Hey, all. So you guys have intrigued me. I started out buying an EcoFlow River Pro with the extra battery thinking I'd run my headphone amp and DAC off of this. Well there was noticeable distortion. Like waves of fuzzy distortion with my amp. I was thinking maybe my amp's transformer was too close to the inverter so I moved things around and no change. I do not recommend EcoFlow products, this distortion completely ruined soft passages in music and made it unusable for YouTube videos or Twitch streams due to too much silence. Here you can hear the distortion, I recorded it with my miniDSP H.E.A.R.S. There ongoing noises is my microphone picking up random noise (not sure what) and also because I had to amplify the audio file in order for you to hear the distortion. What you're listening for is the periodic distortion that happens every second or so. You can hear this clearly when music is quiet.
So fast forward to receiving the Bluetti EB120 (1,200Wh Lithium Ion battery bank). This is an older generation battery bank compared to the AC300 previously mentioned, afaik. No distortion with this unit, whisper quiet. As far as sonics (when music is playing) I think EcoFlow and Bluetti are on relatively equal footing, but the Bluetti might be a smidge better (bass less wooly and treble more extended and textured). Actually the bass when amp was powered off the wall was considerably more impactful and cleaner than EcoFlow River Pro, ime, but I have not yet compared Bluetti to the wall, I've only had the Bluetti for listening for maybe 30minutes so far. Btw, I have an iFi iPurifier for AC mains active noise cancelling on my audiophile wall outlet (no other power conditioning).
Then I found this thread. Gosh darn it... I've been spending money on pre-made units and of course DIY sounds better as is always the case it seems (DIY'ed headphones, DIY'ed interconnects, etc.) Seeing as my Bluetti is still within return window I am currently in contact with an electrician who is researching how to build a battery bank to code. He's never done anything like this so he is not 100% sure on all its in's and out's. I would wire it all up myself because it seems pretty straight forward, but I'd rather have it done by a professional. This electrician does electrical work on the side, his main job is fire fighting, so he's very safety oriented. He will make sure it's 100% safe for my setting.
This all being said, I do NOT need a Giandel 5000W inverter... Not even close. I need maybe 300W max, but I will probably splurge for 600W or 1,200W just because of my Watthour requirements. I have bought an Amperetime 12Vx100Ah battery. This will suit my needs fine. I need to power a DAC (25W max while powered on, 16W while off due to analogue board never turning off, only digital processing boards turn off unless unplugged from the outlet) and a 50wpc speaker amp which I use for headphones (35-40W draw not matter what as far as I can tell) making it 60-70W max draw for my system. So @70W the 1,200Wh Amperetime should give me 13.5 hours of runtime minimum assuming 80% inverter efficiency.
I have contacted Giandel asking for THD numbers on their various products and they reported that ALL of their inverters are rated for <3% THD and EMI suppression irrespective of model. So, at least according to them, and assuming THD and EMI are the important factors here, all of their inverters sound relatively the same. Their 600W inverter has dual removable fuses on the unit. I see no fuses on their 1,200W inverter, so I am hoping the electrician will allow me to buy the cheaper 1,200W unit (despite 2,400W surge capability and only 1,400W max battery output at full charge) and I can forego having to buy audiophile fuses for 600W unit. I will report back how Aperetime + Giandel compares to Bluetti EB120 which already seems fairly capable and very good sounding.
Btw, as a side note. I noticed Amperetime batteries were "un-returnable" through Amazon, yet on eBay the genuine Amperetime vendor allows returns, seller pays return shipping (free returns). Also it was cheaper by $10 through eBay with a vendor supplied coupon. Just an fyi for those looking into it. If you doubt the validity of battery powered, pure sine wave inverted hi-fi equipment then buy the battery from eBay, buy the inverter + charger from Amazon and you basically have 30 days to build and try everything out with 100% moneyback guarantee.
Cheers guys, thanks for all the info. Will be interesting to make these battery + inverter comparisons for myself. Hoping you're all correct about Giandel! Hopefully we can get some comparisons between inverters in the future, maybe there's cheaper or even better sounding options out there?