In May 2015 I had major problems coming to grips with recording vinyl from a TTUSB because there was no way of adjusting input levels either in the System sound mixer or Audacity. As a consequence, I was getting a lot of clipping. I was using an iMac with OS 10.9.3. I had a lot of help/suggestions from this forum but finally gave up - I got ill plus it was just too hard. Then last week I decided to have another crack at it, downloaded v2.1.2and voila! the problem had “auto resolved”. NO change in computer hardware or OS updates, so go figure.
If anyone else had these sorts of problems, take heart and try 2.1.2. Thank you Audacity.
You are VERY lucky! I have similar problem (clipping and no way to control it) when recording from a (Teac) USB turntable, and I am new to Audacity, having just loaded 2.1.2 for Mac running Yosemite 10.10.5. I can’t believe we are alone here, so has anyone out there got a solution? and why haven’t Audacity got round this yet - it’s obviously a huge shortcoming of the app.
It isn’t, because Audacity doesn’t apply any artificial gain to the input.
By the same token we didn’t do anything that would of itself have stopped the problem happening for Aroha. More likely it was because Aroha updated to a later Mac operating system or a different Mac, though Aroha does not say that.
Have you looked in the system Sound Preferences to see if there is an input level slider for your USB turntable? Probably there isn’t, because Mac’s rarely provide an input slider for USB devices. Does your turntable have analogue outputs such as headphones out or speaker cables? That gives you the possibility of bypassing the USB and connecting to the stereo Line-In of the Mac (if it has one). The Line-In input level will be controllable.
Or you can try putting a potentiometer after the analogue outputs: https://forum.audacityteam.org/t/horrible-distortion-when-recording-12-singles/4755/9
Gale
Thanks Gale , but that keeps me in the analogue domain and I bought the Teac USB turntable as a quick easy solution to getting my LPs on to my Mac. Audacity has a good UI and I can see me using it for my attempts at guitar and vocals so wouldn’t like to abandon it. Another solution I have seen somewhere is to change the cartridge on the Teac from the high output Audio Technica fitted as standard to something with a much lower output (AT is 4mv, Pickering or Stanton, under 1mv) Does that seem a good solution?
Some USB turntables come only with ceramic cartridges, in which case changing to magnetic will produce noticeably lower output, but at 4mv it sounds as if your cartridge already is magnetic. But yes you could investigate a different cartridge.
Does your turntable have a hidden gain knob anywhere? Some makes have a gain knob under the chassis.
Gale
No gain controls on my turntable so I have taken the plunge and bought a low-output used Pickering cartridge off Ebay, so will report back with results as it may help others in the same situation, but it may be a few weeks away as the new stylus for the cartridge is coming from Oregon and has to get to my little island off the coast of Scotland! 
I didn’t update my OS, so no idea why it improved with the new version of Audacity. However, although things went reasonably well with digitising classical music LPs, when I turned to my 70s rock collection, things were different. I tested my system with Led Zeppelin and Uriah Heap and there was a huge amount of clipping and distortion. I bought a Behringer UFO202, and while there was still no input volume control the recording levels were near perfect and Normalise tidied things up at the end when necessary, plus the sound quality was better. I presume the sound card is better in the Behringer.
Another alternative would be to acquire one of these: http://artproaudio.com/turntable_preamps/product/usb_phono_plus-ps/
It is a combined phono preamp and USB soundcard (its big plus, apart from its build quality is that it has a gain control knob to control the signal level output). You would connct this to the analog RCA outputs from the TEAC (this of course bypasses and “wastes” the onboard circuitry in the TEAC that does the same job, but without gain control it sounds like from your post).
When I converted my vinyl I used my existing hi-fi TT deck and fed the output into an ART Preamp (the DJ-Pre11) and then on into an external Edirol UA-1EX sondcard. The combined ART device was not available at that time - otherwise I would have bought that. This gave me the luxury of not one but two gain controls.
The USB Phono Plus is basically the DJ-Pre11 preamp with an added USB soundcard in the same box.
WC
Many thanks for this info, waxcylinder, if I had known of the existence of this I would never have bought the Teac USB turntable! Since my post, I have been using different software (Wavepad) which is excellent and does have gain control, but cost me almost as much as the black box you are suggesting!
I am now going to sell the Teac USB turntable, which has obvious quality shortcomings compared to my good hi-fi turntable (STD, SME 3009mk3,ADC XLM3) and buy this ART pro box you suggest - thanks again.
But the Mac does not have gain control for the USB turntable and neither does the turntable have a hardware gain control.
So all Wavepad is doing is making the distortion quieter. It isn’t really a solution. You might get a system gain slider for the USB turntable on Windows or Linux, but many USB devices will not show a gain slider on Mac.
Gale
I’m note quite sure what you mean there Gale - if I put my “good” turntable through the ART box, into the Mac via Audacity, I will have gain control from the ART won’t I?
Yes, even if the Mac does not show you a gain slider.
Or as I said but you did not like the idea, if the TEAC has speaker cables or other analogue output and the Mac has stereo line-in, you can use the Mac and Audacity to control the input level that way.
It could still be that it will sound better using the standalone turntable and the ART device. USB turntables might cut corners to provide all their features at the price.
The main point of my comment was to prevent any misunderstanding about what Wavepad was doing. If the Mac does not show an input level slider then Audacity’s recording level slider is disabled. It’s a deliberate decision so you don’t get clipped recordings that sound not clipped until you turn up the playback volume.
Gale
I don’t think you’ll be disapponted with the ART box (IIRC I thinl Bill who is one of our Forum elves uses one of these)
And as for that arm, good indeed - I run an SME 3009mk2(improved) and have done for many years. A lovely piece of engineering and a joy to look at. And I think that Koz (another Forum elf) also has an SME arm.
I did make one expensive mistake when I converted my vinyl. I cleaned the stylus of my cart with alcohol and a fine sable artists brush. Result: glue sticking the diamond to the cantilever dissolved, diamond tip drops off. New cart needed - .
I also started out with an ION iTTUSB but the results were so poor (massive wow&flutter as a result of a light plastic turntable) that I went down the rote I descibed earlier (luckily I managed to sell the ION to a friend).
Peter
I will certainly report back when I have used the ART USB box through Audacity for a while - I’m intrigued to know how well it will digitise the output from my very analytical ADC XLM 3 cartridge.
Yes, the SME arm is a joy that I will never change even though it forces you to use high compliance light cartridges, so I can’t really change to moving coil (couldn’t afford the better ones anyway!)
I ran with a V15III for many years (had an input board specifically designed and built for it for it by QUAD as an upgrade for the QUAD 33 preamp) - until the time came for stylus replacement and a new upgraded Shure cart cost slightly less than replacing the stylus on the V15 (I still have the V15 neatly boxed as a classic piece).
Peter