Simple Symetrical Amplifier

[shaan]

Originally Posted by Esperado

No doubt.
And a protecting circuit is less expensive than golden diamond audiophile caps ;-)

Thank goodness they are not available here, audiophools are still a rarity in India lol. My about to arrive 10uF film caps cost INR100($2) each and I don't believe in snake oil stuff.

[AndrewT]

Originally Posted by a.wayne

From listening experience , amp with multiple caps (16x 5000uf ) don't have as good a bass as (4x20000) , sounds weaker or put another way , everytime I have heard an amplifier that has exceptional bass , slam and control , it is never with large quantity of small caps , in the PSU...

I think if you took the time to properly compare four identical amplifiers, one pair with a big caps and the other pair with lots of little caps you will reach a different conclusion.

[Jay]

I think a.wayne was correct in his observation. There are many things affecting the performance. One of them is the trace inductance as Esperado has mentioned. So there must be a balance considering all possible parameters affecting the performance.

If there is a parameter to suspect, I think it is the maximum ESR. For cheap caps, big capacitance is a big no-no. But for good caps, big capacitance is fine.

Also, they mentioned about higher voltage rating having lower distortion. I have no observation with power supply caps, but I have observed and practiced this with output caps.

About one big versus many smalls, it is almost similar to tone control phenomena. When you get good treble, you get bad bass. When you get good bass, you get bad treble.

[a.wayne]

Originally Posted by AndrewT

I think if you took the time to properly compare four identical amplifiers, one pair with a big caps and the other pair with lots of little caps you will reach a different conclusion.

Taking Too much assumption with your tea again Andrew ..

[AndrewT]

I prefer coffee. But, I still think you are quoting for an apples and oranges comparison

[a.wayne]

I have done the multiple little cappy thing , I did not like the bass , worst the amplifier had no energy, best was as discussed previously , big ballsy bwoys in the main psu , smaller caps closer to outputs on board ...

Copper bars instead of wire , everything as short as possible ....

Just saying ...

[caglarm]

Originally Posted by Nico Ras

Very nice and small. Well done!

Thx. Niko..I was build Ras100 and Ras300 to...I trust your designs.

[Esperado]

Originally Posted by shaan

Thank goodness they [audiophile caps] are not available here [in India]

What the hell are doing the marketing guys ? They canvass Emirs and ignore Maharajas?

Originally Posted by Jay

About one big versus many smalls, it is almost similar to tone control phenomena. When you get good treble, you get bad bass. When you get good bass, you get bad treble.

So true !

Originally Posted by Jay

Your speaker protection idea is the most complex one I have seen on this planet,

My goodness! And I thought it was as simple as the SSA? Just a single comparator with some appetizers around.

Originally Posted by Jay

but it fails to eliminate a (cheap?) relay at the amp output.
Different approach (such as used by Pioneer if I'm not mistaken) is to ground the input and output of the amp when DC is detected at output. I don't know if this approach is effective enough but why not?

Why do you treat my relay cheap ? They thought they where expensive and they are so sad, now.

This protection isolate the loudspeaker during power on/off for no click, noise etc.. and provide a soft current charge in the PSU caps. I would not like to short circuit the Amp output during this time where offset can Rock'nroll in a funky way ;-)

I'm unable to hear any difference between the relays and a big wire soldered across their contact. So, I'm not emotional about it.
Yes, my loudspeakers are impedance compensated both motional and zobel (i highly recommend) , so they present a quasi flat impedance curve, and, so, slight difference in damping factor (internal impedance of the amp) by the (very) little resistance of the relay's contacts is not so sensible.

Last, you can parallel an active device to reduce further this resistance and contacts problems. I use Big relays with two paralleled contacts for each channel.

Of course, you can forget about protection, (a strait line wire is less expensive and sound the best ) if Murphy ignore where you are living. I write this under his supervision.

[a.wayne]

Best no protection , no fuse straight to speaker , of course very dependent on system resolution.

[maxlorenz]

IF one has to use an input coupling cap, I am affraid some people would be able to hear differences between different cap types. For those unlucky to be in such situation I can tell that I just forgot about trying different types after finding those NOS Russian military surplus PETP caps cheap at eBay.