Better sound for the Archimedes with OPA4134PA Burr Brown OA

discuss the archimedes & risc pc, peripherals and risc os/risc os on pi
poink
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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by poink » Thu Jun 16, 2016 12:34 pm

Zarchos wrote:Couldn't we start a new thread 'Archie MiST and Archie superchips design'
I've started a thread 'Enhanced VIDC replacement'. The wishlist is already fairly extensive, and I want to restrict the scope to just the one chip for now! :D T

AndyMc1280
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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by AndyMc1280 » Fri Jun 17, 2016 8:39 pm

Is there a way to get stereo sound from the motherboard or is it mono only on the a30x0 ? I know the A3000 had two speakers but they reduced this to one in the 10/20.

Curious, and slightly off topic.

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Fri Jun 17, 2016 9:40 pm

AndyMc1280 wrote:Is there a way to get stereo sound from the motherboard or is it mono only on the a30x0 ? I know the A3000 had two speakers but they reduced this to one in the 10/20.

Curious, and slightly off topic.
I don't know if there are some easy to grasp points, but these points exist at least at the basis base of the audio daughterboard.(so the easiest points to be able to solder some wires should be underneath on the other side of the motherboard).
Speaking of it, what I can tell you is that I've ordered some CMS versions of the Burr Brown chips, and I intend to desolder the small audio motherboard on one of my A3010s to install this chip instead of the OA there, and do the mod to get direct unfiltered sound from it.
I've got to try using correctly this desoldering station I've got, 1st :mrgreen:
Last edited by Zarchos on Sat Jun 18, 2016 5:57 am, edited 1 time in total.

poink
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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by poink » Fri Jun 17, 2016 11:20 pm

AndyMc1280 wrote:Is there a way to get stereo sound from the motherboard or is it mono only on the a30x0 ? I know the A3000 had two speakers but they reduced this to one in the 10/20.
One speaker, pointing into the back of the keyboard ](*,)

The easy way to get stereo sound out of an A3010 is to plug in some headphones or (powered) speakers into the headphones socket on the back of the machine. (Which, unlike the A3000, will also disable the internal speaker. (I believe the A3xx works the same way.)

If you wanted to do it internally you could...it does require a little bit of circuitry, however. Minimally, you'd need to build a second amplifier circuit (LM386, 4 resistors, 3 capacitors), desolder one of R65 or R66, and connect your circuit to that. This would mean only left or right sound was audible on a connected TV, so, you might prefer to make two amp circuits, and connect one to the headphone jack side of R65 and the the other to the headphone jack side of R66.

edit: like this, if you're OK with the TV limitation. If not, double up the red bit, and connect before R65 (don't remove R65 this time):
A3010-stereo-leftonlytv.png
'CleanVcc' on the schematic is visible (if you're looking for this in the A3010 TRMs, this is from sheet 2 (both versions of the A3010 look the same at a glance in this area).
Zarchos wrote:so the easiest points to be able to solder some wires should be underneath the motherboard
Yes, although, I'd go for the headphone socket, as you don't need another set of blocking caps that way ;) And use the switched pins - 10 and 11, so it doesn't turns off when you plug headphones in.

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Sat Jun 18, 2016 6:02 am

I must say to me it's rather good that plugging in some headphones disables the internal speaker(s).
When you connect an Archie to a TV or monitor and want to have the sound output from it, it's much better not to hear anymore the internal speaker(s).

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by poink » Sat Jun 18, 2016 2:35 pm

Zarchos wrote:I must say to me it's rather good that plugging in some headphones disables the internal speaker(s).
When you connect an Archie to a TV or monitor and want to have the sound output from it, it's much better not to hear anymore the internal speaker(s).
Yes; it makes more sense on a machine targetted at the home. The earlier machines have software control over the internal speakers (I think *speaker off works). However, that's rather inconvenient if you're, say, in the middle of a game and suddenly realise that it's got rather late!

The A3010 has an interesting wrinkle (it's difficult to see how they could have avoided this without increasing cost by adding a second LM386) but if you're using it with the TV modulator, and want the sound only through the TV, you have to open the machine, and unplug the speaker.

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Sun Jul 03, 2016 6:34 am

Another modded A3000.
I had started this project last week end, it was all working ok until I decided to drill the case to install a stereo jack ...
I'm so strong :wink: (understand : clumsy, see my avatar) I drilled too far and damaged a capacitor and a resistor. (and fortunately not the VIDC).
I received the replacement parts yesterday and I fixed that 2 hours ago. (And I've got the feeling I've got a neater picture now).

Pictures (you'll see on the 1st picture this A3000 had already been repaired, there was a socketed chip near the quad operational amplifier).
CR2032 battery holder + new socketed CMOS chip + socketed Burr Brown quad operational amplifier + stereo jack on the right (provision exists in the mod to easily add 2 cinches at the back of the machine, too : I used a cable as found in the PCs to connect a soundcard to the analog sound outputs of a CD ROM drive).
a.jpg
b.jpg
c.jpg
d.jpg
e.jpg
f.jpg
g.jpg
I wrote a note about the mods performed and also to remember if I reopen this machine I'll have to properly solder the replaced capacitor.

If I find some very good quality speakers to replace the internal ones, I'll certainly also replace the standard operational amplifiers by some adequate Burr Browns (2134PA).

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by terriblefire » Tue Jul 05, 2016 4:29 pm

Zarchos wrote:The Archimedes core for the MiST exists, it means the VIDC logic has already been re implemented in an FPGA.
We have the author on *. (terriblefire).
He said he would answer any question related to his project with the MiST.
Couldn't we start a new thread 'Archie MiST and Archie superchips design' ?

To me what's been done for the MiST, in itself is remarkable, but it's also a ramp to hardware development for the real Archies : the MiST becomes a development board and the work so far to create the Archie core, the basis of 'logics' (which ?) to add 'bits and bobs' to.
This was always my intention. Initially I wanted to be able to produce a "Phat" MEMC for my A540 but also to be able to develop podules in verilog and then simply synth them onto a podule card with an fpga. Takes alot of the pain out of the dev cycle.

Unfortunately my MiST board is dead! :(

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by terriblefire » Wed Nov 30, 2016 11:17 pm

My MiST board lives again. I may get some work done on the core over xmas.

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by hubersn » Thu Dec 01, 2016 11:13 am

terriblefire wrote:My MiST board lives again. I may get some work done on the core over xmas.
Good news!

Have fun
hubersn

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by terriblefire » Thu Dec 01, 2016 11:51 am

After my next round of amiga boards is finished I'm planning to investigate build a MEMC card for my A540 that gives me the full 16Mb of RAM.

Zarchos
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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Wed Apr 19, 2017 6:08 am

terriblefire wrote:After my next round of amiga boards is finished I'm planning to investigate build a MEMC card for my A540 that gives me the full 16Mb of RAM.
Hello Terriblefire !
I keep my fingers crossed you are soon going to spend some time enhancing our Acorns ...

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Wed Apr 19, 2017 5:39 pm

Example of what you get with unfiltered + Burr Brown mod :
https://youtu.be/QHF6pu-3GXk

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Thu Apr 20, 2017 6:08 pm

New tracks added including Nevryon's ...
Go to my YT channel : https://www.youtube.com/user/Archimedes75009

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Re: Better sound for the Archimedes with OPA4134PA Burr Brown OA

Post by Zarchos » Fri May 05, 2017 2:29 pm

Another example, because I could really enjoy a remarkable difference :
https://youtu.be/LeItskINAFI
and note it's my cellphone recording the ambient sound, coming from a small pair of Logitech loudspeakers, and not recorded directly from the Archie as I did for the Shadow Of The Beast or Nevryon tunes ...

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