Subject:Line Noise in Turtable Connection

Posted by: VegasKat

Date:9/11/2008 9:37:00 PM

I have SoundForge9, Edirol USB Audio Capture UA-25, Rolls VP29 Phono Preamp, Sony PS-X600 Turnrable with Sony XL 20 cartridge. When I monitor the recording in Sound Forge the level meters bounce around between -75 and -47 with the turntable off or on but not playing. I'm using an RCA Monster Cable with 1/4" plug adapters for the connection. I am in the same room as the wireless LAN hubs. I've tried relocating the turtable/preamp away from the wireless gear and moving the UA-25 off the top of the computer to no avail. Is there any way to reduce the noise or should I even worry about it?

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/11/2008 10:57:42 PM

Two things to consider:
1) Try to identify and eliminate 'ground loops' in your signal path. Do a google.
2) In my experience, Rolls preamps (at least the mic preamps) are noisy and their circuit board design is haphazard. Might want to try a different phono preamp.

Phono outputs are noisy by nature because they are unbalanced and low gain. However, -47dB seems a bit high for the noise floor, although you didn't mention how much gain you are applying through your sound interface or what your relative signal levels are.

Subject:RE: Line Noise in Turtable Connection

Reply by: Chienworks

Date:9/12/2008 4:12:54 AM

Every turntable i've used has terrible noise until it's grounded to the preamp. All decent turntables have a separate grounding wire that must be connected. Simply plugging in the audio cable doesn't accomplish this.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/12/2008 6:39:06 AM

The ground is one reason I went with the Rolls Preamp plus good reviews on line for what they are worth.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/12/2008 6:42:12 AM

If I knew how to tell you the last two I would. I have the knobs set about as low as I can to get a "decent" signal without getting to close to the clipping level or have the clipping circuit activate on the interface. Thanks for your reply.

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/12/2008 8:36:57 AM

**Every turntable i've used has terrible noise until it's grounded to the preamp.**
Sometimes that helps, sometimes it makes the hum worse, esp. if there is not a dedicated ground on the AC line. Using the shortest rca cables possible and not wrapping or coiling them is also good advice. A Tripplite line filter "may" help in some situations, but there is no "one size fits all" advice; these issues can be tricky. I've also used DI boxes to provide a balanced signal and break the ground loop to the computer interface with some success. It all depends on where the hum or bias is being introduced in the signal path, which is not always easy to track down.

Subject:RE: Line Noise in Turtable Connection

Reply by: jackn2mpu

Date:9/12/2008 10:33:37 AM

Is it hum or some other kind of noise? Do you have the ground lead from the turntable attached to you preamp? To rule out things systematically, disconnect the cables to the turntable at the turntable and short the center pin of the cable to it's ground. If that brings no joy, work backwards until you get to the inputs of your soundcard. The noise (if it's not hum) could be anywheres along the line. Finally, have you tried actually recording anything and listening through headphones? You may not even hear any added sound/noise.
FWIW, when I want to record my vinyl to CD, I go from the turntable to a Radial direct box made expressly for a turntable (connecting the ground wire from the turntable to the di). I then go from the xlr balanced outputs of the di to a pair of inputs on my Edirol UA1000 USB2.0 soundcard. Yeah, I get some bounce on the meters in SF, but there's no added noise going on, especially when I'm actually recording from the vinyl.
Jack

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/15/2008 9:20:03 PM

I haven't been able to hear anything in "standby" mode on my Sennheiser HD 595s. I did hear the tine of a musibox snaping back into place on an old recording and other things I've never heard before, so the headphones do a fairly decent job of sound reproducttion. Right now I'm using a 6+/- a/v monster cable from the preamp to the Edirol.
Two questions:
1. Would a pair of 1 meter "Interlink® Datalink™ 100 Low-Loss S/PDIF Style Digital Coaxial Cables work or would that be overkill? I have one I found lying around from an old surround sound set up.
2. What is and where would I get a Radial Direct Box?

Subject:RE: Line Noise in Turtable Connection

Reply by: jackn2mpu

Date:9/17/2008 6:59:59 AM

The Radial DI box you want is the J33 Turntable Preamp Active Direct Box which is currently available from AMS for $199.95. Get a pair of short xlr mic cables and use those to interface with your Edirol. There is a post on the DI to where you can connect the ground lead from your turntable. Also make sure you have good cables going from the turntable to the DI. Monster cables are NOT necessary; get as short as possible rca-connectored cables to go between the turntable and the DI. And remember, keep your audio cables away from any AC power cables; if they must meet, make sure they cross at right angles to each other. As I asked before: is it 60 Hz. hum or some other kind of noise?
Jack

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/18/2008 7:58:36 PM

I don't hear any noise, but I see the meter in SoundForge Recording Monito Mode bouncing around from -75 to -42. It is coming from the Rolls VP29 Phono Preamp. I started by disconnecting the turtable's permanently attached RCA cables, then unplugged the VP29; that is when the meters in SoundForge stopped bouncing.

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/18/2008 10:44:06 PM

It's beginning to sound more like LF rumble or pumping which is often inaudible -- if your preamp has a lo-cut or hi-pass filter (same thing), then that may help; otherwise, you know my opinion of Rolls. I've torn all of mine apart for parts. . .

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/19/2008 7:17:29 AM

I probably went for overkill considering the turntable and phono cartridge I'm using, but I took Jack's advice and ordered the Radial J33, now I "need' that $150,000 turntable I saw on line ;)

Thanks everyone, for your help and advice.
MICHIEL

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/20/2008 7:50:45 PM

And with your new turntable, you'll of course want a $4,000 power cord . . .
[url]http://www.needledoctor.com/XLO-LE-10-AC-Power-Cord-Limited-Edition

Seriously, though, that radial preamp / DI looks like a nice piece of equipment, and the specs are fantastic. If I did more than just occasional recordings from vinyl, I'd probably go that route. Do remember to let us know how it works out.

Subject:RE: Line Noise in Turtable Connection

Reply by: jackn2mpu

Date:9/22/2008 5:04:15 AM

Just to reiterate something with the J33: I've only used the balanced xlr outputs to interface with my soundcard (Edirol UA1000 USB 2.0); have not used the unbalanced rca jack outputs. Nice thing with using the xlr outs is that you don't need to use the external power supply - the J33 can power through the 48v phantom power from an interface's mic inputs.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/23/2008 2:37:17 PM

Now that my 15 ft long XLR to 1/4" cords have I arrived, I realized I could have gone straight XLR to XLR with a 3 ft Monster Interlink cable. Is the Monster Cable worth $25 x 2 vs. the regular Shure $14 x 2 microphone cable that will probably wind up coiled, since I don't need 15 ft?

BTW the couple of "cleanings" I've done with SoundSoap Pro have been amazing, with just the Rolls pre-amp; which seems to continuously put out noise in the zero to 50Hz range without the turntable connected. This is the noise I referred to when SoundForge meter was showing minus 75 to minus 42 on its meter

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/23/2008 3:04:56 PM

Regular XLR cables are fine. Since they are balanced, coiling them is not an issue.

Subject:RE: Line Noise in Turtable Connection

Reply by: jackn2mpu

Date:9/23/2008 3:09:31 PM

For what you're doing $25 Monster cables won't make things any better. Save the money and get the cheaper cables. Monster cables are nothing more than hype. Send the 15 foot xlr to 1/4" cables back.

50 or 60 Hz? That's line noise (aka ripple) from a crappily filtered power brick for the Rolls. Most bricks have little to no filtering at the output to bring down the ripple noise.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/24/2008 6:40:36 AM

So I guess I shouldn’t rush out and buy the ClearAudio Statement Turntable for $150,000 either? All joking aside thank you guys for your help. I'll let you know how it goes.

BTW what would you recommend as a replacement cartridge for my 1982 Sony turntable? I went to Needle Doctor to see if I could get a stylus, but they didn't have any. The next step, for Christmas, may be a new sub-$1,000 turntable. I'm thinking Thorens, any other suggestions?

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/24/2008 12:13:43 PM

I think you'll find a decent selection of cartridges / stylii at musiansfriend.com
They still service a lot of DJs and scratchers.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/25/2008 8:43:01 PM

The J33 arrived today. The line noise is down to a peak of -67+/-, but the output of the J33 is extremely high. I have the Edirol UA-25 input sensitivity set to zero and the peak/limit light virtually glows constantly while the recording meter in SoundForge is in the yellow/red range essentially all of the time. Will this cause excessive distortion? I remember from cassette recording days the level should go into the yellow/red range rarely rather than persistently. I tried reducing the recording level in Windows control panel to no benefit.

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/25/2008 10:01:58 PM

"I have the Edirol UA-25 input sensitivity set to zero and the peak/limit light virtually glows constantly "

The peak / limit light should rarely, if never blink, especially with a low DR /
SNR source like vinyl. You are flat-topping your signal. Turn the inputs down.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/26/2008 6:33:36 AM

The sensitivity on the Edirol is as low as it can go. The Radial J33 has no output control. Is there anything else I can do to reduce the levels? It's conected via XLR "patch" cords.

Subject:RE: Line Noise in Turtable Connection

Reply by: rraud

Date:9/26/2008 7:52:21 AM

As long as SF does not clip, those levels are OK, However if the input stage is clipping somewhere, you need to attenuate the signal. Usually via in-line pads. By your description of the problem a 3dB pad should do it. I would suggest pad(s) with switchable amounts attenuation, should you need more than -3dB. Or, if your handy at soldering, build one yo'self. Resistors are dirt cheap.

Subject:RE: Line Noise in Turtable Connection

Reply by: jackn2mpu

Date:9/26/2008 10:54:25 AM

Have you tried the hi/lo impedance switch on your UA25 in different positions? You'll want it in the low position. I have an Edirol UA1000 interface which has boht a pad switch and an impedance switch for 2 of the inputs on it. I tend to run it in the pad in position so I get a little better settability of the input control. No problems in either position getting a non-distorting input level.The level controls in the Windows control panel won't do squat for you, particularly if you're using ASIO drivers; not sure about wdm drivers though. I also run the impedance switch in the low position.
Levels also depend on what type of cartridge you have. IIRC, moving coil cartridges have less output than the older moving magnetic cartridges. Beware of this when you get a new cartridge. If you're looking for a new needle, you might be actually better served getting a new cartridge instead, but that's just my feelings on the matter. And don't forget to set the balance and ytracking settings on the turntable for a new cartridge. The turntable I use is a 20+ year old Denon direct drive unit with a cartridge from Shure.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:9/27/2008 3:38:08 PM

I'm not much good at soldering. Since I have the Radial J33 connected via balanced XLR cables, should I get the SMPro Audio Nano Patch Passive Volume Attenuator $60 with TSR 1/4" outputs or SMPro Audio M-Patch 2 Passive Volume Control/Switch Box $150 with balanced XLR outputs?

Subject:RE: Line Noise in Turtable Connection

Reply by: musicvid10

Date:9/27/2008 6:55:25 PM

There are many switchable inline xlr "barrel" attenuators for $30 - $35 each, made by Shure, Hosa, Audio-Technica, etc.

You would need a pair for stereo applications -- no need to spend any more, they are nothing but resistive T-Pads in a metal housing.

I keep a handful in my kit at all times for patching line level audio into mic level inputs found on many camcorders.

Subject:RE: Line Noise in Turtable Connection

Reply by: VegasKat

Date:10/1/2008 10:54:39 PM

I wound up with the Nano Patch and having to plug in the adapter for the J33 and all is well. The noise lvel didn't go up with the adapter power.