I would suggest SMSL SU 1 DAC with Topping L30 II ( SE only no Balanced connections ) I`ve actually used other Topping and SMSL Dac Headphone amps like the DX3 Pro & D12, none of the mid range HPA & Pre amp with built in Dac`s I listened to could touch the mentioned combo as far as purity.
The Topping L70 I have not listened to it`s double the price of the L 30 II, but L70 has balanced connections. The L50 as no pre amp mode only a pass through so it only a HPA.
Worth looking over the spec`s of the L30 II and L70 to compare, you just need to also purchase a DAC but no need for volume control. Heads up the SMSL SU1 is no compatible with cellphones it needs more power and USBC Y splitter will not work with 99% of USB-C cables I own it and even reached out to SMSL to ask for firmware upgrade to solve this issue but later realized it`s a USB-C cable issue...
I was able to get it to work using the Fosi Audio DS1 USBC cable with a Y splitter the catch is I was not able to find any other cable that would work other than the Fosi cable I tried a few out of curiosity even made thread on ASR that nobody was able to explain why the Fosi USB-C cable was the only one that works.
Bonus is you can order the Fosi cable separately from the DS1
BUT you need to email Fosi Audio this request as they don`t yet sell them in there selections. I asked them to use Amazon but nothing so far.
If you ordered one you could use the SMSL SU1 with a cellphone using a USB-C y splitter
worth mentioning the other USB-C cables were similar in length to the Fosi DS1 USB-C cable and none worked.
Yes AP mastering did compare the Fosi ZH3 alone side other more expensive units and praised it for it`s value for the money spent.
He didn't have any Topping or SMSL tests only price comparisons. He also said the A70 pro was very expensive compared to the Fosi he had in his hands as is has a built in Dac but didn't mention the less expensive L70 that is in the same high end league as the A70 Pro it appears they are almost twins.
He did not do in-depth comparison's on Digital volume controls vs Analog volume controls in that video.
Some devices with Digital volume raise the bit count on a 16 bit file to 32 bits but this does absolutely nothing to the files information it`s just sales fluff and miss information causing much frustration for millions of people who would have been willing to spend money.
Ap mastering has videos explaining the bit up conversion in depth.
I can`t say for 100% certainty but I seem to remember him stating that when you take the original 16 bit file and raise it to 32 bit then turn down the volume there is still the same loses.
The DX3 pro is very high quality Audio and it appears the Fosi ZH3 is no slouch ether so it boils down to are you satisfied ? I was but my curiosity and high interest in purity pushed me to search that will only have no doubt cost more money so if your happy, be happy
