Record at +50% and change speed after?

I need to convert around 600 singles on Vinyl into MP3 within the next month and am looking for the quickest way to do this.

Would it be possible to use something like the Numark TTXUSB and record them all on 78rpm with the pitch slider at +50% and then batch convert them all later to bring them down to the correct speed (or even record them at the right rpm, but all at +50% to make the conversion easier where some may be 33rpm and other 45rpm)?

I know there would be a slight loss of fidelity due to resampling, but would this work or would the results sound terrible?

Thanks in advance

This page in the manual tells you why you shouldn’t consider accelerated recording:

The big issue is that the RIAA Equalization is then appled to the wrong frequencies in your pre-amp.

Batch processing (chains) in Audacity is pretty primitive and may not be able to do what you require of it here (I’m no expert in this as I’ve never used chains) - see



That and most of the music will be beyond the ability of the stylus to track it. Styluses are designed to move up to about 15,000 times a second or better. Playing a record speeded up gives vibrations well beyond the stylus to track it. You would get music muffled and worse than AM radio quality. Plus all the RIAA bass boost problems.


That’s only 20 per day, perfectly doable at normal speeds surely? And anyway recording a 7" 45rpm single of typical length 3 minutes will only save you 2.2 minutes - you still have to do all the post processing which will be the same if you use 45 or 78 to record.

The best additional tool you may want to consider is Brian Davies’ excellent ClickRepair - it costs a little at US$40 (but that less than 7c per single) but it produces excellent results and does so reasonably quickly (you do get a 14-day free trial which could be just long enough for you …). See this sticky thread:

I record with Audacity, export a 32-bit WAV file, process that through CR and then import the resultant cleaned WAV back into Audacity for processing. This has teh added advantage of giving me a high-quality 32-bit WAV of the original raw recording if I ever want to go back and re-edit.


Thanks for the advice everyone.

My concern regarding time stems from the fact that they are all dance music with an average of 2-3 tracks per disc. I’m guessing that’s around 20 mins of music per disc, add on say 5 minutes per disc for the time to swap it, process, tag etc. That means 25 mins x 600 = 15,000 minutes or 250 hours.

If I spent 8 hours a day doing this (which isn’t possible, but let’s say I could) that’s 31.25 days.

I’m emigrating in around a month and would rather not have to ship 12 flight cases of vinyl due to the cost.

I guess I’ll get what i can done and see where I’m at in a month’s time!

Thanks again for the advice :slight_smile:

You may find this workflow interesting and useful:


OK a suggestion: why not do all the raw capture to your computer of the recordings and then do the post-processing at your leisure as and when i.e. after your emmigration? You should be able to do this in 20 minutes + 1 minute (or less) - a good filing folder taxonomy will help you later.

BTW I think your 5 mins post processing per recording is way optimistic - I’m pretty slick at this process now having done hundreds of LPs and I reckon on the basic recording time x two for the total soup-to-nuts (and before I bought ClickRepair much longer).

But do make at least one backup copy on a separate external disk of the recordings (Personally I would make at least two backups - I have had a hard disk failure on my PC and and external USB hard disk failure … )


Thanks WC. I have the possiblity of being able to rip them all to .WAV and then worry about processing later (obviously I’d have to keep a record of artist/track/remix names as I go). This may save me some time now and allow me to worry about refining the quality of my data later on, after I’ve moved.

Do you (or anyone) have any suggestions as to the most efficient process for doing something like this (and then I’ll develop a workflow for the processing work at a later date). For example, might i be best ripping both sides of a disc to one file, naming it something logical and keeping a list of track details separately and tying it all up later?

I guess this may be worth posting as a separate thread/question?

In terms of doing the ripping, I’ve ordered a Behringer UFO202 and will be using one of my Vestax DJ decks to rip the tracks (obviously not audiophile quality but considering the nature of these discs and the way they’ve been (ab)used already, I think this should be of sufficient quality for my needs.

lol - this is pretty much what I just replied with a minute ago!

That workflow that I pointed you at is my “most efficient” - I wrote that page in the manual (with the help of a few experts on the forum) a while back as my best effort :slight_smile:

One suggestion - if the recordings are still commercially avaible then Amazon or Wikipedia may be a later source of the metadata (trackname/artiste etc.).

You should worry - most of my 45s spent a very hard life on my old Bal Ami J40 juke-box (which my son and grandchildren now own, along with the 45s) :sunglasses:


P.S. hope your emmigration goes well …


Most of them have very sketchy data online and some are white labels etc so I think I’m gonna have to type up the metadata as I go :confused:

The discs haven’t been abused too much - they were always stored well and only used in my spare bedroom, but they weren’t exactly handled with kid gloves and were always played on DJ turntables with straight tone arms and DJ cartridges.

You could be terribly old-fashioned and use pencil & paper, in the 20 minutes of recording tou should have plenty of time to make notes in a little notebook :nerd:


I was even thinking of just snapping a photo of each as I go. As long as I keep the photos in the order I rip that should do the job

Good thought - and that way if you have any that are not white-label and have cover artwork you can use the piccies for online artwork in your music library.


Good thinking!! Thanks :slight_smile:

I also just realised my laptop has HDMI In (which I’m thinking will be better than the Mic input) and my surround receiver has a phono stage and HDMI out, so I’m going to try hooking it all up and see if I even need the Behringer USB phono thingy.

Another quick question if you don’t mind?

Roughly how much disk space will 1 minute of 32-bit WAVE recording use? (I’m trying to make sure I have enough space both on my laptop and on my USB HDD that I’ll use as a backup)

Don’t forget that you will need a phono preamp somewhere in the chain (I think the Behringer device you refer to has one built in).

You certainly shouldn’t be going in via the Mic input as that is designed for tiny signals, note line-level. Some computers have cunning “Mic inputs” that sense the signal level and adjust accordingly and can sustain/support line-level signals. The Behringer device (even at its modest cost) is likely to have a better ADC than your onboard soundcard (I certainly use an external device - Edirol UA-1EX).


Should take 20MB per minute for stereo - half that for mono.


I hadn’t consider the ADC. If I use the phono preamp in my recevier and use HDMI into my laptop, I’ll be going Analog>Digital in the receiver (fine so far), but then doing the Digital>Analog in my laptop and then Analog>Digital again in Audacity… not ideal! I wish I could capture the raw digital data coming off the HDMI because I know the DACs and ADCs in my receiver are pretty top-notch.

I don’t know much about HDMI as input (I only use it t’other way PC=>TV) - but I would have thought that if you are presenting a digital signal to your PC via an HDMI input then the PC should bypass its own soundcard and sebd the digital signal direct to Audacity - you may nead to fiddle around in Audacity with the Input Device in the Device Toolbar to select the HDMI as input. Certainly when converted my MD recordings to WAV/MP3/AAC I used the digital out to the digital S/PDIF input on my Edirola and that totally by-passed the ADC in the Edirol and passed the signal direct to the USB services for output to the PC.

Audacity doesn’t do any ADC conversion on the way in it sits there and expects a digital signal from whatever device is configured as the input device.