This is not just another gainclone

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and yet another
 

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Funny you should say that. I, too was thinking of using marble or granite. In fact, I was looking at 12" X 12" tiles and thinking about cutting them. I have a diamond wet saw from one of my home improvement projects. But, I got anxious and decided to build it this way.

My next project will certainly use marble or granite firstly because of the mass to reduce microphonics and secondly because I just like stone!

BTW, the amp is actually in the two aluminum boxes. The input and pot are in between in the wood.

Vic
 
SLA batteries & caps

I tend to think of batteries as a great replacment for transformers & diodes but I do not think they are fast enough to replace the high quality electrolytic caps

batteries & 1uF gave a very smooth sound, quite pleasant, but once I put the electolytics in they was no question for me which was best.

I'm using DNM 10,000uf slit foil T network types. I have not compared these with black gate or panasonic etc 1000uf types.

If anyone out there has done this comparison I would be interested to hear what your conclusions are.


:nod: mike
 
mikelm said:
thanks for replying on my behalf :cool: I had to take a break from audio & go to work !

I think the amp won't wait but it will have to deal with a monentary tiny drop in rail voltage.

Ok, so you're not talking about speed but rather impedance?

That would be the case with any electrolytic capacitor as well. Instead of using large capacity capacitors, have you tried larger capacity batteries? Or several smaller capacity batteries in parallel? Using small capacity batteries is like using small capacity capacitors. The smaller they are, the higher their impedance.

Of course capacitors are typically a lot less expensive than batteries and can provide a less expensive means of reducing supply impedance. But rather an apples and oranges comparison without having tried higher capacity batteries as well.

why are our ears so sensitive ? ;)

Actually it's the brain that's the sensitive one. In fact, it's actually what you'd call hypersensitive, which is why it tends to "overdetect" and causes us to perceive differences even if none exist.

Which is fine when it comes to determining our subjective tastes and preferences, but quite unreliable when it comes to establishing objective realities such as actual audibility.

se
 
"Ok, so you're not talking about speed but rather impedance?"

to me "speed" implies low impedance at a high frequency. I did not think the term would be so controversial

"That would be the case with any electrolytic capacitor as well."

I thought it took quite special technologies to keep the impedance of big caps low at high frequencies. This is the speciality of the T network caps that I am using at present.

"Instead of using large capacity capacitors, have you tried larger capacity batteries? Or several smaller capacity batteries in parallel?"

I thought 4 x 12V 7ah would probably just about be enough, I guess I could try car batteries, or perhaps submarine batteries would just about crack it. ;)

actually a mate of mine who did his Phd on batteries says Ni Fe batteries that are often used in submarines have a very very low internal resistance. might be worth a try, but I bet you would still get an improvment in quality if you bypassed them with good quality electrolytic caps to reduce HF impedance.

mike
 
mikelm said:
to me "speed" implies low impedance at a high frequency. I did not think the term would be so controversial

To me "speed" is how fast something is delivered rather than how much is delivered. High impedance doesn't reduce the speed at which current is delivered, it just limits the amount that can be delivered due to the voltage drop across the impedance.

As for controversy, I've just always been curious why people use the term "speed" in this particular context is all.

I thought it took quite special technologies to keep the impedance of big caps low at high frequencies. This is the speciality of the T network caps that I am using at present.

Guess it depends what you mean by "high frequencies."

With the possible exception of the big "computer grade" electrolytics, most large value caps have their impedance dropping continuously through the audio band.

Above the audio band, the capacitor's inductance (ESL), which is largely a function of the capacitor's lead spacing, causes impedance to rise.

ESR contributes to the limit as well, though it's rather constant with frequency unlike the primary capacitance and ESL.

I thought 4 x 12V 7ah would probably just about be enough, I guess I could try car batteries, or perhaps submarine batteries would just about crack it. ;)

Hehehe. Don't know that you'd need to go that far.

actually a mate of mine who did his Phd on batteries says Ni Fe batteries that are often used in submarines have a very very low internal resistance. might be worth a try, but I bet you would still get an improvment in quality if you bypassed them with good quality electrolytic caps to reduce HF impedance.

I've tried large values of capacitance, but they just didn't give me what I would consider an improvement. Technically I suppose they would be. But in my own experience, I've found that technical improvement doesn't always translate into subjective improvement.

And before anyone tries to read this the wrong way, let me reiterate that I think people should use whatever gives THEM a subjective improvement.

se
 
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