Tardigrade Build Thread

[Joe Malone]

Sorry for taking a sec to get back to you, 4th of July and all that for us ungrateful colonists.

So I ordered a 24v wall wart and some 12-volt zeiners. I think I have 18's installed.

I'm not following your rationale for how you power things. I'm just a basic level understanding of things, attach 12 volts to the circuit and be done with it, and the whole floating voltage thing I'm reading up on and trying to wrap my head about. Feeling I'm overcomplicating things in my mind. I've done some reading and guessing that you are using the higher voltage and zeners for voltage regulation to reduce ripple. Most common DC wall wart power supplies are floating, and you connect them to the + and - like normal. The 0v is ground and there if you need to ground the chassis or need a common ground for your system.

Yes most wall warts are floating but some reference the 0v out to mains ground. The zeners are used to turn the 24vdc into +/-12vdc as they create a virtual 0v point which the tlakback comp uses as it 0v ground.

I don't understand what you mean about the Trex not being able to supply the correct amount of and type of power. What type of power is it designed to provide, again dc is dc in my mind.

The trex can only put out lower vdc then put in. So is of no use for this project.

[Samson]

For gains between 6dB and 12dB, one would add a resistor across the gain pads, correct?

Yes correct add 6k8 across the gain pads for 10dB.

Hi Joe

I was wondering if I could just get some confirmation of how exactly to calculate and adjust the gain here. I need either a 2dB or 3dB boost above the unity gain to counteract insertion loss from a seperate passive eq stage, so it would be 8dB or 9dB gain that I'll need from each tardigrade channel.

What resistance would be required to place across the 12dB gain pads for 8dB or 9dB (or other) gain? If you can give the calculation to work out any gain value (between 6dB and 12dB) that would be lovely too, in case anything needs to be tweaked.

Thank you very much.

Sam

[Joe Malone]

For gains between 6dB and 12dB, one would add a resistor across the gain pads, correct?

Yes correct add 6k8 across the gain pads for 10dB.

Hi Joe

I was wondering if I could just get some confirmation of how exactly to calculate and adjust the gain here. I need either a 2dB or 3dB boost above the unity gain to counteract insertion loss from a seperate passive eq stage, so it would be 8dB or 9dB gain that I'll need from each tardigrade channel.

What resistance would be required to place across the 12dB gain pads for 8dB or 9dB (or other) gain? If you can give the calculation to work out any gain value (between 6dB and 12dB) that would be lovely too, in case anything needs to be tweaked.

Thank you very much.

Sam

For only 2dB extra connect 27k between the 12dB pads and for 3dB connect 15k between 12dB pads. 20k between the 12dB pads is 2.5dB

[fragletrollet]

For gains between 6dB and 12dB, one would add a resistor across the gain pads, correct?

Yes correct add 6k8 across the gain pads for 10dB.

Hi Joe

I was wondering if I could just get some confirmation of how exactly to calculate and adjust the gain here. I need either a 2dB or 3dB boost above the unity gain to counteract insertion loss from a seperate passive eq stage, so it would be 8dB or 9dB gain that I'll need from each tardigrade channel.

What resistance would be required to place across the 12dB gain pads for 8dB or 9dB (or other) gain? If you can give the calculation to work out any gain value (between 6dB and 12dB) that would be lovely too, in case anything needs to be tweaked.

Thank you very much.

Sam

Gain = 1 + Rf/Rin = in stock config gain is 2 aka 6db (?)

[Joe Malone]

Tradigrade due to extra invert stage to create balanced output always adds 6dB gain.

If you link 12dB pads 20 × log (1 + 10000/(10000) x 2) = 12dB gain (which includes existing 6dB already)

If you add a resistor between the 12dB pads. Total Gain in dB = 20 × log (1 + 10000/(10000 + R) x 2)

R should be put into the formula in ohms

[Samson]

Yes correct add 6k8 across the gain pads for 10dB.

Hi Joe

I was wondering if I could just get some confirmation of how exactly to calculate and adjust the gain here. I need either a 2dB or 3dB boost above the unity gain to counteract insertion loss from a seperate passive eq stage, so it would be 8dB or 9dB gain that I'll need from each tardigrade channel.

What resistance would be required to place across the 12dB gain pads for 8dB or 9dB (or other) gain? If you can give the calculation to work out any gain value (between 6dB and 12dB) that would be lovely too, in case anything needs to be tweaked.

Thank you very much.

Sam

For only 2dB extra connect 27k between the 12dB pads and for 3dB connect 15k between 12dB pads. 20k between the 12dB pads is 2.5dB

Thank you so much Joe that's great.

[Samson]

Yes correct add 6k8 across the gain pads for 10dB.

Hi Joe

I was wondering if I could just get some confirmation of how exactly to calculate and adjust the gain here. I need either a 2dB or 3dB boost above the unity gain to counteract insertion loss from a seperate passive eq stage, so it would be 8dB or 9dB gain that I'll need from each tardigrade channel.

What resistance would be required to place across the 12dB gain pads for 8dB or 9dB (or other) gain? If you can give the calculation to work out any gain value (between 6dB and 12dB) that would be lovely too, in case anything needs to be tweaked.

Thank you very much.

Sam

Gain = 1 + Rf/Rin = in stock config gain is 2 aka 6db (?)

Thank you for that I think it's making sense. Cheers

[Samson]

Tradigrade due to extra invert stage to create balanced output always adds 6dB gain.

If you link 12dB pads 20 × log (1 + 10000/(10000) x 2) = 12dB gain (which includes existing 6dB already)

If you add a resistor between the 12dB pads. Total Gain in dB = 20 × log (1 + 10000/(10000 + R) x 2)

R should be put into the formula in ohms

Thanks for the extra detail Joe.