronics.
Click to expand...
In this context it means that the connection is bad - the 'line in' on most basic sound cards is unbalanced, so you should have a shielded cable running from the recorder (probably terminated in a jack connector or RCA) to the computer (3.5mm jack). If the earth is faulty it means that the shield of the cable (the outside braid) is not connected properly at both ends.

kollontai77 said:
2. What's an audio interface?
Click to expand...
The sound card in the computer.

Do you have access to another cable? Have you tried it?

One other thought - what kind out output are you coming out of the recorder on - what's it named?

I'm sure that we'll all get to the bottom of this....

Cya
Andrew
 
OK. I'll describe things a bit better.

The Uher Reel to reel is Mono, very old (mid-late 60s), and is battery powered. It has had an adaptor specially made for it - from a 5 pin Radio Phono jack, to a couple of RCA female plugs- one labelled "play", the other "record". To connect this to the computer, I bought a male/male RCA plug, and then a female RCA/male 3.5 plug. In turn, I plugged it into the line in jack at the back of the computer, and ran the sound through the Goldwave software. All plugs and leads are new, and have rubber coverings over the wire.

The soundcard is probably the original one that came with the computer - an ASUS Pentium 3. I don't know anything about soundcards, so don't know how to find out what one the 'puter uses.
 
kollontai77 said:
The Uher Reel to reel is Mono, very old (mid-late 60s), and is battery powered. It has had an adaptor specially made for it - from a 5 pin Radio Phono jack, to a couple of RCA female plugs- one labelled "play", the other "record". To connect this to the computer, I bought a male/male RCA plug, and then a female RCA/male 3.5 plug. In turn, I plugged it into the line in jack at the back of the computer, and ran the sound through the Goldwave software. All plugs and leads are new, and have rubber coverings over the wire.
Click to expand...
OK. Let's look at each bit in turn. You said initially that the Uther sounded good when plugged directly into a stereo, so its definately not the cabling to that point. I'm assuming that's the 5 pin to RCA female cable and the RCA Male-Male adapter.

This leaves the RCA - 3.5mm plug and the soundcard. Try plugging a known good source - say a CD player - into the same lead and see if Goldwave produces better results. If it does it's back to the drawing board - I'm kinda hoping it doesn't.

If it doesn't then try a known good cable - I'd suggest trying a 3.5mm stereo - 2x RCA plug cable. Try this on the CD, if its still a problem then we're looking at the sound card - you'll need to get another one. If you can get it working well on the CD then move back to using this setup with the Uther. Set Goldwave to just record off the channel you're using (or if you can't, record as stereo and convert the file to mono, using 100% of the channel you're using and 0% of the other channel).

Let me know if none of this works and I'll have a think about other options - we might be looking at transformer territory!

kollontai77 said:
The soundcard is probably the original one that came with the computer - an ASUS Pentium 3. I don't know anything about soundcards, so don't know how to find out what one the 'puter uses.
Click to expand...
This will be very standard AC'97 audio with a Crystal or similar chipset - not really suitable for recording. You'll get far better results from a Creative Audigy or move up to a 'real' recording card from the likes of M-Audio.

Cya
Andrew
 
OK. I tried plugging the stereo into the computer. It's a Sony SS-H450, not a hifi proper. It has Audio/Video plugs at the back, one red, one white. Also, headphone and mic jack at the front. I hooked up some leads (different ones this time) to the "line in" socket at the back of the computer, with each of these AV, headphone, mic jacks in turn. Then I tried the same process, with the computer's mic and headphone input. I ran some music through Goldwave (stereo this time).

I didn't get ANY music at all from this. But on some of the tests, there was the same electric hum as from the Uher. The rest of the tests had no sound at all.

Although the Stereo was plugged into a different socket, it was probably on the same wiring, as it came from the socket on the other side of the wall.

Hope this made sense, and that we can figure out how to eliminate the hum. :cool:
 
have you tried plugging a different device into the line in to see if it is actually the computer, if so I would think it maybe the power supply on the pc I have had some probs with this in the past and plugged into different pc with same setup and sweet!
 
kollontai77 said:
OK. I tried plugging the stereo into the computer. It's a Sony SS-H450, not a hifi proper. It has Audio/Video plugs at the back, one red, one white. Also, headphone and mic jack at the front. I hooked up some leads (different ones this time) to the "line in" socket at the back of the computer, with each of these AV, headphone, mic jacks in turn. Then I tried the same process, with the computer's mic and headphone input. I ran some music through Goldwave (stereo this time).

I didn't get ANY music at all from this. But on some of the tests, there was the same electric hum as from the Uher. The rest of the tests had no sound at all.
Click to expand...
As far as I can see the SS-H450's are speakers - what are you driving them with? Have you got access to another source with RCA line outs you can test with - say a standalone CD, MD or cassette deck? Anything with line outs, and preferably with RCA's so you can test the same lead.

You mentioned you got hums from various tests - until you get some kind of audio as well I don't think we're any further ahead.

BTW stick to the line in on the computer. The microphone input is not suitable for recording (but handy for Skype) and the headphone jack is an output, not an input.

Cya
Andrew
 
is your soud card an onboard or is it a pci card? The Pc is noisy in terms of electrical noise. Often audio cards pick up this noise. Open the PC and see if you can move the audio card to the farthest slot away from the graphics card. The graphics card emmints a lot of noise too.
 
SUCCESS!!!

In the course of figuring out whether a new mic worked or not, I discovered what the problem was.

I was under the impression that

Mic input = black jack
Line in = red jack

When in reality it was

Mic input = red jack
Line in = BLUE jack.

So I was getting the hum, because I plugged it into the MIC input by mistake, not the LINE IN.

So that's something to add to the info here.....

If you are having trouble with electric hums, check that you are plugging your cables into the right jacks!

(embarrassed)

PS my soundcard is only 16 bit, but it will do for now. Will get a better soundcard with 24 bit sound later... unless you know of better ones out there?
 
kollontai77 said:
SUCCESS!!! In the course of figuring out whether a new mic worked or not, I discovered what the problem was.
Click to expand...
Exellent! Its always satisfying to get this kind of thing sussed!

kollontai77 said:
PS my soundcard is only 16 bit, but it will do for now. Will get a better soundcard with 24 bit sound later... unless you know of better ones out there?
Click to expand...
An onboard 16 bit interface isn't ideal but its a good place to start and 'play' with the technology until you're a bit more confident. There are a heap of good threads on here discussing the pros and cons of all kinds of different sound cards - read up what you can, and keep your eye on deals.

Cya
Andrew
 
You must log in or register to reply here.
Back
Top