|
Frequently Asked Questions
Why do ADCOM amplifiers use fuses?
That's an easy one! We use fuses to protect your investment in good equipment.
If a fuse blows, something's wrong - but that doesn't mean the amp is defective! Speaker fuses will open if you accidentally touch a wire across the positive (red) and negative (black) speaker terminals when the amp is on. This usually happens during initial setup even though our owner's manuals specifically warn against this practice.
Replace fuses with new ones of the same type and value only! Don't play engineer here. If the fuse blows again, something else may be wrong and a higher value fuse might just harm the amplifier. 
How much power do I need?
Well, we don't know. But we can give you some guidance as to how to find out.
First, visit your friendly ADCOM retailer. He or she can give you all kinds of help on this and other topics. How much power you need depends on a number of variables, among them the size of your room, the efficiency of your speakers and how much you like to annoy the neighbors!
At the showroom, do some listening through speakers of the same efficiency you have at home (your dealer can help you with this). Play the music as loudly as you are ever likely to. ADCOM amplifiers have distortion indicators on the front. If they only flicker occasionally, you're probably in the ballpark. But if they light almost continually, you need more power.
Is one ADCOM amplifier "better" than another?
NO! Let's repeat that - NO!
We don't have a "good - better - best" design approach. Every amplifier uses essentially the same circuitry and uses the best parts we can design in. Period.
Instead of a "good - better - best" approach, we use what's called an ''application specific'' philosophy. In practical terms, that means we design the best 50-watt amplifier we can. We also design the best 250-watt amplifier we can. A customer chooses one of our amplifiers because that particular amp best fills his specific power needs, or his ''application.''
The benefit is that all ADCOM customers enjoy the same high level of sound. They pay different prices based on ''how much'' of that high quality sound they need.
There's a hum in my system. Why?
There are lots of reasons why a system can ''hum''. Some real common ones are the ''noise'' caused by Halogen lights or light dimmer switches. Another common problem is a ''ground loop'' caused by a cable TV connection. To check if this is the problem, unhook the cable feed from your system. If the hum goes away, you've found your problem. The problem can be solved by use of a ''ground loop isolator'' which can be purchased at any electronic supply store.
My amplifier seems to run hot. Is this a problem?
Probably not. Most Adcom amplifiers use output devices called ‘’MOSFETs’’ (which stands for metal oxide semiconductor field effect transistor, if you're curious). We've chosen these devices for their superb 'musicality'. They do, however, run hotter than more conventional bipolar transistors. We have designed our amplifiers with large 'heat sinks' made up of aluminum fins that dissipate excess transistor heat into the air. Just make sure you provide adequate room for ventilation as opposed to stacking other equipment directly on top of your amplifier.
What's the difference between your old amps and your new ones?
Well, the biggest difference goes back to MOSFETs again. Most of our newer ‘’4 number’’ amplifiers (i.e. the GFA-5802) use MOSFETs while all our older ‘’3 number’’ amplifiers (i.e. the GFA-555), used bipolars.
So, are bipolar amplifiers bad?
Actually bipolars have some advantages. As noted above, they produce less heat for a given power output. This makes them suitable for more compact components or for multi-channel, home theater amplifiers. As such, we have chosen to use them in our custom oriented amplifiers, the GFA-5002 and the GFA-5006, where size can be at a premium, and in our multi-channel, home theater amplifiers, the GFA-7500, GFA-7400 and GFA-7300.
Bipolars can have a very detailed, up front sound quality, and with our 2 decades of experience in getting the most out of these devices, we think you'll find that the bipolar's inherent immediacy is nicely tempered with circuit touches that let you hear a rare level of musical integrity.
Can I order parts?
You bet! To order parts or accessories, simply use our contact form or call us at 480-607-2277 and ask to speak to the Parts Department. We accept Visa, MasterCard, checks or money orders. There is a minimum parts order of $25.00. And if you email us, please make sure to include your name, address and phone number. All orders will be shipped UPS ground unless otherwise requested.
How do I arrange for service?
First off, sorry you need it! Probably the most convenient thing to do is contact the dealer where you purchased your Adcom unit. Adcom dealers are carefully chosen for their expertise and attention to service, and can almost certainly help. If you would like to have Adcom service your unit directly, please use our contact form or call 480-607-2277. Please provide your name, address and telephone # along with the model # and serial # of the unit and as detailed a description as possible of the problem you are experiencing. We will issue you a Repair Order # which you must put on the outside of the box before sending the unit to us.
There's a "thump" when I turn off my system.
There are usually two reasons for this: The amp has a large power supply and it doesn't use output relays. Let's look a bit more closely at both.
First, a power supply's job is to filter and store energy until the amplifier circuitry needs it. Adcom amps have HUGE power supplies. That's part of the reason they sound as good as they do. But when you turn the system off, that energy has to go somewhere. The "thump" you occasionally hear is the power supply capacitors dissipating the energy. It's not dangerous at all. In fact, it's just another sign that the amp won't run out of steam when you really want serious sounds.
Yes, we could have used output relays that would disconnect the speakers as soon as the amp turned off. That way, you would never hear the thump. But relays, as we've already seen, aren't great for real high fidelity sound quality. If we used them, you would never hear how good our circuitry is either. Is that a sensible tradeoff? We sure don't think so.
Look at it this way: The "thump" is the same thing as a high performance automobile's rumbling exhaust. The sound alone tells you there's something serious under the hood, right?
Is Adcom equipment rack mountable?
Absolutely! We make rack mount adapters for all our equipment. See the Accessory section under Products for details.
I'm moving to Europe. Can I bring my Adcom equipment?
Yes, thank goodness! All our equipment (with the exception of the ACE series Line Conditioners) can be converted to operate on 230-volt mains systems. Contact our service department for details on having the conversion done.
Do you sell your products direct?
You can purchase ADCOM refurbished products and accessories through ADCOM Direct.
I have lots of records, but I don't see phono inputs on most of your products. Do I have to buy another brand?
Perish the thought! In keeping with our philosophy of offering the most value possible, we've elected not to include phono sections on most of our preamps, tuner/preamps, and home theater processors. Our research shows that the great majority of people don't need them and we can keep our prices lower by not including them.
We recognize, however, that there is a lot of great music out there on vinyl, so you have two options:
1) Our GFP-715 pre-amp does have a phono section, and a really good one at that.
2) There are a number of phono sections available separately at a wide range of prices. If you just want to play the occasional old record on your not-so-great turntable, an inexpensive one could be just the ticket. If, on the other hand, you're a real audiophile with a great record collection and want to use our acclaimed GFP-750 preamplifier, there are some really excellent separate units out there that will allow you to really enjoy those LPs to there fullest. Your Adcom dealer can help you select the set-up that's right for you.
|
