I can't comment on a comparison PC, but I can say that any Focusrite model I've ever used sounded great - in both pre's and converters.

Can you explain a bit why you are thinking of changing up?

I'm gonna be honest man, as a person who is considering an 828 for a basic drum strip, I'm very weary of squished in rack units, I'd wanna be sure they sound the same enough, before I departed w gear that I liked. Just to make sure. I don't know that much about circuit design or even electronics beyond the basics, but I just don't like the idea of having to modify a well liked design to fit a rack space requirement, between proper cooling ventilation, and whatever else, I think tome equipment takes to it better than others.

This is one of the reasons why I didn't get an la-610, becuase the compressor side is a modified cousin of an la-2.

That said, something like the isa I wouldn't expect to sound that different, or bad, just becuase it is fairly neutral in general, and the character is probably more from the transformers than any other component, so if they're in there, it's probably a good buy.

As far as the converter option, it's kind of pricey, and while it's probably good, I wouldn't expect anything special, or we all woulda heard about it by now, and it came out w the last generation of converters did, so if it were me, unless it was a crazy deal, or your out of analog ins, I'd be putting that loot towards a new interface, or standalone more state of the art converters of higher quality.

I actually have the focusrite liquid saffire 56 as main interface. I like it because it as the direct monitoring fonction that let you mix head phone mix without even going into the computer, so 0 latency. Of course the preamps are somewhat ordinary. At the time I got it with an octopre and recorded an album for a local band here. It was ok but not enough 'pro' to my taste.

So I got a ISA two and a Mytek AD96. The ISA sound very good on guitars and drums and some vocals.

I wanted to replace the octopre, so I sold it and chose the 4-710 thinking it could give me various sounds and I also could use the converters to add more pre and use the adat connexion to send it to the saffire 56.

The 4-710 sounds goob but it doesn't have the power of the ISA and it doesn't have the tube sound I was expected. So I got a used LA-610, now thats a tube sound !! ;)

So to complet my amount of channel I faced this dilema. Do I buy a second ISA Two to have 4-710 and 4 ISA (through the converters of the 4-710)
and use the AD96 for the LA-610 OR I sell the 4-710 and the ISA and get a ISA828 ?

Altought the 710s are very usable, they need attention when setting up the gain staging.
They are noisy if you push the output too much (past 7-8) and most of all they are very easy to overdrive so you need to be very conservative on the gain. Still I like them, the pre sound good and the comp is a nice addition.

What leads me to think about changing is that when I setup an overexited band that wants to record right away. It needs a split of a second to fail with the 4-710. With the ISAs, they sound good all the time. If you don't peak the converters, your safe !

Writing this post, I realise that one test I didn't do is to record with the 4-710 while slaving the clock to the AD96. ( if it can even change the sound.. ) Mytek as a reputation of having a solid clock...
I'm gonna try that right away ;)

I think you'd find that there are a lot of pro's like yourself who like to have a variety of "color" options at hand, so whenever a particular situation calls for it, you can either go totally transparent, or look at the warmth of a high voltage analog channel - or - use a tube stage to obtain that particular coloration as well. We both know it's very much a song /performance dependent choice; sometimes a tube sound is just what you are looking for, other times not, and you want that "pristine" sound of a nice transparent pre, and still other times, you might be looking for that "Neve-ish" sound.

While I don't have a "big bucks" tube pre, I do have an Aphex model 107/ rack mount 2 channel tube pre; I suppose I would put it in the same caliber and ballpark of the Art Pro MPA, in terms of sound and pricing.
I didn't buy the one I have - at least not exclusively - it was included in a pallet of used audio gear that I bought at a local salvage store about 10 years ago. It's not bad... it's certainly not a Neve, not by a long-shot, (It's not even a Presonus) but it's not bad. It gives "that" tube coloration that sometimes works for "gluing" tracks down.

I also have a pair of cheap ART MP Tube pre's that I like to use on guitar, especially for front-loading a solid state amp, I think they warm things up considerably.

I am not suggesting you look at either one of these, but I am suggesting that whatever you end up with... my advice - from one cooker talking over the fence to another - would be to try your best to allow yourself as many different options as possible - but to still maintain a caliber and level of fidelity that you've grown accustomed to. Cheap isn't going to work for you anymore, you're reaching a higher level now. ;)

d/

It would certainly be safer and less expensive to keep the 4-710 and just add a second ISA two.

You got me right, Donny! I've been blessed or damned to have a taste of how different and seducing could be the sound of high end gears.
I'll never want to go back to my old Delta 44/66 cards ;)

I can add that the UA and Mytek clocks seem to be near to equal, at least to my humble ears... (thanks to my morning tests)

I thought, I'd give you a follow up.. I decided to keep everything and add a second ISA Two.
So I'll be with 4-710, 4-ISA, A LA-610, A DBX-576 (Which I ordered new tube. I'll keep it until I get money for another high end pre to replace it..)