Nakamichi cassette deck (CR-2A) playback problems

Kong

Kong

Active Member
Hey there folks, wondering if anyone might have any thoughts about this.

For a number of months now, I've been using this deck to play back old tapes to digitize and preserve. The playback has generally been smooth and problem-free, and when there were quiet passages, I heard relative quiet. Tonight, however, some things occurred which concern me.

A) I started hearing a low-level hum in quiet passages. I tried a totally different tape and the same thing happened. I compared it to recordings just a week ago, and this hum is no where.

B) The tape I was playing tonight had bizarre playback issues. Now, this might just be a function of this one cassette, as it's about 47 years old. But, other tapes that old have played back exactly as I remember them. And, the playback problems with this particulate cassette occurred in varying degrees each playback attempt -- but at approximately the same times in the playback (hard, clipping spikes, followed by a sudden lowering in output; not a silencing, but a noticeable lowering); and, this varied each playback attempt: the spikes occurred at roughly the same places, but varying in the number of times (2 spikes one time vs. 5 spikes another time). Perhaps this particular cassette is experiencing its last breaths, I don't know.

But, that hum in the quiet passages occurred regardless of cassette (age, chemical composition, NR, etc.).

I welcome any thoughts, even one that says I need to go on eBay and buy a "new" analog cassette deck.

Thanks folks.
 
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The hum sounds like a problem with the deck but the other issue sounds like a bad tape to me.

Do you have a blank tape to do a record/playback experiment with? Do you hear the hum if you play a blank tape?

Has the deck ever had any kind of maintenance like cleaning or degausing the heads?

I haven't had a tape deck in a very long time but always lusted for a Nakamichi back in the day.
 
Hmm... interesting idea in the recording of a blank tape.

As for cleaning the heads, have not done that yet.

What is degausing?

And, what about demagnetization? I'm a little reluctant to try this last one as the last time I did that, it ruined the deck (one channel was knocked out, so only one of the chanels played back).
 
cademan said:
Basically demagnetization.

Try pressing and releasing the record button sever times. Sometimes it gets dirty and causes weird things and may even need a little deox.
Click to expand...
Deox...? Deoxidation? How would I do this?
 
Kong said:
How would I do this?
Click to expand...
Very carefully...haha. :biggrin:

Most of the cassette tape decks I have worked on have had a type of linkage that is connected from the record button to a long multi type of switch mounted on the main record playback circuit board.

You can easily look to see if this is the case with your tape deck. If you think yours might not have it, just take some pics and I or someone else here can point it out for you.

Some newer decks use electronic record switch methods rather than mechanical record switches. All mine use mechanical switches with connecting linkage to switch between record and playback.

This long multi switch gets dirty (carbon build up) on the contacts and causes left or right or both channels to drop out during playback and record and sometimes causes weird audible sounds during playback.

My Marantz 5010 cassette deck started to squeal on playback and I discovered when I pressed the record lever a few times, it would clear up so I opened it up and cleaned it with deox.

Deoxit is a chemical spray that comes in a can like WD-40 that comes with a straw that you use to squirt into pots and switches to clean the carbon build up. This is where you would take the deox spray and shoot it into the record/playback switch and work it a few times...maybe even a few hundred times to really get the switch cleaned and to work properly.

Hope this helps. :thumbsup:
 
cademan said:
Very carefully...haha. :biggrin:

Most of the cassette tape decks I have worked on have had a type of linkage that is connected from the record button to a long multi type of switch mounted on the main record playback circuit board.

You can easily look to see if this is the case with your tape deck. If you think yours might not have it, just take some pics and I or someone else here can point it out for you.

Some newer decks use electronic record switch methods rather than mechanical record switches. All mine use mechanical switches with connecting linkage to switch between record and playback.

This long multi switch gets dirty (carbon build up) on the contacts and causes left or right or both channels to drop out during playback and record and sometimes causes weird audible sounds during playback.

My Marantz 5010 cassette deck started to squeal on playback and I discovered when I pressed the record lever a few times, it would clear up so I opened it up and cleaned it with deox.

Deoxit is a chemical spray that comes in a can like WD-40 that comes with a straw that you use to squirt into pots and switches to clean the carbon build up. This is where you would take the deox spray and shoot it into the record/playback switch and work it a few times...maybe even a few hundred times to really get the switch cleaned and to work properly.

Hope this helps. :thumbsup:
Click to expand...
It might rabbit, it might. Working more OT than I care for right now, but as soon as I have some time, I will look into this.

Thank you!
 
RVT1K said:
I'm old enough to get that reference!
Click to expand...
I tried to tackle this this afternoon. Had an old bottle of tape head cleaner. Dropped some onto a cotton swab. Gently rubbed the heads and capstan and little pinchers for roughly 7 or 8 seconds each. Not much visible residue on the swab (there was a little).

Result? The tape played back perfectly. None of the issues I described above occurred again. I cannot believe that this was all that was needed. I may have to review some of my other tape digitizings to see if they might need a re-digitizing. I hope not, but...

Anyway, thanks for the time and input.
 
At 1 7/8, and 1/8" width tape. Takes very little dirt or dust, or mechanical or other issues to affect the playback. Cleaner the tape deck is, the more it's exercised regularly, and used, the better they perform. Enjoy thy Nakamichi. Take care of it, it will take care of you. Treat it gently, give it love, and you get repaid with great musical sounds.
 
KentTeffeteller said:
At 1 7/8, and 1/8" width tape. Takes very little dirt or dust, or mechanical or other issues to affect the playback. Cleaner the tape deck is, the more it's exercised regularly, and used, the better they perform. Enjoy thy Nakamichi. Take care of it, it will take care of you. Treat it gently, give it love, and you get repaid with great musical sounds.
Click to expand...

Heh... I do take care of my stuff. Speaking of which, I probably should purchase a demagnetizer.
 
Glad to see you got things resolved.

Remember when loading "foreign" tapes that any junk/gunk that was in someone else's machine is now in yours.

Tape players need regular cleaning to perform their best. Not only the heads but the switches and pots need love too.
 
wmgwizard said:
Glad to see you got things resolved.

Remember when loading "foreign" tapes that any junk/gunk that was in someone else's machine is now in yours.

Tape players need regular cleaning to perform their best. Not only the heads but the switches and pots need love too.
Click to expand...
Not sure how to "love" the switches and pots. What are pots? LOL

I do use an air can for the rest of the machine.
 
Love = cleaning and lubricating
Pots = potentiometers.......rotary controls for things like volume, bass / treble / balance etc. On a cassette it may include output level, recording level and/or bias adjustments.

There are several threads here on AK that provide guidance on using DeOxit or similar chemicals to clean these items.
 
wmgwizard said:
Love = cleaning and lubricating
Pots = potentiometers.......rotary controls for things like volume, bass / treble / balance etc. On a cassette it may include output level, recording level and/or bias adjustments.

There are several threads here on AK that provide guidance on using DeOxit or similar chemicals to clean these items.
Click to expand...
This is another thread I think I need to PDF. Geez... thanks for the info folks. I thought I knew tape decks.
 
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