@dabassgoesboomboom Thanks so much!
1 Like
Not a problem. I would lean to the Mophie though, over the one you linked - theyâve been making battery banks for a long while. I think Apple Stores sell Mophie, so I assume Apple are happy with them too. Just for feel good factor - I donât have any facts as to why one brand is better than another.
I heard that power banks has switched circuits inside to get correct voltage, so its not a linear power.
They sure do.
But it may be a choice of the lesser of the evils⌠powerbank switching regulators (which by the way, is followed by ultra low noise linear regulators inside the DAC unit itselfâŚ) vs linear PSUâs with mains power coupled leakage current loops and mains coupled RFâŚ
The powerbank has the advantage of being de-coupled from mains RF and AC leakage current loops⌠but only if you unplug itâs charger from the wall of course during listening, otherwise the powerbank is mains power coupled and you defeat this potential advantage entirely.
Best to trust your ears in the end, of course.
Thanks for the advice. I have to say Iâve been pleased with he quality and value offered by the MassDrop products (two different headphones) Iâve purchased. Your advice is likely a safer choice. Iâm still thinking it over.
1 Like
I experimented a little, and tried batteries as power, one 6v 12ah for the Pro-Ject DAC, and 4*1.2 rechargeable AA batteries for my transport (Allo USBridge). And I have to say I am very impressed by the result, far better than the old iFi iPower 5v I was using. The step-up in sound quality was very noticeable.
They batteries last more than one day, so charging them at night. And the lead battery is sealed AGM so safe to use indoor (or so I hope) 
The battery is not as big as it looks on the picture, its about the size of a thick pocket book.
The only problem: I am unsure how the DAC will handle 1 - 1.5V over spec in the long run. Have to wait and see I guess.
Here is a picture:
1 Like
Does it come with charging adapter? And what cables do you use to get it from the battery leads down to microUSB for the DAC? Can you share some photos. I was interested in this same Panasonic for something else.
Iâd measure itâs Vdc output if you can - in case itâs output is greater than 6Vdc. Just to be safe.
No cables came with it, I bought a 5.5x2.5 mm DC connector with cable, and a DC adapter -> micro USB, and then the 4.8mm clips that fits the battery connectors. Also bought a charger.
VC output is about 6.5v when charged, but the DAC seems to handle it. If you buy one, it would be interesting to hear a comparison with a good LPS (I only used iFi iPower 5v before and the battery sounds much better than those).
USB power specification allows up to 5.25Vdc.
Are you sure the DAC isnât switching to USB bus power because your SLA battery is over the limit?
If you unplug the USB cable, does the SLA battery still power the DAC?
Yes, I use the UpTone A>B connectors which have a âcut powerâ switch which I turn off (it needs to be on when detecting the DAC, but then its ok to turn it off). So the DAC only gets power from one source.
This battery business for the DAC and Allo USBridge started as a little experiment cause I was bored, but the sound improvement is big enough that I will keep using it even with a little extra work to charge batteries at night.
1 Like
Iâve discussed PSUâs with a couple famous DAC designers. Their benchmark is always to compare their DACâs PSU section design/performance when connected to AC mains power, with performance powered by a car battery.
SLAâs have lower output impedance than any linear PSU on the market. In addition to being mains power de-coupled of course.
No surprise itâs the best SQ youâve had 
But I am just as surprised as you that the DACâs power input can handle over 6VdcâŚ
Which model charger did you get? Does the battery itself have any electronics to indicate low power (it needs charging)? Or is it just a basic SLA in that regard?
No indicator on the battery, but the DAC shuts down at around 4.5V so thats a good indication but I have a multi-meter so can measure the DC on the battery (right now i have played it for 1.5 days and its at 5.1V so going to charge it tonight).
1 Like
Cool! Iâll pick one up when I get a chance.
Loaded the battery when I slept, it has 6.7V fully loaded, but the DAC seems to work fine (and sounds very good). The only thing I notice is that the DAC gets a little warmer than usual, I guess some internal voltage regulators has to work harder.
1 Like
Stick an LDO between the battery and the DAC; these operate with minimal input to output differentials, so 6V to 5V is achievable. A few quid could save your DAC in the long run.
Something along the lines of this âŚ
1 Like
That might be a good solution, but I think I will run it as it is for now since it seems to work. The DAC gets warm but not hot (a good temperature for warming your hands). And I have been thinking of upgrading, and if it breaks I can explain to my wife that I have no choice but to upgrade since its broken
1 Like
What does she do to achieve the same ?
She says: âIm going out, taking your credit card with me.â
And I reply timidly: Ok
2 Likes
Do you know what type of cable would be suited for connection between battery and DAC? A thin silver plated copper cable? What stat to focus on, resistance, capacitance, �