Palpigrade Build Thread

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Joe Malone
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Palpigrade Build Thread

Post by Joe Malone »

Palpigrade Build Thread
8 Channel balanced to unbalanced output driver kit.

Link to Tradigrade Build thread


Notes and Errata
C2 & C3 are 39pF not 47pF. 39pF gives 200kHz flat bandwidth.
Extra 39pF can be added under pcb to improve CMRR over whole audio bandwidth.

PCB size is 55.25mm (2.18") x 77.35mm (3.05") with 4 x PCB mounting holes 47mm (1.85") x 56.7mm (2.23")
Or PCB can be mounted on the 2 x DB25 mounting bolts.

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Joe :-)
JLM Audio
Capturing Audio without Injury

downbeatstudio
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Joined: Mon Jul 06, 2020 11:01 am

Re: Palpigrade Build Thread

Post by downbeatstudio »

Hi there,
I just purchased some Palpigrade kits. I'm going to be leveraging the LME49720NA and adding them to a summing mixer that's running on +-24VDC. What zener diodes should I leverage to bump down the +-24VDC? Sorry I'm new to adding in zeners.

Thanks for the help!

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Joe Malone
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Re: Palpigrade Build Thread

Post by Joe Malone »

downbeatstudio wrote:
Mon Jul 06, 2020 11:31 am
Hi there,
I just purchased some Palpigrade kits. I'm going to be leveraging the LME49720NA and adding them to a summing mixer that's running on +-24VDC. What zener diodes should I leverage to bump down the +-24VDC? Sorry I'm new to adding in zeners.

Thanks for the help!
Ok LME49720 is max +/-17vdc so you can fit 15v 1W or 16v 1W or 16v 1W in series with 1N4007 to make 16.8v.
8 x LME49720 use 80mA total idle current at +/-15v to +/-17v.

Make sure all 1W zeners are mounted in the air about 1cm or the height of the IDC header of the pcb as they run warm and also need at least 1cm lead length to achieve the 1W rating.

To drop the +/-24vdc add a 39R or 47ohm 1W carbon resistor in series with the +24v and -24v power on the way to the +V & -V of the Palpigrade

or you can replace the 2 x 10R on the palpigrade with 47R or 56ohm 1W which again would need to be mounted about 1cm off the pcb for cooling.

Make sure you have all LME49720 fitted with Zeners fitted & series resistors fitted before powering up.
Joe :-)
JLM Audio
Capturing Audio without Injury

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