Mix Amiga stereo for headphone use

[Photon]

OK, it's time. I want to make music after 11pm without waking the neighbors, or at demoparties without disturbing other musicians.

But I do not subscribe to mono. I wish to hear Amiga stereo mixed together a bit like in WinUAE, somewhere between 20% and 60%.

The way I see it, L and R should be split and all 4 amplified separately. I must amplify up to "200%" to be able to hear anything at all on demoparties.

Something portable the size of two packs of cigarettes running on battery or AC adapter.

I can source stuff myself and do the circuits, but are there ready-made ones or kits?

Any help appreciated to get this done.

[Jope]

http://www.epanorama.net/index.php?index=circuit has circuits for you.

[Photon]

And wart-zapper kits!

It looks like I'm looking for just a small enough mixer with mono inputs. I'll report which one I get.

Edit: this should do what I want, but it would be nice with something smaller with just the two mono line inputs at left. You want pan, not balance.

There are ready-made mix/amp chips, if you want to build. Look for TDA2822, LM386.

Here are some links I found while googling for "mixer headphone amplifier amiga" sort of, for others who are interested in kits/products.


http://www.epanorama.net/zen_schemat...headphone.html

http://sound.westhost.com/project94.htm

http://sound.westhost.com/projects-0.htm#hdp

https://www.circuitlab.com/circuit/5...summing_opamp/

http://www.stagelightingstore.com/Na...paign=products

http://www.cinnamonhillart.com/HMA/HMA%20Kit.html

http://electronics.stackexchange.com...-audio-sources

https://www.google.se/search?q=ampli...A&ved=0CCQQsAQ

https://www.google.se/search?q=ampli...it+%22amiga%22

http://www.google.se/imgres?imgurl=h...tart=0&ndsp=27

http://www.google.se/imgres?imgurl=h...tart=0&ndsp=24

http://www.google.se/imgres?imgurl=h...tart=0&ndsp=24

http://www.google.se/imgres?imgurl=h...tart=0&ndsp=24

[Mark Wright]

I was just about to post a link to that Behringer Xenyx, the older non-USB analogue version of which you can pick up very cheap on eBay, and is perfect for the job. In many ways, it's the modern equivalent of the Realistic/Radioshack mixer pictured below, which served me well for what you require (and is probably cheaper and more oldskool):

http://www.djworx.com/skratchworx/ne...ents&fn_id=232

Back in the good old days I'd combine two sets of stereo RCA/phono cables into a mono/stereo split pair by physically tearing them apart in the middle and twisting/configuring by hand. You'd end up with the usual 2-way L/R red/white jacks on one end, which went into the Amiga ouput, but on the other end, and going into two separate mixer channels... one set of 2-way jacks you'd twisted for mono (faded up half-way, or whatever you desired) and the original set of 2-way jacks (still hard stereo) faded up full. Later, I added an Alesis midiverb module and split three ways, with the reverb faded up to around 10%. That was back in 1991/1992. It made for very pleasant monitoring, especially on headphones. Once the reverb was introduced, I'd find myself engrossed in making, what I believed to be, studio quality dance/house tracks. Of course, once it's removed, you're back to scratchy 8-bit amateurville...

Total cost to achieve "less hard stereo" - $5 for two phono cables; $200 for dentist bills after you've pulled the cables apart with your teeth...

[john1979]

I've been looking for something cheap and that can do stereo narrowing for some time now, but haven't found anything so far.

Mixer boards can do the job, but they are expensive.

Is there a really a cheapo mixer board out there that can definitely do stereo narrowing?

[jkg]

Hi Photon. Have you checked if the Behringer Xenyx 302USB can do the job or does it lack some essential feature that the 802 has? I have no clue about this except that I understand that "hard panning" is not what you want - at least in headphones.

[Stedy]

Hi,

Shameless plug for the mixer part:

http://www.ianstedman.co.uk/Amiga/de...mixer_mk2.html

Headphone amplifiers can be picked up.

Ian

[demolition]

I have the Xenyx 502 which I use as a volume control for mixing together Amiga and C64 sounds, but I think it could be used for mixing together the Amiga channels. It is very cheap in my opinion, probably hard to find something much cheaper. Just get a bunch of RCA to Jack converters from ebay for it. Stedy's solution probably works great, but the box is not as nice.

For the Xenyx 502 I'd hook it up like this:
L Amiga -> Line In 3 (R) and CD/Tape Input L.
R Amiga -> Line In 2 (L) and CD/Tape Input R

This way, you can adjust the master volume on 'Main mix' and adjust the channel mix by turning the 2/3 volume button. At 0, you will have full channel separation and at mid setting, you'll probably be around 100% mono mix. At higher volume, it starts to reverse the two channels.

You'd still have two channels available for other things. Channel 1 is great for a C64 for example since it is already mono.

[Foul]

Originally Posted by Stedy

Hi,

Shameless plug for the mixer part:

http://www.ianstedman.co.uk/Amiga/de...mixer_mk2.html

Headphone amplifiers can be picked up.

Ian

Interesting but too big for me !!! a very small PCB with 2 inputs/outputs mixed together would be cool

You plug it in the Amiga and it's all ! no potentiometers or a tiny one : for exemple would be perfect