Mastering Stereo Insert Switcher with Flip 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.
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mediatechnology
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by mediatechnology »

That is a problem with modification.
Markus designed it using 12V relays to reduce power consumption - turns out 2X 12V relays in series use less power than all 24V coils. IIRC it's 150 mW/relay vs. 200 mW.
I have installed 12V Zeners in places where relays weren't used so the remaining 12V coil in series could be used.

I've had an idea of differentially nulling the primary and secondary signals to extract the color component and then applying gain to the color before blending it back in.
Getting an exact null of color might not be possible but adding gain and mixing it back in gives a greater amount of control.
vintagedesign
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by vintagedesign »

In our latest product we use 50 x 12v relays. To keep the power draw down I use a LM2596 dc/dc switch regulator turned down to +10v.
A LM7812 would have add 5VA extra power draw.
Thomas TK Kristiansson
Sweden
Vintagedesign / TK Audio
bobkatz
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by bobkatz »

Here's a question:

SW1 is for the series resistor
SW2 is to engage or bypass the transformer

I want SW1 to be dependent on SW2. In other words, LED #1 will not light and the "series resistor" will not engage unless the transformer is engaged.

So I connect the + side of external switch 1 to the - side of external switch 2 as pictured here

https://crush.digido.com/?u=Mastering_I ... p=Kirkwood

Download the Mastering_insert switcher.png file

Do I need to add diode logic in this case to prevent interaction between Sw1 and sw2?
bobkatz
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by bobkatz »

I measured the THD of the WE111 transformer. A THD sweep and also 60 Hz at 0 dBu and +10 dBu with 0 series R versus 2k series R

Measurements are in the PDFs in here

https://crush.digido.com/?u=Mastering_I ... p=Kirkwood

It's subtle for sure, but maybe not too subtle for me. I'll put it to use and if I think it needs more color I'll replace the Western Electric with some smaller UTC transformers that I have.
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mediatechnology
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by mediatechnology »

bobkatz wrote: Wed Jul 12, 2023 8:08 am Here's a question:

SW1 is for the series resistor
SW2 is to engage or bypass the transformer

I want SW1 to be dependent on SW2. In other words, LED #1 will not light and the "series resistor" will not engage unless the transformer is engaged.

So I connect the + side of external switch 1 to the - side of external switch 2 as pictured here

https://crush.digido.com/?u=Mastering_I ... p=Kirkwood

Download the Mastering_insert switcher.png file

Do I need to add diode logic in this case to prevent interaction between Sw1 and sw2?
Looks like it will work as drawn.
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mediatechnology
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by mediatechnology »

bobkatz wrote: Wed Jul 12, 2023 10:39 am I measured the THD of the WE111 transformer. A THD sweep and also 60 Hz at 0 dBu and +10 dBu with 0 series R versus 2k series R

Measurements are in the PDFs in here

https://crush.digido.com/?u=Mastering_I ... p=Kirkwood

It's subtle for sure, but maybe not too subtle for me. I'll put it to use and if I think it needs more color I'll replace the Western Electric with some smaller UTC transformers that I have.
Plots show why the 111 is the gold standard.
I think you'll need a transformer with a softer material.
Let us know what you hear in the low end with the 2KΩ.
bobkatz
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by bobkatz »

mediatechnology wrote: Wed Jul 12, 2023 12:32 pm
bobkatz wrote: Wed Jul 12, 2023 8:08 am
Do I need to add diode logic in this case to prevent interaction between Sw1 and sw2?
Looks like it will work as drawn.
Perfect. Thanks very much.
CitricAcid303
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by CitricAcid303 »

Hello,

A realy great Project. Will Build too.

Is it posible to get a Dry Wet function to this? for doing parallel Processing ? Any how a great job, thanks.
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mediatechnology
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by mediatechnology »

Thanks for joining us!

I think you may need one of these: https://ka-electronics.com/shop/index.p ... uct_id=124
CitricAcid303
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Re: Mastering Stereo Insert Switcher with Flip Construction Information

Post by CitricAcid303 »

Thanks, will have a look.
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