Paragraphic EQ RIAA Improved vs NAB Tape

[Thomas LeMay]

Hi,

I am transferring an audio cassette tape which was comercially produced over to DC 6. Under the paragraphic EQ I would normally apply the new released RIAA Improved EQ filter if it were an analog LP. I notice that there is a NAB Tape playback EQ filter which I assume is to be used for audio cassette tapes. Is it ok to just use the RIAA improved EQ for comercially produced audio cassette tapes as they are the same recorded material (songs as would be available on the comercial LP or CD?

Thanks, Tom

[Craig Maier]

The RIAA curves are only designed to be used on transfers made of phonograph records that had been transferred via a flat preamplifier. Applying an RIAA curve to a transfer that has already been decoded by a standard magnetic EQ preamplifier will result in a totally muddy sound having little top-end.

As for the NAB tape preset, that is also designed to be used only when a direct connection is made between a playback tape head and a flat preamplifier. If you are transferring via a tape deck having built in electronics, the tape recording EQ curve has already been reversed.

Note: The reason that we provided the NAB curve was for users of pro grade machines in which the electronics were seperate from the tape transport. Those folks have the option of using a flat preamplifier (like the CTP-XXXX family) to make the transfer and then to apply the reverse EQ curve in software. This methodology can be applied to pro/studio decks, but not consumer decks or cassette players {unless you are willing to undertake some modifications to the machine}. Applying an NAB curve to a transfer that already has it decoded will result in a very heavy and exagerated bassy sound.

[Thomas LeMay]

Hi, Craig,

Thank you forresponding. Her is my setup: I have two flat CBT 1000 pre amps attached to my PC as well as to a phonograph turn table anda portable cassette player (aux mode). So, what type of EQ should I apply if I am transferring an audio cassette taoe through the flat pre amps and over to my hard drive? Tom

[Thomas LeMay]

Craig,

I reread your post and now it seems that even though I am using the CTP 1000 flat pre amps, Iam better off just transferringthe audio cassette over to my pc and then applying the cassette dehiss filter. Then, I can apply a gain normalize filter and that should pretty much take care of a commerically purchased auio cassette tape. Tom

[Craig Maier]

Since you are using the AUX input on the CTP preamp, that implies that you are connected to a tape deck that has a line level output which has already been decoded. So, you only need to reverse the EQ when you are using the turntable. The tape deck has already performed that function for you. So, when the CTP preamp switch is in the AUX position, which is your tape deck, you do not need to apply any NAB EQ.

And, I agree; usually a commercially produced cassette tape needs to be de-hissed.