New JADE DESIGN GOALS
AUDIO CIRCUITS
The JADE has been upgraded with the analog circuit and power supply taken from the Pearl. In addition a new selector circuit board mounts to the back of the input RCA connectors and now uses relay switching for all functions. Front panel selector and tape monitor switches now control the relays which handle the routing of the signal. Previous coax wiring running from the rear to the front selector & monitor switches has been eliminated, reducing the length of the signal path while eliminating much wiring. This also enhances the life expectancy and reliability.
As a consequence the Pearl name has been discontinued and the new product will retain the name of the Jade. The new Jade unit will be available with either the 24K gold plated or black nickel finish on the precision machined brass knobs
Our previous goal in designing the PEARL was to duplicate the sound of the Opal in a one box configuration. Our new goal is to give the new JADE the sound of the Pearl at a significantly reduced cost. We were able to do this by reducing the labor cost of assembly and eliminating the coax wiring previously used to route the analog signal from the rear RCA connectors.
The new JADE comes very close to the OPAL, such that the difference is heard only by straining one's ear in comparative listening test and providing that the accompanying equipment is up to this new performance. For most people’s system this line amp will be the strongest link in the chain. To come so close while reducing the cost by one half represents a monumental achievement. All this was accomplished while maintaining our high standards of parts and construction
POWER SUPPLY
The power supply is built on a separate terminal board and is similar to the Opal in that we have implemented a double pye filter network using two large chokes in conjuction with electrolytic and polypropelene capacitors to maintain an ideal DC voltage. A passive Zener network shunt regulator stabilizes the DC Voltage level. We have again avoided using active feedback in order to maintain the speed of the power supply in relation to the extremely fast analog circuitry. Stability is ensured by the use of a large electrolytic reservoir capacitor and speed is enhanced by using a large [30uf] polypropylene film capacitor as a final filter stage located directly on the analog terminal circuit board. The 200 Volt DC power supply completely eliminates all noise and ripple to below what our test instruments can detect. An AC power line filter is also used to prevent unwanted noise and hash from entering into the unit.
PARTS
We use precision quality parts throughout. Our fixed terminal hand crafted circuit boards are identical to the ones used in constructing the Opal preamp and Topaz amplifier. The ease of replacing parts and the tenfold increase in lifetime durability are added benefits resulting from this board construction. These boards are held elevated from the surrounding metal chassis to avoid any capacitive coupling between components. We import from Denmark our stepped ELMA volume controls that use 0.1% precision metal film surface mount resistors. For selection and tape monitor or processor loop, we have replaced the Shallco switches formerly in the Pearl with relay switching of the analog signal right at the input RCA connectors.