Opal

Design Implementation

Audio Circuits

In our pursuit of the benefits of each circuit topology we ended up choosing a grounded grid configuration. This satisfied our design goal for an exceptionally wide bandwidth that extends well beyond 250,000 hertz. The result is a circuit that highly exceeded our expectations and allowed us to fully implement our primary design philosophy that less is better than more. Being perfectionist, we weren't interested in building the best line amp, we wanted to build the perfect line amp. We proceeded in this direction knowing full well that only GOD could pull that off. So what we ended up with is a circuit of the utmost simplicity that is 99.999% perfect. We do regret that so far we have not been able to pinpoint during our listening sessions just what that 0.001 % of imperfection is doing to the music. We have read in print of one solid state guru who has lambasted all single ended tube circuits as being so simple that a monkey could design them. We would like to assure everyone that we are not monkeys, we just like to keep things simple. Remember that Einstein's formula of E = mc² is about as simple as it gets and it took a lot more than monkey brains to arrive at it.

Power Supply

Of course, nothing is free in this life and to get the best performance out of a superior circuit, one has to feed it with the absolutely purest power attainable. This is the reason why half the weight in our power amp is the result of the power supply components we use and why the line amp makes use of a separate power supply to contain all the magnetic components. It is also why the final filter stage of the power supply must reside in the amplifier chassis and be as close as possible to the active circuits. This final filter stage is of course of the non-magnetic variety, namely a RC filter network. As if three stages of filtering wasn't enough, each channel board has its own large value polypropylene capacitor as a final shunt bypass cap. We have been accused of overkill and we admit that we are so convinced of the importance of pure power that we might be guilty of doing just that when it comes to power supply design. The OPAL power supply completely eliminates all noise and ripple on the DC 200 volt line while also maintaining regulation of the voltage to within 0.002 volts/second of drift. This far outperforms what a battery pack could do !

Parts

We use precision quality parts throughout. Our fixed terminal hand crafted circuit boards, while costing many times more than an equivalent printed circuit board, are well worth the expense and labor to assemble them. The sonic improvement alone warrants the expense. 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 do considerable lab testing in our selection of components. Since perfection is our goal, we don't think parts should impart a signature sound but rather allow the sound to flow through unaltered. The type of parts used therefore must have a synergistic relationship to the circuit they are placed in. It is this relationship of which type of part to use where, that ranks our products apart from the crowd!