Would it be a problem if the supply voltage drifts a 1-2 volts either way during the operation??
For quite long time I have been planning to power class A amp off 4 large car batteries just for fun to see how it sounds. Initially I was to try it with Aleph J but maybe F6 would be also nice candidate.
For quite long time I have been planning to power class A amp off 4 large car batteries just for fun to see how it sounds. Initially I was to try it with Aleph J but maybe F6 would be also nice candidate.
My friend works in car battery store that has a wide range of batteries from small motorcycle to huge ones for a trucks that two persons are needed to move few meters. Borrowing a few of them for a week, either some used or new is not a problem. But I seriously planned to buy four of them to power some Pass amps, especially since most of them use +/-24 supply lately. I just want to try it first to see: 1. How does it sound compared to regular PS, 2. How long it can operate for given battery capacity, 3. How long does it take to recharge them.
ZM, zygibajt is not talking about PSU noise, but slow decrease of supply voltage as the batteries got depleted
I would say it's OK
BTW, Who is nuts enough to operate an A class amp on batteries ?
I know , but I wanna say that I choose "regular" PSU with choke input , rather than battery one
not from sanity reason
regarding in/sanity - who sane will choose to have several A class amps at home , even if needing just one ?
that's case with 75% of nutters around
L'art pour L'Art
Thanks for the answers, sure I'm aware of all of it. I just wanted to try this idea for long time purely for fun and some new expirence.
Regarding the noise etc the batteries are neither perfect. I have read somewhere the deep study of noise of batteries even divided to few categories like lead/acid, Li-ion, Nim-cad etc and they all have their troubles.
Thanks again
Regarding the noise etc the batteries are neither perfect. I have read somewhere the deep study of noise of batteries even divided to few categories like lead/acid, Li-ion, Nim-cad etc and they all have their troubles.
Thanks again
I don't remember either. There was some study with measurements somewhere on the web. If I remember correctly the lead acid were worst than Li-on and I think amongs the best were typical not rechargable batteries if I'm correct.
But for sure even the worst battery very often is better than poor or average power supply. This is my own expirence also. Otherwise i wouldn't bother.
But for sure even the worst battery very often is better than poor or average power supply. This is my own expirence also. Otherwise i wouldn't bother.
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Hi Buzz,
Is it the analyzer or getting harmonic phase that has been problematic?
The harmonic phase display doesn't lock very well for me, I watch that both the fundamental and second harmonic to see that both are in the same direction. This was easier to get a handle on with the BA-3 because I could just turn the pot and watch it change.
Also I get better results with the sample rate higher and the sample size larger. Otherwise I see spurious spikes in the spectrum display.
Hope this helps.
Thanks, Buzz and Botte! I can confirm the problem to use the phase window in Visual analyser.
You have to choose the threshold button to get away the many spurious lines and to see just only the the fundamental and the first harmonic k2. But as Botte said this does not help always...
First I was even irritated that the fundamental was going negative, until I remembered that F6 seems to have the phase at the output opposite to the input, so the fundamental can have negative phase.?.....
That means to me that wenn the fundamental is negative in phase, the k2 should go in the same negative direction, to be in positive correlation to the fundamental...... correct?
Sometimes I had a flipping effect, the k2 phase switched on both sides.
So this function seems not always stable, nevertheless for Windows I like this program very much. Sometimes I have the feeling the distortion values shown are too low, compared to other programs.
Sometimes the picture in the THD window freezes when I try to calibrate, sometimes not. It is still a beta, I hope the final version will be better.
To get the voltage of the output of the amp down (normally 2,83V/8R for 1W measurements) to a value lower than 1V for the sound card input, here are two links
http://www.virtins.com/Virtins_Sound_Card_Oscilloscope_Probe_Manual.pdf
Electronic Equiptment - DIY soundcard scope probe
You have to choose the threshold button to get away the many spurious lines and to see just only the the fundamental and the first harmonic k2. But as Botte said this does not help always...
First I was even irritated that the fundamental was going negative, until I remembered that F6 seems to have the phase at the output opposite to the input, so the fundamental can have negative phase.?.....
That means to me that wenn the fundamental is negative in phase, the k2 should go in the same negative direction, to be in positive correlation to the fundamental...... correct?
Sometimes I had a flipping effect, the k2 phase switched on both sides.
So this function seems not always stable, nevertheless for Windows I like this program very much. Sometimes I have the feeling the distortion values shown are too low, compared to other programs.
Sometimes the picture in the THD window freezes when I try to calibrate, sometimes not. It is still a beta, I hope the final version will be better.
To get the voltage of the output of the amp down (normally 2,83V/8R for 1W measurements) to a value lower than 1V for the sound card input, here are two links
http://www.virtins.com/Virtins_Sound_Card_Oscilloscope_Probe_Manual.pdf
Electronic Equiptment - DIY soundcard scope probe
I use this CordellAudio.com - The Distortion Magnifier
It works great and gives a differential input to the laptop and what's another project.
It works great and gives a differential input to the laptop and what's another project.
then there is teaser ......... what's possible with same technology
as common and proper Greedy Boy , I'm salivating to see something as that on free market ......... while as eternal Pa's orphan I wish all exclusivity to stay at FW and PL stable .....
just look how is laid 22/4 line , across Ugs curves .......
they're made exactly for common FW PSU !!
edit : you can also see what's proper way for drawing triode curves , needed for proper graphical construction of stage ....... as in yore
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that depends very much on the battery and the conditions its used in. here its hardly loaded, noise will be extremely low, voltage or current. there is a reason they are almost always called for in regulator and opamp noise and distortion testing rigs in datasheets from Ti, Linear (Dear old Jim loved the odd battery), National and AD. they make it easier to avoid ground loop currents and switching noise on ground; these days this is of significant advantage.
yeah thats all old testing though, doesnt include any of the polymer types favored in audio today, which are IMO orders of magnitude more useful. If I remember correctly its on the TNT website and they arent really impartial.
jackinnj offered to test some A123 cells for noise on the AP, but shipping lithium batteries by air is difficult and very expensive from Au, only fedex accepts them, maybe someone else will take up this offer to put this to rest? please dont send crappy ebay fake A123.
in short there are more advantages to batteries than noise, but they can be a pita to implement as far as charging is concerned. as used in the F6 I wouldnt think they would need charging often at all.
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