Musical Fidelity X-Pre Fiddlings

[J. R. Todd]

Hello there everyone.

Wasn't quite sure where to put this - Tubes? Solid state? Parts? It's a hybrid indeed.

I have a Mk. 1 Musical Fidelity X-Pre in the following configuration:

SPDIF (PC) -> Beresford TC-7510 -> MF X-Pre -> Arcam Alpha 8P -> HD595

Now, I know this set up is not absolutely perfect but I'm fond of it, and it was the setup that fate decided for me. The Arcam certainly has enough oompf to power headphones. At line level, I think it'd pop 'em, hence the X-Pre. Though I'm sure it's not perfect either, I'd like to assume for the moment that it's neutral. All in good time.

The very first thing I did was to order some of the very fashionable 6H23P-EB ex-Soviet tubes, which sound lovely: very detailed and a little harsh/bass light to begin with, but mellowed out after a few days to present a very nice sound.

Next came a replacement for the quad op-amp. I obtained an Analog Devices OP 467. On paper, it looks rather good, including a slew rate about twenty-five times greater than the already good-sounding MC 3307.

It sounds very, very different. Of course, I'll give it a good few hours to run it. It's a lush (to me, I'm not expert) sound - warm. A more analogue sound? That's not to say that the details have gone, they're just more recessed; if anything, it's far more detailed. The MC sounded etchy in comparison, but I think seperation was better too. I'm not complaining, I'll just have to decide if I like it...sounding good so far.

Anyhow, fiddling being the root of many joys, does anyone have any other suggestions for possible choices? Browsing the forums, the following suggest themselves:

OPA4227
OPA4228
LM4562 Quad - is this the LME49740NA?

I also hope to upgrade the power supply and other caps eventually. I've got some Panasonic FCs to that end, but I'd rather fiddle with op-amps for the moment and then screw it up with my bad soldering later.



P.S. If anyone is searching for lots of information on the Musical Fidelity Can series - X-Can, X-10D, X-Pre - I'd advice a trip to the Rock Grotto