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Playing LPs At 45 RPM for faster PC transfer

Patriot1776

Patriot1776

Cancer Survivor at 26
Alright, I got a speed question.

My digital scale came in today and using it, I found that by backing out the screwed in counterweight on my Ion TTUSB05, I was able to lighten the needle to 1.7 grams as compared to the stock weight of 2.7-2.8 grams I believe.

Audacity has 'change speed' option that allows stuff recorded at 33 1/3 RPM to be sped up to sound like 45 RPM, and 45 RPM to be sped up to 78 RPM. I'm now wondering if it would be okay to play my LPs on it at 45 RPM to speed up transferring them to computer, since I can slow them back down in Audacity. With the needle now weighing in at between 1.65 to 1.74 grams, I'm not as scared to use the cheap turntable until I get my USB Phono Preamp.
 
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Probably OK unless you are obsessive about things - which you may well be.

The end result will have a digitally adjusted pitch. Can you live with that?

I've Audacity before to go from 33 rpm to 45 rpm and it sounds fine, but I'm not the best at detecting pitch.
 
Playing 33 record at 45 RPMs effectively shifts record's bandwidth 1.36 times up. Meaning 20KHz will be 27KHz. However the TT bandwidth stays the same 20-20K. You are likely to loose part of the highs.
 
I'm not that concerned on both those things as the MP3's made from these transfers are going straight to a digital music player for on-the-go use in my vehicle, so I know of course they're not going to sound the same any way. These things will help reinforce my love of playing the records. There are however, I'm starting to find, some songs on a least a couple of my records that I kinda like better at 45 RPM, transferring at 45 will allow me to enjoy these 'alternate' versions of the songs without risk of vinyl damage.

Thanks guys.
 
Yes, you could certainly play at 45 rpm and use software pitch correction on the files. But is it really worth it? Whatever time you've saved by fast playback is somewhat (if not wholly) negated by the time it takes to process the files with pitch correction. Then there's the issue of quality degradation, which may not be important to you, but still begs the question: if you're going to do a job, shouldn't you do it right?
 
I'm probably not going to do it a lot, as there are times when the loss of highs does matter, but this time it wasn't. This was one record of organ music where to me the tempo was dragging really bad on a few songs, and two of them actually sounded better at 45 RPM, so I saved two versions of them. One at 45 and one at 33 1/3 for both of them.
 
Patriot1776 said:
I'm probably not going to do it a lot, as there are times when the loss of highs does matter, but this time it wasn't. This was one record of organ music where to me the tempo was dragging really bad on a few songs, and two of them actually sounded better at 45 RPM, so I saved two versions of them. One at 45 and one at 33 1/3 for both of them.
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That's interesting..... are you a fan of The Chipmunks? :D
 
I wouldn't do it. The speeds are not compatible.

The RIAA EQ is highly frequency dependent (read that speed dependent to the stylus). Therefore will "reverse EQ" the transfer horribly wrong.

The upper midrange (that was seen as treble) will have a hole in it. And the bass will get a boom in the upper ranges. At least if my hand eye "trying to see the RIAA curve" visualization worked that is the specific problems you will have. Regardless, the EQ will be wrong.
 
For the purpose described, that might not be a bad idea if the TT could do 78rpm. That would really save time.

And on a really fast PC, slowing down the track would only take a couple of minutes per LP.

But, highs will be lost (unless the cart is a high quality MC with a frequency response of 20Hz to 50kHz and the PC is sampling at a higher sampling rate, eg. 88kHz at least.

But doing all that is like jumping down from your balcony on to a matress in your yard. It will most certainly get you there faster, but there are pitfals and in the end (slowing down and sampling down) negates the gain, in the same way you would need to put your bones and clothes together after the jump.

Now, on prefering certain LPs running at 45, I can totaly feel you. I have watched certain movies on DVD in FF - the only way I could be able to later say "I've seen that movie - it sucks...".
 
Slowing down side A of the the album I did today only took 40 seconds actually, while side B took 35 seconds.

Side A was about 18 minutes long and the transfer took 14 minutes at 45 rpm. Side B was 16 minutes and took 13 to 13 1/2 minutes to record at 45 rpm, so I did save some time. My PC is a dual-core unit with both CPUs running at 3.4 GHz.

However, 48kHz is the highest sample rate I can go, as mp3's can't handle any higher samplerates. I've got 96kHz sampling available in Audacity, but the resulting WAV's can't be converted because of the samplerate.
 
I was able to lighten the needle to 1.7 grams as compared to the stock weight of 2.7-2.8 grams
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Operating a cartridge at too low a tracking force can do *more* damage than the slightly increased wear of tracking at a higher force. Optimal tracking force is related to the stylus compliance - too little force for the specific compliance & the stylus will momentarily leave the groove, chiselling out tiny fragments when it returns. Especially at higher than normal playback speeds, where the groove lateral velocity will be higher than design anticipated.

And as Grainger said, pitch correction alone won't get you back where you should be. Still, Ion/usb/mp3 isn't going to get really high fidelity results at any speeds.
 
Am I in the Twilight Zone? Doesn't anyone except steerpike2 realize that the reverse RIAA EQ will be all screwed up?

Maybe tonal accuracy isn't important? It is to me.
 
Diamond Cut production software and tools do this as they allow up-speeding and down-speeding. BUT, they say to sue a flat phono amp with no RIAA and to apply it after the fact. These techniques are useful. But the TT needs to be a decent one and the cartridge should be one capable of Quadraphonic (~45KHz) signal retrieval :)
 
Grainger49 said:
Am I in the Twilight Zone? Doesn't anyone except steerpike2 realize that the reverse RIAA EQ will be all screwed up?

Maybe tonal accuracy isn't important? It is to me.
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Unfortunately for some people convenience comes before tonal accuracy and other "details" like frequency response etc. This is not the reason we ended up down to MP3 and "perfect" downloads? I wonder why does anyone really have to mess around with such "archaic" playback as TTs and records. If I have to record any of my LPs in order to have my music in my trips I use the highest sampling rate possible in my computer and as simple a porcess as i can use...the signal suffers enough through the AD conversion for us to add even more processing to it!
 
Grainger49 said:
Am I in the Twilight Zone? Doesn't anyone except steerpike2 realize that the reverse RIAA EQ will be all screwed up?

Maybe tonal accuracy isn't important? It is to me.
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I agree with you!

It may be possible to play the record at 45 rpm, use an inverted RIAA curve digitally, convert the speed down to 33 1/3 rpm, reapply the RIAA curve. But after all the digital conversions, I'm sure you will lose quality and time. Not worth it!

Also, even if the digital conversions resulted in accurate reproduction, which I doubt, 20 kHz signals at 33 1/3 rpm will become 27 kHz at 45 rpm. How linear is the cartridge response above 20kHz? If not linear, this will add errors to the end result.

Also, how accurate does the cartridge track at 27 kHz + ? If mistracking increases, so does damage.

In my opinion, the whole process is not worth it. If the listener prefers the recording played at a higher speed, record it at 33 1/3 rpm and digitally speed up the file to the preferred speed, then save. Saves time, saves records.
 
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