trbau Posted May 28, 2016 Report Share Posted May 28, 2016 Hi Forum, maybe someone has an idea: I am trying to use a realtime FFT analyzer App on my iphone/ipad to visualize what my microphones on my (new) Sound Devices 633 will record. I bought a TRRS input jack>TRS Jack for IOS devices and tried to connect everything on the 633, the Headphone out, the X1/2 out and even the XLR main outs with the ipad's input. None of the FFT apps gets any input signal at all. The strange thing is, if I plug the same cables not in the SD633, but into other devices, like the headphone OUT of my Fostex DC-302 Field Recorder, PC, music station or whatever, the FFT Apps work instantly... there is definately a (loud) signal on the 633 outputs, I have tested this with headphones. I absolutely have no clue why it does not work. Audio is Audio, right? Is the audio signal the 633 outputs in any terms different from what my other devices output? Never encountered such a problem before Quote Link to comment Share on other sites More sharing options...
osa Posted June 1, 2016 Report Share Posted June 1, 2016 Just a thought - Are you sending mic level? Quote Link to comment Share on other sites More sharing options...
Abe Dolinger Posted June 1, 2016 Report Share Posted June 1, 2016 What's the exact cabling from the 633 to the device? It's possible that the way the adapter is wired is causing the signal to cancel out. It's even more likely if you're going from a balanced connection to an unbalanced one. Quote Link to comment Share on other sites More sharing options...
trbau Posted June 2, 2016 Author Report Share Posted June 2, 2016 Quote Just a thought - Are you sending mic level? I think its line level, at least the 633 Headphone out is really loud on a headphone Quote What's the exact cabling from the 633 to the device? I use this cable. The grey side is in the iphone, the right is in the 633 headphone out. Like I said, the strange thing is, with exactly this cable, it all works on the Fostex DC-302 headphone out http://www.thomann.de/de/rode_sc7.htm?ref=search_rslt_rode+trrs_374154_3 is the 633 Headphone out balanced? how can I find out? Quote Link to comment Share on other sites More sharing options...
Rakesh Anderson Posted June 2, 2016 Report Share Posted June 2, 2016 Headphone out is stereo, not balanced. tip-left, ring-right, sleeve-ground. A balanced signal on a TRS would be mono: Tip-hot, Ring-cold, Sleeve-shield. The manual probably has the pinouts for all the connections. Your ipad probably wants to see a mic level. Maybe what your sending is too hot. Try sending out your source prefader out the x1 or x2 or main outputs at mic level. The X3,X4 is line level only. The cable you linked to, I think, is for a balanced mono source like a mic, to the Ipad input which has 4 conductors TRRS. tip-headphone out left, ring-headphone out right, 2nd ring-ground, sleeve mic input. Quote Link to comment Share on other sites More sharing options...
Prahlad Strickland Posted June 2, 2016 Report Share Posted June 2, 2016 Yeh sounds like a wiring problem, cancelling out. Quote Link to comment Share on other sites More sharing options...
Rakesh Anderson Posted June 2, 2016 Report Share Posted June 2, 2016 I bet that cable with a trs to trrs, is only using the tip and the sleeve on the trs side because the the mic input on the ipad only uses the the second ring and sleeve for the mic input. Either way it's unbalancing a balanced connection. If you turned down the headphones to almost nothing it might work and you would be getting the signal from the left side of the headphone out. Maybe the x3x4 with the 20db pad might also work, but I dont think it would be low enough for mic level. you should put a multi meter to that cable and see what is connected to what. Quote Link to comment Share on other sites More sharing options...
trbau Posted June 2, 2016 Author Report Share Posted June 2, 2016 thank you, quite confusing with all this wiring... I will try this with the Mic Level on X3/4 asap but what wonders me is, why does it work with the same cable on the Fostex DC-302? Or on my Yamaha Workstation Keyboards Headphone out? Or on my Radio's Headphone out? With all these sources it works... very strange Quote Link to comment Share on other sites More sharing options...
trbau Posted June 2, 2016 Author Report Share Posted June 2, 2016 just tried again, with nearly a dozen other cables I bought. No luck with none of these cables. Again all cables work on other devices but not on the 633. I have tried the Main Output XLR L/R of the 633 - no signal in the iphone (both, line and mic level) X Out 3/4 - no signal in the iphone (only line level) Headphone out - no signal in the iphone (tried all dB boosts) I am clueless, I never have encountered such a strange thing. I checked the cable routing with a multi meter: the "X" means, they are unused is this how it should be @Rakesh Anderson? Quote Link to comment Share on other sites More sharing options...
Rakesh Anderson Posted June 4, 2016 Report Share Posted June 4, 2016 The headphone out on the 633 L,R may be out of phase and cancel out when summed would be my guess based what you've presented. If you made a cable to go out fot the x1, or x2 you may have better luck. The cable you're using is a proprietary rode mic cable. I'm no expert so to take this with a grain of salt. But if you're trying to get some sort of analysis of what the mic and pre are doing, I'd think you would want prefader signal to avoid the mix buss limiter and headphone amp. But Like I said I don't know nothing. Quote Link to comment Share on other sites More sharing options...
macrecorder Posted June 4, 2016 Report Share Posted June 4, 2016 Well, the polarity of that lead is reversed, because the ground goes to the mic input and the signal to ground. But generally, Apple products are quite idiosyncratic. I can get a timecode signal into an iPhone using a similar lead, but the exact same lead with the same unit refuses to register anything on an iPad. Quote Link to comment Share on other sites More sharing options...
al mcguire Posted June 4, 2016 Report Share Posted June 4, 2016 There is really a much better use for the headphone output, one it is designed for. Quote Link to comment Share on other sites More sharing options...
Bash Posted June 5, 2016 Report Share Posted June 5, 2016 Apology up front - I am going to sound really old, but.... Why not use the meters on your 663 to show you level, and your ears to indicate the high sounds and the low sounds!! In the mean time - your cable is wired pretty much wrong. Try half unplugging the cable, first at the 663 end, then at the iPhone end - this may work or may not, but it might be worth a try. Good luck, sb Quote Link to comment Share on other sites More sharing options...
trbau Posted June 5, 2016 Author Report Share Posted June 5, 2016 thank you, I already ordered mini XLR cables to try to connect to X1X2, maybe this will make a difference Quote Link to comment Share on other sites More sharing options...
trbau Posted June 6, 2016 Author Report Share Posted June 6, 2016 I had success with the Main XLR Outs L/R! It seems to have something to do with the impendance If I use 2 of these http://www.thomann.de/de/monacor_ma_100_15.htm it actually works, when I set them to "high impedance" Quote Link to comment Share on other sites More sharing options...
Bash Posted June 6, 2016 Report Share Posted June 6, 2016 It may be nothing to do with the impedance, but more to do with that the Monacor gizmo looks as if it takes a balanced input, but sends out an unbalanced output, which is, coincidentally, the answer given by a number of people above!!! Quote Link to comment Share on other sites More sharing options...
trbau Posted June 6, 2016 Author Report Share Posted June 6, 2016 no, the Monacor gizmo does have a dipswitch "high" and "low" impedance. It only works on "high" on "low", nothing happens as usual Quote Link to comment Share on other sites More sharing options...
osa Posted June 6, 2016 Report Share Posted June 6, 2016 Fwiw - friend of mine plugged his apple trrs phones into my 633, and on a boom panned mono straight up he panicked because there was no audio in phones but printing to tracks. I tried to explain it was phase cancelled but he called me crazy because they work on so many other devices. Can't put my finger on it but since you originally spoke headphone out to apple device in, i think there is an answer in this somewhere... -Ken Quote Link to comment Share on other sites More sharing options...
trbau Posted June 10, 2016 Author Report Share Posted June 10, 2016 it works with the cables from KVConnect. The built in attentuator is the key. Topic can be closed. Thanky to everyone here who gave me tipps for this problem. (however I still wonder, why it worked with some other devices in the beginning, since they also use line level) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.