PDA

View Full Version : Baking a tape to "stabilize" the sound?


mbself
2009-06-27, 09:40 PM
I know now that baking a tape before transfering it to digital is considered a good practice on tapes of a certain age or newer tapes stored in poorly regualated climates.

But, my question is this:

What exactly does it do? I have older cassettes that have a weird, slow "wooshing" sound. Almost a phaser effect where highs seeme to come and go. The sound will be good and then slip out for a few seconds and then slip back in to the good.

Is this the type of thing that baking will correct, or is that just the sound of a tape FUBAR'd and baking would do nothing for it? I know that in a very strict sense the purpose of baking is to simply allow the tape to hold together during playback without disentegrating in the playback mechanism and gumming up the transport.


I could experiment, but if someone knows.......

direwolf-pgh
2009-06-27, 10:20 PM
I've never heard of anyone baking a cassette :popcorn: be sure to take lots of pics

dude87
2009-06-27, 10:41 PM
See http://en.wikipedia.org/wiki/Tape_baking for some general info on tape baking and when to try it.

paddington
2009-06-27, 11:13 PM
it won't fix the whoosh.

over time, stored tapes can have a weak magnetic pull affecting them on one side or the other (could be a speaker, electrical line or many other things). After years of sitting in the same place, that electro-magnetic disruption has the effect of skewing the bias on the one side of the reel to be different that the other. When the tape plays back in a linear fashion, you get:
good-fadeto-bad-fadeto-good-fadeto-bad
over and over

usually, the tape is screwed when you have this problem

in some cases, an azimuth adjustment can minmize the problem.

mbself
2009-06-28, 10:29 AM
I've never heard of anyone baking a cassette :popcorn: be sure to take lots of pics



:D I know, it is a funny image. I have reels as well, but the cassettes are the only ones with this particular sound. Obviously would have tested the process on blank or something of little value first. I think the temp most people recommend is about 135 so actually doubt it to be hot enough for any melting to occur. Especially if you protect the tape from direct heat from an oven element. Placing a baking sheat on the bottom shelf and the cassette on the top shelf should do the trick. Would probably do the same for a tape in a metal reel.

Thanx jameskg. Great info. Will save the effort then.

showtaper
2009-06-28, 10:40 AM
:D I know, it is a funny image. I have reels as well, but the cassettes are the only ones with this particular sound. Obviously would have tested the process on blank or something of little value first. I think the temp most people recommend is about 135 so actually doubt it to be hot enough for any melting to occur. Especially if you protect the tape from direct heat from an oven element. Placing a baking sheat on the bottom shelf and the cassette on the top shelf should do the trick. Would probably do the same for a tape in a metal reel.

Thanx jameskg. Great info. Will save the effort then.

Your problem is more likely a bad pressure pad. These do not age well. Instead
of doing their job (helping to maintain tape to head contact) they can actually
cause the tape to skew making the sound you describe. A good double capstan
deck does the same job, making the pressure pad redundant.

I would suggest you try both of these techniques:

1) Remove the pressure pad and play the tape in a good double capstan deck.

2) Buy a new cassette tape (one held together with screws) and put the tape
you want to play in the new shell (thus having a new pressure pad).

This has worked many times for me.......

mbself
2009-06-28, 10:54 AM
Your problem is more likely a bad pressure pad. These do not age well. Instead
of doing their job (helping to maintain tape to head contact) they can actually
cause the tape to skew making the sound you describe. A good double capstan
deck does the same job, making the pressure pad redundant.

I would suggest you try both of these techniques:

1) Remove the pressure pad and play the tape in a good double capstan deck.

2) Buy a new cassette tape (one held together with screws) and put the tape
you want to play in the new shell (thus having a new pressure pad).

This has worked many times for me.......


Thanks, this may work to rescue something i want badly to fix.

Oh, and by the way, my oven only goes down to about 170 and even if it went to 100...cheap home oven thermostats are terribly innacurate. Probably need to find a food dehydraytor or something similar. Anyone have a Blue M oven? :lol4:

GRC
2009-06-28, 03:42 PM
Your problem is more likely a bad pressure pad. These do not age well. Instead
of doing their job (helping to maintain tape to head contact) they can actually
cause the tape to skew making the sound you describe. A good double capstan
deck does the same job, making the pressure pad redundant.

I would suggest you try both of these techniques:

1) Remove the pressure pad and play the tape in a good double capstan deck.

2) Buy a new cassette tape (one held together with screws) and put the tape
you want to play in the new shell (thus having a new pressure pad).

This has worked many times for me.......

+1.

Your problem isn't likely to be sticky tape syndrome, but more likely the tape 'wandering' over the heads due to pressure pad failure or some other distortion of the cassette shell or the hubs; it's the change in alignment, the movement over the playback head, that's causing the whooshing phasing sound.

The tapes affected by the problem that requires baking are typically Ampex tapes - what brand do you have here?

If you ARE considering baking the tape, I'd recommend removing it from the case first!

mbself
2009-06-28, 11:35 PM
+1.

Your problem isn't likely to be sticky tape syndrome, but more likely the tape 'wandering' over the heads due to pressure pad failure or some other distortion of the cassette shell or the hubs; it's the change in alignment, the movement over the playback head, that's causing the whooshing phasing sound.

The tapes affected by the problem that requires baking are typically Ampex tapes - what brand do you have here?

If you ARE considering baking the tape, I'd recommend removing it from the case first!


with the evidence pointing towards magnetic field issues as described by jameskg or pressure pad failure, as you and showtaper have suggested, baking is definately out of the question on my cassettes. Thanks.

paddington
2009-06-29, 12:11 AM
bake them after you xfer, anyway... should be a great youtube vid :lol:

Ask Tom Scholz of Boston (Baaastin) about having to bake tapes... he took so long to finish "Third Stage", he actually had to bake some master reels to finish mixing!

ChrisF
2009-06-29, 04:14 AM
there was a pretty good explaination in the smashing pumpkins archive newsletter a few months ago about the subject. and a tape they were talking about baking in the newsletter was hosted on thetradersden from a previous transfer from years ago

http://www.thetradersden.org/forums/showthread.php?t=428&highlight=ignoffo

Hello again,

Welcome to the second Archive Newsletter. I am now entering the third week on the job, and I just want to say that I’m really excited about the project. I want to get into the more technical details about the archive. One of the biggest problems with storing media that is over 20 years old is tape deterioration. One example of this is the Ignoffo Demos. Mark Ignoffo was a studio engineer that worked with the band in 1988-89. The band would record demos at Reel Time Studios and then sell them at shows. The Moon Demo was a demo tape that was sold at shows in 1989 for $5. The songs from this period would include Stars Fall In, Daughter, and Bye June. These songs have been widely bootlegged out, but the quality has been questionable because many of these were sourced from old cassette tapes. The band has the original reels from those recording sessions in the archive. Throughout the years, these tapes have started to deteriorate and flake. Recently, the band has started to rescue these recordings. A technique to rescue tapes that are starting to flake is through baking. The tapes would be placed in an oven, and baked for a specific period of time. This restores the tape so that it can be transferred. In these cases, we often have one chance to transfer the tape before the tape is lost for good. The Ignoffo Demos were baked for 72 hours! Then they ran them through Pro Tools at 24-bit/96kHz, and the outcome was amazing. They sound so much better than the bootlegged versions that fans have. This would definitely be an upgrade if you already have these songs.

The next step is to rescue other tapes and reels that have started to deteriorate. All of the material in the archive is stored in a climate controlled environment in order to preserve them, and slow down the effects of time. Tapes and reels aren’t the only material that we have to carefully monitor. Paper is another concern for us. I’m currently going through and cataloging the band’s posters. I have found some early posters from the Gish era, and there are a few that have started to show their age. A way to combat this is to store them in acid-free polyester Mylar sleeves. The Library of Congress also uses the same types of sleeves for archival storage. I’m creating a system that will catalog and preserve all of the posters and artwork from the band. Eventually this system will include all of the promotional material that I’ve talked about in my recent blog post. I hope this sheds some light on what we’ve been doing. I’ll talk to you all next week!

Frank