Head phone amp less than $9 bucks.

http://www.parts-express.com/stereo-2-x-150mw-class-ab-lm4881-headphone-amplifier-board--320-321

Last edited by QuikSanz on 08-Sep-2014 at 12:42 AM.

@Hypex

Check with different headphones too...

My PC and my Pegasos had never problem by connecting any kind of speaker and/or headphones...

While MacMini headphones/speakers connector is very choosy and it recognize only 1 plug on 4 different plugs I used...

Sometimes a little difference of dimensions of plug devices is the key for a working situation or not-working one...

_________________
"When the Amiga came out, everyone [at Apple] was scared as hell." (J.L. Gassée, former CEO of Apple France and chief of devs of Mac II-fx, interviewed by Amazing Computing, Nov 1996).

@Daedalus

I have a CD-IN but find it useless when I have two CD drives, didn't they think about that?

I've considered adding a socket myself, but I would really need it on the front, and the only spot is a drive bay.

@QuikSanz

Well there is a stereo here also so it looks like I will have to hook into that to do the job. The only thing is, apart needing to plug a heap of wires into the back of my A1; is that I will need to turn down the volume on the monitor, turn on the stereo and plug the phones in for it all to work. Seems like overkill. But since I bought a TV monitor without a headphone socket I suppose I have only myself to blame.

@Hypex,

Fortunately you have a volume on the monitor. At least you'll be able to adjust the stereo and monitor separately.

Chris

@Hypex

Quote:

Hypex wrote: @broadblues Quote: Pluging directly to the main speaker out din't work? I didn't try that as I expected a line-out to be too weak. And expected a normal headphone jack.

The Line out on sound cards are usually very strong, to be able to drive headphones. This can usually be obseverd if you try to parallel connect two sources, like a CD-player line out with a computer's line out. The CD will be almost muted because the computer soundcard is such a strong driver.

_________________
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> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715,

Line out is 10K ohm impedance at around 2 to 5 volts, only a couple Mw. Headphones are from 8 to 32 ohms and need at least 100Mw.

Chris

@QuikSanz

Normal Line out, yes, like in the RCA from a CD/DVD/TV/radio. And then defined to be +/-0.5V p-p IIRC.
But most sound cards are closer to 10 ohm rather than 10kohm and can provide higher voltage to be able to drive headphones and unpowered PC-speakers. They simply have a headphone amplifier on the output.

Maximum volume out from a sound card can often overdrive a line-in on an amplifier if it is close to spec (+/- 0.5V).

Last edited by Deniil715 on 09-Sep-2014 at 09:14 AM.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@QuikSanz

Slightly fiddly but yes I can turn it down.

@Deniil715

That's interesting.

IIRC on the Amiga I found the opopsite to be true when mixing CD audio with the Amiga output. I used some resistors to mix them together for the final output.

@Hypex

Yes I know. The Classic audio out was not very strong and I also found other sources that were stronger. It had like a "true" line out level and impedance while newer sound cards seem to be designed to drive headphones.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715

I read it was said the Amiga output was half what it should be. So from this I have a theory that the mixng circuitry halved the volume of each channel before combining.

Getting back on topic, I hooked the A1 up to a stereo, then the headphones to the stereo. And somewhow, I have a stereo that doesn't mute the speakers when headphones are plugged it! Seriously! I can't catch a break!

@Hypex

If you have a stereo that doesn't mute the speakers you most likely have A/B switches to switch off your outputs manually. Or maybe simple mute would do it only for the speakers..?

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

Just to clarify, line level is 1V RMS which can be up around 3V p-p, depending on load and other factors. Standard sound cards aren't known for following specs though, and most have far too low an impedance so that they can drive headphones at a decent level. Convenience is more important than sticking to the specs, but it works for most normal uses so it's fine.

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@Deniil715

I don't know, I only found out, I've never seen a stereo without an auto-switch. It was a gift. It also has another problem, CD stuck in, but I could switch to AUX. It's a Sharp CD-E550. So far can't find much on it. Except some free service manuals that aren't free. I hate lying websites. I just need a user manual.

@Hypex

try here, hope itr helps:
http://elektrotanya.com/sharp_cd-e500_cd-e55_cd-e44.pdf/download.html

and click on the "bottom" link 'Get Manual':

..
The preview is worse quality than the original pdf.
This file is downloadable free of charge: Get Manual
(You are not logged in, only 2 downloads per day possible for you.)
..

Last edited by jabirulo on 12-Sep-2014 at 04:39 PM.

@jabirulo

I found this too last night. But it is useless to me. There is no download link in the OS4 browsers. Do I need a PC just to do a simple HTTP download nowdays!? Ridiculous! I would have left it on had I known that.

@All

Well it appears I've had a SNAFU. Possibly an audio PEBKAC. Or as I would call it dodgy headphones. The plug was smaller than usual and looks ike it wasn't all the way in. Depspite me pressing it in to make sure. So it looks like problem solved. Wish these new headphones were more comfortable. Even though they have padding. They were only six bucks.

@Thread,

Clearly my post, #11 State from the manual you must enable the headphone amp in software. What we need is some way to poke at it.

Chris

@Thread,

This makes me wonder. I don't know what DSP chip is used for the Nemo/Cyrus boards but I bet it has more features than just what is advertised but we can only access 1 of them. AHI is great for taking care of what comes out of it but controlling it is a Software issue.

Chris