What's new
That are the rules for QSound, if you don't want it, don't use it, simple as that. Standard cabinets can't be used for QSound unless you apply some changes, there is no other way around it.
We're arguing the same point here, I think.

Reality is putting a Q-Sound amp in non-Qsound cabs is a silly endeavor.
 
That are the rules for QSound, if you don't want it, don't use it, simple as that. Standard cabinets can't be used for QSound unless you apply some changes, there is no other way around it.
We're arguing the same point here, I think.
Reality is putting a Q-Sound amp in non-Qsound cabs is a silly endeavor.
True, but you know users right. ;)
 
So an new astro City will not be able to benefit of the Q Sound because the speakers are not alligned that way as in the Capcom cab?

i have a nvs 4000 in use with the cps2 and 3 and planning to get These amps running in my cab. but now i am not sure if it is any use.

or Change in Quality.

one think i can tell though that the "impress" Version of this amp which can be powered with jamma power was not use. total bad humming. returned it back then to the seller.
It depends on the type/model of the cabinet, the ones with speakers face forward over the player head, works just fine.
astro-city-01.jpg
yea these exactly i have. so i will try out the amps i think. thank you very much for your information
 
@wuemura I'm wondering if I'm getting trolled or if you're serious.

For once, since we're having a civil discussion, I'll give you the benefit of doubt and believe that you actually know what you're talking about but I need to point out that the first circuit you've shared could work only if we're having a reactive load on one end which this is not the case as speakers are resistive loads.
This means that if you actually want to produce a phase shift you need active circuitry and not just a network of resistors and capacitors. Anyway, this is completely irrelevant in this context.

In your post, you insist on using the term "decode" which is completely incorrect, because there's nothing to decode. All the phase shifting and fuckery the audio engineer did to achieve the three-dimensional sound was done during the recording/encoding process.

Again, you don't need THAT precise amp to enjoy QSound, and you don't need either some special speaker placement, you just have to follow the basic, simple standard to achieve proper stereo sound:

stereo-speaker-placement-cropped.jpg


with the tweeter at your ear's height.
This is not some special QSound setup, this is the absolutely standard speaker placement for proper stereo playback which has been known for 40 years.

I don't mean to sound like a douche (a QSound Amp isn't that expensive after all, so if you still want to try it out yourself, by all means, go for it), I just want to debunk some myths about this amp so that people can choose whatever they want without thinking "I must use this amp at all cost".
 
@wuemura I'm wondering if I'm getting trolled or if you're serious.
I ask myself the exact same thing.

donluca said:
For once, since we're having a civil discussion, I'll give you the benefit of doubt and believe that you actually know what you're talking about but I need to point out that the first circuit you've shared could work only if we're having a reactive load on one end which this is not the case as speakers are resistive loads.
This means that if you actually want to produce a phase shift you need active circuitry and not just a network of resistors and capacitors. Anyway, this is completely irrelevant in this context.
Looks like you don't know what a R-C phase shift network do...
http://www.learnabout-electronics.org/Oscillators/osc31.php

donluca said:
In your post, you insist on using the term "decode" which is completely incorrect, because there's nothing to decode.
Prove it!
You Just talk, you don't back up anything you say with any evidence. To DECODE QSound you need a matrix DECODER, that it's the problem with you, you don't even know what a matrix decoder is!
https://en.wikipedia.org/wiki/Matrix_decoder

donluca said:
All the phase shifting and fuckery the audio engineer did to achieve the three-dimensional sound was done during the recording/encoding process.
There are no pre-recording or encodings with QSound in CPS2 games.

donluca said:
Again, you don't need THAT precise amp to enjoy QSound
Prove it!

You know what, forget it.
You don't understand how a matrix decoder works and want to come here to "debunk some myths" with no evidence?
If you say people don't need that Capcom amplifier to decode QSound YOU HAVE TO PROVE IT! Show us some evidence, them people might start to believe you.
 
Looks like you don't know what a R-C phase shift network do...http://www.learnabout-electronics.org/Oscillators/osc31.php
And you're still failing at understanding the fundamental difference between a resistive load and a reactive one and how you can't just apply an R-C filter to obtain a phase shift when you have a resistive load.
Since I'm talking to, as you stated yourself, an "hardware developer" (which means absolutely nothing unless you're more specific, you could be someone who designed washing machines, telescopes, or boats, but whatever), I'm taking for granted you know how passive networks work, so I shouldn't be here explaining the differences between a resistive load and a reactive one.
Hope you enjoy the read: allaboutcircuits.com/textbook/alternating-current/chpt-11/power-resistive-reactive-ac-circuits/

Prove it!You Just talk, you don't back up anything you say with any evidence.
QSound is a proprietary encoding system and as such there's no documentation and I can't prove anything, like you're trying to do. I only make educated assumptions based on my knowledge of how electronics work and digital audio encoding and decoding.
When I'll get my hands on a QSound amp, I can make a comparison, but of course you might want to refute that due to being a very "unscientific" way of proving my point.
The only thing we have is the board and, honestly, looking at the circuit is more than enough for me to get to the conclusion that it is nothing more or less than a common power amp.

To DECODE QSound you need a matrix DECODER, that it's the problem with you, you don't even know what a matrix decoder is!
https://en.wikipedia.org/wiki/Matrix_decoder
A matrix decoder doesn't have absolutely anything to do with QSound. Actually, if you *really* want to stretch the definition of what a matrix decoder does, you might say that QSound was an alternative to the traditional matrix decoding, created to give you a 3D effect without using extra hardware.
Since you're speaking of matrix decoders, you should be familiar with one of the most famous and used one which is Dolby Pro Logic which was initially used to encode 4 discreet channels of audio to 2 and then, through a dedicated processor can get the original 4 channels back. Notice how it didn't achieve this through a network of caps and resistors, but a custom processor dedicated to the decoding of the signal.

There are no pre-recording or encodings with QSound in CPS2 games.
[...]
Prove it!
You know what, forget it.
You don't understand how a matrix decoder works and want to come here to "debunk some myths" with no evidence?
If you say people don't need that Capcom amplifier to decode QSound YOU HAVE TO PROVE IT! Show us some evidence, them people might start to believe you.
Since you speak with such an attitude about QSound, which, again, it's a proprietary system, I can only guess that as an "hardware developer" you were part of the team that developed it?
If so, then please speak up and let us know exactly how it was developed and please accept my apologies.
Otherwise, if I were you, I'd just follow your own advice and forget about this and let the people judge by themselves.
 
donluca said:
And you're still failing at understanding the fundamental difference between a resistive load and a reactive one and how you can't just apply an R-C filter to obtain a phase shift when you have a resistive load.
Since I'm talking to, as you stated yourself, an "hardware developer" (which means absolutely nothing unless you're more specific, you could be someone who designed washing machines, telescopes, or boats, but whatever), I'm taking for granted you know how passive networks work, so I shouldn't be here explaining the differences between a resistive load and a reactive one.
Hope you enjoy the read: allaboutcircuits.com/textbook/alternating-current/chpt-11/power-resistive-reactive-ac-circuits/
Just to make sure, you said you are a experienced guy that fix DAC's and everything and doesn't know that the circuit I've posted it's used at amplifiers input stage?

donluca said:
QSound is a proprietary encoding system and as such there's no documentation and I can't prove anything, like you're trying to do. I only make educated assumptions based on my knowledge of how electronics work and digital audio encoding and decoding.
When I'll get my hands on a QSound amp, I can make a comparison, but of course you might want to refute that due to being a very "unscientific" way of proving my point.
The only thing we have is the board and, honestly, looking at the circuit is more than enough for me to get to the conclusion that it is nothing more or less than a common power amp.
Please, don't give us this "proprietary" crap, the patents are available online.
Also YES you can prove it.

Do I have to tell you how to inject a signal at the amplifier input and mesure the output with an oscilloscope?
- Here little grasshopper, you input the signal here and mesure it here.

donluca said:
A matrix decoder doesn't have absolutely anything to do with QSound. Actually, if you *really* want to stretch the definition of what a matrix decoder does, you might say that QSound was an alternative to the traditional matrix decoding, created to give you a 3D effect without using extra hardware.
Since you're speaking of matrix decoders, you should be familiar with one of the most famous and used one which is Dolby Pro Logic which was initially used to encode 4 discreet channels of audio to 2 and then, through a dedicated processor can get the original 4 channels back. Notice how it didn't achieve this through a network of caps and resistors, but a custom processor dedicated to the decoding of the signal.
Can you prove a matrix decoder has nothing to do with QSound?
Doesn't the "traditional" matrix decoder deals with out of phase information? Doesn't the QSound patents describes in fase and out phase signals and mixing?
Didn't I decoded the Ryu Stage soundtrack so ANYONE can experience QSound with their own TV?
qsound-decode.png


If it has nothing to do with a matrix decoder how was I able to decode it? DIDN'T I GOT THE 4 CHANNELS BACK?

donluca said:
Since you speak with such an attitude about QSound, which, again, it's a proprietary system, I can only guess that as an "hardware developer" you were part of the team that developed it?
If so, then please speak up and let us know exactly how it was developed and please accept my apologies.
Otherwise, if I were you, I'd just follow your own advice and forget about this and let the people judge by themselves.
Non-disclosure agreement, I can't talk specifics, sorry.
So far, thanks to the hard work of ValleyBell and superctr they unlock half the secrets of QSound, the other half are inside the Capcom power amplifier, that board has the missing secret hidden in plain sight, a very basic QSound matrix decoder, it explain why it uses 6 operational amplifiers to handle a stereo signal.

"If I were YOU", I would reverse engineer that board, it has a few components anyway and draw a schematic out of it to show EVERYONE OVER HERE that THERE IS NO MATRIX DECODER IN THERE. I DARE YOU to do it, I really do.
Then be man enough to come back here and say you are sorry and that you were wrong about that board.

Or, forget about all this and back away because there is no myth to be debunked here.
 
Last edited:
Dude, all that anger towards something so meaningless doesn't do you well, it's bad for your health. Take a deep breath. Chill.

Now... QSound amps have been around forever (and people have possibly been frying them by feeding them 18VAC, but that's another story) and by now people would have found out if there was a matrix decoder (big spoiler: there isn't), but if you're so sure of it, then by all means, do not hoard this for yourself but submit your findings to the MAME team, open a ticket on github and let everyone know of how silly they've been. There you go: https://github.com/mamedev/mame/issues
I assure you that lots of people (including me) will be eternally grateful for your contribution.

Besides, if/when I'll get my QSound amp I'll inspect the board closely and see it myself (besides, I wanted one just for the sake of having one). Until then, I've already made my point: the 3 dual opamps are configured with a buffer and the other two driving the power amp. Nothing fancy. Maybe I'm wrong, we'll see.

No need to dare anyone doing anything. What I do, I do mostly for the community and share what I know and help others.
It's not a challenge, it's a hobby I'm passionate of and do in my free time whenever I can.


And finally, here's a friendly tip from someone who's been an angry kid on the internet in the past for way too much time and yelled at people and took things way too personally: keep your temperament in check, do not make ad hominem attacks, be humble and always keep an open mind.

For now, let's call it quits, I'll come back when I'll have anything meaningful to add.
 
Angry? Because I use bold letters? Hummm..

Why would I waste my time with MAME team? Let me tell you a history, the engineer responsible for many of the Yamaha FM sound engine join mame dev without telling anyone who he was and contribute with some code, what MAME team do? Scrap all his work because of ego, a bunch of kids telling the guy who created the Yamaha sound chips is wrong.

In relation with QSound and MAME:
mame-higher-standars-qsound.png

Qsound-superctr.png

https://github.com/mamedev/mame/pull/3821

ValleyBell and superctr did a monumental job and got treated like garbage. On my part, way before the ValleyBell and superctr new QSound engine, I gave "MAME Team" 4 or 5 QSound decoded sound tracks directly from the only CPS2 board I could find because the MAME sound engine at the time had nothing to decode from, they trashed.

MAME team are putting the MAME project into a corner, it doesn't matter how much code updates it receives people are caring less and less about MAME. Developers rather prefer to join other projects or start their own instead of collaborating with MAME, take bsnes for instance, what bsnes does MAME didn't even figure it out yet and if you look at mamedev github, their are taking parts of byuu code into MAME core.

Take this example, problem with the Yamaha YM2203, I bought the main board, the sound chips, the shields recorded everything, they only acknowledge witch means they are not sure. Latter with an informal talk with superctr I ask if he knew what is wrong with it since their online player suffers from the same problem, out of the blue, ValleyBell comes saying he know what the problem is and knew how to fix it, and he DID IT!

It was like 2 minute conversation with a very friendly and intelligent person to get it done. That sound engine at MAME still broken, ask if ValleyBell will push his PR into MAME's code, NOPE. What for? To be called names? So MAME dev people would tell him that his code is worthless?

I'll never, EVER, try to contribute anything with MAME again. If you want to see any evolution related with QSound try libvgm or vgmplay.

PS: Read my signature.
 
Last edited:
Fair enough.

I know there's been lots of drama involving the MAME dev team and this is not the place to discuss this as I don't want to derail the thread (which has lots of meaningful and important information).
They have their own way and let's just stop here. Some people don't like their way and that's 100% fine, I can see why, not going to defend them or anything.

I know libvgm quite well and check it from time to time, I'm always interested in seeing how those evolve and each step towards a more accurate sound/music reproduction is always warmly welcome on my side.
I'll keep an eye open to see any evolution.
 
On the capcom amp there are not Ics for qsound decoding because they are on game pcb only, the capcom amp is still a good amp pleanty of power and use Elna Duralex II high quality audio caps so it is a very good amp and match just perfect with capcom q games, as I said before it is basically 12v 2.5amp minimum the 18v are only a legend. Classic old games + classic old Crt 15Kz CGA RGB monitor+ classic old power amp is just a perfect union! I must say that the naomi amp wich is very similar but not offer the same sound with capcom q games so there is really something special..
 
without 2.5A it will not start up for sure, here is the schme and the trasformer I have builded for the Q amp, and it works flawlessly exactly like the original one. It only cost abou 3€ ;)
 

Attachments

  • DSC_1534.JPG
    DSC_1534.JPG
    643.4 KB · Views: 229
  • DSC_1535.JPG
    DSC_1535.JPG
    537.9 KB · Views: 258
  • DSC_1536.JPG
    DSC_1536.JPG
    282.8 KB · Views: 220
Last edited:
Now I'm going to build an external volum pot, every one for channel ...I will use the amp with jamma pcbs and my 20" PVMs monitors...they are all mono and have the worst speacker ever made..
 
Last edited:
Current will vary based on the load/volume. Most of you will not utilize even half the wattage on a different cab with its stock speakers.

On the Q25, the speakers are one of the biggest features of the cabinet and the fact they are in a bookshelf style enclosure. Unfortunately, the manual does not list the speaker specs and there is no sticker with the specs on the back. Just the Capcom part # CSP - 001A.

My Q25 is right next to my NNC and due to the higher quality speakers and amp, the NNC doesn't even touch the clarity at higher dbs. The other downfall of the NNC is the rear enclosure is entirely plastic and resonates easier, as well as the monitor bezel and cover being plastic also. Granted, you could use sound deadening material to help reduce resonation and vibrations. It's just not gonna beat a wood bookshelf enclosure inside a fitted wooden top box.

YwIUvGt.jpg


From working in an arcade during the 90s. The US Big Blue with the same speakers and Qsound amp overpowered the rest of the cabinets at our location. I always had to go back and turn the volumes down, as the regular employees loved turning them up and turning the attract modes on for CPS2 games.
 
Q 25, great cab! Glorious mistsubishi tube drived by a great nanao ms8-25FAR....and yes about the amp the current vary based on load/volume, obviously, plus the rated 12v 2.5a needed before the rectifier must be multiplied x 1,41 jus after the rectifier so we have the legendary 16-18V approx wich are not used obvioulsy...
 
Last edited:
What I still don't understand is how Capcom did to put this transformerless amp in the capcoms impress. The transformerless version has a horrible ground loop of its own with cps3. I haven't had time yet to test this version of the q sound amp, I simply removed it from my cabinets and replaced it with the version that has the rectifier and transformer ...
 
Q 25, great cab! Glorious mistsubishi tube drived by a great nanao ms8-25FAR....and yes about the amp the current vary based on load/volume, obviously, plus the rated 12v 2.5a needed before the rectifier must be multiplied x 1,41 jus after the rectifier so we have the legendary 18V approx wich are not used obvioulsy...
My Q25 uses a Toshiba tube with the MS-8-25FBC variant. Both combinations look amazing on that cab after you properly tune the monitor.

My cabinet runs the transformer at 14v, which is likely from me not using a step-down and running 110v.

However, after looking at the PSU, chassis, amp, and its components. There is no reason for me to run a step-down when everything is rated 20+% over 120VAC. The safety margin is there.
 
the genuine capcom-kitamura transformer is very compatible with the attention of the entrance must be given exactly 100v or 120vAC (accordingly with the right color wire). I had to use a 230to100V stepdown because the standard 220to110v didn't work ... the LED on the amplifier went out…by the way the Q25 is absolutely heavy ad awesome cab, Toshiba tube + ms8 its great if not even better…the issue is that when you touch the cut off you will influence the gains too so obtain a perfect balanced white can be tricky afther years only just now I can do that easily...

Sorry for my terrible English...
 
Last edited:
finally I forgot to mention the CPT-003A model which was distributed here in Italy in 1996 in a few pieces, this version I think quite rare accepts 220v and 240v I never tested it, but it was present in my kit of Red Earth Eu
 

Attachments

  • DSC_1539.JPG
    DSC_1539.JPG
    518 KB · Views: 277
Back
Top