Anthony,
I will do all I can to stand behind the product. My concern is the shipping costs from Australia. How would it be if I asked Bob what the amp needs to get back to normal operation? While I'm not familiar with tube-type Bob Carver amplifiers made before my arrival a couple of years ago, If they're anything like our current products, that blown fuse will minimize the damage, making it inexpensive and easy to repair.
My intention is to repair it at no cost to you, irrespective of its age, and irrespective of the damage, but shipping a heavy amplifier from the southern to the northern hemisphere might the unnecessary and risky overkill. I'll speak to Bob and Jordon as I promised I would, in an earlier post. I will reply through your email address assuming it is still current. We will provide either shipping instructions or directions for your local technician to affect an immediate and convenient repair.
Unlike the Sunfire products which were utterly and totally unique, with our current philosophy of point-to-point wiring of readily available capacitors and resistors, any technician with any talent at all will be able to repair these, certainly, for years to come. There are no proprietary components. There are no integrated circuits. While it's true that some of our capacitors are special order, that's because of the quantities we buy and and your technician will be able to source the equivalent.
I don't expect a phone call, Anthony, but if you wish to communicate with me directly, use Carversunfire@Gmail.com. All forum members are invited to contact me likewise if they need to. In the meantime, sit tight and I hope to respond to you in the next couple of days. Please understand that I was already booked up for the remainder of the week and did not expect to see your post. My policy is to respond within 24 hours to as many inquiries as I possibly can, but in this case, I do need to speak to Bob who is, at all times, working on inventions unimaginable.. In fact, the only reason we're going through this, is Bob worked on the Amazing Line Source for seven years and if he retired, he realized, no one would ever get to hear this product. In his words, "I was going to ride off into the sunset with Peggy but could not get myself to abandon the Amazing Line Source project." So, whatever Bob is doing, and wherever he happens to be, I have to grab his attention, shake him a bit, ask my questions, and report back to you
You guys might find this interesting: we actually underrate tube fuses so that they will easily blow if the tube has a slight defect. Today's tubes may have microscopic impurities. A high-quality new-old-stock tube will typically be free of such impurities and have an even longer lifespan--actually indefinite when used in one of our current amplifiers. If the impurity lands on the wrong internal component, in a thoughtless design which does not use tube fuses, the tube will fail taking out components downstream. To refuse to use circuit boards at this price, and taking steps to ensuring reasonable protection for the components in the amplifier, any manufacturer able to duplicate our DC restorer circuit, would enjoy incredibly long component life.
I continue: When a tube fuse blows in one of our amplifiers, the impurity is vaporized and when the fuse is replaced with the proper value, you're set to go. I've seen this happen once so far in my two years and the amplifier miraculously seemed to heal itself as Jordon predicted. Of course, the amplifier did not heal itself, but rather, the vaporization of the impurity allowed the tube to return to normal function. The key is robust construction, using some fairly expensive components, and careful fusing where applicable. We WANT the fuse to blow (BTW, few ever do).
We actually state this in the owners manual: We tell people not to worry if the tube fuse blows because, unlike other designs, it's often no big deal. If the fuse blows in one of the original Sunfire woofer amplifiers, for example, it's a catastrophic failure. Fortunately we are familiar with the subwoofer amp problem and are comfortable with repairing and upgrading such units. In the case of our power amplifiers that we market today, a blown fuse may not signal any problem at all.
Next, by using point-to-point wiring, we do not incur the variable series resistance inherent in the traces on circuit boards. Of course it's incumbent upon us to use high-quality internal cabling, so we do. You see, the formulae for determining, for example, the gain of any particular stage, involves factors such as resistance. Well, nearly everything has some sort of resistance. If we can control it, we come closer to the theoretical ideal as specified in the formulae used in amplifier designing.
As an aside, lest you think this is so much hyperbole, Bob has been collecting theater and industrial amplifiers since he was a teenager. Many had the original tubes. After some fresh capacitors, some of these units are still operating perfectly with tubes that are nearly as old as Bob. Ever the curious scientist, Bob began to wonder why some of these tubes never seem to wear out. He ascribed that to two things: the tubes were better in those days, and the collateral circuitry and bias scheme were not as destructive as we find today. That said however, many of these units did not sound very good. Bob's challenge was to elicit natural sound, at all frequencies, at all levels, and still extend tube life. Our proprietary DC restorer circuit turned out to be the answer. This is exactly why we decided to extend the warranty beyond the usual 2 to 5 years so common in our industry.
Incidentally, and not to be nasty, I nonetheless got a chuckle at the mention of Marantz who nearly went out of business and was just purchased by Sound United, the company who owns and sells Polk and Definitive Technology, two speaker brands unlikely to ever be driven by Audio Research or any current Carver product. One assumes they will cover the warranty currently in existence, but D&M Holdings was a gnat's eyelash away from being taken over by the bank.
Finally, and this may or may not apply to Audio Research, the amplifier's internals should be, in some fashion, electromagnetically laid out. Circuit boards can be confining, forcing the designer to compromise. At Onkyo for example, the girls who assembled the electronics followed a manual showing how many twists per inch they were to manually create when doing wire-dress. Companies like Yamaha and Arcam use conductive wire ties that bleed unwanted extemporaneous energy to ground. All this stuff adds up but sticking with circuit boards engenders certain compromises.
We will probably use a circuit board in our $2500 amplifier for economic reasons. That said, we really do prefer point-to-point wiring but would rather build an affordable unit with some innocuous compromises as opposed to offering no unit at all in that price range.
By the way, and I assume we are not alone in this process, first the amplifier is designed as a concept by Bob. Next a block diagram is created. At that point, a prototypical schematic diagram is created by Jordon, submitted to Bob for comments and then finally, a true prototype is hand assembled by Jordon. At that point, Bob, who pretty much has the final say-so, will listen to the amplifier and I guarantee you, he will suggest immediate subtle changes, not to the sound, but to the circuitry that produces the sound. He realizes, unequivocally more than most, exactly what changes result in benefits and which can be destructive. I've seen him do it on motel room beds – – snipping out resistors and caps and replacing them with parts from RadioShack and immediately opening up the top end frequencies as he predicted it would. This is how he tuned the solid-state Carver amplifier to match the sound of the Conrad Johnson under test for the guys at Stereophile. Not being amplifier designers, they thought that the production model based on this design, was not the same as what was submitted for the test, not realizing that the changes cost under a dollar!
I would also like to make something clear: if I could afford it, Audio Research components would be on my short list (with a handful of other brands). Because of my background and my connections, I can deal with reliability issues more easily than the average consumer. Just as with the Arcam surround-sound receivers, which I represented for many years, one has to accept the fact that Ferraris need more attention than Chevrolets. So, if I were wealthy, I would certainly consider the top-of-the-line Audio Research components because I feel they are incredibly natural sounding and very transparent.
For those of us living in the real world however, there are inexpensive amplifiers from China that sound decent and have been pretty reliable lately. It's a good way to get familiar with the world of tubes. I guess we fall somewhere in the middle. Our current "entry-level" amplifier is 350 W RMS at $9500 a pair...not a bad deal. Jordan and Bob have been working on the new 35 W per channel tube-type amplifier, complete with our DC restorer circuit which extends tube life, component life, and reduces distortion dramatically, at around $2500 as I said above. That will give us three models since the top-of-the-line silver sevens are now $32,000 a pair (actually, not a pair, four components – – two power supplies and two amplifiers).
