does anyone know what if any equalization was applied by the average record
recorder back in the "old days" (like the forties)? were they all cut flat?
I was thinking of the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

thanks,

--
DVB systems
c/o Ken Bouchard
1520 Big Valley Dr.
Colo. Springs CO 80919
USA

www.dvbaudiorestoration.com

Ken Bouchard wrote:
does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

Try

rec.arts.mov...on.sound
and
rec.audio.pro

I'll bet that someone there knows.

I'm sorry, that should have been

http://groups.google.com/group/rec.a...d?lnk=li&hl=en

Sorry

"Ken Bouchard" wrote in message
...
does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

**The only recorders available (outside Germany) during the (early) 1940s
were 'wire recorders'. Fidelity was appalling. I've worked on a few, but I
don't know what, if any, equalisation was in use.


--
Trevor Wilson
www.rageaudio.com.au

In rec.audio.pro Trevor Wilson wrote:
: **The only recorders available (outside Germany) during the (early) 1940s
: were 'wire recorders'. Fidelity was appalling.

Hmm, the bit of playing I did with a couple of old wire recorders
was that the fidelity could be surprisingly good... certainly as
good or even better than the cheap handheld cassette recorders
commonly in use in the 1970s.

Scott

Trevor Wilson wrote:

"Ken Bouchard" wrote in message
...
does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

**The only recorders available (outside Germany) during the (early) 1940s
were 'wire recorders'. Fidelity was appalling. I've worked on a few, but I
don't know what, if any, equalisation was in use.

Disc recorders were commonplace too.

Graham

Trevor Wilson wrote:

"Ken Bouchard" wrote in message
...

does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)


**The only recorders available (outside Germany) during the (early) 1940s
were 'wire recorders'. Fidelity was appalling. I've worked on a few, but I
don't know what, if any, equalisation was in use.

Ken may have got the date wrong but he probably can tell the difference
between a flat disc and a reel of wire.
I have seen the recording booths in shops in a couple of old movies
(possibly Brighton Rock?) which would give a clue to the date.

--
Eiron

There's something scary about stupidity made coherent - Tom Stoppard.

My Dad had an old record maker circa the 40's and it had a mic that plugged
straight into the unit. So what ever was in the pre amp was what you got.

The fidelity was typical 40's radio "sound" but that too was dependent on
the mic and the cutting stylus on the machine...but coming from Sears or
Woolworths you certainly didn't get a Nuemann mic or cutting stylus

Don


"Ken Bouchard" wrote in message
...
does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

thanks,

--
DVB systems
c/o Ken Bouchard
1520 Big Valley Dr.
Colo. Springs CO 80919
USA

www.dvbaudiorestoration.com

Ken Bouchard wrote:

does anyone know what if any equalization was applied by the average record
recorder back in the "old days" (like the forties)? were they all cut flat?
I was thinking of the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

There is an overwhelming case for saying that the recordings could not
have had a frequency response with constant velocity over the audio
range. At lower frequencies, the grooves would have cut into each
other. If the curve had been constant amplitude, the HF would have hit
a slew-rate limit on playback. This was the reason for the "Blumlein"
characteristic which was constant amplitude below a certain frequency
and constant velocity above it.

The actual shape of the curve was determined by a single time constant
(RC or RL) and the 'turnover frequency' refers to the intercept point of
the asymptotes. With a magnetic playback cartridge, the constant
velocity portion of the curve gives a constant output voltage, so the
replay characteristic for the constant velocity bit (below the turnover)
appears to fall towards 6dB/octave with decreasing frequency.

Usually magnetic cutterhead driven by a relatively constant-voltage
source would give this characteristic automatically and the turnover
frequency would be determined by the RL ratio of the coils. British
commercial companies tended to use around 250 to 300 c/s and American
ones around 500 c/s; but there was no standard, pre-RIAA.

Home recorders used a variety of curves but, as far as I know, they are
not documented anywhere. If you can get hold of the recorder, you can
measure it. The service manual for military equipment sometimes
includes a DC resistance figure for the coils and an impedance value at
1Kc/s; you can calculate the turnover from this.

In all other cases, you will need a correction circuit which gives
6dB/octave boost below the turnover frequency (which should be variable
by a front-panel control) and a good ear.

Most cheap recorders would have also had a number of other time
constants in the amplifiers and these will add to the difficulty. There
were inadequate inter-stage coupling circuits, poor output transformers,
rarely any feedback (they needed all the gain they could get) ... and
the microphones were often unbelieveably bad.

Some recorders used crystal cutterheads, so Blumlein at anything up to
1Kc/s, or above, may prove necessary.

Military audio letters were a different matter. They may well have been
recorded on better quality equipment with an operator who had had some
experience (and very occasionally some skill). Look for the
groove-twinning that characterises a Presto recording, then start with
500 c/s Blumlein and only change it if it sounds wrong and there is no
other explanation.


I have occasionally had 'recording booth' discs that turned out to have
amazingly good quality, but they are very rare indeed. Usually your
correction efforts are limited by the S/N ratio - and intelligibility is
the only thing you can aim for.


Good Luck!

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

"Ken Bouchard" wrote in message

does anyone know what if any equalization was applied by
the average record recorder back in the "old days" (like
the forties)? were they all cut flat? I was thinking of
the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters
home. does anybody KNOW this"? I'd rather not have any
guesses since I've been doing that myself:-)


Here is detailed technical information about legacy magnetic recorders,
including some schematics:

http://history.acusd.edu/gen/recording/begun6.html

Don Nafe wrote:
My Dad had an old record maker circa the 40's and it had a mic that plugged
straight into the unit. So what ever was in the pre amp was what you got.

The fidelity was typical 40's radio "sound" but that too was dependent on
the mic and the cutting stylus on the machine...but coming from Sears or
Woolworths you certainly didn't get a Nuemann mic or cutting stylus

Don


"Ken Bouchard" wrote in message
...
does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

thanks,

--
DVB systems
c/o Ken Bouchard
1520 Big Valley Dr.
Colo. Springs CO 80919
USA

www.dvbaudiorestoration.com


My father also had one, but it was converted to a chest of drawers
when it died to hold small parts before I was in grade school.
You see one on ebay every once in a while.
Crystal mic, recording voice primarily.
Stenography aid to business and marketed
to the public as a way to send a personal message
to loved ones.
We really take for granted being able to talk
to another over distance.
Doubt there was a formal equalization curve,
you might find some manufacturers spec out there.
Try this link:
http://history.acusd.edu/gen/recording/links.html

Ken Bouchard wrote:
does anyone know what if any equalization was applied by the average record
recorder back in the "old days" (like the forties)? were they all cut flat?
I was thinking of the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

Most of them had a single-pole filter for emphasis. Some of the higher
grade Presto machines actually had controls on the emphasis filter.

If you use an RIAA filter, you'll be in the basic ballpark above 500 Hz
or so. And below that it's all screwy on those machines anyway.

I can probably dig up some Presto and Rek-O-Kut manuals if you want to
actually calculate the filter constants out. But the top end on those
cutters, especially the piezo ones, were so ragged anyway that knowing
where the main pole of the emphasis network sits isn't going to help you
very much.

Oh yes, also check the manual for the Millennia Media phono preamp. It
should have emphasis constants in the back for a couple of those machines.
--scott


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

Trevor Wilson wrote:

**The only recorders available (outside Germany) during the (early) 1940s
were 'wire recorders'. Fidelity was appalling. I've worked on a few, but I
don't know what, if any, equalisation was in use.

No, there were lots of home disc recorders from outfits like Presto
and Wilcox-Gay. They cut lacquers cold with a non-feedback cutting
head and fixed pitch. Fidelity was appalling. But you come across
a lot of those old discs.

Lots of USO and Red Cross canteens had the machines available so folks
could record a disc and send them home. When they arrived, usually they
would be played over and over again on the family phonograph, so you can
add excessive wear to all the other ills.
--scott


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

On Mon, 20 Feb 2006 23:08:15 -0500, Ken Bouchard wrote
(in article ) :

does anyone know what if any equalization was applied by the average record
recorder back in the "old days" (like the forties)? were they all cut flat?
I was thinking of the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

thanks,

--
DVB systems
c/o Ken Bouchard
1520 Big Valley Dr.
Colo. Springs CO 80919
USA

www.dvbaudiorestoration.com



Would that be before the RIAA EQ curve?

Ty Ford


-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com

In article ,
Ty Ford wrote:
On Mon, 20 Feb 2006 23:08:15 -0500, Ken Bouchard wrote
(in article ) :

does anyone know what if any equalization was applied by the average record
recorder back in the "old days" (like the forties)? were they all cut flat?
I was thinking of the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

Would that be before the RIAA EQ curve?

Yes. RIAA wasn't until '53, right?
--scott


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

I think in the long run you will find out that the system was tuned and
tweaked to get the most out of the human voice. I don't believe the goal was
ever to get the best frequency response, dynamics or anything else we now
consider to be elements of high fidelity. When I was a kid I had a very old
Dictaphone that used little green plastic disks with a square hole in the
center. The whole thing was just a little bit bigger than a 70's style
portable mono casset recorder.

As far as some of the comments I've read about wire recorders, it was my
understanding that those were mostly developed and used by Bell Telephone.
Round, steel wire was used first, but it twisted in the pickup gap and that
caused a rolling phase shift effect that made it obvious that it was a wire
recording. Later a steel flat ribbon was used. I've seen pictures of ribbon
recorders that had reels that looked like they were 6 feet across. These
things were dangerous, because the ribbon was moving fast and it had great
tensile strength. The wire broke and could uncoil in a very violent way. For
that reason paper tape was developed and then later polyester came along.
Iron oxide mixtures were found that could be reasonably stuck to the backing
material, at least to get through the machine a few times without flaking
off.



"Ken Bouchard" wrote in message
...
does anyone know what if any equalization was applied by the average
record
recorder back in the "old days" (like the forties)? were they all cut
flat?
I was thinking of the recorders you could buy at Sears or recorders
located
in Woolworths to be used by military people for letters home. does anybody
KNOW this"? I'd rather not have any guesses since I've been doing that
myself:-)

thanks,

--
DVB systems
c/o Ken Bouchard
1520 Big Valley Dr.
Colo. Springs CO 80919
USA

www.dvbaudiorestoration.com

"James Lehman" wrote:


Round, steel wire was used first, but it twisted in the pickup gap and that
caused a rolling phase shift effect that made it obvious that it was a wire
recording. Later a steel flat ribbon was used.

Actually the ribbon was the first to be used. The Blättnerphone and the
Marconi-Stille systems both used it in the 1930s, long before wire.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

"Arny Krueger" wrote in
:

"Ken Bouchard" wrote in message

does anyone know what if any equalization was applied by
the average record recorder back in the "old days" (like
the forties)? were they all cut flat? I was thinking of
the recorders you could buy at Sears or recorders located
in Woolworths to be used by military people for letters
home. does anybody KNOW this"? I'd rather not have any
guesses since I've been doing that myself:-)


Here is detailed technical information about legacy magnetic
recorders, including some schematics:

http://history.acusd.edu/gen/recording/begun6.html

Thank you Arni for this wonderful off-topic bit of information,
since the original post was about acetate disk recorders.

--
Bob Quintal

PA is y I've altered my email address.