I get around the RIAA curve by recording slow. High frequencies on a 78 when
played at 33 1/3 will be presented to the RIAA circuitry at just under a
third of their original frequency. i.e. 10,000 cycles at 78 will be just
over 3,000 cycles at 33 1/3 which means less suppression of the high
frequencies at playback.
The result is a fabulous kick of bass and depth , and clarity and
transparency for the high frequencies. I have digitized thousands or
recordings this way and am satisfied that it works for most recordings - but
not all. e.g. Columbias - notably 'Gentlemen Prefer Blondes' is one of these
exceptions.
Once you play a 78 through an RIAA preamp at full speed, you kill much of
the high frequency information and you cannot equalize it to get it
back-Anyone interested in a sample to illustrate this, please advise me and
I can send an example. I have covered everything from symphonic, opera,
blues, jazz and spoken word and have samples I can send as mp3's. The link
below is a slow transfer of the Gigli/Caniglia version of Verdi's Requiem.
I did adjust the bass eq slightly to smooth it out, as there was a bit of a
hump in the curve before eq. the trble is kept intact - all the best to the
group and a Merry Christmas to All-Mickey Clark
http://www.amazon.com/Verdi-Requiem-CDN255-Royal-Serafin/dp/B004YZCJTW/ref=sr_1_2?ie=UTF8&qid=1387645955&sr=8-2&keywords=verdi+requiem+m.c.productions
Mickey
----- Original Message -----
From: "Doug Pomeroy" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, December 20, 2013 1:52 PM
Subject: Re: [ARSCLIST] Record Equalization
> The Radiotron Handbook entry shows only one curve "used by R.C.A. Victor
> for 78 r.p.m. shellac discs, 45 r.p.m. and 33 1/3 r.p.m. fine groove"
> discs. As there was no RCA Victor before 1929, this does not tell the
> whole Victor story and does not answer the specific question Steve Smolian
> asks (about electrical Victors made in the short period before November of
> 1925).
>
> Maxfield and Harrison's 1926 paper describing the Western Electric system
> clearly indicates a bass turnover of 200 Hz and pre-emphasis ("constant
> acceleration") above "approximately 4000 Hz". This was before electrical
> record players were widely available and this curve was developed in
> consideration of playback by acoustic record players.
>
> As has been mentioned, Victor raised the bass turnover over the years from
> 200 Hz to 300 Hz and finally to 500 Hz. Nick Bergh knows the cutting
> equipment used and speaks with authority on the subject of EQ. I showed
> him a Victor ledger sheet from December 1926 which includes a column
> marked "Eqlzr." and it only shows the words "on" or "off" which doesn't
> tell us what we'd really like to know! It's safe to say that at Victor,
> experiments with various cutting equalizations were being done
> on an ongoing basis.
>
> Doug Pomeroy
> Audio Restoration and Mastering Services
> 193 Baltic St
> Brooklyn, NY 11201-6173
> (718) 855-2650
> [log in to unmask]
>
>
>
>> Date: Thu, 19 Dec 2013 18:36:58 +0000
>> From: "Gray, Mike" <[log in to unmask]>
>> Subject: Re: Record equalization
>>
>> From Radiotron Designer's Handbook, 4th Ed. 1953, p. 728, item 17.5:
>>
>>
>> "There is no 'optimum' cross-over frequency because the choice is
>> necessarily a compromise. Where distortion is the principal criterion, a
>> low cros-over frequency from 250 to 350 c/s will be adopted for standard
>> groove 78 r.p.m. Where needle scratch is troublesome with 78 r.p.m. a
>> high cross-over frequency of say 500 c/s may be adopted."
>>
>>
>> On page 730, under Practical recording characteristics:
>>
>>
>> "There does not appear to be any generally accepted definition of
>> published recording characteristics."
>>
>>
>> In the two figures on this page, European characteristics show several
>> cross-over points, ranging from 300 Hz (Decca ffrr)
>> to 600 Hz for EMI 78 rpm. Note that there is no pre-emphasis at all for
>> the EMI discs, which are 'flat' up to 10 Khz.
>>
>>
>> American 78s, however, show a boost of ca. 12 db at 10 KHz ...
>>
>>
>> FWIW
>>
>>
>> Mike Gray
>
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