How should pre-RIAA records be played on modern equipment — sorting out practical options

How should I play records from the pre-RIAA period?

Questions answered on this page: How can I play records recorded before the RIAA standard (1954) on modern equipment?

First check: is the record really pre-RIAA?

First, check whether the record in hand was actually recorded during the pre-RIAA period.

• Stereo LPs (1958 onward) → RIAA curve
• Monaural records after 1954 → some labels had likely already switched to RIAA
• Reissues → if re-cut, most likely RIAA

For when each label transitioned: → When did each label switch to RIAA?

The following options apply if, after checking, the record is likely from the pre-RIAA period.

Option 1: listen with RIAA as-is

The easiest option, and in many cases perfectly practical.

The major curves of the pre-RIAA period (Columbia LP, NAB, AES, Orthophonic, etc.) all have turnovers around 400–500 Hz, not far from RIAA's 500 Hz. The difference in high-frequency pre-emphasis is somewhat larger, but is unlikely to be a fatal problem in normal listening.

Listeners at the time also used tone controls to compensate for the differences between labels' curves. In some cases, the difference may not be so great that listening in RIAA would ruin the experience.

That said, as someone who uses a variable-EQ phono equalizer and plays back with reference materials in hand, I cannot say definitively that the difference is negligible.

This leads us to Option 2.

Option 2: compensate with tone controls

If your amplifier has tone controls (bass and treble adjustment), you can use them to adjust the audible balance.

It is not a precise correction, but it is practical. In fact, this is what pre-RIAA-era listeners routinely did.

Option 3: use a variable-EQ phono equalizer

If you use a phono equalizer that allows you to switch turnover and high-frequency pre-emphasis values, you can try playing back with settings close to the curve used at the time of recording.

However, there are caveats:

• The exact curve used at the time of recording may not be known. Many pre-RIAA recordings have no record of the curves used. Settings are only estimates.
• The EQ curve is only one element of the signal chain. Simply matching the three parameters of a curve does not reproduce the "sound as recorded" (→ EQ curve vs. mastering).
• "Settings that sound preferable" and "settings used at the time of recording" are two different questions (→ Can you hear a difference when you change the EQ curve?)

Accept that "the right answer may not be known"

When it comes to playing pre-RIAA records, the recording curves used by some labels have been identified, but for others, there is no definitive answer, or opinions remain divided. Furthermore, the recording chain at that time was complex, with many variables that cannot be captured by the three parameters of the EQ curve alone.

The settings available on a variable-EQ phono equalizer are approximations, and there is no guarantee that any given setting is correct. Understanding this and searching for the sound that is best for you— that is a realistic way to approach pre-RIAA records.

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