#73 Focusrite Saffire 6 USB 2.0 teardown

Initially, i was thinking of getting and modding a Scarlett 2i4 to use as an updated and more flexible in-ear headphone amp, to replace my aging modded M-Audio Fast Track (incidentally, the subject of the very first article on this blog). I even ended up with two 1st gen ones as well as two 2nd gen ones. But recently, i came across yet another deal i couldn't pass up - a Saffire 6 USB for a nearly ridiculous 36e, shipped(!). Virtually the same structure as the 2i4's, but i can definitely get more money (back) from reselling those, and keeping the Saffire. That, and i had come across instructions for a mod to the Saffire 6, to enable stand-alone operation.

Unlike the later Scarletts, there's a few more screws to remove before being able to pop the cover off. But then again, since this is virtually from the same generation as the other Saffires, the Pro 24 and Pro 40, it's no surprise the style of enclosure is also similar. 

Perhaps unsurprisingly, even the insides resemble its relatives. Perhaps not the most cost-effective, what with all the cables and connectors and crimping necessary, but hey, i guess it was during a more generous(?) time for Focusrite. 

The power supply section is a bit of a departure from what we've seen before, or after, depending on how you wish to count. The phantom power is supplied by a tiny Texas Instruments LM3488 boost controller, driving an International Rectifier / Infineon IRFR024N MOSFET. In case this looks familiar, the same setup is used in the same role, in the Scarlett 18i8 (1st gen, at least). Why reinvent the wheel, right?

 Nearby is a pair of also-familiar OnSemi NCP1521B buck converters, providing the 3.3v for the digital side, and the 1v for the Xmos core supply (as seen in the Scarlett 2i2).

Here's where things are looking a bit different - there's no boost-converter and/or inverter, to provide a bipolar supply to the opamps on the analog side. On the other hand, here we have a pair of Microchip MIC2505 low-dropout regulators, interestingly enough. The above-mentioned M-Audio Fast Track had a similar setup - go figure...

Moving on to the rest of the board, coincidence or not, we come across the same Xmos XS1-L8A-64-TQ128, also found in the later Scarlett 2i2. Same with the SMSC / Microchip USB3343 interface and the Microchip PL611 clock generator. The firmware is stored in an Adesto AT25DF041A 4Mbit / 512Kbyte flash memory.

Perhaps unsurprisingly by now, there's more deja-vu in store. Just as in the Scarlett 2i4 gen2, handling the audio conversion is a Cirrus Logic CS4272 and an AKM AK4384ET. 

But on the analog side, we encounter differences yet again. Granted, the JRC NJM2122's are nothing new by now, nor are the OnSemi MC74HC4066 or Texas Instruments SN74HC4066's, but interestingly enough, all the other opamps are Maxim Semiconductor MAX4477's. Since these are specified for a maximum supply of 6v (in total), that would then explain the two low-dropout regulators in the power supply.

And that about covers the teardown side of things. I think i'll save the modding for another article, and i'll probably include a (partial, at least) re-cap, because CapXon & Jamicon. Especially since i'll be keeping this, and i'd kinda prefer to save me any headaches down the line.