Sounds good, i like it, you may appreciate too.

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I bougth this Phillips, MCM590, some International Model, the one you may find everywhere...constructed in Holland, and imported in parts to be assembled in the destination country.

It is producing 15 volts of audio over 4 ohms, distortion may be something alike 0.5 percent when reach -20 dB above maximum, of course.... reaching -10dB, it may distort around 1 percent, and will remain the same till the top maximum volume.

Consumption, marked behind the set is 125 Watts, but it have some lamps, the old ones, filament lamps, not LEDs, and those have enormous consumption.

It is too much heavy to use some switching supply, i think a big transformer is inside, as the Central control weigth is around 5 Kg...maybe 10 pounds, not sure.

Headphone output have one relay switching when you plug the headphone...it is a 6W, 10 percent maximum distortion, 22 ohms traditional chip audio amplifier.

The line in, or auxiliary inputs are awfull...sounds not good.... remember some tape deck sound.

I am happy with it, i cannot call it Hi fidelity, as have not a flat response to make blind comparison...always some effect is on, so, impossible to compare in a fair way....but sounds good, i can call Hi Efficiency....Hi technologie.... Hi everything you want...but i cannot say hi fidelity, as i could not compare, as equalization on is creating some problem.

Output amplifier have a low noise fan, small heatsinks, and the board seems small....could no open 18 monthes guaranteed, covering everything, except Nuclear War!

I will put some text and 2 images.

I am waiting some discrete design to assemble Class D at home, sun or latter it will appear to us...something without chips....old good way, using soldering iron...and big parts..hehe

I am Brazilian, so, English not good...sorry guys!

regards,

Carlos
 

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Hi Carlos,

So that thing uses UCD does it? I wouldnt' judge the technology based solely on how they've implemented in there, for obvious reasons.

Do you plan on attempting to modify it at all?

There are already some very interesting class d projects you could try that involve soldering iron and no chips/modules, including UCD.

Regards,
Chris
 
ClassD4sure, no, i do not want to modify

I am very satisfied with that equipment.

But i want, also, to try something discrete too.

I cannot say it sounds perfect, as speaker always disturbing as week part in the hi fidelity chain...but i think, research will develop more and more.

It can be, if not already are, the sound of our future.

I have to read all entire forum...i did not done it yet, only Solid State, this one i read it 4 times... all threads...Ufah!

regards,

Carlos
 
I may have jumped the gun here due to a misunderstanding on my part.

I doubt this uses a UCD modulator. It's probably some IC based circuit right?

Anyway Carlos, if you start reading this forum you're going to see alot about UCD, well worth paying close attention to. ;)

I would expect it to be ... a little better.... than what you got there :)

3000W PMPO...... heh, will they ever stop this stupidity??

Regards,
Chris
 
Yeah! bill, always flying in circles... waiting some nut!

But you are welcome in the places i am, as i like you very much....no!...it is not the same love i have to Grim...., he is squared!.... i really like you, you are funny, full of sense of humor, you know how to turn threads happier, to move us to have some fun, to broke all those snobish we have:

You always laugh when we say:

" I beg your pardon Mister"...ahahaha...i now what you mean.

This way, as you can understand second and third intentions....maybe fourth intentions "inserted" "under" the text, i am sending you again.... to make you happy.

A gift.

My Dear Fitz

regards, happy to see you here... there are more hot sausages man!

Carlos
 

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Hi destroyer X, welcome to the classD forum! I am fully committed to the switching power amplifier concept now, so have been away from the Solid State forum lately. The UcD does come in circuit board modules made by Hypex, as you know now, unlike what the sheet you posted an image of says. I'd say that a decent UcD circuit can be constructed by the DIYer from scratch, but tweaking may be necessary to get it right. Some MOSFETs may die in the process as well. However, IMO, a working less than perfect UcD type circuit is easier to do than a comparable sounding analog one.

I saw mention that the name UcD seems immodest. That point struck me since I named my SMPS design the Universal SMPS (USMPS or UnivSMPS for short) before I even knew about UcD. I can only think that the name for mine does fit since the controller concept is easily implemented with no exotic parts and without fuss using the ubiquitous CD40106B (74C14), the totem pole drive (half-bridge performance is superior to push-pull) is the common IR211x, and the output transformer is toroidal--easier to obtain and wind than EI ones. But I admit bias, as I know it does implement trade offs for the sake of simplicity.

I have yet to get around to building a UcD circuit. so cannot attest to how well its name fits. I suspect that the name is very appropriate, indeed. I may not actually build it using discrete parts, so any rendition I do may be closer to my original Nchamp (N-channel amp) design instead.
 
Hi guys.

I second the welcoming of Carlos to the Class D forum, certainly good for some extra life around here.

I'm currently picking away at a +-75V max full bridge UCD sim, nothing but transistors in it so far, and that's how I aim to keep it. I think there's a strong possibility of being able to drive it differentially with an audio transformer to step up the input, or could breakdown and do the dual op amp input. Discrete class A stage there would be the ultimate, but simplicity is the goal, nice low part count, as well as quality, of course. A transformer certainly seems suitable.

Interested ?

Regards
chris
 
Subwo1 and classd4sure, thank you very much to invitation and good reception too.

I have to confess you, frankly, i am ignorant about digital matter..even the old 7401 or that family.

I am completelly stupid related that business, i am making enormous efforts to understand you all....it seems you are all top scientist discussing something i never heard....i will be around, as someone that is cleaning the room and trying to understand slowly.

I will be here, as i am very excited with class D....and i thank you the attention.

But really, not beeing fake humble, do not loose too much time with me for a while, as i even cannot understant the basic knowledge and even the English you are writting. SMPTS....switched....do not know...Pulse....t+triggered.... S=Supply?

So, as young kid, i am learning slowly...will be watching you...really following each one, and each word.... in some monthes i will be more ready to enter the club...really enter!

Thank you in advance, because the kindness of warm receipt here.

But i really intend to be a little hidden, as i am turning a little shy related my ignorance in that subject.

regards,

Carlos
 
Sure, that your MCM590 aren't UcD based, because:
1) Output amplifier have a low noise fan. MA240 (80w) UcD based amp have not heatsink even.
2) MCM590 have not so much smart specs yet.
3) as far as i see, UcD is still not in use by Philips itself. They sell licenses for use UcD to the second companys(i.e. Hypex etc). Newest Philips chip "The TDA8931 is a switching power stage for high efficiency class-D audio power amplifier
systems. It contains a Single-Ended (SE) power stage, drive logic, protection control logic,
a full differential input comparator and a HVP charger to charge the SE capacitor (see
Figure 1). With this amplifier a compact 1 ´ 20 W closed loop self-oscillating digital
amplifier system can be built. A second order low-pass filter converts the PWM output
signal into an analog audio signal across the speaker."
And this is not UcD again..

PS: Subwo, i can hear in the UcD name several words, well associated with class D amplification..i.e. you(U) see(c) D(D)??
destroyer, I had choice my avatar after your avatar has been seen, but i agree that your avatar just a state of the art.:cool:
 
No problem, Carlos. I have the less than laudable habit of not learning more than I have too. The only CMOS chip I know much about is the one I mentioned, and a little about the exclusive/or chip, I think, the CD4028, which is often used as a way to produce both an in-phase and out-of-phase signal without a timing penalty. :?: I can't brag since I forget way more than I learn.

Chris, I really can't even say I am an expert at Hi-Fi, so I don't know what to think about the project. :xeye: I personally will be satisfied with several hundred watts peak to drive my sealed concrete subwoofer, and very small satellite speakers. I intend to make the plans for the sub public since I know of no manufacturers who would be interested in it. The reason I held onto the idea before now is out of deference to my family.
 
Hi Ivan. I think we will "see" much more classD because of the UcD. I think the letter "D" was chosen more because of the fact that A, B, and C were already in existence as classes of amplifiers rather than standing for "digital". I had a copy of _Electronics_World_ magazine dated around (c.) 1968 which showed the first DIY classD amplifier project I ever saw. But it was an old copy of the magazine, I was not into electronics yet when it came out.
 
Hi Sub,

As far as hi-fi goes ... it's a proven concept at least.

As far as the power level goes, yes it's foolish, I'm only interested in several hundred watts myself. Non the less, I plan on making the modulator portion of it capable of handling at least 150V. I don't think cost would be any more. Realistically I think both the drivers and the output coils will be a limiting factor, but, ya know, gotta learn somehow.

When I get it a little more ironed out I think I'll share it anyway.

On the other hand, concrete subs.. sounds like just the kind of thing that could make use of a few thousand watts :)

Regards
 
Carlos, some models won't open if the cassette door is closed. But, I don't think that would apply in this case.

Chris, I would be interested in learning more about your project if for no reason than curiosity. The original N-champ had no theoretical limit on how high the power supplies could be since it was driven by optos (Except for the rating of the outputs.). Later, I simplified it to use the IR211x. :) Now I am wondering if I can drive just the lower MOSFET and let the upper one swing high with the flyback voltage of the output choke, then stay there until the lower MOSFET turns back on. Have you tried that way yet on the simulator?
 
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