Flex 6400- XLR too DB connector back of radio

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  • Updated 4 weeks ago
Done some searching and I haven't really found the answer I was looking for. I understand the DB connector on the back of the radio is unbalanced for line audio input. Pin 1 is your positive, then you have a variety of pins all going to chassis ground.

What is the work-around so i can run some balanced pro-audio gear into it? I saw this in Amazon and didn't know if I could get it to work, I would be happy at this point even plugging it into the 1/8' jack in the interim. 

I've read everything from Balanced, to Un-Balanced, to the Flex 6400 being Pseudo-wired at the 1/8' connector. 

I just want a solution that is going to work without any audio issues or hum....

https://www.amazon.com/gp/product/B00FC4YR58/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

The schematic for the link  is provided in the picture. 

Thanks for any input. 

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Kevin Darrah

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Posted 1 month ago

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Art - N4QNT

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Hello Kevin, hoping some of my info can guide you along. I'm really into the ESSB thing using quality Mics and outboard gear, you can checkout my QRZ for a good audio chain diagram example  just to get any ideas.. First off using the DB ACC input will not represent a Balance input to the 6400 audio circuit in opinion of others it's just a better mechanical connection by screwing down the DB plug instead of just pushing in a Mini 1/8 jack. Both inputs still utilize the unbalanced pre-amped Pseudo audio circuit.. The key to using say a high end dynamic mic or condenser style mic which starts off with an XLR balance cable then to any desired Rack Gear to amplify the Mic input will be balanced till you switch to unbalance going into a 1:1 unity gain 600ohm transformation box >>> https://www.sweetwater.com/store/detail/DTI--art-dti-2-channel-hum-eliminator,, than the final output unbalanced cable XLR to 1/8 Mini: https://www.amazon.com/CableCreation-3-5mm-Stereo-Female-Cable/dp/B01JY2C4YO/ref=sr_1_1_sspa?keywords=Cable+Matters+%281%2F8+Inch%29+3.5mm+to+XLR+Cable+%28XLR+to+3.5mm+Cable%29+Male+to+Male+6+Feet&qid=1563463166&s=gateway&sr=8-1-spons&psc=1,, plug into the back of the 6400 1/8 inch input... I've had great success with this connection arrangement..  Scroll down the page a little to see the Audio Diagram  https://www.qrz.com/db/N4QNT ...

Take care,
Art N4QNT '73


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Kevin Darrah

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Thank you for the very informative information Art... I really do appreciate it! I have went ahead and ordered the items and look forward too using them along with the audio gear here shortly! It has saved me some footwork and some trial and error, just trying to find something that will work.

Again Thank you, once I get everything going here I will drop another post!
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Art - N4QNT

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Your welcome Kevin.. any future questions feel free to email me... take care
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Kevin Darrah

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Unfortunately the DI box did not work for me.... The Hosa Transformer I originally posted however worked excellent for me.... SO I am sure with different bands, different equipment and installations, things will very... But I appreciate the information, and thank you for taking the time to acknowledge my post. I was just leaving a comment here to let people know that they have different options if one particular instance doesn't work. 

This is what worked for me:

https://www.amazon.com/gp/product/B00FC4YR58/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 
(Edited)