Magnificent sounding pair of Audio Research Balanced Tube Mono blocks with over 200 glorious tube watts of power enough to drive almost any reference loudspeaker. This pair uses 8 KT120 tubes per channel and, unlike the recent power amplifiers from ARC that use solid state power regulators, uses a tube regulated power supply with a 6550 tube. I have run many loudspeakers with these mono blocks and compared them to many other state of the art amplifiers. I have not found anything that comes close to the majestic sound of these behemoths. They are simply unparalleled in my listening experience with both electrostatic and dynamic speakers. This pair is offered with a complete set of two unused brand new tube sets (32 KT 120 power tubes) besides the 16 KT 120 tubes already in the amplifiers. That’s roughly 48 KT 120 tubes that at current market prices for these tubes is worth several thousand dollars. You will not need new tubes for a long while with these amplifiers. Some points to keep in mind in deciding whether to buy these amplifiers: 1. These are large fan-cooled tube amplifiers that are fully balanced. You’ll need the place them in a room with sufficient ventilation as they run pretty warm. 2. I used these with ARC Reference tube preamplifiers. You can use them with other balanced preamplifiers or DACs that have a volume control. 3. The Bluebook value as attached is around $5000, which does not include the two spare new tube sets I am including with mine. Do your research and see what 32 KT 120 tubes cost (mine are factory matched octets, which are being sold on eBay for $1000 per octet). 4. Check the weight and size of these amplifiers. They are around 90 pounds each in their factory boxes. Shipping costs will be considerable. No international shipment of these amplifiers. I welcome local pickup if you are in the San Francisco Bay Area. 5. The physical condition is as shown, and reflects several years of use. The front panel looks as shown in the pictures. The covers are fastened with a lot of screws, and I think I’m missing a couple of screws on each amplifier. But each amplifier cover is held with over 20 screws, so they are plenty there to hold each panel tightly. 6. The custom made wooden stands are not included with the sale. 7. This is a top of the line audiophile amplifier. Don’t bid unless you know what it takes to set up and install each amplifier. Bias for each power tube is set with two remote controls as shown. Unlike current ARC amplifiers, these use a digital power meter and bias values are shown in a large digital readout (which I prefer). 8. These are considerably more powerful than the largest current model 160M ARC amplifiers that cost close to $35,000! At this price, they are a bargain! They are so well built that they will last a lifetime with careful use. 9. Keep in mind there are two boxes, one for each amplifier. On Mar-14-24 at 16:39:00 PDT, seller added the following information: Added the option of local pickup. Also wanted to add that the amplifiers will come with two custom made plastic covers.