Quicksilver MX-190 Vintage and Rare Tube Amplifier

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This is a rare tube amplifier from Quicksilver from the early 1980's.

The MX190 can deliver 95W per side (we actually got a bit more on the bench), which makes it capable of driving most vintage and high efficiency speakers.

The design features replaceable driver cards which let you choose what mode to run the tubes in. This model is equipped with the pentode cards.

Biased, tested, and certified to be working as it should.

This was built in the 1980's and would EASILY cost about $10k in todays dollars to match the parts quality and design.

In very good condition with no major dents or scratches.

Pentode Input Boards Installed (12BY7A & 7308)

Service Notes:

• RCA Jacks Replaced
• All tubes tested and verified
• Input board adjustments completed to service manual spec
• Output tube bias set

7308 = Amperex Gold Pin
12AY7 = Channel Master
EL34's = Vintage Mullard

MS190/MX190 Stereo Amplifier
95 watts per channel
Manufactured 1981-1985
Retail Price $2000-$3000

Quicksilver MX-190 Owner's Manual

The SkyFi Testing Process for Amplifiers (Tube):

We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and tubes are inspected for signs of stress overheating or cracking.

We then power up the unit carefully and run a simple 1k sine wave while monitoring the output on an oscilloscope for signs of distortion or noise. Finally we run the amplifier to its full rated power into the appropriate resistive load provided by our Sencore amplifier tester. If there is an issue, it will usually be noticeable at this point. If it all looks clean we will often test for THD (Total Harmonic Distortion) measured by our Keithley distortion meter, and compare it against the original manufacturers specifications. The amplifier the remains powered on to "burn in" on our test bench for a few hours to make sure there are no heat related issues. If there are balanced inputs available they will also be tested.

We also test all tubes for output gain and leakage on our calibrated B&K 747 tester against the original manufacturers specifications. If needed, the tubes will be replaced from our vast NOS (New Old Stock) vintage or modern inventory.

Final testing involves pushing actual music thorough the amplifier. We've learned over time that some issues are only noticeable to a trained ear while listening to familiar source material. Our test bench has reference vintage KEF speakers that we're very familiar with which quickly reveal any discrepancies. Some amplifiers will then move into our listening room where they are tested with our in-house reference speakers of choice.

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.