ELP Turntable - Ask Me Anything!

[Jerfo]

Even with the low rip level for CD4 I would expect to see more of the FM modulated signal over 30kHz- 45kHz, doesn't seem to be a lot got through in that frequency range. Worth a try though.

Here's a spectrum sample from the CD-4 adjustment record:

There are a couple peaks in the 40-48k range above the noise floor, so that gives me hope.

 

[Jerfo]

Could you do it at 96/24? Thanks! (just curious)

Oops! It was, but I forgot to extend the range on the spectrogram. Let's try that again:

 

[Jerfo]

Quick update: I've cobbled together an improved digitizing setup, which involves a couple of buffer guitar pedals; a little unusual I know, but they help with impedance issues. This has significantly lowered the noise floor on my rips. Using the following convoluted path, I was able to successfully and correctly demodulate my CD-4 calibration record as played from the ELP:

ELP -> 2x Buffer -> Behringer U-Phoria UMC202HD (at 24/96) -> Inverse RIAA -> PSpatial Audio Stereo Lab software CD-4 Demodulator -> WAV file

This is very encouraging!

 

[fredblue]

I have a couple of CD-4 calibration LPs, so my plan is to use those from this point on.

ok

 

[Jerfo]

See the edited top post for links to a rip that I made from the ELP...

 

[winopener]

it feels like none have suitable Quad mixes where you can really get anywhere near true isolation in any one channel.
while Cat Stevens is a torture test for sandpaper/distortion bursts, the mixes are a mess and feel kinda unhelpful to see if things are separating properly.

That's exactly the reason i suggested that disc, first of all *tracking* of the CD4; then if tracking is ok, next step is separation, and, other that setup disc, i know no better CD4 source for checking the separation than Average White Band, especially Pick Up The Pieces.

 

[kap'n krunch]

Oops! It was, but I forgot to extend the range on the spectrogram. Let's try that again:

View attachment 50515

Thanks!
I see this was sampled at 192K
Very interesting peak at around 48K...

 

[Jerfo]

Thanks!
I see this was sampled at 192K
Very interesting peak at around 48K...

No, it was 96k. That red line at 48k is just the VST's way of showing the upper bound of the input signal.

 

[fredblue]

That's exactly the reason i suggested that disc, first of all *tracking* of the CD4; then if tracking is ok, next step is separation, and, other that setup disc, i know no better CD4 source for checking the separation than Average White Band, especially Pick Up The Pieces.

oh absolutely, of course nailing the tracking is the main thing. i was just saying for Jerfo's sake that i feel it is maybe easier to work out what's going on when setting up CD-4 gear using some Quad mixes than others.

also, i agree totally the AWB Quad mix has some fantastic tracks for adjusting the separation pots. that big saxophone blast at the beginning of the solo of Pick Up The Pieces is a good distortion test if trackings out and so forth it'll splat and i have been on the receiving end of such sandpaper-y unpleasantness a few times!

i respect you have been at this a lot longer than i have and i still haven't perfected CD-4 by any means so i certainly would not dispute your methodology or advice.
i've only mucked around with CD-4 for approximately 5 years now, though its been intense/intensive (!) through 4 different stylii (only one works "ok", the other 3 patchy at best) and 4 demodulators (2 ok, 2 positively junk).

i would say its not as straight forward a system as some people have made out in the past. personally i think because they weren't going for maximum separation but instead best sound quality with least distortion (which is absolutely fair enough).. but this is possibly another discussion for another day lets see how Jerfo gets on with the ELP! good luck to him!

 

[DuncanS]

Here's a spectrum sample from the CD-4 adjustment record:

View attachment 50514

There are a couple peaks in the 40-48k range above the noise floor, so that gives me hope.

There is something there, they look like discrete tones.

Quick update: I've cobbled together an improved digitizing setup, which involves a couple of buffer guitar pedals; a little unusual I know, but they help with impedance issues. This has significantly lowered the noise floor on my rips. Using the following convoluted path, I was able to successfully and correctly demodulate my CD-4 calibration record as played from the ELP:

ELP -> 2x Buffer -> Behringer U-Phoria UMC202HD (at 24/96) -> Inverse RIAA -> PSpatial Audio Stereo Lab software CD-4 Demodulator -> WAV file

This is very encouraging!

Great, fortune favours the brave!

 

[paligap]

Thanks for the info and rips. By the way, I love your Silence and Self-Reflection album. Anything in the works?

 

[Jerfo]

Thanks for the info and rips. By the way, I love your Silence and Self-Reflection album. Anything in the works?

Thanks! I won't have anything anytime soon, unfortunately. I have some rough outlines for some new material but I haven't had any time to develop them beyond that.

 

[fredblue]

Video on Laserdiscs is analogue, read by a laser, and there’s never been a debate about it!

Analogue vs Digital is how you store the information, not how you read it. And before digital information is brought into digital circuitry, it is read by analogue electronics, because our physical world is inherently analogue!

just re-reading this with fresh eyes, this is a very interesting perspective you put forward!

i had heard previously that the ELP was limited to equivalent 44.1kHz.. wonder what components restricted the turntable to that (a pre-amp? an ADC/DAC?).. and question now how accurate that info actually was seeing as we have Jerfo here proving to be getting higher resolution from the turntable.. hmm..

 

[fredblue]

Thanks! I won't have anything anytime soon, unfortunately. I have some rough outlines for some new material but I haven't had any time to develop them beyond that.

just curious what record cleaning system/method you use at present?

fwiw i found cleaning the old CD-4's in an RCM that wet cleans and then sucks all the crud out helped somewhat.. though several discs just seem beyond help.. yes Jose Feliciano's Compartments, i'm looking at you! all 3 copies i have of his CD-4 of that one must be trashed because they all demodulate like dogs! (no offense to Pupster, or subwoofers!) woof!

 

[Jerfo]

just curious what record cleaning system/method you use at present?

Here's what my simple (?) 14-step cleaning routine looks like:

1. Load Side B of the record on a direct drive turntable.
2. Use my Vinyl Vac (connected to a small Shop Vac) to do a dry clean on Side B as a first pass on getting rid of dust.
3. Spray my homemade cleaning solution (featuring either Triton X-100 for Tergitol) on a paint edger like this: Shur-Line Paint Edger Pad Refills for Classic and Pro Edgers and Corner Painter (2-Pack)-2001047 - The Home Depot . Spread the solution all over Side B using the edger.
4. Run the Vinyl Vac over Side B for just one quick revolution to get the excess cleaner off.
5. Spray distilled water on a second paint edger and spread over Side B.
6. Run Side B through a thorough Vinyl Vac dry.
7. Flip the record over to Side A.
8. Repeat step 2 for Side A.
9. Use the cleaning solution edger on Side A.
10. Use the Vinyl Vac to clean the solution edger.
11. Repeat Step 4 for Side A.
12. Use the distilled water edger on Side A.
13. Use the Vinyl Vac to clean the distilled water edger.
14. Repeat Step 6 for Side A.

This process gives me spiffy clean records and keeps my paint edgers from getting moldy and gross.

 

[fredblue]

Here's what my simple (?) 14-step cleaning routine looks like:

1. Load Side B of the record on a direct drive turntable.
2. Use my Vinyl Vac (connected to a small Shop Vac) to do a dry clean on Side B as a first pass on getting rid of dust.
3. Spray my homemade cleaning solution (featuring either Triton X-100 for Turgitol) on a paint edger like this: Shur-Line Paint Edger Pad Refills for Classic and Pro Edgers and Corner Painter (2-Pack)-2001047 - The Home Depot . Spread the solution all over Side B using the edger.
4. Run the Vinyl Vac over Side B for just one quick revolution to get the excess cleaner off.
5. Spray distilled water on a second paint edger and spread over Side B.
6. Run Side B through a thorough Vinyl Vac dry.
7. Flip the record over to Side A.
8. Repeat step 2 for Side A.
9. Use the cleaning solution edger on Side A.
10. Use the Vinyl Vac to clean the solution edger.
11. Repeat Step 4 for Side A.
12. Use the distilled water edger on Side A.
13. Use the Vinyl Vac to clean the distilled water edger.
14. Repeat Step 6 for Side A.

This process gives me spiffy clean records and keeps my paint edgers from getting moldy and gross.

well that feels fairly 14-pointedly comprehensive enough for even the grimiest of CD-4 LPs!

good job Jerfo, good job!

edit: fwiw however, i've had some CD-4's that were noisy (or poppy or demodulated patchily) even after a good few spins in the RCM and several plays with a Shibata and/or MicroLine and yet in at least one case (Donny Hathaway's Extension Of A Man) i came across this situation quite by accident where even after a good few cleans and a number of plays with a "CD-4 suitable" stylus i used one of my ellipticals by mistake (think the Denon, may have been an old Ortofon) which then started to rake out what i can only describe as small clumps of dust and crud..!! these may have been impacted in by the elliptical stylus of a previous owner of the disc, i don't know but it was a real surprise.. and, lo and behold next time i played it with a Shibata/ML the disc was less noisy and demodulated better. spooky or what!

 

[soundsation]

Interesting 14 step cleaning method, and I will try some of suggestions. I don't have a fancy spin machine, but of course when started with CD-4 and simple wet cleaning, I noticed sometimes CD-4 cleaning is sometimes easy to push more grime into grooves compared to normal lp.

FredBlue, interesting discovery. I have some duplicates of CD-4 lps and interesting to compare effects of an elliptical played on one trac at particular weight, and 2nd trac played at more tracking weight, and then compare with shibata. I don't know I would put the 2nd tracking weight of my M7-21D, but I think I would like to try a test like your discovery. Used CD-4 records can vary quite a lot: look great, but noisy, some not look so great and are not noisy. I have a James Taylor Gorilla CD-4, and is scratched up, but is quiet, and a great disc.

 

[fredblue]

Interesting 14 step cleaning method, and I will try some of suggestions. I don't have a fancy spin machine, but of course when started with CD-4 and simple wet cleaning, I noticed sometimes CD-4 cleaning is sometimes easy to push more grime into grooves compared to normal lp.

FredBlue, interesting discovery. I have some duplicates of CD-4 lps and interesting to compare effects of an elliptical played on one trac at particular weight, and 2nd trac played at more tracking weight, and then compare with shibata. I don't know I would put the 2nd tracking weight of my M7-21D, but I think I would like to try a test like your discovery. Used CD-4 records can vary quite a lot: look great, but noisy, some not look so great and are not noisy. I have a James Taylor Gorilla CD-4, and is scratched up, but is quiet, and a great disc.

i think appearances can be deceiving with CD-4..

i've a copy of the Doobies' Vices which looks to be in amazing condition yet splats like a right old splatterer on a couple of tracks and yet another copy which looks ropey by comparison with a scuffed up disc surface, dogeared sleeve and all but doesn't distort on those same tracks!
Road Angel is one of those tracks, i wince everytime on the good-looking disc, i know the distortions coming. whether the disc was pressed like that or damaged by a previous owner i don't know?

i've had some Quads that were problematic when fresh out of the shrinkwrap such as Godspell CD-4, as fresh as new old stock can be with a 40-year old record, skips several times with horrible distortion in places

 

[MidiMagic]

Since RIAA specifies an additional 18 dB/octave roll off above 22 KHz in addition to the 20.9 dB attenuation already at 22 KHz, I am surprised you got anything at 30 KHz.

 

[J. PUPSTER]

oh absolutely, of course nailing the tracking is the main thing. i was just saying for Jerfo's sake that i feel it is maybe easier to work out what's going on when setting up CD-4 gear using some Quad mixes than others.

i respect you have been at this a lot longer than i have and i still haven't perfected CD-4 by any means so i certainly would not dispute your methodology or advice.
i've only mucked around with CD-4 for approximately 5 years now, though its been intense/intensive (!) through 4 different stylii (only one works "ok", the other 3 patchy at best) and 4 demodulators (2 ok, 2 positively junk).

Which one Freddie, a Shibata on a AT440Mlb?