When to apply reverse RIAA/78 turnover

[Dan McDonald]

Re: When to apply reverse RIAA/78 turnover

So a reverse-nab might be a good place to start on an old home open-reel recording being played on a more modern open reel, then adjust til it sounds good?

Thanks Craig

[This message has been edited by Dan McDonald (edited 11-06-2001).]

[Beautman]

Re: When to apply reverse RIAA/78 turnover

While we're on the subject, does anyone know if 1940s home recording discs (e.g., Recordio, etc.) were intended to be played back with eq and, if so, what the turnover points are? The bass sounds rolled off to me on a flat transfer, but maybe it's just the medium.

[Craig Maier]

Re: When to apply reverse RIAA/78 turnover

Reverse NAB is provided in Diamond Cut software for instances wherein a tape recording would have been transfered through your sound card directly from the tape head output of the tape machine. In the case of an early tape recorder with its own home grown and non standard equalization, it would not be correct to say that starting with reverse NAB is necessarily going to accurate results. I would suspect that it would be too agressive in amplifying the bottom end of the spectrum, and also probably too agressive in attenuating the top end. At the end of the day, you will probably just have to rely on your own ear to determine the correct equalization on such a tape. Of course, you can start with the reverse NAB curve and modify it. I would suggest bringing it up and immediately cloning it under a new name before modifying it. When you get it sounding the way that you like it, save it under a new preset name for future reference.

[Dan McDonald]

Re: When to apply reverse RIAA/78 turnover

Thanks, Craig. I'll give it a try.

The reverse riaa makes a big difference in cylinder and early 78 recordings. I wasn't aware of the problem until reading this thread. Thanks.

Dan McDonald

[praxel]

Re: When to apply reverse RIAA/78 turnover

[QUOTE]Originally posted by Craig Maier:
[B]Early home magnetic tape recorders, including models from the 1955 time period often "rolled their own" internal EQ.

Hi !
My Ampex recorder from -55 had the NAB curve. I rebuilt it later to CCIR, which is the modern standard . Revoxes from the early sixties had CCIR.
If you play a NAB tape on a CCIR machine, you would hear it as a boost in the treble region, and a little lack of bass .

Professional recordings from the fifties mostly includes the standard curves.

The nasty part with correction curves is that in the 6db filter, capacitors are used, and when applied in series, they twist the phase 90?. If the playback filter does not match the recording filter due to the phase issue, there will be some frequency regions that will be out of phase, a problem that sometimes can be more annoying than the frequency response.

Peter

[Craig Maier]

Re: When to apply reverse RIAA/78 turnover

Ampex, Crown, and Magnecord were the top end brands in the 1950's. All of those would have adhered to some standards for Eq. However, there were a lot of low end brands which payed little attention to equalization standardization.

[praxel]

Re: When to apply reverse RIAA/78 turnover

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Craig Maier:
Ampex, Crown, and Magnecord were the top end brands in the 1950's. All of those would have adhered to some standards for Eq. However, there were a lot of low end brands which payed little attention to equalization standardization.<HR></BLOCKQUOTE>

Sure Craig. I misred Daves posting, and thought it was made on a professional recorder.

Best Peter

[dismuke]

Re: When to apply reverse RIAA/78 turnover

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Craig Maier:
If you transferred a 78 recording via an RIAA preamplifier and you want the sound to have the proper frequency response balance, you need to reverse the RIAA curve and add back in the correct turnover. The paragraphic EQ in the Diamondcut products has the presets to do just that.<HR></BLOCKQUOTE>

Question: By that, do you mean if I record throuh an RIAA preamplifier and use a "Reverse RIAA w/ 500 Hz 78 Turnover" on an old Brunswick (which is listed in the guide's appendix being 500 hz) I will have restored the recording to the correct equalization setting? Or does it mean that I simply have removed all equalization on the recording and will need to go back in and add the "78 RPM 500 Hz Turnover Curve"?

Also, do you have a listing for turnover frequencies for other labels such as Hit of the Week, Cameo, Romeo, Perfect, etc? Would the settings for Okeh necessarily be the same as for Columbia and Vocalion the same as for Brunswick?

[Craig Maier]

Re: When to apply reverse RIAA/78 turnover

A preset that says Reverse RIAA with xx turnover means that it reverses the RIAA and also, at the same time, applies the correct turnover. As for the eq curves on various additional record labels, we are compiling an updated listing for our next release of the software.