Crazy Cassette Deck Curiosities.

[MacJunky]

Ok guys, I am in need of your great wisdom.
[edit]
Heh, yep, you know that if it is old, MJ is probably interested in playing with it. :P
[/edit]
Please excuse the length. :P



**** Backstory, testing and other happenings ****

My sister recently bought a car made in the early 90s(that surprisingly seems to get similar gas milage.. er, kilometreage as my mother's 2007 Civic) and does not yet have a CD player for it so I thought I should slap some good music on a few cassette tapes.

Now, since I already have a Sansui G-4700 Receiver(that looks like pure raging pwnage in a box!) connected to my computer and a JVC KD-55 Stereo Cassette Deck chilling in my bedroom I just grabbed the KD-55 and connected it up.

Initial testing with a barely used Fugi DR-I Normal Bias went extremely well and I was in shock at the quality of the recording. Really, I am serious, this KD-55 was recording at such a good quality I think I can safely swear that I have never heard a better sounding cassette tape. REALLY!

Anyway, once I had two full Deathstars albums recorded onto the tape my sister and myself go out to her car and test it. Yep, you guessed it. The tape sounded like total crap.

It was extremely muffled and the volume was very low even though other tapes sounded like regular tapes do in her car's deck. I bring my tape and one from her car back inside and test both in my KD-55 and again, mine sound spectacular and hers sounds (again) just like your average audio cassette.

At this point I am reasonably baffled so I grab my mother's AKAI GX-ASX that was sitting around in a corner of the living room unplugged. I connect it to my G-4700 in place of my KD-55, pop in a test tape and proceed. The KD-55 recording in the GX-ASX sounded just like it did in my sister's car as well as my old RCA RP-1830A walkman thingy.

Next I try recording with the GX-ASX but the resulting recording was nothing like the KD-55 recording and more on par with your lower quality cassette tape recordings when played in the GX-ASX, KD-55 or RP-1830A. I could not test in my sister's car as by now she had gone to bed but I am willing to bet that it would have sounded like the other players.

It would seem my issue is with the JVC KD-55. I would really love to use it but I do not know what to do to make it's recordings play in other devices.
Listening to it's recording now and it sounds freaking spectacular! Not quite up to the quality of the audio file on my HDD but with both my headphones and speaker setup it is getting reasonably close. I never had any idea tapes could sound like this!


**** Other notes and important points ****

* Both cassette decks were connected to my receiver with the same cables in the same arrangement.
* Both play other tapes with the same or at least very similar sound quality.
* Both players initially received a quick wipe with some 99% isopropyl alcohol on read/write/whatever heads as both had accumulated plenty of dust over many years without use.
* All tests were done using the same song played by iTunes in Mac OS X on my P5K connected to receiver via onboard analog line-out with iTunes and system volume maxed as well as identical itunes equalizer settings.
* In all tests the VU meters or similar LED arrangements were almost redlining at peak.



**** Theory ****

My best theory, I think, is that the KD-55 was recording to the tape slightly off centre so the other players could not read all of the needed area to produce proper sound.
To be quite honest though, I have very little experience with cassette decks so I have no idea if it is even possible for parts to shift in this manner.

[Tazer-[X]]

Oh yea, nice 1, I would say its safe to assume were all ANALOG challenged here?

[sswilson]

Only two things come to mind here, but I'll keep mulling it over.

1/ You're using some form of noise reduction on the deck to record the tape and the playback decks don't support that format.

2/ You're biasing (metal etc...) the tape in a format that the players don't support.

3/ (I know I said two... :) ) Is it possible that by some freak of nature you managed to put the tape in A side up on the home deck and B side up on all of the others? I've had issues like you describe (related to alignment) with auto reverse decks not liking the tape in one particular direction.

My best guess though is that you are correct on your alignment assumption.... Do you have a commercial tape laying around which has the test audio at the beginning? I'm not positive on this, but I always wondered if higher end units could use that for self alignment.

[3.0charlie]

I know you said the VU meters were "up there", but I remember my TEAC deck had both volume and recording level adjustment knobs. And those 2 adjustments had no impact on the VU merters. When recording, I had to do tests first to find the correct recording level. Otherwise I would have the exact problem you are having.

Man, that was a long time ago - 20 years! hehe, I remember those Maxell XL Metal cassettes, costing me an arm and a leg...

[MacJunky]

Originally Posted by sswilson

1/ You're using some form of noise reduction on the deck to record the tape and the playback decks don't support that format.

ANRS is off on the KD-55 and all the dolby stuff on the GSX-AX is also off.

Originally Posted by sswilson

2/ You're biasing (metal etc...) the tape in a format that the players don't support.

the tape says it is normal and when I put the tape into the GX-ASX it auto detects it as normal. The KD-55 is set to SF/NORM(100%) but has the option of Fe-Cr(110%) and SA/Cr-O2(150%). Am I correct in assuming NORM is normal?

Originally Posted by sswilson

3/ (I know I said two... :) ) Is it possible that by some freak of nature you managed to put the tape in A side up on the home deck and B side up on all of the others? I've had issues like you describe (related to alignment) with auto reverse decks not liking the tape in one particular direction.

The KD-55 and GX-ASX do not support auto reverse. My RP-1830A supports auto reverse but plays each side fine if recorded from anything other than the KD-55.

Originally Posted by sswilson

My best guess though is that you are correct on your alignment assumption.... Do you have a commercial tape laying around which has the test audio at the beginning? I'm not positive on this, but I always wondered if higher end units could use that for self alignment.

test audio? Could you elaborate a bit more please? Is this heard as static or actual tones or even heard at all?

*Edit
Oh, do you mean a short little bit of audio that rapidly increases in pitch? If so I just found a tape that has one.

Originally Posted by 3.0charlie

I know you said the VU meters were "up there", but I remember my TEAC deck had both volume and recording level adjustment knobs. And those 2 adjustments had no impact on the VU merters. When recording, I had to do tests first to find the correct recording level. Otherwise I would have the exact problem you are having.

The VU meters respond to adjustment of the Input Level knob but not to the Output Level knob. If I turn the Input Level up the VU meters max out and the audio sounds bad even in the KD-55. If I turn it down it sounds quieter than previously in every unit including itself.

Even the Rec EQ dial with settings from -2 to +2 has extremely little effect on the recorded audio.

[sswilson]

The test audio I'm refering to on comercial tapes is about 5 seconds of tones scaling up from low to high. (Same idea as the DBX headers we hear on VHS tapes).

ANRS is off on the KD-55 and all the dolby stuff on the GSX-AX is also off.

What exactly is ANRS? Sounds like a proprietary noise reduction system.

That would be the first place I'd look, especially since it works great on that unit, but sounds like crap on the others. Maybe the switch is stuck in the on position?

[MacJunky]

I doubt it, the switch is off and I can hear the difference when turning it on and then to super.
I don't know what happened but since I played a commercial tape from around the house the quality is not quite as bad with the others playing a recent KD-55 recording. It still sounds bad but it is slightly better. I have not touched the ANRS switch since the first testing.
If I play the KD-55 recording in the GX-ASX with either dolby B or C it sounds horrid. Same with the dbx set to tape.

I do not know the specifics on ANRS but it is mentioned a bit here:
ANRS...and a real beauty....sigh..... [Archive] - pink fish media
JVC KD-85 - Any Info On It? [Archive] - AudioKarma.org Home Audio Stereo Discussion Forums
diyAudio Forums Archive - "Vintage" JVC Cassette Deck; metal bias?

RE: arsclist Dolby and unintended consequences
Re: [ARSCLIST] Dolby B, et al and now ANRS
[ARSCLIST] Dolby B, et al and now ANRS

[MacJunky]

I can't seem to find any tapes with the test audio you mentioned. Was it more common during certain years? Was it more common on tapes produced by certain companies?
Do any cassette decks built in 1978 even support self alignment at all? I am betting that this does not and I am just hallucinating about the audio quality or remembering incorrectly or something.

[sswilson]

My experience with cassette would have been mainly mid - late `80s and I would have purchased the majority of my tapes in europe.

[MacJunky]

Ok, I dealt with it by hand&ear. I figured that I may as well play with it so I got a fine tipped marker and marked the default adjustment screw positions and with a commercial tape playing went at it with a screwdriver. I used the most recent commercial tape with the least use I could find, a big shiny tunes 6 tape. Please don't laugh, when I got it I was not into the whole music thing so I did not know what I actually liked and did not like very well. It was purchased as a part of initial testing.

Anyway, I did not care for the majority of it(the wussy/wannabe rock and rap) so it did not get used much and thus in my opinion made a good candidate. I just played it in each device I had then tried to make the KD-55 match the others that all sounded basically the same. Nothing fancy I know, but after that I played the previous KD-55 recording in all the devices to make sure it sounded the same across all (Using only one seat of headphones directly connected to all devices). after that I made a new test recording on the test tape and tried it in everything as well including my sister's car.

Seems I was very close to spot on but the deck in my sister's car has just slightly different alignment than the GX-ASX and RP-1830A. It is easy enough to compensate for that though if I need to record anything else for her and want as close to perfection as possible, at the moment it sounds good enough anyway. There is no bloody way I am digging the deck out of her Cavalier for adjustment unless I absolutely have to.

So, in the end about a bit over a full clockwise turn of a screw and all is working nicely. :P
I should have done this sooner.