Conference napalm::commusic_v1

    Dropout is usually thought of as a tape problem, not a transport
    problem.  You don't say anything about what kind of tape you're using,
    so there's not much to follow up there.  Older, much-reused tape will
    be more susceptible.
    
    Be that as it may, the fact that the dropout seems to be confined to
    the drums is curious, leading suspicion away from the tape.  Is there
    any chance you have an intermittent connection somewhere on the path
    from the drum source to the recorder?  Have you tried replacing the
    cables?  Are the drums live?  Are you monitoring the sound at high
    levels while recording?  High level ambient sound can aggravate some
    mechanical intermittents.
    
    I'd put my money on an intermittent.  I've had no problems with
    cassette dropout, and whatever apparent dropouts I did hear were always
    ultimately traced to an intermittent, usually a bad cable, plug or
    jack.
    
    len.
    

    
    
    re: .-1
    
    	As far as tape is concerned, I'm using TDK "Soundmaster" 
    10 minute Chrome cassettes. 
    
    	To clarify the cabling/etc. The drum machine goes thru
    a MIDIverb II then direct to the 4 track. I also use the
    MV II for guitar FX, where it appears to work fine. Running
    the TR505 direct to the machine seems to exhibit the same 
    symptoms.
    
    	Perhaps a larger question is in order: What exactly 
    is a dropout. Maybe what I'm hearing is something other
    than a dropout.
    
    -T
    

    Well, Tom, not having heard it, we can't do a whole lot.  The fact that
    you mentioned edge tracks having more problems makes me think about
    tape squirm.. are the pinch rollers really, really clean ?
    
    But those kind of problems would be more apparent on sustained tones
    rather than abrupt percussion.  Since I don't understand it, I've never
    really trusted dbx.  Did some 8-track recording on live drums with dbx 
    years ago, and they sounded bizarrely compressed and unreal to me. 
    First impressions, I guess.  It could be the dbx tracking circuit is
    slow, and fast percussive signals outrun it somehow.  Not to rathole 
    this, but I like Dolby C.
    
    Another thing; the finest tape is useless unless the deck is
    specifically biassed for it.  The slow speed of cassettes makes this
    doubly critical.  Do you know if they biassed it for the tape you use?
    
    karl

       To answer your question, tape dropouts are audible as (hopefully)
       brief intervals where the sound coming from the tape disappears
       or is diminished.  This really is a rare problem with today's
       tape, especially when fresh.  It will be more likely to occur
       near the ends of the tape, due to manufacturing processes.

       Have you tried using other types of tape?  Does the problem occur
       with the noise reduction circuitry disabled?  If you record a
       continous tone for the length of the tape you'll be able to hear
       if it's really responsible for the phenomena you're experiencing.

       

    
    
    re: .-1
    
    Karl, I know it's hard to analyze a problem that can only be described
    by hearing it. I was (secretly, perhaps) hoping that it was a common
    problem with gear of this type.
    
    I believe that the rollers are clean, but the deck has not been biased
    for the tape I'm using. 
    
    Brian Rost has graciously agreed to "have a listen" to see if between
    the both of us we can come up with a description. I still have the
    chance to return this deck, so hopefully having someone else hear it
    will prove conclusive, though I doubt it. 
    
    -T
    

    
    
    re: Karl's reply
    
    	I didn't mean to give the impression that it's only the outside
    tracks with the problem or more problems. The technican who worked
    on the machine mentioned this in his labor report.
    
    -Tom
    

    
    Two things come to mind immediately.
    
    1) pressure pads on the tape may be worn or damaged. This can cause
       tape dropouts even with the deck cleaned and aligned.
    
    2) the drum signal is overloading the deck's inputs. You seem to be 
       running the drum machine uncompressed. Try recording the drums at
       a lower VU level to see if the 'dropouts' go away. If so there's
       probably nothing wrong with the tape, but your recording technique.
    
    Good luck
    
    CdH
    

    
    
    re: .-1
    
    	I forgot to mention that I did compress the drum machine
    using a DBX 163X compressor. The bass track was also done
    this way. 
    
    	As far as worn pressure pads, do you mean on the tape itself? 
    I've used more than one tape with more or less the same results.
    
    

    
    A dropout sounds like a gremlin simultaneously turning the "tone"
    control to full bass and the "volume" control to full off, and then
    turning them back up again.  Total time in the dropout can be as short
    as 1/20 sec or as long as a full second.
    
    What's usually happening is the tape is not being held snugly against
    the record or playback head, and as the tape loses contact, the first
    loss is of high frequency signals, followed by the low frequencies.
    As the tape comes back into contact, the lows come back first.  
    
    Dropouts can be caused by dirty heads, dirty tape, stretched
    (non-planar) tape, over-used tape, tape abused by tape transport
    mechanism, tape capstan and/or pinch roller out of alignment, old
    (stiff) tape, etc...  The cure is to clean the works  thouroughly, and
    try some fresh tape.
    
    [note- if the tape edge looks "ruffled" then it's a capstan/pinchroller
    problem and the tape machine needs to be serviced by competent
    technicians- who should be warned of the pinch alignment problem so
    they don't get their calibration tape eaten by your misaligned
    rollers.]
    
    	-Bill
             

    I forgot to add-
    
    One of the worst cases of "dropout" I ever saw was caused by the
    cassette's pressure pad becoming detached from the spring and falling
    off!  It was on a brand-name tape that had become a little overheated,
    softening the adhesive between the felt pad and the metal part.
    
    	-Bill

    Tom - could you describe what you're hearing?
    
    len.
    

    
    
    Ok, I'll try... :-)
    
    
    	I guess the best description is a sort of a "glitch" in the
    sound. Instead of being a clean recording, the sound is garbled for
    a split-second and then returns to normal. 
    
    	It's important to note that I don't hear it from the source
    as I monitor during recording. Only on playback.
    
    	I'm not sure this description helps any.. :-(
    

    Does it always occur at the same place? (Indicating it's a recorded
    glitch.) Or does it happen at various places on the tape, indicating
    a playback problem...
    
    Edd

	the tape is losing contact with the head.  I can fold up or
	slant away or get loose so that it is not tight.  This can be
	intermittant in old decks.
	Tom

    
    
    re: Edd
    
    	It always appears in the same place, once recorded. 
    
    re: Saturation
    
    	But I'm running *very* low levels. 
    
    re: Everyone
    
    	Thanks for all the info so far. It has helped me attempt to isolate
    the problem.
    
    -T
    

    
    
    	After having a second set of ears listen to it, it appears
    that what I'm hearing is indeed dropouts and that it's fairly
    random, meaning that it's probably not on the recording side, 
    but during playback. 
    
    	I've been told that dropouts are fairly common in 4 track 
    cassette decks. I can accept this, but it does disappoint to
    some degree. :-( 
    
    	That problem identified, what do *you* do to help minimize
    dropouts on your 4 track machine?
    
    -T

    First off, use good quality tape. (I assume you are.) Pay special
    attention to the cassette housing. I've found that sometimes the
    plastic shell isn't screwed together properly and it allows the
    tape to 'drift' in the path. Always more noticeable at the tape
    ends, less so in the middle.
    
    Second, keep the tape path C-L-E-A-N, including the pinch rollers.
    Get a good tape cleaning kit and a can of compressed air.
    
    Edd
    

Since I'm waiting for my first-ever 4-track to arrive via UPS, I was interested
in the references in .17 and .18 to dropout being "common" in these machines.

Just so I know the difference between a problem which warrants repair and an
annoyance which I've got to live with, how common IS this problem if one
follows the recommendations supllied in .18? Does it happen hardly ever, or
almost always, or what?

Thanks in advance.

Cheers,
	Bob

    
    
    	In my case, it's pretty frequently, but intermittant. 
    
    

Well in the years I had my tascam 234 I never had tape dropouts. I always used
top of the line tape, I always kept it clean and de-magnetized.

I did experience dbx breathing, and tape saturation that aggravated the 
breathing problem. This can sound like dropouts. Typically the bass guitar
or drum track will cause breathing problems, dbx recommends boosting the
high end when you record and cutting it when you play back/mix to help
manage the problem. Saturation will cause the dbx to breathe as the dynamic
range gets screwed up when you clip. Sounds like you aren't clipping but 
you still might be breathing, also a too low recording level will cause dbx to
breathe in certain circumstances (according to the engineer at dbx I talked
to a bunch of years back) I may have seen that with my old dbx 128 that 
I used in my stereo but can't be sure.

I have heard many horror stories about dropouts being common, but in my case
I never have seen one on a 4 track. I have experienced them on a stereo
cassette and always when using inferior tape.

I recommend:

Sony HX-PRO
DENON HD-8
Maxell UDXL-IIS
TDK SAX

in that order based on my saturation and sound quality experiments using my 
8 track cassette machine (Tascam 688), which in theory should have all the
problems of any tascam 4 track since it uses two of the same heads.

dbii

    Have you mentioned what kind of tape you were using?
    
    The advice to use good tape is really good advice.  You don't want to
    have to scratch 3 perfect takes on the first three tracks when you
    discover that there is some problem on track 4.
    
    As my deck is permanently biased to TYPE II - I buy the best type II
    tape I can get my hands on and in the thickest (shortest playing time)
    formulation I can find.
    
    Right now that's Maxell UDXL-IIS C-60s.
    
    I think it's important to try and find thicker formulations because
    4-track tapes are subjected to more abuse than normal tape recording
    due to the constant playback, rewinding and FF that goes with doing
    re-takes and re-mixes and what not.  That tape tends to get stretched
    or worn out faster.
    
    Now I'm sure there are many people who have never had problems with
    C-90s, but I had one (on a SYNC track) and that was enough hassle
    (I.E. redoing EVERYTHING) to decide to do whatever I could to lower
    the risk.
    
    I suspect that most people are experiencing minor drop-outs that are
    either hard to pick out in the mix or just not all that noticeable.
    
    However, if you use a sync track, your far more likely to experience
    problems with drop-outs.

    
    
    	So, *are* dropouts common or not? 
    
    	I'm doing some more recording tonight. I'll post the results
    of this tommorrow. 
    
    
    -T
    

    Back in the good old days when I had a Tascam 244 I never had obvious
    dropout problems.  Some minor, infrequent dropouts were evident listening
    through headphones, but listening to cassettes through headphones is a
    depressing experience anyway.  I share db's experience using Maxell
    C-60s.  Of course when I replace the 244 with a 38, dropouts have never
    been an issue, but 30 minutes worth of tape now costs about 10 times as
    much.
    
    I think somewhere back near the beginning Tom mentioned compressing the
    drums.  Part of the reason I asked what the dropouts sounded like was
    the possibility that the compressor was "overreacting" to the drum
    transients; I have had very weird sounds result from a maladjusted
    compressor.
    
    I am still suspicious of the fact that the dropouts are limited to a
    particular source.
    
    len.
    

    OK, I'll fess up, I heard Tom's deck last night, and I heard some
    dropouts.  Not *major* ones, I had to strain to hear any and even then,
    the first one I heard disappeared (ah! dirt on the head!).  BTW, Tom's
    deck runs at 1-7/8, and 3-3/4 decks will always have less dropouts,
    it's a simple matter of the more tape area per unit time (a function of
    tape width, number of tracks and tape speed) the less audible effect a
    dropout will have.
    
    I think cassettes are *very* prone to small dropouts.  One thing I
    learned through experience is that the ends of the tape, probably due
    to the process of attaching a leader, are more likely to have dropouts
    then the rest of the tape.  I now always wind off about a foot of tape
    before I start recording. 
    
    Obssession with cleanliness is the best defense.
    
    							Brian

    
    
    	I did some recording last night and I'm happy to say that
    the problem seems to be gone. I've starting using only TDK-SA
    10 minute tapes and keep the deck really clean and I'm getting
    clean recordings.
    
    	It seems that you have to get the right tape and keep the
    deck clean, especially cleaning it everytime I use it. 
    
    	I also know that you need to de-magnetize perodically.
    How often is this needed? 
    
    -T
    

    I personally don't think tape head magnetiation is the booga it's
    made out to be. I've *never* heard an audible difference after doing 
    it.
    
    Be that as it may, I always de-mag before making a critical tape. Other
    than that, it's whenever I remember. (3-4 months on some of my dex)
    
    It's quick, easy, and won't hurt anything, so do it whenever you think
    of it...
    
    Edd

    Perhaps a bit late, but what the heck...
    
    I've used multi-track cassette for years with *no* dropout problems,
    provided that I used virgin tape.  Old tapes are definitely susceptible
    to dropouts.  I've used TDK-SA and Maxell UD-XLII and UDS-II type tapes
    with no problems.
    
    I've used two different decks since 1980, both Tascam (and both run at
    3 3/4 ips).  The first was a Tascam 144 (4-track dolby B) - I only
    experienced dropout once, and that was due to trying to use a TDK-SA
    that was over 5 years old (and well-worn).  My current deck is a 238
    (8-track, dbx).  I've used only Maxell UD-XLII 90 minute cassettes,
    with no dropout problems.
    
    I clean heads before every use.  I demagnetize about once a month
    (depending on use - usually light).  Purists would have you demag every
    time you use the deck ... I've not found that to be necessary.
    
    An aside - I overloaded a couple trax the other night with a very hot
    (signal-wise) drum part, and experienced no breathing whatsoever (yes,
    I was using dbx).  Maybe the 238 - which uses type II - has improved
    dbx circuitry?
    
+b (who doesn't have time to note much anymore)

    On demagging various numbers have been bandied about as to how often. 
    But most telling, to me, was a controversial article in Audio many
    years ago (late 70s, maybe?) where a test was set up measuring tape
    machines that were regualrly demagged against ones that were never
    demagged.  The results showed first that magnetic field buildup on the
    heads and other metal parts in the tape path was extremely low, and
    that demagging had no measurable effect on frequency response, THD or
    S/N ratio.  Of course, the article didn't cause folks to stop
    demagging.
    
    							Brian

    While I'm fanatic about keeping things clean, I tend to demagnetize
    my open reel decks only a few times per year.  What I've heard about 
    the residual fields is that it will eventually start to erase the highs 
    on the tape.  Since I don't play individual tapes very many times, or
    indeed USE the open reel dex much, I see/hear no problem.
    
    I DO demagnetize my cassette decks much more often; as a result, 
    cassettes I recorded in the early '80's still sound fine.
    
    karl

yeah, exactly, karl. I think I might do a demag on the reel decks about once
a season. The cassette players get it about once every month. 

Now, cleaning fluid, that's another story. The reel decks get that every
time a tape goes on. And I get oxide off the capstan every time I clean it, too.
The cassette decks get cleaned about once every 8-12 hours playing time. 

The only time I heard a difference after doing a demagnetization was on an old
deck that had probably never ever had it done (and probably 1000s of hours
playing time). 

Just don't demag near your tapes or make sudden moves, or let the power cord
fall out while you're doing a demag. 

/pjh

    
    	the only dropouts i ever suffered came from poor tape quality.
    I frequently recorded slightly in the red and rarely had staturation
    problems.
    
    	I used to use Maxell UDS-II's c-60 or c-90 but i am now completely
    sold on DENON-HD8's. To my ears these tapes are completely superior
    to the maxel's.  But then again, i'm not recording lately either
    soooo....
    
    	bob