Jadis JA80 Tube Monoblocks w/Sound Anchor Stands - Made In France

Free Shipping on *ALL* Electronics (Excluding Speakers, Contiguous 48 US States Only)

General:

Amazing sounding set of tube monos from Jadis.

If you've been eying our set of remarkable 845 Jadis monos but need a bit more power, this might be the perfect solution.

These are cosmetically near perfect and will come with matching sound anchor stands that are a super match for getting them off your floor.

The current model of these monoblocks retails for over $25k.

Configured for 8 ohm output.

Technical Note:

Cathode resistance was changed from a stock value of 3.3 ohms to 4 Ohms by an authorized Jadis service center to allow use with 5881 tubes prior to arriving at SkyFi.

Our testing was performed with KT88 tubes and the bias level achieved with the altered resistors was acceptable for proper performance.

Both amps tested to 60W of clean power per channel before clipping. The original owners manual claims that these are 80W amplifiers, but all of our searching indicates that true RMS power is 60W.

Shipping Note:

Due to the weight and fragile nature of these tube amplifiers and stands, these will ship freight anywhere within the lower 48 US States for a flat $600. This figure includes full insurance, and this freight charge will be added during your checkout.

These are also safely packed and palletized to ship worldwide, just contact us for a quote. Pallet is 240 lbs with dimensions of 40" x 48" x 33" (W x D x H).

Recommended Cables:

Select Series KS1016 Copper RCA Analog Interconnects (Pair) - WBT Connectors

Summit Series Monocle XL Speaker Cables (PAIR)

Summit Series BiFocal XL Bi-Wire Speaker Cables (PAIR)

Summit Series - PK10 Palladian Power Cord (10 AWG/Gauge)

The SkyFi Testing Process for Tube Amplifiers:

We start with a visual inspection of all internal components to make sure that there are no signs of heat stress or damage. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect resistors and other passive components for signs of overheating. If tube arcing has occurred in the past we can usually spot discoloration on the output tube sockets. On vintage units we often spot check select capacitors for value and ESR.

If the amplifier passes visual inspection, we move on to a full test of all of the tubes. We use an Amplitrex AT-1000 Tube Tester which is capable of testing both emission and Gm with a high degree of accuracy. We document the results of each tube and replace any weak or suspect tubes before proceeding. When we power on tube amplifiers for the first time we usually use a variac and current limited AC supply and slowly raise the voltage up to nominal mains level while monitoring plate, screen, filament, and negative bias supply voltages where applicable. If everything is in order we feed a low level test signal into the amplifier’s input and monitor its output on an oscilloscope across an 8 ohm dummy load. At this point we are just looking to verify basic function and confirm that the output transformers are not damaged. Once we have verified that the amplifier is safe to operate, we connected it to full mains power. For fixed bias amps we set the bias to manufacturer spec. For cathode biased amps we monitor the plate to cathode voltage to determine if the output tubes are operating in a safe range. Once the output section is verified we move onto bench evaluation.

We start by feeding the input of the amplifier with a low level 1KHz test signal, slowly increase its amplitude while monitoring the amplifier’s output on an oscilloscope for signs of noise, clipping, distortion, or improper channel balance. We continue increasing the signal level until the amplifier reaches clipping. At this point we take an output power measurement and compare it to the spec sheet of the amplifier to verify proper performance. We finish off the bench evaluation with a 1KHz square wave check and a 20Hz to 20KHz sine sweep to assess the amplifier’s frequency response characteristics. This battery of tests will usually reveal if the amplifier has any issues that need further attention.

Before the device leaves the bench, we perform a listening test with actual music using a variety of preferred test tracks. Our benches are outfitted with familiar monitor speakers which help us identify inconsistencies that will not always show up on our test gear. The main things that we are listening for are hum or noise with no signal present, proper center image, clicks, pops, or any other obvious undesirable audio characteristics.

If the unit passes all of these tests it is moved to our long term testing rig where we simulate real word operating conditions for 6-8 hours. For tube amps we like to run this test at least twice. This allows us to monitor the unit for signs of thermal runaway or intermittent issues that only crop up when it has fully come up to temperature. We find this step to be essential, especially for vintage units.