Early 33.3 RPM and late 78 RPM Columbia Recordings from 30th Street Studio, NYC

[Craig Maier]

Early Columbia LP's and late Columbia 78s were recorded at the Columbia 30th street recording studio in NYC circa 1949 and included the original broad way cast of "South Pacific'. This recording studio was widely considered to be the best in the country at it's time (low noise and distortion and wide bandwidth). The LPs were mastered on laquer and thus the very low noise floor of their product.

NOTE: The first monophonic Columbia Microgroove LP release occurred on June 21st, 1948. It was the Violin Concerto in E Minor (ML4001) and used a grove width of 0.003 inches rotating at 33.3 RPM. Originally, these were mastered on lacquer using a 0.003 inch grove width, but the studio(s) switched over to magnetic tape circa 1949 (Magnetephon), best played with a 1.0 mil stylus.

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[Craig Maier]

The Diamond Cut Productions VPP has the ability to re-eq transfers made from RIAA or Flat to the early Columbia curve (and other EQ curves as well).

Columbia records played on an RIAA based system sound substantially different than those transferred or played using the Columbia curve. The Virtual Phono Preamp) VPP has the ability to re-eq the transfer making it sound the way that the Columbia recording engineers had intended them to sound.

[Doug_78]

My focus is on digitizing 78 rpm records from the R&B and early rock era in the 1950's. On that, see files from Fisher for their tuner 70-RT released in 1954. It seems that there were at least 4 de-emphasis curves used, based on the record label and the record rpm - AES, RIAA/ORTHO, LP, NAB. Only one of them could be the RIAA curve used for 33-1/3 and 45 rpm vinyl, but I can't be sure from the phonograph equalization Figure 4, and the record equalization guide provided in the manual.

I also seems that it makes more sense to have the de-emphasis curves in the software, although many specialty audio to USB converters have a non-switchable RIAA curve already incorporated. The only exception I have found so far is the Parasound ZPhono MM/MC phono preamplifier with USB, now apparently obsolete. There seems to be a sizable argument whether a freestanding converter will give better performance than a computer sound card for digitizing records.

In any event, it appears that more 78 rpm de-emphasis curves, or provision for custom curves, would be helpful. I realize this can be a big rabbit hole, and it would be excellent to get some informed guidance on ways to configure such a system without overkill for what is needed. However, it seems clear that digitizing 33 1/3 rpm is a whole different animal than 78 rpm.

I can't find a way to upload a graph and a table within the website limit of 19.5 KB, by converting within Foxit pdf editor, and it won't take htm files.

Comments welcome. Doug

[Craig Maier]

For 78s, there were only two curves, both being low frequency turnover curves (American 78s were 500 Hz and Euro 78s were 250 Hz). There may have been other 78 curves, but they were not standard. Once the LP era came in, HF rolloff (de-emphasis) was added for LPs; many variants existed up until around 1954 or 1955. You can find the LP variants under the presets section of the Virtual Phone Preamp (VVP). Here is a screen shot a few of the presets for non-standard LP eq curves:

[Craig Maier]

Here is another view of the alternate LP curves available. Scroll the presets list to see all of them.

[Craig Maier]

Here is a comprehensive list of VPP Re-EQ presets available to you in the DCversion 11 software: