Guest jbangelfish Posted December 2, 2003 Report Share Posted December 2, 2003 I got to thinking about what people have said and also what I have said. My first Parasound amp always seemed to lack the "oomph" that I was expecting from such a powerful amp, bought the second one and bridged mono. This combination seemed to solve my problem although I used to think my left channel might be weak. This combination was not used with the 9,s but on another system. Anyway, I decided to switch amps just to see if it made a difference. The other Parasound amp seems to have brought the bass that I was expecting, especially when I listened close at either side of the speakers. I might need to do some positioning adjustments to appreciate it more out in the listening area but it certainly seems to be present. So, my conclusion is to suspect one of the Parasound amps may have been wired out of phase to the speaker posts. I suppose I could reverse the wires on the binding posts to test my theory but I'm not sure this is a good idea. If it has a problem, I'd rather it was bench tested and checked by a technician instead of my ears. I also did some adjusting of the upper level controls as someone suggested. Setting the lower mid to -6 took some brightness out of that area and made bass seem more prominent. I set the upper midrange at -3 and left the treble at 0. This worked out well for vinyl and even sounded good with a cd but maybe a tad bright. The AR9 booklet states that when using a powerful amplifier and listening to loud music, all switches should be at 0 and any adjustments made on your amp/preamp, unfortunately, I have no controls. I sure don't want to damage anything so any thoughts on this would be appreciated. Link to comment Share on other sites More sharing options...
ninohernes Posted December 2, 2003 Report Share Posted December 2, 2003 Take a look at Adcom power amps. http://www.audioadvisor.com/store/mfglisti...umbs=1&Filter=0They have massive, I mean massive, power supplies. Even the lower powered models have these huge power supplies. These amps are great sounding once they break in. Link to comment Share on other sites More sharing options...
Guest jbangelfish Posted December 3, 2003 Report Share Posted December 3, 2003 I have checked out Adcom amps before and thought that they were fine but not necessarily better than what I have. They could be but I doubt it. What is a massive power supply? The Parasound amps have two 1200 Va toroid power transformers each with a current capacity of 50 amperes continuous and 90 amperes peak. The AC power requirement is 1000 watts each amp. Would this not be a massive power supply? How do these specs compare with the Adcoms? I'm not trying to say that the Parasounds are the greatest thing out there but they seem to be very powerful amps. Link to comment Share on other sites More sharing options...
ninohernes Posted December 3, 2003 Report Share Posted December 3, 2003 The GFA-5802 is 450 watts into 4 ohms (300 into 8) and draws 1440 watts of AC. The GFA-5500 is 350 watts into 4 ohms (200 into 8) and draws 1165 watts of AC. The GFA-5400, which I own, is 200 watts into 4 ohms (125 into 8) and draws 960 watts of AC. I like the way these amps sound. They sound warm like tubes, but the bass is tight and controled like transistors. They use MOSFET transistors, this is why they are so warm sounding. Here is a little article describing the benifits of MOSFETs.An important reason for using MosFet transistors in the output stage has to do with their rugged reliability. MosFets simply aren't affected by heat the way normal transistors are. Get the typical transistor really hot, and it goes into "thermal runaway", drawing more and more current, getting hotter and hotter until poof, it's a goner. MosFets, on the other hand, reduce the amount of current they conduct if they become excessively hot. They're self-controlling and therefore very reliable. Another advantage of this characteristic is it allows ADCOM to bias the output stage fairly high. This makes it operate as a Class A amplifier under most normal listening conditions. When higher power demands come along, the amplifier "switches" to class A/B operation.These amps get really hot, but they never distort, and allways sound great! I originally looked at the Parasound amps, but after I listened to the Adcoms, I immediatly changed my mind and got the Adcom, much lower distortion as compared to the Parasound. I use it to power my monitors in my recording studio, which are AR-3's. These are the cleanest amps I have ever heard at any price. I am not downing the Parasound units, they are definatly good sounding amps, but for the AR-9's I feel that an Adcom is better suited. Link to comment Share on other sites More sharing options...
r_laski Posted December 3, 2003 Report Share Posted December 3, 2003 Bill, I meant to post a reply on your other thread. Grabbed the wrong one.Rich Link to comment Share on other sites More sharing options...
Guest jbangelfish Posted December 3, 2003 Report Share Posted December 3, 2003 Joe: Have you ever used the HCA 2200 II? It must be very similar in design to the Adcoms that you are referring to. It also uses MOSFET technology and is pure class A up to >6 watts (probably not there too often but maybe more than I think) and switches to AB. They are dual mono, balanced circuitry, silver plated wiring to outputs, use DC servo direct coupled and on and on. The distortion is .05 at full power and .009 at typical levels. The damping factor is >1000 at 20hz, S/N >114db, dynamic headroom only 1.5db (could be a weak point). I don't claim to understand (but I have a reasonable understanding of most of it) as I'm not an engineer but I believe that they were designed well by John Curl. You will certainly know more about this than me. Don't take any of this as an arguement, I know better than to argue about engineering, way out of my league. In any case, I'm not overly anxious to run out and buy a couple more amplifiers yet. My wife thinks I'm nuts for what I've spent already and convincing her that I needed the AR9's was a pretty hard sell in itself. She doesn't seem to understand why anyone needs 6 pairs of speakers, 3 turntables, 5 cartridges, 4 amplifiers, 3 preamps, separate phono preamp, etc. Go figure, Link to comment Share on other sites More sharing options...
ninohernes Posted December 3, 2003 Report Share Posted December 3, 2003 The specs of the Adcom GFA-5500 and the Parasound HCA-2200 II are virtually the same. The only real difference is in the power supply. The Adcom draws more. The sound difference is purely subjective. I prefer the Adcom just because it sounds rather warm like tubes, but the bass is really tight like transistors, but dont let the warmth throw you off, this amp can has a wonderfull sparkle in the high registers. Heifetz's violin realy comes through as if he were standing in the room with you. (classic records 200 gram vinyl) The Beatles (Mobile Fedility box set) sound like never before, and Bill Evans trio Live at Shellys Manhole, sounds like your right in the Cafe, the bass is so solid. And I feel the grand test is when I play my uncompressed master tapes (analog of course, digital recording is a laugh) in my studio. With no compression, there are huge spikes from the quietest sound to the loudest one, and the Adcom takes them very well. In closing, you know as well as I do, amplifiers, speakers, cartridges etc. are highly subjective to personal taste, but I really do think that you would like the Adcom. I am only 17 years old, but I have listened to alot of equipment. Link to comment Share on other sites More sharing options...
Guest jbangelfish Posted December 4, 2003 Report Share Posted December 4, 2003 Joe:How does one so young as yourself obtain the title of recording engineer? I'm not doubting you, it just seems like quite an accomplishment for your age. When I was 17, my main concern was if I had a date for the evening. This was 1969 and if you wanted good music, you had to go to a concert, so I went to quite a few. This also put me on a quest to have good music at home. It wasn't until the mid 70's that good stereo seemed to reach the mainstream or at least where I'd heard enough to convince me that it existed. AMT, Bose, Klipsch, Ohm, Infinity, EPI and some others began to create things that varied from the normal 2 and 3 way box even if it was just changing the types of drivers within. AR, Bozak and others were in there as well. Big amps were rare and expensive but I learned way back then what a difference they could make. I bought a Crown IC150 preamp and Crown DC300A amp new in 1975 and have never regretted the purchase. My son still uses both components every day, the amp has been repaired once in all these years at a cost of $125 and the preamp has never been in the shop. I also am a much bigger fan of analog than digital recordings but will admit that some good digital seems to exist. Whether it can be as good as analog, I don't know but I usually do not find it so. I have a Telarc "digital master" of the 1812 overture on vinyl which is supposedly not compressed or altered in any way from the master tape. I can't say that it sounds digital in any way and seems to be an excellent recording, just very difficult to track when the cannons go off. I have a "digital master" of Cat Stevens, Tea For The Tillerman on 200g vinyl, paid 40 bucks for it and it sounds different from the original. Certainly not better but different and while I'd call it a good recording, I think I would call the original better, certainly more natural sound. I have never had a rerelease CD of an old album that sounded anything like the original vinyl, not even close. Too bad, I'd like the convenience of CD with the sound of vinyl. Some seem to be getting better but at least 90% of my CD's irritate me in some way as being grainy or harsh. I guess it's up to guys like you to correct this so let me know when you figure it out. Thanks, Link to comment Share on other sites More sharing options...
ninohernes Posted December 4, 2003 Report Share Posted December 4, 2003 >Joe:>How does one so young as yourself obtain the title of>recording engineer? I currently record for a chamber music group in my area called the Adirondack Ensemble. The group brings in world class musicians from around the country, and around the world. I realy enjoy working with the ensemble. I have also done recordings here and there for NPR. I abosultly love analog, and that is my main medium of recording. I record most works directly to two track tape, as you probably know, direct to two track yeilds the higest fedility. When I must multitrack, I do use digital, but I do mix down the digital masters to my analog machine. I dont have the money for an analog multitrack at this point, I am more worried about paying for college! I will be going to college at Columbia College in Chicago. There I will major in audio arts and acoustics with a concentration in recording. This past October, I was invited to attend the Audio Engineering Society convention. It was really great to meet producers and engineers, and talk about gear. And about the CD reissues, they suck, I know. Poor digital re-mastering just ruins the sound of the originial master tape. Link to comment Share on other sites More sharing options...
Guest jbangelfish Posted December 5, 2003 Report Share Posted December 5, 2003 Good luck to you in all of your endeavors, college as well. Thanks for your input. Let me see where I stand when I biamp and get things situated better. I should have all that I need for a very good sounding system, just need to fine tune things a bit. Keep the analog going but if you can fix digital, please tell others how it's done, they obviously need help. Link to comment Share on other sites More sharing options...
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