Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
Dumb stereo/mono jack troubleshooting
This is a silly question, but I've recently inherited an old '70s Yamaha organ. I plugged in some stereo headphones into the headphone jack, but am only getting sound from the left headphone.
If the organ were mono, I'd be getting sound in both ears, right? As in, my headphone plug's stereo contacts would be making contact with the single contact in the jack, yes? So am I correct in assuming that the headphone jack is supposed to be stereo, and a wire's come loose inside?
Comments
If the headphone jack in the organ were mono, you'd only get sound out of the left side. The tip of the plug should go to the left side.
The ring of the plug either wouldn't make contact or would end up at ground, but it shouldn't give you any signal.
@NeonSilicon Duh, then my mental model of headphone plugs was wrong. Just tried it out with another known mono source and facepalmed. Off to buy an adapter then. 😀
@NeonSilicon Or is an adapter a bad idea?
That's a good question. If the adaptor makes it so mono source is connected to the tip and the ring of the headphone plug directly, then the mono signal would be there in both headphones, but then the headphones would be hooked up in parallel so that the headphone amplifier would be seeing half the impedance. That might cause a problem. It would depend on the headphones and the amplifier and where everything is at in the tolerances.
It could be that the output of the organ is stereo and that it is just a coincidence that the output is only coming out the tip. Can you find a manual for the organ?
@NeonSilicon Manual has very little detail. I’ll try and track down something more detailed.
What is the model?
@espiegel123 It’s a Yamaha CN-70. Little rinky dink thing originally purchased in the 80s.
I found a service manual that I think is the correct one. The scan is a little blurry but, it looks like the output to the headphones and the main speaker are from the same power amp IC. The jack is a mono switched jack that directly disconnects the main speaker when the headphones are plugged in. The main speaker is an 8Ω speaker. The IC is an HA1370 power amp. I'm guessing Hitachi, but I haven't been able to find a data sheet for it to get details.
I think maybe the organ came with a dedicated set of headphones originally? Given the nature of these sorts of IC's in general, I'd say it can probable handle a normal set of 32Ω headphones with the two sides paralleled. But, I'd be careful with sticking any expensive headphones on the jack with an adaptor.
I can send you the manual I found if you'd like or point you to the site, but the sites for these old manuals are a little bit suspect to me and I don't quite trust them and some of their not legit looking adds telling me to click to protect my Mac. The manuals and datas heets do seem to always be the real things though.
Such great sleuthing, @NeonSilicon — I’m in your debt! I found it; didn’t think to search for a service manual, not that I would’ve known how to decipher the content. I’ll try with an adapter and cheap headphones.
I've done lots of web searching for schematics and manuals for old circuits. BTW, that organ has some fun circuits in it too. I like the expression pedal circuit. Also, there are several classic NJM4558 op-amps (the Tube Screamer IC) and some cool older transistors that are a bit harder to come by now. None of these are particularly valuable and they were kinda transistor radio level IC's, but they have audio characteristics and they overdrive in ways that I really like (so do lots of other people). I'll definitely be hanging on to the schematics to refer to in the future.
A couple of the hints for making it easier to find older manuals and schematics is to do the Google search for images and then limit them to black and white and line drawing.
It looks like your organ should be fun to play and I hope it works out well for you with the headphone output.
Great tip on schematic searching, I’m forever obscure documentation at the moment...
I’m not sure if this help but can you run it through the iPad just like a guitar through an interface, connect it in AUM or a daw/host, then add mono to stereo, other fx if you like, then send out to speakers headphones…
Yep, I did consider this but I don’t want to go to that trouble when simply wanting a tinkle — much prefer a mechanical solution. Thanks though!