18:06:15	 From Gary Louie - PNW Secretary : Nov 21 meeting - if you wish to attend the live meeting, it's at Digipen campus in Redmond WA - proof of vax required.
18:07:54	 From Alex George  To  Gary Louie - PNW Secretary(privately) : Gary, can we get the slide deck or wait for the recording?
18:09:47	 From Gary Louie - PNW Secretary  To  Alex George(privately) : Yes, we expect to post the video and have the slide decks available.
18:10:02	 From Luke Pacholski : Just got a question from FB: will the recording of tonight's presentation be available to the public?
18:10:55	 From Gary Louie - PNW Secretary : Yes, we expect to make the video recording and PPT deck available.
18:11:52	 From Don Hartley, CTS : Yes. Nice group of people here.
18:15:29	 From Tom Hannon : Hi Dan, Tom Hannon thannon6912@sbcglobal.net   thanks-a-bunch.
18:18:36	 From Bob Cavanaugh : Hi Jamie. Long time.
18:20:20	 From Dan Mortensen : Everyone please turn off your cameras
18:31:14	 From Robert Pettus : How do we post questions?
18:31:19	 From Luke Pacholski : I was just going to say presumably most people know what bias is and what its function is, but some might not and it might be helpful to go over that. If Jamie isn't doing that now.
18:32:09	 From Dan Mortensen : Post questions here
18:34:28	 From Dan Mortensen : and I’ll ask them. I also might ask you to elaborate.
18:38:36	 From Alex George : This is magic! Before I forget, does this process squash the dynamics?
18:39:56	 From Robert Pettus : I've heard some tapes where the bias frequency was not constant, especially in very early tube machines; I'm guessing from a power burp. I have a very early digital CD of some of the early Sun masters, and the bias was aliasing with the early digitizers, so you could hear the whistle. In the middle of the song, the bias frequency (and thus the whistle) took a wild swing. Wouldn't this mess up your process.  Note: later transfers don't have this problem.
18:45:21	 From Jerry Jensen : How is the center frequency chosen for the FM demodulator? The response of the demodulator must be close to DC, so at some point the correct speed at rest must be chosen, no?
18:47:11	 From Alex George : Just  curious: back in the day, did artists compensate for the tape medium's limitation to where this process could negate that and create undesirable artefacts?
18:50:57	 From Stephen DeVore : His audio might’ve dropped out.
18:51:07	 From Luke Pacholski : We lost him entirely.
18:51:12	 From Stephen DeVore : Or froze.
18:55:07	 From Bob Cavanaugh : I learned when I was working for Dolby that if you are doing transfers or whatever of audio material, it's worthwhile to audio-bandwidth-limit the original. Whatever noise or bias or digital aliasing will pass otherwise and possibly mess up your transfer.
18:59:56	 From Dan Mortensen : Bob C, I’m not sure how your comment relates to this presentation, as they can’t bandwidth limit the transfer as it would wipe out the bias which is used to effect the process. If I understand correctly, which is dubious.
19:00:04	 From Luke Pacholski : I'll just put this into the chat as to not interrupt again, but one tape I'd love to see Plangent run on is the mix reel for Blues Power on In Concert from Derek and the Dominos. At one point the pitch noticeably goes up, and then a few minutes later it goes back down. When the track was remixed it thankfully didn't have that problem; clearly on the original mix that section was mixed separately and edited in.
19:00:33	 From Dan Mortensen : Luke, your interruptions are helpful.
19:01:46	 From Wayne Bretl : Dan Mortensen - their process separates the audio and bias, so  the audio can be band limited
19:02:03	 From Dan Mortensen : OK, I’ll make that comment then.
19:02:39	 From Gary Louie - PNW Secretary : I think Bob C infers that those Sun transfers might not have had that whistle had they been band limited?
19:03:10	 From Bob Smith : timing is much tighter on the second
19:03:13	 From Dan Mortensen : Ah
19:05:19	 From John Chester : Re: bias causing whistle — Certainly important to either have adequate anti-aliasing filter on ADC, or make sure you have one in your signal chain prior to the ADC.  We’ve checked carefully for that problem and our ADC’s do have good anti-aliasing.
19:05:45	 From Mike Matesky : Sorry to be late. Just finished recording session. -Mike
19:06:37	 From Alex George : How often did you see tempo issues?
19:06:47	 From Ignacio Irigaray : the reproduction head is a standard one?
19:07:55	 From Herb Savran : How effective is this on spoken word recordings?
19:08:08	 From Bob Cavanaugh : Gerry - I'd have to give more consideration to it, but yes, or at least maybe.
19:08:36	 From Bob Cavanaugh : If I had audio time, I could describe why.
19:08:54	 From Robert Pettus : RE: Bias frequency question: I thought I had lost it. It is "Mystery Train" from Elvis. There is a huge spike at 16,292 hz. When I was younger that really bothered me, but I find that now I am old, I can't hear it.  I had to slow it down to 1/2 speed.  I'm processing it for upload.
19:08:59	 From Stephen DeVore : Would this work with Cassette recordings?
19:09:22	 From Stephen DeVore : (Cassette originals.)
19:11:11	 From Gary Louie - PNW Secretary : We plan to have plenty of time afterwards for live chat with cams/audio.
19:18:10	 From Alex George : Any case of content detail that cannot be heard in the playback of the original tape but now you hear after your processing? (Overall, this process is sheer magic!)
19:27:17	 From Bob Smith : surprisingly the difference can be observed over zoom !!!
19:27:33	 From Mac Perkins : is there a list of all the recordings you have processed?
19:28:03	 From Alex George : and available to purchase?
19:28:20	 From Stephen DeVore : $?
19:28:24	 From Luke Pacholski : I have absolutely no idea what Jamie is talking about.
19:30:36	 From Gary Louie - PNW Secretary : Hoffman forums thread on Plangent (long) - https://forums.stevehoffman.tv/threads/the-plangent-process.399347/
19:36:24	 From Simeon Cran : Why is there such diversity in the bias frequencies chosen for each tape machine model? Were the designers of these machines choosing different tradeoffs? What are the tradeoffs?
19:37:50	 From Simeon Cran : Could you do your transfers at slower speeds so the head bandwidth isn't so critical?
19:38:31	 From Robert Pettus : In the early days, powerful high frequency signals were hard to generate.  So a lower frequency was easier to generate, but a higher frequency worked better. The actual frequency was a compromise.
19:39:04	 From Robert Pettus : Some home consumer machines had bias frequencies as low as 50Khz.
19:39:48	 From Don Hartley, CTS : RME ADI-2 Pro
19:40:35	 From Jamie Howarth : Yea that one can do 768 though it doesn't sound super great.
19:41:12	 From Jamie Howarth : And how to word clock it with other converters that sound better.
19:41:12	 From Robert Pettus : Also, the exact frequency was unimportant so long as it was at least 2x or 3x the highest audio frequency.  Frequency stability had no value.
19:42:27	 From Robert Pettus : didn't I read that the THD of the bias frequency added to the noise by effectively giving a DC component to the bias frequency?
19:43:47	 From Robert Pettus : Lower speeds would give a lot more phase shift in the bass.
19:46:16	 From Simeon Cran : It's surprising that THD of the bias makes the noise worse - if higher bias frequency gives lower noise, wouldn't adding harmonics make the average of the bias components be at a higher frequency and thus give you lower noise?
19:47:17	 From Simeon Cran : Ah! makes sense! Thanks
19:47:30	 From Robert Cochran : It's the symmetry of the bias that is important
19:51:00	 From Jamie Howarth : One of my slides does show that if we backtrack later
19:56:36	 From Mac Perkins : What filter bandwidth do you normally wind up using?
20:04:07	 From Bob Cavanaugh : Rainey days to do it? Move here!
20:04:35	 From Bob Cavanaugh : hahahahahaha
20:07:41	 From Robert Pettus : Sounds like the Jackie Gleason Orchestra
20:09:11	 From Bob Smith : It is clear this process is not turnkey, but rather part art, part science, requiring considerable knowledge and technique on the part of the engineers.
20:09:28	 From Dan Mortensen : Yes, indeed.
20:11:56	 From Bob Cavanaugh : Jamie was never likely to do something to support his life on Nantucket that as easily duplicated...  DUH!
20:12:28	 From Bob Cavanaugh : OOOPS. sorry jAMIE...
20:13:12	 From Bob Cavanaugh : Sorry. I'm a really bad typist...
20:14:41	 From Alan Garren : how do you deal with speedpoint? changes at this
20:15:13	 From Alan Garren : how do you deal with speed changes at this point
20:15:41	 From Dan Mortensen : I’ll hold off asking until he’s through this part.
20:16:41	 From Jamie Howarth : He's showing the nominal setup and there is sometimes some drift and the system tracks and reflects the drift
20:17:07	 From Stephen DeVore : The DAW screen is too blurry to see what is being done on it.
20:17:17	 From Dan Mortensen : Thanks, Jamie
20:17:29	 From Jamie Howarth : digital de-emphasis.
20:20:13	 From Eric Weber : try again, Interesting concept on digital eq, to do an RIAA vinyl digital eq with 192 kHz output…. To take out the phase issues in the typical analog version
20:20:17	 From Jamie Howarth : "Music To Listen To Records By"
20:20:46	 From Stephen DeVore : The music is kinda cool, actually. The large bells were odd. lol.
20:21:59	 From Robert Pettus : I love elevator music. So relaxing.
20:22:06	 From Alex George : what is the output format? lossless mp3?
20:23:50	 From Luke Pacholski : Lossless PCM. John is currently using WAV.
20:25:38	 From Jamie Howarth : scrape flutter
20:25:50	 From Alex George : WAV. ... nice!
20:27:13	 From Alan Garren : or any fixed surface ie guides
20:28:32	 From Robert Pettus : Quite a bit different than my Dad's 1950's era Webcor
20:30:58	 From Alex George : Outside of bias, is the lack of sound fidelity largely attributed to the mechanical tranport of the tape recorder?
20:32:29	 From Bob Smith : that is right in the most sensitive region of the human auditory system
20:33:35	 From Alan Garren : its also what some of the people using tape are looking for, it makes the sound more aggressive, "more bite"
20:38:06	 From Robert Pettus : I'd say the #1 was electronic quality, #2 transport quality, then bias quality. UNLESS one of the factors was stupidly wrong.
20:38:24	 From Robert Pettus : Sorry, transport, electronics, then bias.
20:39:02	 From Bob Cavanaugh : show me?
20:39:45	 From Alex George : you almost had me scratching my head there with the first response, Robert! :-)
20:41:31	 From Robert Pettus : It's late on the east coast. my second statement is closer to my opinion
20:42:04	 From Alan Garren : baseband
20:42:17	 From Robert Pettus : BTW, FACINATIING presentation!!!!!
20:42:40	 From Alex George : This is magic!
20:43:10	 From Dan Mortensen : Alex, is this answering your question?
20:43:21	 From Dan Mortensen : This is all mechanical distortion.
20:43:52	 From Alan Garren : as we in broadcast called it, friggin magic, fm
20:43:54	 From Alex George : just for argument: can we build a precision tape tranport today where tape can be a viable recording medium?
20:44:28	 From Dan Mortensen : Let’s ask that in a little while after we’ve explored all this distortion analysis.
20:45:13	 From Gary Louie - PNW Secretary : Sorry, the late Dale Manquen's site (manquen.net) now seems to go to a viagra site.
20:45:26	 From Bob Cavanaugh : Tape machines are a machine shop product.
20:45:44	 From Alan Garren : we need to get back upave a copy of it, I h
20:45:44	 From Luke Pacholski : Dale's site still works here.
20:46:20	 From Luke Pacholski : Also various scrapes over the years on the Wayback Machine.

http://web.archive.org/web/20190202095952/http://www.manquen.net/
20:46:43	 From Gary Louie - PNW Secretary : Eek, Google gave me fake link
20:46:55	 From Jerry Jensen : Is there any fleeting hope of this fantastic process being completed without two experts hand-tweaking several aspects?
20:47:08	 From Rick Chinn : perhaps someone should get in touch with Dale’s heirs (sons?) to make arrangements to harvest the site and/or to pay for it to remain online.
20:48:02	 From Dan Mortensen : Jerry: What would be their incentive to remove themselves from the process?
20:48:16	 From Luke Pacholski : Mortality?
20:48:28	 From Dan Mortensen : There is mortality.
20:48:42	 From Bob Smith : Thank-you to our presenters. This has been an exceptionally informative presentation. I have an 0530 start tomorrow. Must fade to black very soon.
20:48:50	 From Rick Chinn : jh: why would dale’s sons want to remove themselves from the process?
20:48:59	 From Robert Pettus : Nothing wrong with digital so long as you understand the limitations. The trick is to optimize whatever technology is available. They made great recordings at 78rpm to wax.
20:48:59	 From Dan Mortensen : Take care, Bob, good to see you as always.
20:49:02	 From Luke Pacholski : http://www.manquen.net/audio/
20:49:07	 From Rick Chinn : BS: it sounds like corporate is still pulling your chain. take care!
20:50:21	 From Mike Matesky : As with Bob, I’ve an early morning recording session (7:30 a.m.!) requiring setup before. As I type I’m already fading to black. Thanks so much, Jamie and John. Excellent!!
20:50:37	 From Mac Perkins : Dale's flutter database is there on the wayback machine site.
20:51:14	 From Luke Pacholski : http://web.archive.org/web/20190121222113/http://www.manquen.net/audio/docs/Flutter%20database%2002-8-28.htm
20:51:19	 From Robert Pettus : I have enjoyed this presentation immensely. However, morning comes pretty early around here and we're pushing midnight EDT.  Will the dropbox links be distribued by email somehow?
20:51:24	 From Alex George : Is the source colored by any of the A2D and D2A?
20:51:46	 From Don Hartley, CTS : Thank you for a great presentation!
20:52:01	 From Rick Chinn : I must depart now. Really interesting presentation!
20:53:33	 From Eric Weber : The vintage toy for analysis….  https://drive.google.com/file/d/1RelXF1f4ikmBWV1hTKT1CtXO378hSADm/view?usp=drivesdk
20:55:41	 From Alan Garren : what are the harder transfer problems
20:56:28	 From Jerry Jensen : To answer my earlier question, No. And experts like these  are few if any.
20:56:57	 From Chris Myring : Thank you,  John and Jamie. 0500 here and I'm still awake!
20:58:30	 From Gary Louie - PNW Secretary : The Plangent public Dropbox link was previously sent out to ticketholders in email to give the Powerpoints, but here it is again: https://www.dropbox.com/sh/99lk8inz03iadrd/AAAOrJDFZCJQUymNasKr8YLJa?dl=0
20:58:53	 From Simeon Cran : My cynicism about the record industry is being triggered. Which corner of the industry is actually prepared to spend the time and money to do transfers with this sort of care?
21:00:47	 From Chris Myring : Which machine do you favour for multitrack recovery?
21:01:21	 From Mac Perkins : Is the bias signal taken from both ntracks summed or just one?
21:02:09	 From Luke Pacholski : Explanation of azimuth to those not familiar?

(I am, but others may not be)
21:03:49	 From Eric Weber : So any classical projects ?
21:04:28	 From Alex George : any interesting anecdotes about the way sound mixing was done back  in the day, stylistic. or otherwise? (I noticed one othe instruments in one of the transferred ouput was louder relative to other instruments ... is that because the instrument's output was compensated to pop out above the tape noises during the original mastering?)
21:05:31	 From Alex George : Has any of the original recording artist listened to your transfers? If so, what was their reaction?
21:05:39	 From Robert Pettus : How do I upload the demonstration file about bias artifact to this dropbox?
21:10:53	 From Mac Perkins : Next trick, automatic azimuth correction.
21:11:44	 From Matthew Sutton : Thanks all, gotta jump. Incredibly impressive array of talent at work on solving this problem. Great to see it in depth.
21:11:46	 From Alex George : Mac, that would require a robotic mechanism? LOL
21:12:05	 From Dan Mortensen : Nice to have you with us, Matt
21:13:22	 From Greg Dixon : We had a great meeting with Tom Fine about Mercury Living Presence that should be online
21:16:00	 From Simeon Cran : Really great!
21:16:11	 From Alan Garren : kudos
21:16:33	 From Alex George : Terrific presentation ... outstanding talent!
21:17:00	 From Jayney Wallick : Absolutely! Many thanks!
21:17:07	 From Mac Perkins : Thank you Jamie and John for your development of the Plangent system and presentation tonight.
21:18:21	 From Randy Karl : Thanks for the presentation! Gotta go it's after 11 here.
21:20:28	 From Gary Louie - PNW Secretary : It's Alan Garren and his evil twin
21:21:23	 From Stephen DeVore : Gotta run, but Need Paying work: Have Degree in Audio Engineering; UW Sound Production Certificate; Certificates from The Recording Workshop which is in Ohio. Have done Film Sound. And long time ago got certificates in Pro Tools: PT101, PT201, PT210M, and PT210P. Cheers! Stephen DeVore, 206-288-3881.
21:21:29	 From Don Hartley, CTS : Wonderful discussion tonight! I have to go now. Have a nice evening!
21:23:40	 From Simeon Cran : No mic here, but me: Redmond WA, software engineer with much love for electronics, ex MSFT,  ex radio/TV industry in Australia. Lots of fond memories of these old tape machines from lots of Australian music and voice over recording studios.
21:29:33	 From Chris Myring : In the UK. No mic and camera on this computer, sorry to say. A lifetime 'on the road', in the studio and repair shop. Long time Ampex List member too. Thanks to all for the presentation. Website: myringwiring.co.uk
21:38:00	 From Luke Pacholski : DANSOUND INC
21:42:17	 From Wayne Bretl : applause!
21:43:37	 From Stephen DeVore : Tea Time, perhaps.
21:44:31	 From Luke Pacholski : brb
21:50:58	 From Chris Myring : Please put me down for a Tea Time Chat reminder. I'd like to give it a try, work permitting.
21:59:01	 From Luke Pacholski : Does anyone care to watch a minute or two of the show I did in May?