I have been trying to learn analogue audio without much success. There
seems to be no more books available anymore that teach the basics of
analog audio electronics.

I recently purchased a SONY ES cassette deck (TC-KA3ES) and am stuck
using it due to my lack of in depth knowledge of audio electronics.

For easy recording, when I put a cassette in the unit, I can set the
appropriate record level for the tape type by playing the input source
and adjusting the REC LEVEL dial properly. This is easy to do and I've
done it.

The problem comes in when I try to use the advanced features for
recording. There is a CALIBRATION button, and associated with it are
three dials as follows:

1. BIAS Calibration
2. REC LEVEL Calibration
3. REC EQUALIZER Calibration

I followed the directions in the user manual. I adjusted all three
dials as per the instructions.

Where the confusion on my part comes in has to do with the REC LEVEL
calibration dial vs the completely separate REC LEVEL dial when not
using the manual calibration option. Using the manual calibration
option after pressing the CALIBRATION button, tone signals are
generated and placed on the tape while I am making adjustments with the
three dials mentioned above.

How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN? Can I
still using the regular REC LEVEL dial while recording without
screwuing up the manual BIAS and REC EQUALIZER adjustments I made?

Any and all comments are most welcome.

Thank you.

BigS

To make a long story short... The REC LEVEL calibrates the level meters so
that what you record at 0 plays back at 0. This guarantees that you won't
set the recording level too high or too low, and that (when using Dolby NR),
the Dolby circuits receive the signal -- both during recording and
playback -- at the correct level.

If this doesn't make sense -- and it probably doesn't -- you'll have to read
a book on how analog tape recorders work and are aligned. A detailed
explanation would take an awful long time.

BigS wrote:

How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN? Can I
still using the regular REC LEVEL dial while recording without
screwuing up the manual BIAS and REC EQUALIZER adjustments I made?

Yes. The input level control adjusts the level BEFORE the meters. The
record level control that you adjust with a screwdriver adjusts the level
AFTER the meters. The screwdriver control is calibrated so that the
tape overloads around +3dB on the meters. Now you can use the level
control to adjust the level of your input so that the signal never
goes above that.

There is some discussion of alignment in the FAQ although for the most
part it is for regular tape machines, which have some additional alignment
controls that you won't find on cassette decks.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Fri, 05 May 2006 16:24:21 -0700, BigS wrote:


Where the confusion on my part comes in has to do with the REC LEVEL
calibration dial vs the completely separate REC LEVEL dial when not
using the manual calibration option. Using the manual calibration
option after pressing the CALIBRATION button, tone signals are
generated and placed on the tape while I am making adjustments with the
three dials mentioned above.

How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN? Can I
still using the regular REC LEVEL dial while recording without
screwuing up the manual BIAS and REC EQUALIZER adjustments I made?

Any and all comments are most welcome.

Thank you.

BigS

I have a similar deck.
Just follow the instructions and it will be biased up properly for
whatever tape you use.
You can tweak the bias a little if you want a brighter sound, albeit at
slightly higher distortion.

Sony has one of the better routines for setting the deck up to tape.


--
flatfish+++
"Why do they call it a flatfish?"

On 5 May 2006 16:24:21 -0700, "BigS" wrote:


How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN?

It's connected in the circuitry at a point and voltage level to be
equivalent to if you actually fed the signal into the line in jack at
same level on the meters.

Can I
still using the regular REC LEVEL dial while recording without
screwing up the manual BIAS and REC EQUALIZER adjustments I made?

Yes, of course. That's what the rec level dial is for! The rec level
calibration does just that, it CALIBRATES the record level dial so it
reads correctly.

When you change the bias it changes a lot of things like frequency
response, distortion and how much of the signal is retained on tape.
the purpose of the record level cal is so that after you have tweaked
bias and record eq so it sounds just right for the tape you are using,
you then calibrate the record level so that what you see is what you
get. That is, the meters read exactly the same during recording as in
playback. If you change the bias without compensating by
re-calibrating the rec level, the signal will be slightly different in
record and playback.

The rec level cal should always be the last step in the set up
procedure. Does that make sense?

Julian

BigS wrote:
I have been trying to learn analogue audio without much success. There
seems to be no more books available anymore that teach the basics of
analog audio electronics.

Betweeen 1996 and 2000, I wrote a monthly series in Recording Magazine
called Oops Wrong Button (their title, not mine) which, if you read the
whole series, you would have a very good grounding (no pun intended - a
couple of the articles had to do with grounding) in all you want to
know. I have suggested that they publish those articles as a
compendium, but they seem to be more interested in software, interviews
with cool producers, and DIY articles on modifying inexpensive mics -
all good stuff but little in the way of fundamentals.

I seem to be retired from writing for Recording these days so check
your library, or eBay for a collection of issues from that period.

The problem comes in when I try to use the advanced features for
recording. There is a CALIBRATION button, and associated with it are
three dials as follows:

1. BIAS Calibration
2. REC LEVEL Calibration
3. REC EQUALIZER Calibration

That was covered in one of my articles about analog recorder
maintenance. Not the pushbutton method, but the real
tweak-the-internals method.

Where the confusion on my part comes in has to do with the REC LEVEL
calibration dial vs the completely separate REC LEVEL dial when not
using the manual calibration option.

The Rec Level Calibration sets the amount of magnetization on tape when
the meter reads a certain reference level (usually 0 VU) This is
something that you can optimize for a particular formulation of tape,
just like bias and record equalization. This sounds like a pretty cool
recorder to give you external access to these adjustments.

How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN?

The internal tone generator applies a tone at standard level so you can
optimize the performance to the tape. What you're actually doing is
calibrating the meter so that it reads 0 VU when you have the level
recorded on the tape optimized.

Can I
still using the regular REC LEVEL dial while recording without
screwuing up the manual BIAS and REC EQUALIZER adjustments I made?

Yes, and you should. Once the recorder is calibrated to a particular
type of tape (manufacturing is usually consistent enough so that you
don't need to calibrate for every cassette you insert as long as it's
the same brand, and from the same batch - buy it by the carton and
calibrate once), use the main Record Level knob so that the meter hits
0 VU on peaks.

If you don't have a background in electronics, recorder setup can be
extremely confusing.

Several years ago a gentleman from this group stopped by, and I spent
several hours demonstrating how to align and set up an open-reel deck.

I don't think he got much out of it, because he didn't know much about
physics or electronics.

This has nothing to do with intelligence, but rather having knowledge that,
for the average person, is esoteric.

William Sommerwerck wrote:

If you don't have a background in electronics, recorder setup can be
extremely confusing.

This has nothing to do with intelligence, but rather having knowledge that,
for the average person, is esoteric.

That's why I wrote that series of articles - to give that knowledge in
a way that most readers could understand it.

The problem comes in when I try to use the advanced features for
recording. There is a CALIBRATION button, and associated with it are
three dials as follows:

1. BIAS Calibration
2. REC LEVEL Calibration
3. REC EQUALIZER Calibration

I followed the directions in the user manual. I adjusted all three
dials as per the instructions.

Where the confusion on my part comes in has to do with the REC LEVEL
calibration dial vs the completely separate REC LEVEL dial when not
using the manual calibration option. Using the manual calibration
option after pressing the CALIBRATION button, tone signals are
generated and placed on the tape while I am making adjustments with the
three dials mentioned above.

How can the REC LEVEL calibration be correct since it is being done
using the test tones rather than my actual input via LINE IN? Can I
still using the regular REC LEVEL dial while recording without
screwuing up the manual BIAS and REC EQUALIZER adjustments I made?

What type of material are you recording and what is your source?

The REC LEVEL calibration is largely used as a point of reference but
in most audio recording you prefer your tone to come from an outside
source. The best measure of where your inputs should be set is indeed
the signal you're recording. If you can get a measure of where its
peaks seem to be you can set your levels accordingly.

A lot of better decks have a limiter which prevents your signal from
getting overmodulated once you've set the levels. It is not intended
to bring the whole signal down all the time and if you entire signal is
consistently way too hot it won't sound good with OR without the
limiter but a limite IS good for heading off the occasional peaks which
are too hot.

Regardless, I would mainly use the material you're recording as a point
of reference unless that material as tone at the beginning, which is
the exception rather than the rule.

The BIAS and REC EQUALIZER settings will be different. BIAS will be
according to what type of cassette you use and the EQUALIZER will allow
you to adjust the response of certain frequencies. Both of those
should be done before you set your REC LEVEL.

All the responses have been good - hope this clears some things up.
You'll get a feel for it once you've done it a couple of times.

Craig

http://www.pro-tape.com

Adobe - Apple - Avid - Canon - Denon - Digidesign - Fuji - JVC - Lacie
- Marantz - Maxell - Nitro AV - Panasonic - Primera - Quantegy - Rimage
- Samson - Sennhesier - Sony - TDK and more!

Sales/Rentals/Service

Authorized Apple Reseller and Service Provider

Thank you all for your assistance!! This is a quantum leap for me in
terms of understanding what I'm doing.

BigS