[DBaldock9]

Anyone know if this device can operate without the battery?

Yes, the F1 will work without the battery connected.
Although, when I've run mine without the battery, I was using a USB Charger that can supply 2.1 - 2.4A of current.
You may end up with audio distortion if you use a low current power supply (like a 0.5A PC USB port).

 

[DBaldock9]

For those who have a Walnut F2, on my modified model (op-amps replaced with MUSES-8920E, Differential Line Drivers replaced with AD SSM-2142SZ), I was able to play WAV files of my CD .flac rips, for a little over 6 hours on a battery charge today, using the Balanced output, driving various IEMs.

 

[prionsarebad]

For those who have a Walnut F2, on my modified model (op-amps replaced with MUSES-8920E, Differential Line Drivers replaced with AD SSM-2142SZ), I was able to play WAV files of my CD .flac rips, for a little over 6 hours on a battery charge today, using the Balanced output, driving various IEMs.

I am thinking of getting the F2.

Will there be any issue, as far as you know, using it as a DAC/amp on my phone and UAPP?

Also, in your opinion, what are the best, cheap op amps to roll with on the F2? I prefer a rich, analogue sound, v-shaped.... Old school

Thanks!

 

[DBaldock9]

I am thinking of getting the F2.

Will there be any issue, as far as you know, using it as a DAC/amp on my phone and UAPP?

Also, in your opinion, what are the best, cheap op amps to roll with on the F2? I prefer a rich, analogue sound, v-shaped.... Old school

Thanks!

I haven't tried to use the F2 with my phone, since my LG V30 has a much better DAC chip in it.
As a USB DAC, the F2 only supports playing 16-Bit / 44.1-KHz or 48-KHz WAV or MP3 files.

While it's been discontinued, there appears to be one LME-49720-HA - Dual Op-Amp (TO-99 round metal case) still available from the USA on eBay -
https://www.ebay.com/itm/LME49720HA...ise-OpAmp-Metal-case-LME49720-HA/174286005296
If not, the LME-49720-NA - Dual Op-Amp (DIP-8) version is more readily available.
Another Op-Amp with good Bass response is the OPA-1622 - Dual Op-Amp (VSON-10) on DIP-8 header.

 

[prionsarebad]

I haven't tried to use the F2 with my phone, since my LG V30 has a much better DAC chip in it.
As a USB DAC, the F2 only supports playing 16-Bit / 44.1-KHz or 48-KHz WAV or MP3 files.

While it's been discontinued, there appears to be one LME-49720-HA - Dual Op-Amp (TO-99 round metal case) still available from the USA on eBay -
https://www.ebay.com/itm/LME49720HA...ise-OpAmp-Metal-case-LME49720-HA/174286005296
If not, the LME-49720-NA - Dual Op-Amp (DIP-8) version is more readily available.
Another Op-Amp with good Bass response is the OPA-1622 - Dual Op-Amp (VSON-10) on DIP-8 header.

I also have Lg V50, David, but the reason i have interest in the F2 is because my audiophile guru (who has a lot of expensiver gear, and experience) says that, despite the quality/price etc, the F2 is one of his favourite dac/amps (of any price) because it has an old-school analogue sound that is difficult to get these days. I'm not sure whether he has swapped the op amp or not.

Just this last week i performed my first op-amp roll on my Topping NX3S, and at his recommendation chose the old-school 5532p op amp.....and to put it mildly i've been blown away by what a $2 op-amp mod can achieve (the screwdriver i needed cost $5!!!!).....v-shaped, musical, just a delight!

 

[ricesteam]

So, the USB port on my Walnut F1 broke and I failed to repair it. While browsing for a replacement, I noticed the Walnut amplifiers have been completely discontinued. Does anyone know what happened to them? Are they coming back? What are some budget alternatives? I like to be able to roll OP amps.