Tone generator for Bias setting on tape decks

[Straight Tracker]

[QUOTE=Johnny2Bad;2824174]An upper limit for bias tone generator would be 10 Khz for any 1/4" tape machine or smaller (eg cassette 1/8"). QUOTE]

With all due respect, Compact Cassette tape is 5/32" wide.

Sincerely,

Ralf

[barrymagrec]

Originally Posted by Johnny2Bad

An upper limit for bias tone generator would be 10 Khz for any 1/4" tape machine or smaller (eg cassette 1/8"). You can substitute 20 Khz if the machine uses at least 1/2" tape and you are recording at 30 ips. 400 Hz is a good second tone, you only use the two. A 1 Khz tone can also be useful, however. Record the two bias setting tones at -20Vu (cassette) -10Vu (consumer tape deck) or 0Vu (professional tape deck). Ideally the playback will show the same Vu level as the record, but somewhat more important is the playback levels of the two tones relative to each other.
.

The width of the tape has no bearing on the frequency of bias test tones, the speed does.
If you do a bias line up at 0VU, which is almost peak level, you run the risk of tape saturation giving a false result, especially at lower speeds and higher frequencies. The same applies for checking overall frequency response.

[df_genius]

Thanks all guys. I said 15k as the Nak 682ZX and 680ZX I have do have 400Hz and 15Khz tone generators for setting bias. Yes I know most decks use lower frequencies for bias (the Sony TC-K75 I have and the Aiwa AD-6900's I used to have used 8Khz) but 15Khz is most suitable - I have a 482 and a 482X and two Akai GX-77's and 15Khz will be fine for those (the Akai is specc'd out to 26Khz at 0db and 33Khz to -20db).

Yes I know I could use an MP3 player, but this is DIY audio, so It'd be nice to create a simple circuit for it as well

[oshifis]

Originally Posted by Johnny2Bad

Every tape formula has a distinctive smell and some brands carry a distinctive family smell; it's relatively easy to learn how to identify a tape formula by smell alone by storing a reel of tape in a plastic bag as well as the box and just just sniffing the bag storing the tape.

Now I remember that unmistakeable Scotch smell (R2R) and early Maxell (Cassette) in the '70s with nostalgy...

[dangus]

Another function generator chip is the Intersil ICL8038, although judging by Futurlec's pricing it costs over 4 times as much as the XR2206. Google Wien Bridge oscillator for a more traditional sine wave generator.