Iphone as test tone generator

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Tubetec

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Just wondering whats the best test tone app for the Iphone ,
It will be pretty much this phones only job and if I can irradicate as much of the other garbage spyware all the better .
Doesnt need to hook into the internet appart from to download few apps to get up and running .
 

cyrano

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I use "Sonic" by Von Bronu. Not sure if that's the best one, but it's free.


I find it next to impossible to find something on Apple's appstore. Even if you know the exact name the darned thing doesn't find it.

It does seem to find games for every search term I ever tried.
 

Ike Zimbel

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Just wondering whats the best test tone app for the Iphone ,
It will be pretty much this phones only job and if I can irradicate as much of the other garbage spyware all the better .
Doesn't need to hook into the internet apart from to download few apps to get up and running .
I have used AudioTools by Studio Six Digital for years. I also own a couple of the hardware boxes (The Audio Toolbox) designed by the same guy, Andrew Smith. Both have been a regular part of my kit for along time.
 

Gold

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I have used AudioTools by Studio Six Digital for years. I also own a couple of the hardware boxes (The Audio Toolbox) designed by the same guy, Andrew Smith. Both have been a regular part of my kit for along time.
Do you use it for line level audio? I have the Audio Toolbox but It seemed like using for line level audio was an afterthought. I could never get to the point where I trusted it. I feel the same way about REW so it probably has more to do with my computer phobic brain than the kit.
 

Tubetec

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Ive kinda abandoned the whole experiment with the Iphone now , there was an issues clearing the previous users profile and none of it was worth the hassle in the end .
 

Ike Zimbel

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Do you use it for line level audio? I have the Audio Toolbox but It seemed like using for line level audio was an afterthought. I could never get to the point where I trusted it. I feel the same way about REW so it probably has more to do with my computer phobic brain than the kit.
Hi Paul,
A couple of Audio Toolboxes have been my main audio test kit for years. I have one on my bench and the 2nd one travels in my fly-in tool kit. I have been very happy with them, for the most part. There's a few things that I wished they did better but for day-to-day test and measurement and repair work, they've been great. Of interest, I can get better (IOW, lower) distortion measurements by using the Audio-Tools App and an 1/8" to balanced line-level out interface that I make as the source for the signal, and the Audio Toolbox as the distortion analyzer. I presume that means that the App and an iPhone have a lower distortion output than the built in generator on the Audio Toolbox.
I will just add that a friend generously lent me an AP Porta-One for several years, so I did have access to that level of test gear for a while. Was it "better" than the Audio Toolboxes? Yes, but not enough for me to want to buy one and schlepp it around with me (or take up that much space on the bench). The three features that I appreciated on the AP vs the ATB were:
1) The ability to do distortion measurements in the 0.000% instead of 0.00% (as mentioned, partially, above).
2) The ability to do amplitude sweeps from 9.5 Hz to (IIRC) 150 KHz (this is how I know that my 1/8" interface box is -3dB at around 125 KHz and flat down to 9.5 Hz). The ATB only does these sweeps from 20Hz-20KHz, useful, but hard to get the full story.
3) The generator on the AP has a "Gen Load" measurement that shows you the input impedance of the DUT, which is also very handy.
 

Gold

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Thanks Ike,

I have an AP Portable One. That’s what I use for the most part. I’m missing a good FFT. I wanted the Studio Six setup for acoustic measurements and line level work.

Do you use two devices, like an iPhone and an iPad? One as a Signal Generator and another and the Analyzer? My troubles always revolve around trying to use the interface as both Signal Generator and Analyzer. I can never seem to get the levels right and be confident they are where I think they are.
 

cyrano

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Ive kinda abandoned the whole experiment with the Iphone now , there was an issues clearing the previous users profile and none of it was worth the hassle in the end .

Lemme guess...

It wasn't removed from the previous iCloud account?

If so, there isn't much you can do, unless the previous owner (you?) is willing to remove it.
 
Joined
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Just wondering whats the best test tone app for the Iphone ,
It will be pretty much this phones only job and if I can irradicate as much of the other garbage spyware all the better .
Doesnt need to hook into the internet appart from to download few apps to get up and running .
I've used Signal Suite and Audio Tools on my iPhones for ten plus years. Can't remember the last time I turned on my 40 year old Leader hardware oscillator. The Leader can't do half the tricks the phone apps do anyway. Just need to be circumspect about driving anything that might have a DC offset or phantom power. I have a retired phone that I use as a test device so that if on the off chance I do kill the built in headphone amp I haven't killed my day to day cell phone.
 

pinebox

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I use the same app, AudioTools, its great and does exactly what I need, but the UI is in desperate need of updating. For instance, I would much rather have the ine level readouts be the entire screen and I could read it across than room than have it be so small and cram all the adjustments on the same screen. Everything looks really old and just rigid. I know its not an issue for a lot of people but it drives me nuts.

Open Sound Meter is going to be a really good contender if the developer keeps up the update schedule hes demonstrated. If it had THD N I would probably not bother with any other app. Its free on OS and like $50 for iOS.
 

Ike Zimbel

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Thanks Ike,

I have an AP Portable One. That’s what I use for the most part. I’m missing a good FFT. I wanted the Studio Six setup for acoustic measurements and line level work.

Do you use two devices, like an iPhone and an iPad? One as a Signal Generator and another and the Analyzer? My troubles always revolve around trying to use the interface as both Signal Generator and Analyzer. I can never seem to get the levels right and be confident they are where I think they are.
Right from my earliest days as an Audio Toolbox user I had a lot of back-and-forth with Andrew Smith about features. Eventually we came to an impasse, as he had intended the platform primarily for acoustic measurements etc. and I was using it primarily as a test bench device. So, requests like "could you make the amplitude sweep go, from, say 10Hz-30KHz?" or "how about a two-channel version of the iAudio Interface?" just didn't gain any traction.
As far as level accuracy goes, I am mostly still using the hardware platform (ATB) and when I need to be really sure what level I'm sending, I use a "Y" cord out of the generator output and loop the 2nd channel to the Right input on the ATB, with the DUT in the Left channel, and yes it can be a bit fiddly with loading etc.
The Porta One definitely inspires more confidence on that front, but I've gotten along very well with the ATB, and have many satisfied customers for things like calibrating various compressors with involved calibration procedures...API2500 for example. In your situation, I would recommend a secondary measurement to verify the output, like measuring the voltage with a DMM. I find once you do get it where you want it, it's stable.
 

Mr. Moscode

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Thanks for the info. I didn't know these existed.

I did get Waves for the Mac but didn't have an interface that goes beyond 20kc so it wasn't that handy. If I could get a box that goes to 100k in and out I would put the output of the ACVM into it. Otherwise there's a DSO on my bench.

I have Tone Generator on my Android. It can do sweeps and goes way below 10hz, but nothing above 20k. One thing I've noticed with phones out is high noise levels from the headphone jacks, like digital RF noise. It makes doing some things with a distortion analyzer impossible. I have Leader equipment from long ago and used to be that works exceedingly well. Sig gen good to 1mhz as are ACVMs. My work is amplifiers - tube mostly. For $400 or less you can get DSOs that do Fourier analysis. Mine's good to 200mc.

If I were a studio tech I'd want this software, too.
 

Tubetec

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Yeah the underlying issue with the phone was Icloud ,
I enquired about an ipod touch as well and was told you cant even download an app without signing upto Apple ,
that will not be happening , so I guess that its not for me .
Maybe a jail-broke Ipod touch might be possible ,but I have no clue whats involved there.

The Apple USB C headphone adapters arent properly picked up by Win7 , initially the remote volume control worked fine, being picked up as an HID input device , the Audio which conforms to USB UAC 2 isnt avaialable in WIN7.
There was something I saw relating to Win 10 and authoring drivers for the older Win OS's but I dont have access to a Win 10 pc to try that idea out ,
Maybe Android or Linux are other possible avenues with UAC2 compatabillity worth exploring , but REW and Reaper are my usual go to apps that I like to use.
 

corgan4321

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I’ve been using REW for distortion measurements successfully with a small RME interface. Sometimes I run my oscillator from Audio Tools out of my phone, hook up to the DUT and output to REW for measurements. Considering I bought AudioTools for my first iPhone almost 15 years ago it feels like a high quality setup for free.
 

Tubetec

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I can live with even more basic functionality,

Just a simple on the go sig gen , more an integrity check than a bench unit for bandwidth or distortion measurement ,
Simple audio playback/record , but I dont fancy putting Itunes on my PC or getting caught up in Apple's DRM carry on .
I think I'll simplify things down a notch and just create a series of Wav file test tones which the media player spits out ,
no fancy graphics , just level and frequency from a drop down list , I can easily arrange the test tone so it forms a +/- balanced output ,
There was an option when I plugged in the dongle , headphone or other ,presumably meaning line out , I can only assume the headphone exposure monitoring is off in that case .
Right now Im disabling everything and anything I can in the options relating to the phone ,its sensors ,its endless list of reason to contact the mothership , but the I'OS only allows a limited amount of tinkering under the hood or bonnet as we call it here .
Notifications of all sorts had to get disabled , a dozen different excuses for the thing to make bleep noises or vibration alerts , all gone ,

I just want to hijack the Apple's audio capabillities , 48khz ,24 bit is plenty good enough and upto +8dbu , but I still need to verify this .
A series of wav files might be played sequentially to form a test routine very much like an automated test set , the Fluke at the DUT output ,
using the mic input , suitably padded down for simple visual inspection of the waveform on the Iphone would be a nice extra , even the typical media player musical visualiser with a scope mode would suffice , maybe such a thing is included in Ios.
 

Tubetec

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So it appears the basic functionality I need for balanced signal generation and media player/recorder is easily do-able on the stripped out Iphone

No 3rd party apps required , no ET phone home in the middle of the night ,no wifi ,bluetooth ,phone function or sim ,Apple health permanently off ,almost every green toggle in the entire iOS is set to off , All the many bundled apps and reminders are gone, uninstalled or otherwise out lunch ,
I think I might actually be able to live with the thing :D

Combined with a good Fluke meter that reads in dbu/dbv ,youre test tones on the handheld and a few patch cables , you already have a very powerful on the go test rig ,

Re-jigging the microphone input on the 3.5mm TRRS as an aux input to a scope type waveform display on the phone is the obvious icing on the cake . Of course theres many many ossiilloscope apps both free and very cheap , the kind of thing IT college kids do as projects mainly , there are a few nicer ones with multimeter and db scale readouts , and your still down the bargain basement at less than a 5 euros for the licence . Theres even a few that mimic the phosforesence with persistance curve , very nice indeed , pleasing on the eyes .

An important thing I was able to do was go into audio settings and set it so the default file format is WAV , now I can easily find a set of high quality WAV test tones at any sampling frequency /bit depth, any fundamental frequency or level . That also ensures any so called lossless data compression /format conversion never happens in the archiving system , assuming its only wavs I'll put on to it of course.

There was one other nice gadget that caught my eye , its an audio adapter cable for the Iphone which can function as either stereo line in or out on a single TRS jack . That way if you have an older phone with the built in headphone jack you also have the use of the line in via the Lightening socket . I know there might be better DAC's and DA's but the miniscule size of these audio interface are what makes them super handy in a mobile test rig situation .Battery supply is also easy to arrange.
 
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Tubetec

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Until this week Ive never touched a smart phone in my life , the more functionality I can dump on this thing the easier my life is
Maybe there a few here who know more ,
I was thinking of using a cheap memory card reader to transfer files to the phone ,
that way I avoid the USB sync process entirely and I can get itunes off my PC at the same time ,
Will iOS detect that the test tones are not music , if its just wav files I'm loading up why should it care ?
Does DRM kick in and try to throw a spanner in the works ?

I have auditioned music on the iphone , just over standard headphones , more that likely it was default format AAC ripped from CD ,
I was pleasently surprised I have to say , I've now switched to 48khz 24bit uncompressed as default , it has higher rates available but in view of the fact that the dongles are 48khz 24 bit max I decided to stick with that to avoid any needless power being consumed , who knows maybe the SRC process might cause some fractional level shifts or introduce extra undesirable delays in the signal chain , either way no need for it to be consuming battery power .

By kill switching off all the apps it seems to have extended the battery life a good bit , that was the original issue why the device was retired ,
Its already lasted several days now on a full charge which seems like a long time for smart phone .
 

Whoops

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Until this week Ive never touched a smart phone in my life , the more functionality I can dump on this thing the easier my life is

There's a lot you can do with it, it's a great tool

I was thinking of using a cheap memory card reader to transfer files to the phone ,

I don't know any iPhone that has a Card reader slot, at least none of my iPhones had that,
and I've only used iPhones as I can't stand Android phones and tablets. As I can't stand Windows also

that way I avoid the USB sync process entirely and I can get itunes off my PC at the same time ,

I transfer files to the iPhone using iTunes, but if you don't like iTunes there's other alternative apps for that, that work with iOS devices

Will iOS detect that the test tones are not music , if its just wav files I'm loading up why should it care ?
Does DRM kick in and try to throw a spanner in the works ?

A Wave file it's just an audio file, so the phone will just treat it as audio, it doesn't matter that what is inside the audio WAV is music, noise or silence. It will play whatever is there

By kill switching off all the apps it seems to have extended the battery life a good bit , that was the original issue why the device was retired ,
Its already lasted several days now on a full charge which seems like a long time for smart phone .

If you at any point feel the battery is too wasted you can get a replacement battery from iFixt. Not only they sell the parts but they also have step by step guides with photos explaining how to change the battery in every model plus many repair guides
 

Tubetec

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Battery performance is at 82% of original capacity ,were not so bad ,

I found out the best way to record audio on the iphone without a third party app is via the camera , voice recorder app is of no use .
Theres a setting on later iOS that enables HD audio recording in camera mode , internal mic works in stereo ,external headset mic in mono and the previously mentioned line in/out cable presumably does what it says on the tin .

I think it probably defaults to 48khz/24bit in hi res mode ,still a two track recorder with video is very useful to have alongside the tone gen ,

Its possible to find either an SD card or USB A female to Apple adapter so data can easily be transferred from a PC without the use of itunes and USB device sync which is an extra mess .Again a simple step that prevents a lot of needless hassle in the long game ,

I got the phone for nothing , even a refurbished model doesnt cost much , dedicating a decomissioned iphone to running a few basic audio/media tools ticks a lot of boxes for me , ok it doesnt do +30dbu ,but gain is cheap nowadays .

The only function I need that isnt cooked into iOS is the audio fft/scope/DVM and theres many to choose from .
Then again if the phone could function as a stand alone reverb or effects generator how cool would that be on your pedal board or tube mixer .
Iphone based stomp box , its all very possible , imagination is the only limit to creativity .
The hardware to do it is piling up all around us in boxes and drawers .
 
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