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RIAA Preamps still needed?

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Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 2:37 pm
by ef37a
H,B, I have actually got a Behringer UFO202 which is a variant of the UCA202, a very basic 2 in 2 out, neg ten 16 bit converter. I have had several of the latter and they are quite good enough for duping cassette or vinyl (if you have a hi fig and tt)
The UFO has RIAA corrected phono inputs and at £25 or so it is not going to compare with a Quad pre but I could hook it up to the Rega P if you like and see how it does?

Really depends on how "hi fi" you want or need the disc repro? If you are getting a turntable my preference would be to look at pawn and charity shops for a modest integrated amplifier? You get disc corrected output on tape sockets and TRUE latency free monitoring!

Sony, Marantz, Philips...Denon, never made a bad ANYTHING IMHO!

Dave.

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 3:04 pm
by Humble Bee
Thanks folks! Sorted! :thumbup:
Sorry for hijacking the thread... :?

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 3:10 pm
by Tim Gillett
As a point of interest, sometimes it's best to transfer a disc direct with no RIAA EQ.

The RIAA EQ is only valid at the proper recorded speed. A really warped disc may not play at 33RPM without the stylus jumping out of the groove. Replay at 16RPM or even half again may be the only way to get the stylus to track. Then digitally we can speed the file up to 33 RPM , then perform the RIAA EQ.

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 3:32 pm
by James Perrett
The only problem with using an input with no equalisation is that it needs to have an input impedance of 47k ohms. If the input impedance is different the pick up cartridge will no longer have a flat frequency response.

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 3:49 pm
by Hugh Robjohns
Tim Gillett wrote:A really warped disc may not play at 33RPM without the stylus jumping out of the groove. Replay at 16RPM or even half again may be the only way to get the stylus to track. Then digitally we can speed the file up to 33 RPM , then perform the RIAA EQ.

True, and even stranger things have been done in the name of extreme and specialist archive sound recovery work... But there's obviously a lot more involved than just finding a way to bypass the standard RIAA equalisation and slowing down the turntable! ...As I'm sure you appreciate.

Amongst the other important technical considerations are the cartridge load impedance as James has already pointed out (depending on the specific cartridge being used), vertical tracking angle control, and various low frequency issues including the loss of Low frequency programme audio and frequency-shifted rumble components to mention just two...

H

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 5:23 pm
by twotoedsloth
Hello,

Thanks all of you for your thoughts.

As far as I can tell, it's going to literally be show and tell. I'm pretty sure the guest lecturer is not really too concerned with sound quality. He is not interested in transferring to a digital (or tape/cassette) format, it's mostly just to show off turntable technology.

A local shop is offering to rent me a turntable for $50 CDN, but I think that a new turntable is just $100 CDN, so I'm mulling over the idea of just buying one, who knows, it may be useful down the road?

If I do rent the turntable, I will also need to track down an RIAA preamp, or so it looks. Hopefully the one they rent us has a USB port.

Thanks everyone for taking the time to read and respond to this.

Re: RIAA Preamps still needed?

PostPosted: Thu Feb 07, 2019 6:21 pm
by Kwackman
DGL. wrote:find an old Hi-Fi cheap either via ebay or charity shops, something lower end from one of the Japanese manufacturers should be good enough for most uses.

^^^^^^^^
This might be worth checking again.
Local free ads/Gumtree etc might get you a cheap solution.

Re: RIAA Preamps still needed?

PostPosted: Fri Feb 08, 2019 3:08 am
by Tim Gillett
Hugh Robjohns wrote:
Tim Gillett wrote:A really warped disc may not play at 33RPM without the stylus jumping out of the groove. Replay at 16RPM or even half again may be the only way to get the stylus to track. Then digitally we can speed the file up to 33 RPM , then perform the RIAA EQ.

True, and even stranger things have been done in the name of extreme and specialist archive sound recovery work... But there's obviously a lot more involved than just finding a way to bypass the standard RIAA equalisation and slowing down the turntable! ...As I'm sure you appreciate.

Indeed, but given that this was not directly related to the thread topic, or a specific request for information on this specialised topic, I chose not to go into such details.

Re: RIAA Preamps still needed?

PostPosted: Fri Feb 08, 2019 10:40 am
by Hugh Robjohns
Er... quite! :lol:

Re: RIAA Preamps still needed?

PostPosted: Sat Feb 09, 2019 9:27 am
by Tim Gillett
Hugh Robjohns wrote:Er... quite! :lol:


:lol: