lengcm 0 Report post Posted August 5, 2003 Just picked up this plug from Mackie. A funny looking RCA plug with a resistor in it. Believe it or not, it actually "cleans" up the sound between the highs and the mid range. It really does magic... Mackie care to share with us how this "magic" plug works? Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted August 5, 2003 Can I give a shot at this? I guess this is the only time when something crazy/magical can be described perfectly in electrical terms. Most digital out circuits are left on all the time, so while you are enjoying the sound from the RCA plugs, there's signal "coming out" of the coaxial circuit as well. In transmission line theory, an open ended line is reflective so you signals get reflected back to the source -> electrical "corruption" of the original signal occurs at this instance. However, when the circuit is terminated with a resistor, in this case I guess it's 75ohms to match coaxial output, there would be not reflection of the signal at all. (If different resistances are used instead of being matched, then there would be a different level of reflection -> perhaps a different level of degradation as well). I hope this answers your query. Share this post Link to post Share on other sites
Sipher 0 Report post Posted August 5, 2003 it suppose to block out RFI if i'm not wrong i had one too. from Mackie of coz Share this post Link to post Share on other sites
Northern Oak 0 Report post Posted August 5, 2003 I'd one too! From Mackie of course. I'd tried "So Nice" by Stacey Kent and it's so hollow and nasal without the plugs. Share this post Link to post Share on other sites
adhoc 0 Report post Posted August 5, 2003 wouldnt rfi be solved by grounding at the source? Share this post Link to post Share on other sites
Tenson 0 Report post Posted August 5, 2003 Sounds interesting and worth a go! Can someone confirm the resistor value please? Has anyone tryed this with an Arcam Alpha9? Cheers, Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 5, 2003 This is just for the COAXIAL electrical output RCA socket isn't it? Share this post Link to post Share on other sites
lengcm 0 Report post Posted August 5, 2003 Yup the MMP (Mackie's Magic Plug) is for the Coaxial out only. Share this post Link to post Share on other sites
Tenson 0 Report post Posted August 5, 2003 Come to think of it, my CD player has 2 pairs of phono outputs. As I only use one would it be an idea to terminate the other pair as well as the coaxial? Cheers, Share this post Link to post Share on other sites
headphonecrazy 0 Report post Posted August 6, 2003 Forgive me asking, but how and where do u actually use the "plugs". I'm guessing they are like the 75ohms terminators used for terminating video signals in video systems? Share this post Link to post Share on other sites
scholes25 0 Report post Posted August 6, 2003 How can we get it from Mackie? I am interested too. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted August 6, 2003 (edited) How can we get it from Mackie? I am interested too. If it's a 75ohm shorting plug, then you can just make one easily by yourself. Get a cheap RCA plug and solder a 75ohm resistor between the hot and gnd. Usually plugged into unused digital out. But for the analog RCA IN, most people would use a direct shorting plug. Can be make by simply shorting the hot and gnd on a cheap RCA plug. That would reduce RFI that is picked by unuse socket. Edited August 6, 2003 by jtfoo Share this post Link to post Share on other sites
Mackie 0 Report post Posted August 6, 2003 (edited) wouldnt rfi be solved by grounding at the source? EMI/RFI is prevalent around us and not easily eradicated, sad to say. Digital ouput of cdp is unlike line input/output where U can short it directly to ground. In fact, the Plug in question may not work for all cdps and intentionally made for Marantz cdps. Strangely so, I've applied on various makes and it still works. Insert this plug only at your cdp's "Digital Output" RCA socket. Edited August 6, 2003 by Mackie Share this post Link to post Share on other sites
Mackie 0 Report post Posted August 6, 2003 Can I give a shot at this? I guess this is the only time when something crazy/magical can be described perfectly in electrical terms. Most digital out circuits are left on all the time, so while you are enjoying the sound from the RCA plugs, there's signal "coming out" of the coaxial circuit as well. In transmission line theory, an open ended line is reflective so you signals get reflected back to the source -> electrical "corruption" of the original signal occurs at this instance. However, when the circuit is terminated with a resistor, in this case I guess it's 75ohms to match coaxial output, there would be not reflection of the signal at all. (If different resistances are used instead of being matched, then there would be a different level of reflection -> perhaps a different level of degradation as well). I hope this answers your query. Thanks Oak, I couldn't have said it better! Share this post Link to post Share on other sites
scholes25 0 Report post Posted August 7, 2003 Hi Mackie, Thanks for the heads up, but I am a total cable idoit. I do not understand a lot of the things you say. For eg, what is the following items and where can I get it? 1. 75ohm shorting plug, 2. 75ohm resistor 3. What is the hot and gnd of a rca cable? 4. direct shorting plug Sorry mate, I am just so hardware illiterate. thanks for the advice. BTW, I am still considering the about the offer you gave me, and trust me when I say it is very attractive. Give me about another week. I should be able to give you the answer then. Thanks again. If it's a 75ohm shorting plug, then you can just make one easily by yourself. Get a cheap RCA plug and solder a 75ohm resistor between the hot and gnd. Usually plugged into unused digital out. But for the analog RCA IN, most people would use a direct shorting plug. Can be make by simply shorting the hot and gnd on a cheap RCA plug. That would reduce RFI that is picked by unuse socket. Share this post Link to post Share on other sites
