Ancient Nakamichi 250 tapes to be transferred / digitized

k9gardner

New Member
[I have to make an edit here: It's a 350, not a 250! Sorry. The 250 was a player only, obviously I'm talking about cassettes that were recorded on this machine, so it's a Nak 350. Sorry for any confusion. I'd change the title if I could get in there, but may not be able to.]

I have a good number of cassettes, some high quality for the time and some not at all high quality, from the late 70's and early 80's, that were recorded from various live performances, that I want to attempt to capture. I'm guessing that these tapes have one more pass – if any! – left in them. They were originally recorded on my Nak 350 portable, which I still have. But I'm worried that its transport may not be the best for the job, and it also hasn't been touched in decades and no doubt needs to be serviced.

If there's anyone with experience with these machines, I basically am wondering whether it will be best to stay with the same machine for this purpose? I was thinking about getting either a similar vintage stationary device (like a 500) or a somewhat newer one like the BX-1, which I've seen good reviews of, one of which is currently for sale on eBay with new belts and idler, which sounds like a good grab. But I'm not sure if that's warranted, or if I should just go with new belts in the 350 and see how it goes.

Thoughts? Anything else I should know or do? I've read about putting the tapes through a cycle in a fruit dryer to precondition them before attempting to play them, but not sure whether that's necessary or not.

Any suggestions will be much appreciated.
 
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For alignment reasons you should have the best playback results using the machine they were recorded on. So I would tune up the 250 and give it a go.
You should not need to bake your cassette tape. I would check to make sure the pressure pad was still intact. I would also FF-RW each tape prior to playing.
 
For alignment reasons you should have the best playback results using the machine they were recorded on. So I would tune up the 250 and give it a go.
You should not need to bake your cassette tape. I would check to make sure the pressure pad was still intact. I would also FF-RW each tape prior to playing.

Fully agree. The only other thing I'd add is that you should probably find a worthless tape and play that back a few times before putting anything priceless in the machine.

It may also be worth it to have the machine serviced by a pro. If the deck is belt driven it's almost guaranteed it will need new belts at this point.

bs
 
As stated, it would be best to playback on the same player as the tape was recorded. I'm not sure of the reason, but Nakamichi tapes sometimes don't play well on other payers. I'm the Maintenance Engineer for an archiving company. We use Tascam 122MKIII and Nakamichi MR-1s to playback tapes for digitization. Because we get tapes recorded on many different players we have to adjust the azimuth per/tape before we can digitize. It's a PITA. Some players are so far off on azimuth the tape head has to be adjusted several turns before we get a high-end peak. The head sometimes gets caught inside the cassette and won't unmount until we reset the azimuth. We have college students perform the digitizations which has resulted in replacing around 25 head/mounts because of stripped azimuth mounts. Stat with your deck, or another Nakamichi for best results.
 
couple of tips.

clean the heads, capstans, rollers, and any moving/stationary parts that touch the tape.
use Qtips but be very careful of leaving threads on the parts you clean.

demagnetize what you can. I use an Audio Technica cassette demagnetizer. it has electronics
on it that sends a wide freq signal to the heads and decreases the volume automatically. then
does it again. you can hear the difference. its a small investment and afterwards you can sell
it on ebay.

next use the nak or another machine to rewind the tape at least one pass. this removes/minimizes
the sticktion tape has "developed" by sitting around for a couple of decades. bring it back to
the beginning of side 1 or not.

next, find some high-end cassettes for possible transplant of your original tapes that develop a
squeal. the squeal doesn't make it onto the transfer but any slippage/blockage "MAY' find its
way as wow/flutter/warble/high-C-arias.

separate the tapes by equalization type and dolby status. this minimizes the errors of doing
large batches and forgetting to reset both for each and every tape.

I usually demag before each tape and check the capstans for crap accumulation (much more
visible on the capstans)

then if you are digitizing the tapes - do find the max level on each tape. digitization fails
if the peaks are above the 0db digitization max. adjust the NAK's tape output to suit.
using -1 is Ok and up to you. and you are on your own if there's a channel imbalance,
I'd correct it on the way in as opposed to post-processing the digital version.

as a note I have this one commercial tape that does not do well on a NAK but is perfectly happy
(highs no longer muted) on a Denon. go figure.

I wouldn't worry about tape damage (binder, oxide falking off) these symptoms were for the
last user r2r tapes. I have cassettes dating back to early 70's before the big peaks that are
still fine.

good luck and enjoy the music. I have a similar goal with my cassettes and LPs and CDs and SACDs...
 
I would have the 350 refurbished, aligned, and measured (especially playback response). Then I would also purchase a deck with Play Trim
(Yamaha, NAD) and have that one refurbished, too. Then each tape would be digitised using the deck it sounds best on.
Clean the heads after each pass.

There is no need to aim for -1dB. Use a good ADC and keep sufficient headroom, the range -12 to -6dB is fine. No need to search for each tape's peak. After all you know that there is only so much level that can come off a tape. Raise the levels
and correct for any remaining tape or transfer problem in post production. Use good software.
 
tried the high headroom trick. two problems - noise level rises with that headroom, I hear compression,
but depending on the music - like rock, a little compression works in your favor. you may even like
a lot of compression like some of today's Cds.

I have about 1000 self and commercial cassettes and struggle with the varying levels, and whether
even the dolby level are correct ( some tapes have a dolby level tone which is perfect for digitizing).
(and sometimes I cannot tell whether its dolby encoded or not - is there a software algorithm
that can detect this? - I can easily program it to be an add-in to any post-processing app)

the next problem are the metal tapes with skyhigh peaks. going down far enough to avoid saturating
the digital recording means artificially raising the noise levels. in addition, having a NAK means not doing
the tricks needed for any other deck. especially the late 1970's decks. I used to have pioneers, technics
and completely stopped using them and continued with any NAKs from the golden age.

as far as post processing. its yet another step that 1) consumes time especially for 250 or 1000 cassettes
2) are you sure the algorithms are correct. or take a chance what you dialed for that one and only pass is correct.

cases in point
1) recording a phono signal w/o a phono preamp and then through software perform an RIAA filter
2) adding dolby B, C, S processing using computer software
3) pop/click removal - these algorithms change about every ten years

in all three cases, as audio progresses you may not be happy with what you did 10-20 years ago
(like I started to do then). why? bad sound. I tossed all those - about 500 tapes worth and their
digital counterparts. these were self recorded

another case is Sweetvinyl with a continuously variable pop/click remover AND ability to
listen to pre and post and adjust not for the levels (like in audacity) of the pop/clicks
but for the changes in SQ. major difference right there. can you hear the difference
with headphones plugged into your computer when using audacity, or...

next up is Audacity did not implement certain resolutions until V2. (see release notes) so
anything you digitized you had to do over again.

and if you're anal do the cleaning and the demag. the very first time you use a demag
especially on a NAK, you will always use one even if you're just playing. reason why
is that NAKs have such incredible high frequency response that you will hear the difference.
and of course, if you don't have a demag then all you can do is clean the heads but even the
early 1970's Ampex and BASF (real chrome) have survived.and do not pollute the heads.

years ago, the rule when recording from tape to tape was to use the better quality deck
as the source playback, and to invoke all the filters. so for me it was NAK to Sony
and dolby on to dolby on. and if you recorded on a NAK, any NAK will be better
than a non-NAK with the best possible NAK being a Dragon with playback optimization.
do note that NAK messed with the IEC curves for a range of decks so it would be
absolutely correct to use the same deck as the original for playback. I would not use
any non-NAK deck unless its calibrated like a NAK. try Naktalk.com for loads
of information on this exact topic. tapeheads also has lots of information on this,

if your tapes are valuable to you and you used a NAK, you cannot do them justice by
lowering your standards. and especially if there's a small chance of tape deterioration
in which case, head over to tapeheads, there are dozens of threads about one-pass
processing. there's a great set of threads on using a car polish.

BTW I forgot to include that if you rewind, use the NAK or a head-lifting deck. there are
decks from before the golden age that still pass the tape over the heads (even lightly is not
good).

however I've only used about 6 software recording apps - I didn't like any processing
they offered so I came to the conclusion to capture only. maybe in 10 years ther's be
break throughs in fourier transforms appled to signal processing that retains the
original SQ while blasting the baddies.

some folks process their digitized to channel balance, raise ("equalize") the volumes,
remove hum, change the spectral balance (make a Epic sound like an EMI), and
about a dozen other thing. I prefer to keep the capture pure - like keeping a
painting versus the digitized picture of such. but your reasons for digitizing
may not require keeping it pure and original. for example, for voice recording
by all means, crank up the volume , apply noise filters. but not for good music.

so, to be fair, try both. both will require a understanding of peak volume and
the ability to adjust. since the OP's recordings are his, there will be some
semblance of consistent and repeatable volume management and no
need to post-adjust. (you probably adjusted max vol to db level max for that tape)
and for the future, there will be better algorithms to
improve the SQ. do note that once you do the non-reversible conversions
it's like converting a 24/192 hi res to MP3 - you cannot go back.

apologies for overdoing this. but my early tapes are also super precious.
and I would like to do the very best possible for them.
 
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