TomHoward Posted March 30, 2015 Share Posted March 30, 2015 Afternoon all I have a couple of condenser mics which have 7-pin XLR between mic and power supply. Being a school someone has lost/liberated the cables so I need to make some replacements. They are 5 cores plus shield (as ground is connected twice), but some cores are thicker than others (power and signal cores together). To get around this I'm thinking of using 8-core cable and doubling up the cores for the 3 thicker cores. Does anyone know of a nice 8-core plus shield cable? Would shielded Cat6 do or is it still and doesn't handle like mic cable?I need around 10m and I'd rather not buy a roll if I can avoid it. Thinking of buying a 10m shielded cat6 cable and cutting the ends off. Thanks, Tom Link to comment Share on other sites More sharing options...
sam.spoons Posted March 30, 2015 Share Posted March 30, 2015 Cat 5/6STP is well documented for audio so I think you'd have no problems (though I haven't used it myself), it doesn't handle like decent mic cable though. It may be cheaper to buy the cable in cut lengths rather than buy a cable and cut the ends off. Link to comment Share on other sites More sharing options...
pete10uk Posted March 30, 2015 Share Posted March 30, 2015 Afternoon all I have a couple of condenser mics which have 7-pin XLR between mic and power supply. Being a school someone has lost/liberated the cables so I need to make some replacements. They are 5 cores plus shield (as ground is connected twice), but some cores are thicker than others (power and signal cores together). To get around this I'm thinking of using 8-core cable and doubling up the cores for the 3 thicker cores. Does anyone know of a nice 8-core plus shield cable? Would shielded Cat6 do or is it still and doesn't handle like mic cable?I need around 10m and I'd rather not buy a roll if I can avoid it. Thinking of buying a 10m shielded cat6 cable and cutting the ends off. Thanks, Tom I don't think network cable is the right stuff for you on this, it won't coil up or out correctly and the wires are solid instead of stranded, meaning with movement they may break. I've never seen a 7 pin XLR mic before, so guessing they are either very old, expensive or used outside my audio experience, I've done a quick google and there is a company (designacable.com) who makes cables up for specific uses, they say when it comes to this type of mic, there is no real standard to pin outs and each has different requirements. I think you'll be much happier with good quality mic cable. Link to comment Share on other sites More sharing options...
Oldradiohand Posted March 30, 2015 Share Posted March 30, 2015 You're going to have to tell us what mic it's for - sounds like a tube mic and there is some variance in the pin outs. Heater circuit is the two thicker wires, two for audio and a couple for bias plus screen. There are some cable manufacturers who make specific tube mic cable. Don't forget, tube mic supplies bite! Link to comment Share on other sites More sharing options...
Jivemaster Posted March 30, 2015 Share Posted March 30, 2015 Don't be surprised if some cores have 300VDC above ground. I think data cable is a poor choice as it will not coil well and may not handle the voltages present. Be very sure that any cables and connectors are rated for appropriate voltages. With the voltages I'd expect in a tube mic I'd certainly be looking to buy the correct cable from the approved suppliers. Link to comment Share on other sites More sharing options...
TomHoward Posted March 30, 2015 Author Share Posted March 30, 2015 It is indeed a tube mic. The exact pinout is as follows Pin 1 signal (thin core)Pin 2 signal (thin core)Pin 3 Power red (thick core)Pin 4 ground/shield (commoned with 7)Pin 5 Power black (thick core)Pin 6 signal (but two thin cores joined together!?)Pin 7 ground/shield (commoned with 4) Scroller cable is almost appropriate apart from it's one signal core short. Even the best Cat6 sheilded doesn't handle like mic cable? I only need 2x 1.5-2m cables (between stand and PSU) so I can't see custom cable being viable. Link to comment Share on other sites More sharing options...
Lufty Posted March 31, 2015 Share Posted March 31, 2015 canford audio do a cable for valve microphones part no 30-938 Link to comment Share on other sites More sharing options...
Jivemaster Posted March 31, 2015 Share Posted March 31, 2015 It's a tube mic, therefore it NEEDs high voltage DC therefore jury rigging a cable intended for data or 24v is going to be less than ideal. As tube HT could easily be 200 - 300VDC then suitable cable is an essential. Link to comment Share on other sites More sharing options...
pete10uk Posted March 31, 2015 Share Posted March 31, 2015 It is indeed a tube mic. The exact pinout is as follows Pin 1 signal (thin core)Pin 2 signal (thin core)Pin 3 Power red (thick core)Pin 4 ground/shield (commoned with 7)Pin 5 Power black (thick core)Pin 6 signal (but two thin cores joined together!?)Pin 7 ground/shield (commoned with 4) Scroller cable is almost appropriate apart from it's one signal core short. Even the best Cat6 sheilded doesn't handle like mic cable? I only need 2x 1.5-2m cables (between stand and PSU) so I can't see custom cable being viable. I'm not sure you have a choice, if you run a simple risk assessment and keep in mind the potential 300v present coupled with working in a school, your personal risk to anything going wrong is certainly not worth it. Apply the sleep test, if little Jonny with an unknown heart condition touched the mic and the + network cable snapped giving the ground 300v and little Jonny didn’t make it, could you sleep at night? The cable suggested above from canford with 2 Neutriks is about £35 per cable + your time, designacable.com want £30 ish per cable. There are obviously cheeper suppliers out there for both raw materials and also pre made options. As soon as you invest in new ones you can guarantee the old ones will turn up. Link to comment Share on other sites More sharing options...
sam.spoons Posted March 31, 2015 Share Posted March 31, 2015 +1 (I hadn't thought of it being a valve mic). If it's a valve mic, network cable is totally unsuitable, the insulation is not designed for high voltages and it would definitely fall outside health and safety guidelines. http://www.blue-room.org.uk/public/style_emoticons/default/rolleyes.gif Link to comment Share on other sites More sharing options...
TomHoward Posted March 31, 2015 Author Share Posted March 31, 2015 Thanks for the Canford part number, that looks about right. I couldn't find any suitable cable from CPC or RS. Is the designacable listed on their site please? I can't find anything suitable Sorry - found it via eBay. Can't find it on their site though. That did give a lead though - Sommer Octave cable is another valve mic cable, available from our german friends for less than £3/m. Just got to work out if it's worth soldering them or just buying them. Many thanks Link to comment Share on other sites More sharing options...
pete10uk Posted March 31, 2015 Share Posted March 31, 2015 Thanks for the Canford part number, that looks about right. I couldn't find any suitable cable from CPC or RS. Is the designacable listed on their site please? I can't find anything suitable Sorry - found it via eBay. Can't find it on their site though. Ebay was where I found it. But worth a call to them. Link to comment Share on other sites More sharing options...
TomHoward Posted March 31, 2015 Author Share Posted March 31, 2015 I have ordered up 6m of Sommer Octave cable and 2x m&f 7-pin Neutrik, so I can go and look for the existing cables one last time safe in the knowledge I will now find them.Thanks for the pointers Link to comment Share on other sites More sharing options...
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