Still getting static, Mac OS 10.4.11

[khoffcran]

Hello All - Based on my post in my prior thread, it was suggested I was losing USB synch, resulting in sudden (then persistent) bursts of static interference while recording from vinyl.

Following the suggested fix, I disconnected all other USB devices (except the keyboard / mouse combo). I made sure no other programs were running. This worked for two albums. When I began to record again today, I almost immediately ran into the static burst problem after beginning the recording.

Here's my setup: 2006 iMac 5,1 (2.16 GHz Intel Core 2 Duo, Memory 1GB 667 MHz DDR2 SDRAM, OS 10.4.11)

Denon analog DP-300F TT into ART USB Phono Plus V2 A/D preamp, then standard USB 2.0 cable directly into USB port (no hub).

Audacity 1.2.5

Audacity 1.2.5 is the proper release to use, given the Mac OS 10.4.11 (Tiger) I use.

I had the same problem in the past when using a USB turntable. I had hoped the problem was from EM interference forming a feedback loop through the ungrounded USB cartridge, or the open RCA plugs. So I got a very good analog TT and USB interface. But I still have the same problem.

I've tried switching USB inputs. All three USB 2.0 inputs give the same result.

Any other ideas on a fix? In reading prior threads on similar-sounding problems, it seems as if this problem might be endemic to the Audacity 1.2.5 / Mac OS 10.4.11 interface.



Thanks Much, Keith H, khoffcran, NJ / USA

[billw58]

Although 1.2.5 may be the "recommended" version for OS X 10.4.11, I've been using 1.3.x for a couple of years (on 10.4 and 10.5) and much prefer it. So as a start I'd recommend installing 1.3.12. You can have both versions installed at the same time, you just can't run both at the same time. And 1.2.5 will not open projects saved in 1.3.x.

Second, do you have any other recording applications available to you? I'm thinking it might be worthwhile seeing if the problem is specific to Audacity, or is somewhere else in your system. Fission by Rouge Amoeba http://www.rogueamoeba.com/fission/ has a free download (it has limitations until you pay, but you could test your setup with it). SndSampler is a venerable shareware program http://www.sndsampler.com/ . You could also install "Line In" from Rogue Amoeba http://www.rogueamoeba.com/freebies/ - it's free, and allows you to route any sound input to your speakers. This would verify if the static is from the turntable/USB combo, or is specific to Audacity.

-- Bill

[khoffcran]

Thanks Bill. I do have 1.3.12, and I used it tonight. I also disconnected all other USB inputs (except for keyboard/mouse combo), and closed all other programs. I still got the static after some time. I closed the program, re-opened and tried several times, and several times I got through a few album cuts, and then got the static. I also tried reducing the input level, thinking there might be a connection between input level and frequency of static, but there appears to be no correlation.

I think it's unlikely it's from the TT at this point. I had the same problem with a Numark TTUSB. That's one of the reasons I switched to the analog TT / A-D interface. (The other, of course, it that it's nice to have a real TT again, instead of that piece of junk).

After using 1.3.12, I do agree it's a lot more flexible. I will try other software, as you suggested, and see if I can isolate the problem to Audacity.

Thanks much for your help, and the links to the other software candidates.

Keith H, NJ / USA

[khoffcran]

Hello Bill, All - OK engineers of the world, what do you make of this? As suggested by Bill, I just loaded a copy of the shareware SNDSAMPLER 6.4.1 and used it. Obviously, my knowledge of the program is less than rudimentary at this point. However, the test yielded this interesting tidbit: SNDSAMPLER allows you the choice of either saving to whatever amount of RAM you want to use, or to your hard drive. When I saved to the RAM, I had pristine sound. When I tried to save to the hard drive, I got - not intermittent - but instantaneous loud static on top of the vinyl source material, that was identical in sound quality to that which I got sometimes when using Audacity, which of course always saves to the hard drive.

All other variables were kept constant. That is, no other programs were running, no other USB ports were used. Analog TT thru ART USB Phon Plusv2 A-D interface, into USB 2.0 port on my iMAC5,1 (Intel, OS 10.4.11).

What's up with that?

Thanks for any help,

Keith H NJ / USA

P.S. - Is there any way to make Audacity save temp files in RAM, before transferring to HD?

[khoffcran]

Just thought of a workaround to allow editing in Audacity, where I'm comfortable (and where there's a pretty effective noise reduction effect): Record raw data in SNDSAMPLER to RAM, save as
AIFF file, import into Audacity 1.3.12 as AIFF, edit at will, then export as AIFF (for eventual incorporation into iTunes as AAC file, an acceptable lossy coding.)

Not exactly elegant, but until someone has a better solution...

Still working, Keith H, NJ / USA

[bgravato]

P.S. - Is there any way to make Audacity save temp files in RAM, before transferring to HD?

Yes, in audacity 1.3.12 go to Preferences -> Directories and under Audio cache check the option "Play and/or record using RAM".

Not sure if the option is available in 1.2.5.

[billw58]

The Record to RAM option has been removed in 1.3.13-alpha, so that is not a long term solution.

Keith:
You certainly have a head-scratcher of a problem there. Are you powering the ART from the USB hub or with an external supply? If the former, then I would speculate that disk activity is causing noise on the USB power connection. You could also try the "Pre amp line out" from the ART into the Line Input on your iMac.

-- Bill

[khoffcran]

Thanks Bill - No, I'm using an external AC power supply, rather than powering the ART through a USB hub. I will try the pre-amp out (RCA to 1/8" input).

Keith H, NJ / USA

[khoffcran]

Thanks All - Well, I eventually picked up the static again when recording to RAM in both Audacity and SndSampler. So that ain't it.

However, I've now recorded about an album's worth of cuts without static interference by going, as suggested, from the ART USB interface's RCA phono outputs directly into the 1/8th" soundcard input in the iMac5,1 (recording onto the HD). Although I might be giving up the tiniest bit of fidelity compared to he USB input, I'm certainly gaining overall if I no longer have to deal with the intermittent - although persistent and common - problem of static interference. That tends to confirm, by the way, the suggestion that loss of USB synchronization (whatever the heck that means) is the culprit.

In searching old threads with the keyword "static", this appears to have been a long-standing problem for several people using OS 10.4.11, although something similar seems to occasionally be a problem in other operating systems and platforms.

I'll keep my fingers crossed. Thanks to all for your help. If anyone else checks in with this problem, I would suggest having them avoid the USB input.

On the upside, I got to discover this site, and I'm delighted with the fabulous Denon DP300F analog TT and ART A/D preamp I originally thought would solve the problem. Plus, now that I don't have to worry about other USB devices and (apparently) running other programs, I can go back to completing other computing tasks while listening to the music I'm recording!

Keith H, NJ / USA

[billw58]

Do you have another Mac you can try the ART out on? I'm wondering if it could be the ART, and not the Mac? And have you tried a different USB cable between the ART and the iMac?

I've been using a Behringer UFO-202 on a dual G5 10.5.8 with no problems at all. I'm not sure how "common" this problem is on 10.4.11.

-- Bill