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We even had people from VGMRIPS discuss on the topic of the Capcom AMP being required for the effect to function properly. That was a topic of conversation there a while ago. I think around August.

The three small one sided ICs on the PCB are operational amplifiers. They are connected on a sort of equalizing circuit which does the analog part of the Q-SOUND processing.

Is there any schematic of that amp around the net?
 
The op-amps are simple buffers, they have nothing to do with equalization. I've understood what you're trying to say, but you need more advanced circuitry to achieve what you say.

Most of the caps and resistors are required to bias the opamps and adjust the gain stage and make them work without oscillating.
There are surely some low pass filters there but that's it.

Btw, you guys are really making me want to get a Qsound amp just to play with it a bit. I'll put an alert on ebay and see if I can snag one for a fair price.
 
Getting an amp generally isn't the problem. It's getting the transformer that appears to be incredibly difficult to find that is the problem.
 
Trust me, once you got the amp in your hands and know the specs of its components it's a matter of rustling through your PSU box to get the right one. That's why I really want one. Unless there's something really fishy going on (and it might be, I had a Cambridge Audio Phono preamplifier which had the strangest power supply section I've ever seen in my life) it shouldn't pose a problem.

The real issue is that there might be different revisions of the board, with each needing to be fed different power, but that's another can of worms.

I'll get back to this thread when/if I find a Qsound amp board at a fair price.
 
@wasspat, don't take this a personal attack, but rather a warning to all other potential buyers to avoid the spreading of misinformation: the "Q-Sound" amp provided by Capcom is an absolutely standard stereo power amp with no custom circuitry or IC on it.

The entire Q-sound improving thing is on the CPS1/2 motherboard themselves, you can use any amp and enjoy Q-Sound.

You've swapped the amp so that was bound to change the way the sound it's reproduced, but it has absolutely no impact whatsoever on the whole Q-Sound business: as I said that's already taken care of on the main board.

If you want to get an original Capcom Q-Sound amp then, by all means, go for it, but if you want to buy it expecting to get some magical Q-Sound effect out of it know that you're much better off with other newer (even cheap class T amps) alternatives which will provide you with better audio quality.
I’m not taking this a personal attack don’t worry :).
All I can say :
- I’ve got some experience in sound, I’ve mastered 4 records from my former bands and friends. I guess I can well separate the sound and compare between different sound systems. When I said, I can fell a better separation of the sound with my Q-sound setup I guess you can take it as a « good » feeling. I’ve try with a common amp and I can tell you the sound is really enhanced, not a big revolution and I guess common people will don’t fall down with the difference but it’s real, there is a difference.
- Does it worth 100-150 dollars (instead of a cheap amp at 15 dollars)? Surely not! But in the arcade, you know that the experience depends of the people, you can play emulation, conversion, bootleg, original hardware etc etc. For me it’s a real pleasure to feel a difference in the sound on cps2, when I play Sf2X I enjoy more the music, the sound, and my experience is better. For some people, I’m sure the difference is so low than they’ll regret to pay as much for that. It’s a question of conception.
- Concerning the hardware, I haven’t enough knowledge on the q-sound tech but what I’ve know is the q-sound was define to change all the sound harware, some Hi Fi was designed to have the Q-sound hardware inside (my friends have a Aiwa hi Fi with q-sound inside). Just don’t forgot than Q-sound was an huge fail! With the arrival of Dolby all their plans was ruin. There is so few Q-sound records, Capcom will leave the q-sound after Zn-2 ... It wasn’t just a commercial trap, they thought it was revolutionary (and for me it was in 90’s), with a 2019 conception it seems a trap, but I don’t think it was.
 
Trust me, once you got the amp in your hands and know the specs of its components it's a matter of rustling through your PSU box to get the right one.
So far, no one has it working with any PSU besides the original transformer.
 
Trust me, once you got the amp in your hands and know the specs of its components it's a matter of rustling through your PSU box to get the right one.
So far, no one has it working with any PSU besides the original transformer.
Not sure about that, I used to own a Capcom Impress and the amp from the factory is powered without its own power supply, 12Volts DC if I remember correctly.
 
So far, no one has it working with any PSU besides the original transformer.
I've looked at pictures of the transformer and it looks like your typical, average transformer. Has anyone actually measured the voltage it outputs?

I mean... there's no magic in electronics, it's just math. Once you've discovered the voltage range at which the components work, you feed it and you're good to go.

@wasspat, replying to your points:
- The improvements can derive from a very simple fact, which is that there are not two amplifiers which are exactly the same, not even from the same brand and model due to tolerances (although the higher you go into hi-fi and hi-end scale, the better the tolerances). Of course, Q-sound amps were made for just one job and they surely, 100% have better coupling with a CPS2 motherboard (output/input resistance matching, etc.), so it's not surprising you hear differences and, eventually, improvements.

- Agreed 100%. Just get what makes you feel good is, at the end of the day, what really matters.*

- Q-sound became a marketing gimmick and god only knows what they actually did with that. There were several projects under the same name and they even made some custom DSPs to create a more three-dimensional sound. We're talking about an age where format and technology wars were your everyday business and confusion reigned among the customers about what to do and buy with their cash.
All I can tell from watching some pictures of the Q-Sound amp, is that there are no DSPs, no custom ICs, just plain simple op-amp + power amp circuit you'd find in any amplifier.

* Speaking of which, I've tried as long as I could to stand my Astro City original speakers until I couldn't bear them anymore and upgraded them. I'm one to keep those kind of things as stock as possible, but enough is enough, I wasn't enjoying my games anymore so I decided to swap the speakers for better ones.
 
The Capcom transformer is 17 volts AC as I recall.
14VAC AO Wiki has been updated to reflect it.

Bxl3PKX.jpg
 
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@donluca

May I ask which speaker you bought to replace the ones in the Astro?

Thanks
Sure, it has been a very unpleasant search due to people suggesting crappy computer speakers and other stuff I wouldn't touch with a stick from a mile away. That really angered me as there's a thread on (IIRC) AO where, following OP's advice, several people dumped their money on those Logitech PC speakers and some crappy Chinese ones form Aliexpress and were sorely disappointed with the results (I wasn't half surprised).

Truth is, you cant' ask miracles from a 3" speakers, you can't bend the law of physics, especially since they're technically mounted as open baffle (not the proper term as they don't have a proper case, but still).

After thinking of going hi-end with some very expensive speakers, I decided to settle with something more affordable since they are still going to sound sub-optimal due not being in a proper case (with bass reflex, proper damping, etc...) and I found an italian company named Faital which makes lots of speakers ranging from cheap to very expensive, but they always show the frequency response of each so I could have an idea of their capabilities.

In the end I bought those: https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=401000150

They are not a perfect fit, but I managed to fix them by angling them in a way where the screws will keep them nice and snug. I should take a picture to give you a better idea, but I really don't want to move the cab an open it.

I've paid them 16€ each but I really can't recommend buying them unless you're in Italy due to shipping costs.

And bear in mind that the differences are not night and day. Sound is less shrill, a little more detailed and with better mid-bass, but that's about it and that's as good you're gonna get with a 3" speaker. You want more bass or anything, you have to do some serious modding and go with larger speakers (I'd say at least 5").
 
@donluca

thanks for the Information. you ntook the 4 ohm Version?

there seems also to be a neodymium Version of the Speakers. no idea what difference this would make though.

too bad they won't fit perfect. i will ask for the shipping Price there. thank you very much.
 
No problem, glad to help.

I took the 8Ω version because I have a small custom amp inside which works better with 8Ω speakers.
The original Astro ones are 4Ω IIRC, so you might want to go for that.
 
Right now, I would KILL for an alternative way to power the amp. I've just been told that US Customs has destroyed my transformer. (Drilled a hole right through it). We need to find a transformer that can be used as a replacement for the original as it looks like they cannot be imported anymore.
 
My guess would be that in the x-ray they only saw a solid metal block. An overzealous Customs Person must have been certain that there was illegal drugs hidden in there, so better drill it open to make sure. Grumble, grumble.
 
Right now, I would KILL for an alternative way to power the amp. I've just been told that US Customs has destroyed my transformer. (Drilled a hole right through it). We need to find a transformer that can be used as a replacement for the original as it looks like they cannot be imported anymore.
@Artemio finally measured the voltage going from the original transformer and it read 11.2V AC

https://twitter.com/Artemio/status/1191544118817755136?s=20

Knowing this, we may calculate the voltage drop caused by the bridge rectifier so we can use a DC PSU as well.
 
Strange. Perhaps I'll have a 12V DC input I could provide to see if it works. Though it's weird that the setup in the picture looks like an Impress 12V version of the board, but there's no coil on there so that would be the 18V version.

Didn't see it in the tweet thread, but I wonder if it's getting any sound out of there.
 
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