Battery Power Supply

[sima66]

one cell per device is sufficient

personally i think it will be difficult to tell difference in sq with cable length from battery under 15"
as i often ran tests at these lenghts

Thanks Nigel,
That will make my life much easier! ;-)

[nige2000]

one cell per device is sufficient

personally i think it will be difficult to tell difference in sq with cable length from battery under 15"
as i often ran tests at these lenghts

Thanks Nigel,
That will make my life much easier! ;-)

of course short wires are the "done thing"

only after realising your dac has 4 pcm1704 per channel
what dac did you have before it?

[sima66]

of course short wires are the "done thing"

only after realising your dac has 4 pcm1704 per channel
what dac did you have before it?

Before I had Audio Aero Capitole CDP.

What "4 pcm1704 per channel" means?!
Is that good or bad?

I found only this specifications (which again, don't tell me much):
Decoding Software: DigiMaster 1.4
D>A Sample Rate: 2.8224MHz
Digital Processing Capability: 48 Bits
Digital Resolution: 26 Bits

[nige2000]

http://www.cmy.com.my/product_info_407001-100173.htm

[jkeny]

BTW, I just came across this quote from John Swenson

"Particularly for computer use you need a supply that can respond to a VERY wide range transient loads, from single digit Hz. up to many MHz. Audiophile capacitors simply don't do this. There is NO single capacitor that does this, it doesn't exist. It takes multiple capacitors of different characteristics to do this well. "

I believe these batteries might well be the single capacitor that he states doesn't exist!

When I first started using these batteries I was drawn to them by their low internal impedance (i.e. high current capability) & their steady 3.2 voltage during discharge until they reach 90% or so discharged. Having previously read about battery usage in DIY audio, mostly SLA car battery, I realised that the lower internal impedance batteries sounded best so I figured the LiFePO4s would be great with the lowest impedance of any battery I had seen. Internal impedance determines how much current can be delivered instantaneously which also dete

Initially, I used a scheme to charge these batteries but only when they were not powering the devices. I then discovered that when I connected a charger while playing that it made no noticeable difference to the sound - I realised that these must be operating as very large capacitors suppressing noise from the charger - cool!

My theory is that these batteries have both a low & very stable noise level along with a very fast transient response which would seem to answer John Swenson's requirements above & why they sound great powering any digital circuits including computer motherboards & digital audio devices. Not only that but they act as huge capacitors & PS "noise eaters" too - even cooler!

He further states:

"Unfortunately the common response to this is to parallel several different capacitors right at the output, this doesn't work either. The inductances of the different caps interact with each other causing high impedance at multiple frequencies."

which is one reason why a capacitor across the battery is detrimental - we've already realised that capacitors across these batteries slows down the sound - the internal impedance of capacitors rises above a certain frequency which I don't believe happens with these batteries

[sima66]

http://www.cmy.com.my/product_info_407001-100173.htm

I don't want to be out of topic, but now I just got curious! :)
Again, those specs and numbers doesn't tell me anything (not familiar)!
I bought this DAC because I read the people statements and comparations.
Ten years ago it was one of the best. But, since digital world is moving fast, I'm curious how those specs look NOW comparing to some other good DAC's?

[tony]

Adam you have the last of the best multibit dac chips. Wadia were at the pinnacle. Married to sonicweld diverter and your dreadful PC build skills you still end up with a beauty!

[nige2000]

http://www.cmy.com.my/product_info_407001-100173.htm

I don't want to be out of topic, but now I just got curious! :)
Again, those specs and numbers doesn't tell me anything (not familiar)!
I bought this DAC because I read the people statements and comparations.
Ten years ago it was one of the best. But, since digital world is moving fast, I'm curious how those specs look NOW comparing to some other good DAC's?

what are the best dacs out there?

it was just the sound i heard in your place
i had not heard some of the good aspects of the sound before with sigma delta dacs i've heard here
but i have heard very little dacs of this class so im no expert

your wadia is based on r2r dac burr brown pcm1704 chips which are no longer in production about 60 euro each if you can get em, i guess the mass market is for smaller and cheaper these days

i wouldnt doubt some of the modern dacs are build for profit (target market and price point) and not for "thee best sound possible"
the guys that build the 931/922 sure put some effort into it id imagine it could still wipe the floor with some of the modern stuff

i suppose spdif was the way back then
it would be interesting to see if it could be hacked to put a modern usb to i2s into them

cant find what i was reading the other day but apparently they put a monumental effort into power supplies

the newer wadia 321 looks uninspiring to say the least

[rickmcinnis]

Just a note of appreciation to jkeny for his best capacitor discovery.

Not to forget his acolyte, nige2000, who brought the message to those who would listen ...

[nige2000]

Just a note of appreciation to jkeny for his best capacitor discovery.

Not to forget his acolyte, nige2000, who brought the message to those who would listen ...

i came in through the side door,
after fran found linear supply was better to power a pico psu,
multiple linear supplies were all the rage until i brought in two 80-100 amp/hour sla batteries to power a pico
3 alkaline batteries in series to power the os
the aim was then to get picoless status (no switch regs pre mobo)
lifepo4 was the prime candidate for the 3.3v supply as i had a cuinas i liked the speed and noise floor
it was soon realised that lifepo4 had superior qualities and then was used throughout

the little bit of electronics knowledge i have is based on what ive learnt from fran and Jkeny (mostly dac stuff)