Hi guys,
I finally managed to get a couple of Klark Technik DN410 parametric eq's from eBay (thanks to Dick Rees and Marlow Wilson for the offers to help with getting stuff shipped to me!).
However, one of the DN410s hasn't been working. I've been trying to use it as an unbalanced insert on channels of a Mackie Onyx 24:4 (using an insert cable that is 1/4" TRS to 1x M-XLR and 1x F-XLR). It will pass audio without problems (and each of the filters will work without any obviously audible problems) and then it will suddenly stop passing any audio at all. This can happen in the middle of programme material going through or when there is a break in programme material (in which case, when the programme material resumes, no audio will pass through). If I then really crank the gain on the Onyx mic preamp, it will suddenly start passing audio again (although it may stop doing so within five minutes). In that regard it seems to be behaving like a "dry" solder joint.
The issue is on both channels "A" and "B" of the DN410.
I believe I have excluded a problem with the Onyx channel strip because I've had the problem on two different channel strips which have otherwise been working. Furthermore, things start working immediately after I pull out the insert cable.
I also believe that I have excluded a problem with the insert cable because I have tried two different insert cables and encountered the same problem.
I should note that the DN410 has output balancing transformers. However, my other DN410 appears to work when inserted unbalanced, so I don't think that it's the fact that I'm inserting unbalanced although the unit has balanced inputs and outputs. Having said that, I have not tried using the DN410 with balanced connections.
Ordinarily, at this point, I would simply take it to a repair technician. However, I have tried to replicate the fault at home (the Mackie mixer is at church) on an A&H Zed10fx and have been completely unable to. The A&H doesn't have inserts on each channel, but does have inserts on the left and right main outs. When the faulty DN410 is inserted on these left and right main outs, it always seems to pass audio. So I'm not sure I'll even be able to demonstrate a fault to a repair technician.
Does anybody have any suggestions as to what might be going on with my misbehaving eq and what I should do about it?
Any advice would be much appreciated.
Thanks.
Regards,
Matt