Static Impulse Problem

[DJBohn]

I have been having problems restoring some LP's lately. It has to do with impulse noise that I'm assuming may possibly be some sort of static discharge. The amplitude of the impulse noise varies anywhere from small to several db. But the time duration of the impulse noise is only about 0.05ms in length. Sometimes it's just a few here or there, usually masked by the music. But now & then there is 1 to 3 of these every 1 to 3/100 sec., which can be very annoying during quiet passages. The Expert Impulse Filter tends to miss these because they are so quick and it's a real time consuming pain to try and remove them with the Interpolate feature.

I'm not sure where the problem is comming from. I even get these with new un-used records. I have electric heat, so my home is usually very dry, especially these winter months. My monitor is also within inches of my turntable, but it has better than normal shielding. (It also has auto-degausing that makes a "snap" when turned on...) I don't get any hum or noise from the monitor to the turntable though. I remember people having similar problems like this years ago with record playback - static discharges from the LP to the cartridge. Would the investment of a ZeroStat gun reduce or eliminate this problem? They are somewhat spendy. (note: I do wet clean my records before playing) I'm also wondering if my old sound card (Hoontech DSP 24/96 Value Card) could be starting to go bad. Any suggestions with this problem would be appreciated.

[Craig Maier]

I have heard that same type of noise on very dry days here and it has been the static discharge problem from the record to the phono cartridge. Wiping the record with a soft cloth with distilled water just before playing has helped in my situation. But, if you can not get rid of the noise during the transfer, I have also been able to eliminate it using the software. I have used the HQ mode in the Expert Impulse filter with the Size set to around 2 to 3 and then I adjust the tracking control until the system finds these (with the threshold control set to minimum).

If you want, send me a short snippet of the transfer, say 10 seconds and I will try to fix it and then send you the recommended filter settings.

[Craig Maier]

BTW - my email addy is:

dctools@aol.com

or

craig@diamondcut.com

[DJBohn]

Thanks Craig. I think I'll go at the heart of the problem. I'll try & increase the humidity in the house & invest in an anti-static platter mat for my table. I've seen some for around $15. I've been using a felt mat that came with the table. The Original rubber platter mat was not included with the purchase. I've seen the Milty ZeroStat guns on sale too for about $75. Better to eliminate the problem at the source than to try and deal with it in the restoration process. As for "whiping" my precious rare near new records, I think I'll pass on that...

By the way, you'll find this interesting. I transfered some special LP's to the computer over the past few days. These records were so clean, the only thing I used DC6 for was to record them at 24/96. No impulse filtering was needed because there were no ticks and pops. The Continuious Noise Filter was also not used. No Punch & Crunch, No Fade In's or Fade Outs - nothing was used. The period between the tracks was dead silent. With the music normalized to 0 db, I used the Continuious Noise Filter to measure the Signal to Noise from a sample between 2 tracks. This is what it measured:

At 23Hz it was -85db
At 70Hz it was -90db
At 90Hz it was -95db
At 150Hz and up, the Signal to Noise was off the scale (>-100db)

And here's the best part. Playing these records, I got these specs using a Moving Coil Cartridge.

Before I forget, I hope you & yours had a good Christmas & have a good (and safe) New Year as well!

[Geebster]

Just for anybody's information; and it pertains to this thread...

I got a Z-Stat back in the heyday of vinyl, when they were all the rage. They were pricey then as they are now. I felt that it didn't offer that much a difference to justify it's rather steep price. I finally gave it to an audiophile buddy at the time... Never found out if he liked it any better than me.

I have found having a humidified environment and a good thorough 2 pass clean ( Clean, Play album side, clean again) does much more, in my experience than the Z-Stat. But, If you really want one, go for it...

GB

[Craig Maier]

DJ -

The more accepted way of measureing signal to noise ratio for vinyl would be the following (which is a wide bandwidth measurement):

Using the Diamond Cut VU meter, measure the loudest passage of the recording. Write down that number in dB. Now, measure one of the between cut grooves on the VU meter. Subtract the second number from the first number. That will be your S/N ratio.

For example, a record plays its loudest passage in Diamond Cut with a reading of -12 dB on the VU meter. It plays its softest passage at -55 dB. The signal to noise ratio of this recording will be 43 dB in the example given.

Using the Diamond Cut Spectrum Analyzer or CNF display can be misleading in that the S/N ratio involves amplitude as well as bandwidth. The VU meter accounts for the entire spectrum whereas the spectrum analyzer only measures it on a spectral bucket by bucket basis. If you wanted to calculate S/N from the Spectrum Analyzer, you would have to take the square root of the sums of all of the squares of each frequency bucket to obtain the correct value. So, if the CNF was set for an FFT Size of 4096 as an example, one would have to make 2048 spectral measurements and apply the formulae. It is easier to use the VU meter!

Note: The S/N ratio of a properly recorded and maintained Vinyl LP played on quality equipment can be around 50 to 60 dB prior to noise reduction using the Diamond Cut Software.

[DJBohn]

Hey Geebster, I had one as well & used it regularly but never had any problems with LP to cartridge static discharge. I purchased it when I put my first quality system together & used it all the time so I don't remember if I had a problem to begin with or not. I do remember the apartment had electric heat and it was very dry though. These devices have proven themselves and are sold mostly to the medical industry. When used correctly, they generate like amounts of positive & negative ions to obtain a neutral charged surface. The trigger needs to be squeezed slowly & then released slowly toward the same location. If used correctly, from my experience with them, I never had any static problems in the past with them like I have been having lately without one.

[DJBohn]

Thanks Craig. Actually I was kind of cheating with the specs anyway. These were quality LP's - Nautilus "Super Discs" - direct from the master tapes. I guess I should mention they were dbx encoded LP's.

[Geebster]

Hey DJ...

Yeah... That's why I got the Z-Stat in the first place as my Father's Company used them in their Labs for years before they were available to the normal consumer.

My application and situation is probably different than yours as I have never lived in a dry environment. I have had joint problems since a young adult and always required humidification in my residences as it helped my joint condition.

The impulses that I was hearing was due to the imperfections in the vinyl, not static as in your case. So, for my living conditions, I really had no need for a Z-Stat as static wasn't and isn't a problem with me.

And besides, the software is so good (for me at least) about getting rid of short impulses, I don't worry about them too much anymore until I fire up DC6 or Mentor.

GB

[DJBohn]

Geebster - I know what you're saying. It's been a real bummer with this static problem as the LP's I'm doing now are new un-used or near new condition & otherwise sound squeaky clean. Although DC6 could handle the static quite nicely, being a purest I'd much rather stop the noise at the source & re-record them onto the computer. We can not forget that any restoration to audio, no matter what you use or how you use it is still a destructive means to the original sound. You're changing something. Of course no one likes ticks & pops, so some restoration is usually necessary with most record sources. But I usually go by this rule of thumb - Less the better - only use what restoration is really necessary. But someone elses personal tastes in the sound may be more important than taking a purest approach. To each their own I guess.

By the way, I found a page of information listing several dirt cheap tweaks you can make to improve your audio listening experience. The site also offers a free PDF you can print that you can use to align your phono cartridge. The tweaks can be found here.

http://www.enjoythemusic.com/superio...ile_tweaks.htm

[Geebster]

I guess I try to take the middle of the road approach. Meaning that I don't want to degrade the sound or change the timbre of the recording by using the software, but I am not shy about using the software to get rid of any noise that interferes with what is most important to me: the enjoyment of the music.

I don't let charts, graphs or statistical findings worry me too much anymore. I let my ears be the judge to determine if what I am doing is a good thing or a bad thing. When I like what I hear, I stop processing the file... and do what I was put on this earth to do: Listen and Play music.

GB

[DJBohn]

Hi Geeb, I understand where you're comming from. I've taken that approach on a number of occasions, but usually with just my own records. Occasionally I will find a need to use the Punch & Crunch in a recording with a noisy background, or say maybe to add some reverberation to a small group recorded in a tiny dead sounding studio. I have found though the human hearing is too susceptible to improper conditioning or personal taste, at least when it comes to equalization. What could be a silk purse to one's hearing could be a sow's ear to another. So I tend to rely more on test measurements of my source equipment played back into the Spectrum Analyzer and compensating for EQ problems usually with the ParaGraphic EQ (or several of them...) while keeping my hearing completly out of that equation. At least that way I feel I have a shot at getting the EQ'd sound close to what the recording studios intended for you to hear.

[Geebster]

I guess that's why I trust my ears so much, since I've spent the better part of my adult life inside some sort of studio!!!

A musician buddy of mine claims that I was born with what he calls "perfectly flat hearing". Meaning that when I am mixing a piece of music, I don't like it too bassy or too trebley.

Under some situations, I do have to make allowances for the venue in which the piece will be heard and adjust to it's sonic quirks. But, for the most part, I can be thankful that I can trust my ears to at least some degree.

GB

[DJBohn]

Geebster, you're lucky to have been gifted with that kind of conditioning. I myself have only been lucky enough to have had access to a small recording studio on just one occasion, and it was in a high quality FM radio station. (But boy they sure had some nice equipment though!) I unfortunately grew up being subjected mostly to cheap cartridges & low quality cassette & (heaven forbid) 8-tracks connected to inexpensive receivers. I got sick of listening to everyone elses noise so I plunged into higher quality equipment in the late 70's and never looked back. Even though my standards were much higher, I still found differences in sound from one good speaker to the next, so I chose to rely more on what I measure. Limited finances tend to limit available sound quality. I could only wish I had had your exposure to the studios over the years! You must have a lot of good stories to tell!

[Geebster]

Hi DJ...

I'm really dating myself here, but I got introduced to good HiFi by my father, as he was always a perfectionist and always had to have the best audio that his pocketbook would allow. Back then, there wasn't stereo!!! But, boy we put together a killer home HiFi. We had a Scott integrated Amp with a whopping 30 Watts!! connected to a Altec-Lansing BiFlex Speaker that was about 5 foot high and about 30 inches wide. What we had was a beginning model of what A/L would later design as the "Voice of the Theater" speaker.

I can remember listening to all kinds of cool music on that HiFi... Esquivel, Ahmad Jamal, The New York Symphony performing Prince Igor ( a multi-multi record set!!) and so on.

My Mother was a Piano teacher, so I guess I was destined to be in the music industry with all that music surrounding me. Although I was trained in Violin and Cello; oddly I spent most of my working years as a DJ or Sound Guy.

I have too many stories to tell, especially about all the famous characters I have met in the music industry. Just like in the real world, some are super nice and easy to get to know and others are jerks.

Now I spend most of my time writing and performing my own music locally, and on occasion am a "hired gun" for mostly local recording projects.

Err... Sorry about that... I didn't want this to turn into my life story or anything!!!

But, it sounds like you like music as much as I do, and that is all that matters.

GB