Phono Transfer System Construction Information

Construction information for DIY projects, including the MS Mid Side Matrix, Elliptic Equalizer, Mastering Console, Phono Transfer System, Insert Switcher and the Dual Class-A Amplifier. You can post your baby pictures here.
Audio1Man
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Re: Phono Transfer System Construction Information

Post by Audio1Man » Thu Jun 11, 2020 11:23 am

Hi Brian

If you have access to an Audio precision the RIAA curves & tests are part of the software tests.
Duke

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JR.
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Re: Phono Transfer System Construction Information

Post by JR. » Thu Jun 11, 2020 11:55 am

I suspect he is looking for a piece of hardware that can sit in line to facilitate monitoring the RIAA equalized feed going to the cutting head.

He just needs a typical riaa playback circuit without the 40 dB of gain at 1kHz....

JR
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brianroth
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Re: Phono Transfer System Construction Information

Post by brianroth » Thu Jun 11, 2020 6:48 pm

JR. wrote:
Thu Jun 11, 2020 11:55 am
I suspect he is looking for a piece of hardware that can sit in line to facilitate monitoring the RIAA equalized feed going to the cutting head.

He just needs a typical riaa playback circuit without the 40 dB of gain at 1kHz....

JR
Indeed, my goal is a tidy, already designed solution. As mentioned in an earlier post, adding a big-ass pad in front of a conventional phono preamp seems silly since Wayne designed a line input device with the RIAA playback curve. I've been slowly re-reading this thread to verify the deemphasis curve is very accurate, although the primary reason for this app is to ensure the cutting amp isn't farting <g> or otherwise acting up. You cannot playback the lacquer if it's destined to go through the plating and pressing steps.

Bri
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mediatechnology
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Re: Phono Transfer System Construction Information

Post by mediatechnology » Thu Jun 11, 2020 9:07 pm

Brian -

All you need to do is pad the cutterhead drive level and feed it into the RIAA EQ portion of the EQ Monitor board at J4.

You'd need to populate IC6, IC7 and if you want a balanced output to drive the monitor, add the THAT1646s at IC10/11.
You don't really need IC7 either but it will give you a gain trim.

See: https://proaudiodesignforum.com/images/ ... 092719.pdf

Feedback monitoring is something a little different - the RIAA is applied to the output of the feedback coil preamp.

The PTS is being used by a number of facilities for cutting.
The FLAT MM preamp is used as a feedback coil amp, the EQ Monitor board to provide Inverse RIAA and then using IC7 to sum modulation and feedback. A second RIAA board is then used to EQ the feedback path.

Gus Elg at Sky Onion is using it this way and he would be a good contact for you for any questions you might have on this project.

I just had a client tell me that it used to be that about 1 in 10 projects were mastered for vinyl - now its 1 in 2 or 3.
https://ka-electronics.com

Plandemic Series: "Pland3mic - Indoctornation" https://proaudiodesignforum.com/content ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://proaudiodesignforum.com/content/Plandemic.mp4

CDC: "For 6% of the deaths, COVID-19 was the only cause mentioned. For deaths with conditions or causes in addition to COVID-19, on average, there were 2.6 additional conditions or causes per death." https://www.cdc.gov/nchs/nvss/vsrr/covi ... /index.htm

billshurv
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Re: Phono Transfer System Construction Information

Post by billshurv » Wed Jul 01, 2020 4:15 am

There is a scary chance I will get my build running by the end of the week! Watch this space.

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mediatechnology
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Re: Phono Transfer System Construction Information

Post by mediatechnology » Thu Jul 02, 2020 3:45 pm

Glad you're getting closer!
https://ka-electronics.com

Plandemic Series: "Pland3mic - Indoctornation" https://proaudiodesignforum.com/content ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://proaudiodesignforum.com/content/Plandemic.mp4

CDC: "For 6% of the deaths, COVID-19 was the only cause mentioned. For deaths with conditions or causes in addition to COVID-19, on average, there were 2.6 additional conditions or causes per death." https://www.cdc.gov/nchs/nvss/vsrr/covi ... /index.htm

grufti
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Re: Phono Transfer System Construction Information

Post by grufti » Wed Jul 08, 2020 9:56 pm

No way! One down [nearly] ... n+1 to go. I know the feeling

billshurv
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Re: Phono Transfer System Construction Information

Post by billshurv » Sat Jul 11, 2020 6:39 pm

Having to work from home with two under 5s has not been conducive to working on projects. Work has been particularly manic as well, which is a good thing in the grand scheme of things. If I can get the test cables I need finished final visual inspection of the soldering and I can start testing.

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mediatechnology
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Re: Phono Transfer System Construction Information

Post by mediatechnology » Sat Jul 11, 2020 7:50 pm

Last November I got a puppy - a Spaniel/Border Collie mix.
Very high energy dog...
It's been hard for me to build boards to replace what I've sold.
https://ka-electronics.com

Plandemic Series: "Pland3mic - Indoctornation" https://proaudiodesignforum.com/content ... nation.mp4
Plandemic Series: "Plandemic - Doctors In Black" https://proaudiodesignforum.com/content/Plandemic.mp4

CDC: "For 6% of the deaths, COVID-19 was the only cause mentioned. For deaths with conditions or causes in addition to COVID-19, on average, there were 2.6 additional conditions or causes per death." https://www.cdc.gov/nchs/nvss/vsrr/covi ... /index.htm

billshurv
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Re: Phono Transfer System Construction Information

Post by billshurv » Sun Jul 12, 2020 4:44 pm

Two manic breeds crossed. Yup I can guess how that turned out :)

By end of tomorrow my brownie points balance will be very positive so I'll cash those in for time to get things up and running and start testing things.

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