Modifying the Musical Fidelity X-10 v3

Interestingly enough, there really aren't too many audio buffers out there on the market. Typically a buffer will help match the high output impedance of a source such as a cd player or preamp to the low input impedance of an amplifier, especially solid state. They can also be used, in the case of the Musical Fidelity X-10, to add the warmth of tubes to a solid state source like a DAC (digital audio converter).

Musical Fidelity sold these half width components as a series. You could get a miniature CD transport, the tube buffer, the DAC and headphone amp and stack them all up :) Below is a photo of someone's system showing what the collection could look like.

Someone's nice Musical Fidelity System

The Musical Fidelity v3 series is no longer being produced, and hasn't been for a few years now. I owned the DAC for a time, which was very good but lacked musicality and depth in my humble opinion. The most appealing component is the aforementioned tube buffer, mostly because there really is little competition in the price range for an equivalent product. The only other tube buffer I know of in this price range is the Yaqin CD1, CD2 and CD3 which I have not tried yet. The impressions I've read so far range from middling to very good.

Going back to the Musical Fidelity X-10. The circuit is based on two miniature pencil-sized 6112 tubes with leads that go directly to the board. That means that you can't replace them unless you're willing to solder ;) Add this to the fact that the unit does not have an on/off switch and that they haven't been produced for years and you'll find that most of the units in circulation could probably use a new set of tubes. Pricing fluctuates wildly, and is typically based on whatever the item was last listed for on Audiogon. You'll typically see them listed for $125 to $250, or selling on eBay for $80-120.

A Stock X-10 v3

In the interest of adding some warmth to a solid state CD player. I picked up a pair of units on the cheap, each to modify a little differently. Opening it up revealed relatively generic parts like Jamicon caps in the power supply and signal path. I decided to replace all parts of interest with some more audiophile-type parts from PartsConnexion. I also noticed on the back side of the board that there was some discoloration from heat near the MOSFETs. I saw that user PinkFloyd over at RockGrotto Forums had installed heatsinks to dissipate some of that heat. He also sells parts kits to modify nearly all of the Musical Fidelity X series components (no affiliation). I opted to go my own route, as usual ;) Below are some photos of the two units, please click to enlarge.

Unit 1, Note the red Black Gate non-polar caps

Unit 1

Unit 2, Note the large Mundorf non-polar caps mounted on standoffs

Unit 2

Unit 2

Unit 1 features:

• Nichicon FineGold Caps to replace the Jamecons
• Black Gate NP and power supply caps
• Kiwame and Takman resistors in signal path and PS
• Neotech PCOCC Copper in Teflon hookup wire
• GE NOS tubes
• Heatsinks on the MOSFETS

Unit 2 features:

• Nichicon FineGold Caps to replace the Jamecons
• Mundorf Non Polar Caps
• Elna Silmic power supply caps
• Kiwame and Takman resistors in signal path
• Neotech PCOCC Copper in Teflon hookup wire
• GE NOS tubes
• Heatsinks on the MOSFETS 

Both sound quite a bit more detailed than stock, with notably more separation. The tubes seem to make most of the difference. The non-polar caps, I'd imagine, would be the next most important.

The Fine Print:

Please remember that modifications can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties in this thread can not / will not be held responsible if you attempt a posted modification and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and mods, if performed improperly, can be a fire hazard. Please keep this in mind.