12v trigger from BHK Pre to BHK250

I have had both Pre and 250 for a few months. Today I received 3.5mm mono cable from amazon. Here is the question: BHK Pre has two 12v trigger outputs R and L. BHK250 has only one 12v trigger input. Which PRE output to choose?

I connected the cable from Pre L → 250. Both power switches are on (standby on) and both front panels are off. I used the PRE remote control to turn on PRE but nothing happens to 250. Is there something wring in the cable connection or if device is defective?

Any advice would be appreciated.

Either trigger out is fine on the Pre is fine. There are two outs so that the Pre can trigger monoblocks.

I suspect the cable first rather than the equipment.

I always use stereo cables as triggers as I find monos sometimes do not work.

I personally am using mono cables, but have used stereo as @elk does. I have seen some 3.5mm connectors that are slightly too small and are loose when inserted. Is your connector firm when inserted?

Did you try the second (R) 12v out on the Pre?

Do you have a multimeter? I’d test the cable for conductivity. It’s a good thing these cables are cheap for your wallet. It’s a bad thing they are cheap because there’s likely zero quality control at the factory.

You can build your own like I did. I was tired of the ugly little cables.


I have had no problems with mono cables but I agree the cable is the first thing to check because they are so cheap.

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Plug the cable into the other pre trigger. If you can now trigger the amp, the cable isn’t at fault, the left trigger is. Then you can debate whether it’s worth sending the pre back for repair or be happy with triggering the amp with the right trigger. If you still can’t trigger the amp, the cable may very well be faulty and that’s when you try another cable. Still can’t trigger the amp with either pre trigger and a replacement cable, time to call PSA customer service.

Thanks for all advice. I also tried a stereo cable with no success. The connection hole on PRE is much larger (about 1mm) than the one on 250, so I suspect the loose connection causes the issue.


I suggest trying yet another cable. I do not recall anyone previously reporting the connections on the preamp are too large.

Do you have a delay set for the 250 trigger?

I tried two sets of cable one is new just brought from amazon and one is an existing stereo cable. The difference between pre and 250 hole size is obvious. Anyhow it’s not a big deal not using the trigger feature because I don’t have any other gear to troubleshoot.

I tried delay of 0, 5, 15, 50. Not sure how it works … it counts from the pre button push?

Yup. I have mine set to 10. The Amp button will blink after 10 seconds, and after a few blinks will stay steady.

Very odd.

I do not have a additional hypothesis to offer. :frowning: