Simple OptoPlay Mod... WOW!!!
Apr 27, 2004 at 8:02 AM Post #16 of 30
Quote:

Originally Posted by doobooloo
Actually...

The OPA2132 probably won't work since it requires +/- 2.5V...

Hmm. What could work in this position?




Doob, what is the voltage input to the opamp on this device? It can't be less than 2.5V, right? I will do some opamp looking up, once I know the voltage.
 
Apr 27, 2004 at 8:12 AM Post #17 of 30
Quote:

Originally Posted by Iron_Dreamer
Doob, what is the voltage input to the opamp on this device? It can't be less than 2.5V, right? I will do some opamp looking up, once I know the voltage.


Thanks for your help Peter!
 
Apr 27, 2004 at 4:23 PM Post #22 of 30
Quote:

Originally Posted by Iron_Dreamer
Doob, what is the voltage input to the opamp on this device? It can't be less than 2.5V, right? I will do some opamp looking up, once I know the voltage.


I measured the voltage across V- and V+ and it is 5.0V. But, I don't think it's a dual-votage (+/- 2.5V) that is required by many of the opamps that have been mentioned since the V- is simply connected to the USB ground IIRC.

And IIRC the Mosa headphone driver actually works with single supply... whereas most of the opamps mentioned in this thread needs a dual (+/-) supply...
 
May 12, 2004 at 6:43 PM Post #23 of 30
Quote:

Originally Posted by doobooloo
I took the MS6308 (Mosa Electronics) opamp/headphone driver out and just connected the in to out on the unit, and when connected to the PPA, the sound is just phenomenal.



I have an Optoplay and am thinking about trying this out. Just so I get it straight, to do this mod you remove the MS6308 chip and then jumper INA to OUTA, and do the same for INB and OUTB. Does it use the non-inverting or inverting inputs, i.e., +INA(B) or -INA(B)? Any other tricks/tips? It doesn't seem too bad to get access to the insides...
 
May 17, 2004 at 8:04 AM Post #24 of 30
OK... got time to take some pics...

DSC01471-med.JPG


DSC01474-med.JPG


DSC01477-med.JPG


DSC01479-med.JPG


DSC01481-med.JPG


Full resolution pics can be found here:

http://www.seas.upenn.edu/~doo/OptoPlay/

Anyhow,

Quote:

Just so I get it straight, to do this mod you remove the MS6308 chip and then jumper INA to OUTA, and do the same for INB and OUTB. Does it use the non-inverting or inverting inputs, i.e., +INA(B) or -INA(B)? Any other tricks/tips? It doesn't seem too bad to get access to the insides...


Apart from what I did in the pics, I think seeing the traces on the bottom side of the PCB makes it rather clear - the -INA/B and OUTA/B are already pre-connected together, so all that is needed is connecting the +INA/B and either the -INA/B or the OUTA/B. Since I am not an electrical engineer, I don't know why those two are pre-connected like that, but I thought heck, if those two are already connected together, there's only one other thing to connect!
tongue.gif


Hope this helps!
 
May 18, 2004 at 2:17 PM Post #25 of 30
I did this mod last night. Very simple to do. Note that there is a screw behind the main red Optoplay plastic sticker by the USB cable. It's quite necessary to remove this screw before trying to get the case apart
tongue.gif


As far as the sound goes, I'd have to agree with doobooloo's comments above, it definitely sounds much cleaner. I'm hesitating to say much more since I've just got my homebuilt CMOY working and I've just gone from 'absolute crap sound card -> Senn HD570' to 'Optoplay mod -> CMOY -> Senn HD570'. However, comparing it to the 'Optoplay (unmodded) -> CMOY -> Senn HD570' setup, the sound seems much cleaner. I found the highs to be quite harsh/annoying with the unmodded Optoplay; now it is a much cleaner and more natural sound. Can't wait to hear it when my HD580s arrive.

Thanks very much doobooloo - now maybe I can move on to building that PIMETA... this is getting habit forming.
 
Aug 8, 2004 at 10:28 PM Post #27 of 30
As a newbie's first project, I followed this mod and found this really works fine. Since then, I couldn't stop...
frown.gif


All caps on the optoplay were replaced with Black Gate NX-Hi-Qs, which gave the opto more refined tone and resolutions. Finally two coupling caps (two 0.47 uF caps close to the output jack) were changed from black gate to Mundorf Supreme silver/gold.

Mundorf silver/gold caps are freaking expensive, but I don't regret at all.
k1000smile.gif


million thanks doobooloo.
tongue.gif
 
Oct 8, 2004 at 6:29 AM Post #29 of 30
hrmm i may have to try this on my waveterminal when the warranty runs out. and i know how to solder smd well enough to play with a $200 card
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Oct 8, 2004 at 6:52 AM Post #30 of 30
Quote:

Originally Posted by kongko
As a newbie's first project, I followed this mod and found this really works fine. Since then, I couldn't stop...
frown.gif


All caps on the optoplay were replaced with Black Gate NX-Hi-Qs, which gave the opto more refined tone and resolutions. Finally two coupling caps (two 0.47 uF caps close to the output jack) were changed from black gate to Mundorf Supreme silver/gold.

Mundorf silver/gold caps are freaking expensive, but I don't regret at all.
k1000smile.gif


million thanks doobooloo.
tongue.gif



Using caps as large as the device itself, I love it!
biggrin.gif
 

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