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The VPP has 4 closed form (exact) Phono EQ Curves. Here is a brief description taken from the documentation. Other EQ curves that are approximations can be found under the presets section of the VPP.
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Record Type (Selector Box)
The lower left corner of the VPP provides a group of selections based on the type of record that you are trying to transfer to your computer. This selection, in conjunction with the “Preamp Hardware” goes through a logical truth table in order to determine the proper algorithms to run to produce the correct phono EQ curve for the particular situation that you are working with. These EQ’s and re-equalization curves are highly accurate because they are calculated in a closed form mathematical technique. The most accurate transfer results will occur when you use a flat preamplifier as your systems input front end. Analog circuit parameters associated with resistors and capacitors in physical RIAA preamps render them less precise. These inaccuracies are reflected not only in the RIAA curve, but also in any of the re-equalization curves that the VPP can provide.
You have the following record options from which to choose:
RIAA Vinyl LP / 45
This is intended to be used on all 45 RPM records and almost all LPs which were mastered post 1955 and some that were mastered prior to that date as well. The RIAA curve was originally called “The New Orthophonic Recording Characteristic” by RCA Victor which was proposed as an EQ standard in 1953 and later adopted by the RIAA. The VPP RIAA curve is defined as having the following breakpoint frequencies: (F {in Hz} = 1 /2 π (R x C) where R x C = Time Constant)
50 Hz Pullout (3180 uSec Time Constant)
500 Hz Turnover (318 uSec Time Constant)
2120 Hz Rolloff (75 uSec Time Constant)
Early Columbia LPs
This EQ curve is intended for many early LPs mastered during the period between 1948 through 1955. This curve was established as a standard for early Columbia LPs. The VPP Early Columbia LP curve is defined as having the following breakpoint frequencies:
30 Hz Pullout (5310 uSec Time Constant)
300 Hz Turnover (531 uSec Time Constant)
1600 Hz Rolloff (99.4 uSec Time Constant)
American 78s
This EQ curve applies a turnover curve only (and the appropriate pullout) for use with 78 records having a 500 Hz characteristic. It does not implement any Rolloff, since 78s did not encode in that manner. Many American 78s were recorded with this curve. For more details regarding 78 Turnover frequencies by record brand, please refer to the “Turnover Frequency” section found in the Appendix of this user’s guide.
European 78s
This EQ curve applies a turnover curve only (and the appropriate pullout) for use with 78 records having a 250 Hz characteristic. It does not implement any Rolloff, since 78s did not encode in that manner. Many European 78s were recorded with this curve. For more details regarding 78 Turnover frequencies by record brand, please refer to the “Turnover Frequency” section found in the Appendix of this user’s guide.
Acoustical
This EQ curve reverses the curve introduced by an RIAA front-end preamplifier and is passive for signals sourced from a flat preamplifier. When used in conjunction with a conventional RIAA hardware preamplifier, this setting would often be referred to as “Reverse RIAA Mode”. It is to be used on acoustically mastered material. Most recordings mastered before 1925 require this setting, including laterally cut 78s, Edison Diamond Discs, Path[FONT=Times New Roman]
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Record Type (Selector Box)
The lower left corner of the VPP provides a group of selections based on the type of record that you are trying to transfer to your computer. This selection, in conjunction with the “Preamp Hardware” goes through a logical truth table in order to determine the proper algorithms to run to produce the correct phono EQ curve for the particular situation that you are working with. These EQ’s and re-equalization curves are highly accurate because they are calculated in a closed form mathematical technique. The most accurate transfer results will occur when you use a flat preamplifier as your systems input front end. Analog circuit parameters associated with resistors and capacitors in physical RIAA preamps render them less precise. These inaccuracies are reflected not only in the RIAA curve, but also in any of the re-equalization curves that the VPP can provide.
You have the following record options from which to choose:
RIAA Vinyl LP / 45
This is intended to be used on all 45 RPM records and almost all LPs which were mastered post 1955 and some that were mastered prior to that date as well. The RIAA curve was originally called “The New Orthophonic Recording Characteristic” by RCA Victor which was proposed as an EQ standard in 1953 and later adopted by the RIAA. The VPP RIAA curve is defined as having the following breakpoint frequencies: (F {in Hz} = 1 /2 π (R x C) where R x C = Time Constant)
50 Hz Pullout (3180 uSec Time Constant)
500 Hz Turnover (318 uSec Time Constant)
2120 Hz Rolloff (75 uSec Time Constant)
Early Columbia LPs
This EQ curve is intended for many early LPs mastered during the period between 1948 through 1955. This curve was established as a standard for early Columbia LPs. The VPP Early Columbia LP curve is defined as having the following breakpoint frequencies:
30 Hz Pullout (5310 uSec Time Constant)
300 Hz Turnover (531 uSec Time Constant)
1600 Hz Rolloff (99.4 uSec Time Constant)
American 78s
This EQ curve applies a turnover curve only (and the appropriate pullout) for use with 78 records having a 500 Hz characteristic. It does not implement any Rolloff, since 78s did not encode in that manner. Many American 78s were recorded with this curve. For more details regarding 78 Turnover frequencies by record brand, please refer to the “Turnover Frequency” section found in the Appendix of this user’s guide.
European 78s
This EQ curve applies a turnover curve only (and the appropriate pullout) for use with 78 records having a 250 Hz characteristic. It does not implement any Rolloff, since 78s did not encode in that manner. Many European 78s were recorded with this curve. For more details regarding 78 Turnover frequencies by record brand, please refer to the “Turnover Frequency” section found in the Appendix of this user’s guide.
Acoustical
This EQ curve reverses the curve introduced by an RIAA front-end preamplifier and is passive for signals sourced from a flat preamplifier. When used in conjunction with a conventional RIAA hardware preamplifier, this setting would often be referred to as “Reverse RIAA Mode”. It is to be used on acoustically mastered material. Most recordings mastered before 1925 require this setting, including laterally cut 78s, Edison Diamond Discs, Path[FONT=Times New Roman]