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Murcia, Spain
Timbob wrote:

Well, spend all day working on a schematic.
With a tl072 won't work. 10k resistors gives you a really low volume, almost can't hear it.
And diodes won't work as well, which is strange, and I can't figure out why. Maybe my plugs are just crap.

What's the average maximum voltage of a line-out on a Game Boy? That schematic is designed for 1V input signals. Maybe if the iput voltage is wrong, then the whole circuit is not working as it should.

Self response:
Line-Out-------------Vpp--------------Amplitude
Pro sound -----------1V------------------0.5V
Stock-----------------0.2V----------------0.1V

So the problem might be the resistors value.

Last edited by DogTag (May 8, 2013 7:51 pm)

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United Kingdom

Wasn't Low-Gain building a chiptune mixer at some point?

Although that was a long time ago.

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DogTag wrote:
Timbob wrote:

Well, spend all day working on a schematic.
With a tl072 won't work. 10k resistors gives you a really low volume, almost can't hear it.
And diodes won't work as well, which is strange, and I can't figure out why. Maybe my plugs are just crap.

What's the average maximum voltage of a line-out on a Game Boy? That schematic is designed for 1V input signals. Maybe if the iput voltage is wrong, then the whole circuit is not working as it should.

Self response:
Line-Out-------------Vpp--------------Amplitude
Pro sound -----------1V------------------0.5V
Stock-----------------0.2V----------------0.1V

So the problem might be the resistors value.

Yeah, 10k might be a bit too much. smile
Changed it to 680 ohm, seems to work better. Loud enough for headphones.

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thursdaycustoms wrote:
Zef wrote:

Yup, I've tried using a headphone splitter in reverse, it does weird things to your stereo and really just doesn't sound good.

That being said, if anyone gets a Stereo solution to this problem that's small and cheap, let me know and I'll pre-order one pronto. I don't have a mixer and I do a lot of 2xLSDJ work, so this would be a Godsend. THISMEANSYOUTHURSDAY (still using my Thursday-boy daily, VERY nice work smile)

Awesome!
Yeah I'll see what I can come up with tonight if possible. I'd like it to have two stereo inputs with panning and one head phone output.
Should I do all jacks 1/8"? 1/4" would be more my style but 1/8" would obviously save space.

I understand it's less rugged, but my whole set-up is rigged in 1/8" right now so that's my preference. It's easy enough to get an 1/8" to 1/4" converter cable for those who need it.

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California
Timbob wrote:


WIP.
Well, it's something tongue
I'm now using 1K resistors. Sound is still quite soft, so I might switch to 680Ohms.
To top one still needs to be connected, I want to do a mono / stereo switch on that one.

!!! this is rad smile throw the schematics on here when youre done. no lie ive been thinking on making something like this all week.

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Timbob wrote:


WIP.
Well, it's something tongue
I'm now using 1K resistors. Sound is still quite soft, so I might switch to 680Ohms.
To top one still needs to be connected, I want to do a mono / stereo switch on that one.

Nice case choice! Haha, that's pretty cool.

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Zef wrote:
Timbob wrote:


WIP.
Well, it's something tongue
I'm now using 1K resistors. Sound is still quite soft, so I might switch to 680Ohms.
To top one still needs to be connected, I want to do a mono / stereo switch on that one.

Nice case choice! Haha, that's pretty cool.

And easy to carry with the rest of the gameboy stuff tongue

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Cleveland, OH

Cart cases are so useful! I had my USB to MIDI adapter board in one for awhile.

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Murcia, Spain

I thought it should be 1kOhms each... weird. Have you changed R4 and R5 as well?

Last edited by DogTag (May 9, 2013 4:18 pm)

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DogTag wrote:

I thought it should be 1kOhms each... weird. Have you changed R4 and R5 as well?

I just took out the whole Op-amp part. couldn't hear anything.
Now I've got 680Ohms. stil a bit soft, but acceptable i guess.

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Murcia, Spain
Timbob wrote:
DogTag wrote:

I thought it should be 1kOhms each... weird. Have you changed R4 and R5 as well?

I just took out the whole Op-amp part. couldn't hear anything.
Now I've got 680Ohms. stil a bit soft, but acceptable i guess.

If you took the amplifier thing out, then forget what I just said hahaha.Why don't you try with a lower value?

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Murcia, Spain
DogTag wrote:
Timbob wrote:

I just took out the whole Op-amp part. couldn't hear anything.
Now I've got 680Ohms. stil a bit soft, but acceptable i guess.

If you took the amplifier thing out, then forget what I just said hahaha.Why don't you try with an even lower value?

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Nottingham, UK

I've got this ultra simple amp design I use a lot. I was going to build an amp into a briefcase, but I thought it'd be cooler to add a passive mixer in as well so I can have multiple inputs, so this thread's really interesting. smile

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Psydney, Australia

I'd always rather make a massive pixer, but that's just me

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ForaBrokenEarth wrote:

I've got this ultra simple amp design I use a lot. I was going to build an amp into a briefcase, but I thought it'd be cooler to add a passive mixer in as well so I can have multiple inputs, so this thread's really interesting. smile

Do share. smile

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United Kingdom

I know you want a DIY line mixer. However, just found this one on ebay:

http://www.ebay.co.uk/itm/Micro-Mixer-4 … 27a3f8ab40

Requires no battery. Haven't a clue what the sound quality is like.