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Re: DAC

Reply #25
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But this would also mean to introduce an additional amp in the chain, is this a bad idea?
If it prevents clipping it's a REALLY GOOD IDEA!  ;)

Theoretically, it's best to minimize the number of active-analog "links in the chain" but in the real it's the high gain circuit (the phono preamp) that's most likely to introduce noise or cause other trouble.

...As long as you are not clipping you don't have to be too concerned with recording levels.   Just make sure you are not clipping and if the level is too low you can amplify or normalize digitally after recording.   This isn't like analog tape recording where you needed a strong signal to overcome tape noise.

Re: DAC

Reply #26
But this would also mean to introduce an additional amp in the chain, is this a bad idea?
The method itself is fine, and free, so you may try it. Who cares about double amping if there is no audible distortion?

In case it does sound bad, something like a passive volume control is fine. Passive means no power supply is required, therefore they can just reduce output rather than boost.

The cheap ones:
https://www.amazon.com/Stellar-Labs-1013015470-CONTROL-HEADPHONES/dp/B008DJTB32

The premium ones:
https://www.jdslabs.com/products/177/ol-switcher/
http://www.jblpro.com/www/products/recording-broadcast/monitor-controllers/nano-patch-plus

All of them should sound more or less the same as long as they are not defective. The biggest concern is durability. The premium ones have a larger knob and will be easier to make fine adjustment.

There are some stupidly expensive models out there, but just ignore them, typical snake oil. I can't recommend which one to buy and you may need to do some research on your own.

Re: DAC

Reply #27
...If I were you, I'd use the preamp.

Here is another inexpensive passive volume control/attenuator .

You can also get fixed attenuators but you have to guess how much attenuation you need or buy multiple pairs, and I can't currently find any that are "reasonably priced".


P.S.
One thing to watch-out for with "cheap stereo volume controls" -  Sometimes the left & right don't track well and the left-right balance can be thrown-off.    It can be fixed digitally in "post production" but it's something to be aware of.  (The phono cartridge or the amplifier circuits or the record itself can have similar imperfections.)


Re: DAC

Reply #28
Concerning clipping: wouldn't that show up as peak = 0 (or 100 percent)? Or will vinyl pops typically skyrocket peaks anyway?
(Listening through every potentially troublesome part on every record isn't that time-efficient ...)
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: DAC

Reply #29
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Concerning clipping: wouldn't that show up as peak = 0 (or 100 percent)?
Yes, if your ADC (or file*) hits 0dB (=1.0 =100%) you're probably clipping.

Usually I check the peaks after recording (I usually use GoldWave) and if they hit 0dB I reduce the levels and start-over.   That is, if I haven't already noticed the meters going "into the red".

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Or will vinyl pops typically skyrocket peaks anyway?
That's possible, but I can't remember actually seeing clicks that were the highest peak.     ...I probably had some LPs that would do that but I've only digitized my records that I couldn't get digitally plus a handful for other people.

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Listening through every potentially troublesome part on every record isn't that time-efficient ...)
Audacity will show red anyplace there is clipping so it's easy enough to listen to those spots to see if it's caused by a click.   GoldWave will tell you what the peak is (in dB) and where it is, but if you have multiple 0dB peaks it will only find the 1st one.




* Of course that's only true before processing.   If you normalize you can have many peaks that hit 0dB without clipping.   

And, most audio editing applications use floating-point so they can internally-temporarily go over 0dB without clipping.    For example, if you boost the bass in Audacity you might see red for potential  clipping.   But, the waves actually go over without clipping so as long as you normalize (or otherwise attenuate) before exporting to regular-integer WAV, your "finished product" won't be clipped.

On the other hand...  If you waveform is truly-clipped and you lower the volume, Audacity will no-longer show red but you've still got flat-topped distorted-clipped waves.  



Re: DAC

Reply #30
Concerning clipping: wouldn't that show up as peak = 0 (or 100 percent)? Or will vinyl pops typically skyrocket peaks anyway?
(Listening through every potentially troublesome part on every record isn't that time-efficient ...)
The uncertainty is when the so-called "unity gain" is unknown. If the recording interface has a mixer app showing the 0dBFS position there will be no guesswork, like creation.png.

For example I can get the digital level right (-1dBFS) but it still clips when I feed a 2Vrms signal into the Realtek, and I don't know what is the meaning of "23" in clip.png.

noclip.png is Realtek's "correct" self-loop input level (31) when the output is 100%.

BTW, how to inline my attached pictures?

Re: DAC

Reply #31
Very informative answers again, thank you.
I will try to connect the phono amp directly to the PC first, and if clipping occurs I'll try to add the stereo preamp. If I'm still not happy I will try adding a passive volume control instead.

This isn't like analog tape recording where you needed a strong signal to overcome tape noise.
Actually a very good reminder! At times I have an analog way of thinking. I have watched a lot of VU meters in my day while recording cassette tapes...

Re: DAC

Reply #32
Talking about pops and clicks. When I did a few needle drops almost 20 years ago, I remember being dissatisfied with the results of pop-removal.
Are there good programs for this today, or do you still have to do a lot of visual inspection / manual editing in the wave forms for a satisfactory result?

Re: DAC

Reply #33
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I remember being dissatisfied with the results of pop-removal.
Are there good programs for this today, or do you still have to do a lot of visual inspection / manual editing in the wave forms for a satisfactory result?
You know what they say...   "Your mileage may vary."

I don't think I've ever ended-up with "digital quality" but the cleaned-up digitized copy has always been better than the original LP.    If you have "pristine" records you can probably get nearly digital sounding results.    (All of the records I digitized were old, and although I tried to take careful care of them, they "deteriorated". )  

Audacity has a Click Removal  effect, which is automatic and Repair where you have to manually find and select the defect.  Or, you can zoom-in and re-draw the waveform.   (For the manual repairs, it's usually easier to "find" the defect in the spectral view.)

Wave Corrector is a fully-automatic program, and it's now freeware.  

I've used Wave Repair ($30 USD) for a long time.   The bad news is that you have to manually find the defects.   It usually takes me a full weekend to fix-up a digitized LP.   The good news is, it only "touches" the audio where you identify a defect.    And, it's got a handful of different repair algorithms/methods and you can get "audibly perfect" results with most (but not all) clicks & pops.

Re: DAC

Reply #34
You know what they say...   "Your mileage may vary."
Yes, I realize this topic is subjective.
Most of my records are not in pristine shape, so I don't expect perfect results. I'm mostly concerned that de-clicking will muffle the audio, which I experienced the last time. I think I ended up just letting it be (if clicks weren't severe) and put up with the imperfections, since there was too much work and mediocre results. But this was almost 20 years ago...

Have you experienced muffled audio with the programs you've used? Maybe this isn't an issue with modern algorithms. But do you sometimes opt to not correct a defect because the result is worse than having the defect?

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The good news is, it only "touches" the audio where you identify a defect.
I take it this is the very reason you use Wave Repair? It still gives a better result than Audacity et al., even though it has not been developed for 11 years?

Re: DAC

Reply #35
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I take it this is the very reason you use Wave Repair?
Well...  I bought it because at the time it seemed to be the best of the "affordable" options.  

But, yes I like the fact that it doesn't "muffle" the sound or introduce artifacts where there is no defect.   In fact, when you "save" it only over-writes the few bytes you've changed so saving is super-fast, even with album-length files.   (It's a good idea to keep a backup of the original because Wave Repair directly over-writes the file you're working on.)  

I have NOT carefully compared or evaluated these programs.    I've only tried Audacity's Click Removal a couple of times and it didn't seem to as good of a job as the specialized applications.  I'm also a long-time GoldWave user and it's click & pop filter doesn't seem to work as well as the specialized programs either.   

Maybe a year or so ago, I had a few LPs to digitize and I was getting impatient with Wave Repair so I tried-out Wave Corrector and Click Repair.  I bought Wave Corrector because it seemed easier to use. 

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But do you sometimes opt to not correct a defect because the result is worse than having the defect?
Yes.  But ironically, the worst clicks and pops are often the easiest to remove...  Maybe because they are easier to pinpoint.   Wave Repair rarely makes it worse.    Like I said, there are multiple repair options and if the defect is short-duration you can usually fix it.   If it makes a particular defect worse, you can simply un-do and try another method or move-on to the next click.

This page written by the developer of Wave Repair has several other software recommendations, and TONS of other information about digitizing LPs.   (As far as I know, this page hasn't been updated for a long time either.)

Re: DAC

Reply #36
Thanks, your explanations have been very informative. I'm sure I'm gonna achieve much better results than the last time I tried this. I have Audacity already installed, but I have a feeling I will appreciate a dedicated program like Wave Repair or Wave Corrector better for this purpose. But my first step will be to setup the gear and start recording.

My apologies to the OP for borrowing this thread.

Maybe the topic could be changed to "ADC" or "Vinyl Recording" to better reflect the questions from the OP and me?

Re: DAC

Reply #37
Hi Vilsen, no problem with highjack. Still reading with great interest.
I've been slowly digitising my Vinyl collection for some time now.
I use Reaper. Gave up on editing sound(Audiograbber with sound tools) as I found it always sounded worst.
I'd rather suffer the Vinyl related imperfections than edit  the life out of them for the sake of getting rid of a little snap, crackle and pop.

Re: DAC

Reply #38
I use Reaper. Gave up on editing sound(Audiograbber with sound tools) as I found it always sounded worst.
I'd rather suffer the Vinyl related imperfections than edit  the life out of them for the sake of getting rid of a little snap, crackle and pop.
I can take some minor crackles, but some of my LP's aren't in great shape so I really need to clean those up. Hopefully I won't have to edit so much on my better LP's. Plus I'm hoping that Wave Repair or Wave Corrector will achieve much better results than the program I used many years ago.

Re: DAC

Reply #39
Ok, please let me know how you get on with the newer restoration software.

 

Re: DAC

Reply #40
I can suggest to look up for ClickRepair. It's not expensive, and I've had very good results with it.

 
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