As mentioned before, the system is set up for bi or tri-wiring so that two or three separate amps may be employed. We now offer two separate binding post plates (see image on left for one of these plates) to give four pairs of binding posts, as well as a toggle switch on the lower plate, for a fully comprehensive set of connection schemes. Our recommendation is to use a solid-state amp on the low end (and it does not need to be super powerful, since the woofers are very efficient) and a tube type amp on the mid range. Since the mid range compression driver/horn is extremely efficient at 112 db, a low power, low distortion amp may be used. There is an external switch that may be employed to cut out the resistors and extra capacitor that are used to lower the sensitively and impedance of the compression driver to match that of the woofer and the super tweeter. This network is necessary when using the system with a single amplifier, but can be cut out of the circuit when bi-amping with a low power tube type amplifier. This scheme follows through on our design philosophy of minimizing active components in the signal path. The purest possible sound may be enjoyed when all reactive components are eliminated, and the Reference Granite connection possiblilities allow for this elimination, and hence the purest possible sound.
If you want the best possible performance with the Reference Granite speaker system, we highly recommend bi or tri-amping, with a good solid state amp on the low end, and a single ended triode type tube amp on the high end. This amp need not be very powerful. In-house, we use the Hyperion HT-88 amp (described on the "amplifiers" page) that is only 18 watts per channel. This is plenty of power for our mid-range driver. So you do not need to spend a lot of money on a triode amp that has a dozen tubes on the output! 10 to 15 watts will do just fine. We then also recommend any decent solid-state amp on the low end, and one of moderate power (100 watts or so, or more if you desire) will do just fine, due to the high efficiency of the twin woofers. Then a small amp of either tube-type or solid state may be employed for the tweeters.