Schiit Fulla 2 Released

Bottom line, if you don't know:

1. The capability of the output stage in terms of current output
2. The inherent output resistance of the output stage (without feedback applied)
3. The capability of the topology to swing the rails (or not, or how close)
4. The capability of the power supply, both in terms of current and voltage rails
5. The effect of any current-limiting inherent in a chip output stage, and/or...
6....the effect of any current-limiting done on purpose to a discrete output stage,

you won't be able to predict how it will perform into any load with simple linear extrapolation.

 

Ok, next time ELI3 - this should consist of hand gestures and cooing sounds only.

J/K, the Ohmic law reminder does help a bunch. But it seems like the implication is that the load for 300ohm measurements should have been chosen to accept more power? That we aren't actually seeing its full power rating because "Higher impedance loads were never current starved"?

Thanks for explaining that, it was rather mysterious trying to derive some rule for this.

 

Pure awesome, thanks!

 

Here's my ELI5 shot:

For the climb up from low resistance, you are current limited, i.e. if you hooked up a 1 ohm load to your Vidar (with no protection circuit) and cranked the volume, you would draw more current than your circuit breaker can handle and blow a fuse or burn down your house. So engineers put limitations on the power for low resistance loads so this doesn't happen. Similar thing happening with Fulla 2 at 16 ohm on USB power.

Once you hit the normal operating region, V^2 = PR = constant, so power drops with higher resistance ("200W RMS per channel into 4 ohms, 100W RMS per channel into 8 ohms"). If you do the math for Fulla 2, 32*360mW = 50*230mW = 300*40mW ~= constant.

 

@ultrabike - don't forget that it's 3.46 Vrms. The p-p voltage is 3.46*sqrt(2)=4.9 Vp-p. That's pretty close to the +/-5V rails.

Edit:

Doh! it's 9.78Vpp! It's more accurate to say +/-4.9V or just 4.9Vpeak

 

I bought the Fulla 1 as a stocking stuffer when it first came out and it was great. This is even better since it sets the stage for upgrades. All these are easy next steps:

-get an amp(Vali 2) connected to the line out
-get a better DAC or turntable to feed the line in
-get powered speakers connected to the variable line out
-get headphones that you couldn't use with the weak headphone jacks in laptops

And of course I think people with an iPhone 7 would certainly appreciate this. Not only because they get a jack but you can't underestimate an analog volume knob.

 

Yeah, the 5V is DC whereas the 3.46V is AC. I just think the the peak to peak voltage gives a clear indication of the limits with regards to the rails.

 

This really looks like a great product. I was looking for a good, portable source to feed both office amp and desktop amp, using the same laptop as source. At the same time, I was hoping to use the same source as a portable dac/amp. Sure... I could buy a fiio product. But it seemed like the only SABF recommended product would be a GO device. Or maybe a tentative Dragonfly recommendation. This is a neat competitor that adds options. Can't wait for reviews.

 

Looks real nice, but I have no use for it (Which is good, as I also have no money for it).
Already have my GO450 on headphone duty, and my magni 2 on speaker duty.

 

Haha, I remember when the LMH6643 was popular during the iBasso opamp rolling days.

 

I reckon Schiit has absolutely nailed the feature list on this. Everything in this form factor is a massive exercise in compromise, and Fulla 2 looks like the best sort of compromise to me.

I've been reluctantly using a Fiio E10K at work for years because there was very little else that could offer USB power + line out + real pot at a decent price. Now I actually have a legitimate upgrade option. There's definitely a market out there for guys who want something cheap to run their M50s but don't want anything that's going to embarrass itself when they upgrade to better system.

 

"Not just a dongle anymore.." - very nice. This seems like quite a power-packed little desktop unit. I suspect that I am looking for a use-case just because it's so damned cute. However, that's not hard- I could find a use for a tiny desktop DAC/amp for my work machine, to replace the ancient USB sound card that I use to drive headphones at the moment. Fulla 2 looks smaller, cuter, and probably better at driving headphones. Not having the extra channels, inputs, mic preamps and so forth might actually be an advantage, less scope for ALSA to go special, fewer devices to randomly reorder on boot.

 

If Fulla2 is similar to Grace M9xx, will it give more power by connecting both 6 & 7 so power comes from dedicated DC power (#6) and only data comes from #7?

 

Nope...see @schiit's reply earlier in the thread.

 

Thank you. I must missed it.