Inmate Systems - Audio Asylum

Bold Eagle 's Advent/Adcom/Rotel System
IP Address: 66.61.57.210	Last Update: January 30, 2019 at 18:54:21
Amplifier:	I'm currently using an Adcom GFA-545 Mk II power amp, vintage 1990+. Rated at 100 W/ch into 8 ohms. Damping Factor is measured at 500. The amp is completely stock. Power supply and amps are dual mono. It easily handles 4 ohm loads with some lower impedance points down to 2.5 ohms with double Advents. The amp has an unusual ease, clarity, and transparency with great bass control and power. The highs have a Non-Bright property in which they seem lacking at first, but you then realize they are there, just very smooth and with no edge or grain at all. Like live music, in fact. This Non-Bright effect is particularly noticeable on high strings and soprano vocals where the usual edge is gone and a very natural sound is heard.
Preamplifier (or None if Integrated):	An Adcom GTP-400 Tuner-Preamp. This turned out to be the best match of anything I have tried. Excellent sound quality with more solid deep bass than the NAD I was using. Mids and highs are smooth; but have a little life to the sound. Tuner section is very good and has excellent rejection figures. 100 ohm output impedance. The GTP-400 has three switched rear panel AC convenience outlets and the capacity is 500 watts, enough for the entire system. Very convenient!
Speakers:	A pair of Advent "New Advent" tweeters and SEAS A26RE4 woofers adapted to the Advent woofer bolt pattern in custom made Original Advent replica cabinets. Fancy flame grain walnut veneer on all sides. An internal front to back brace to stiffen the cabinet. Driver positions are mirror imaged for better imaging. The tweeter is surrounded by a foam wall and the grill panel has been opened up to slightly larger than the foam wall to prevent edge reflections. Crossover comprises a 0.5 ohm series resistor on the woofer to adjust the woofer Q at resonance; and a single series 10 uF Clarity PX film capacitor on the tweeter. Crossover is right at 1650 Hz. Tweeter level control is an L-pad instead of the Advent's switched resistors. With the L-pad, the capacitor sees a constant impedance regardless of tweeter level so the crossover point does not shift with tweeter level settings. Cabinets are about 60% filled with Acousta-stuf. Used on 15" stands with no tilt back, and no toe in. Speakers are 8' on centers in a 12' wide room. Input connectors are gold 5 way dual binding posts on 3/4" centers to accept the dual banana plugs on my cables. The sound is amazingly clear, clean, transparent, and open; with very smooth highs. Bass is deep, solid, powerful and very tight and articulate. The bass extends to 25 Hz with authority. The sound is almost completely detached from the speakers and exists mainly in the virtual image; so the speakers do not seem to be the source of the sound. Instruments have accurate timbre, and voices sound uncannily live. High strings have the right timbre and sound very natural and never bright or edgy. There is a profound sense of ambience and depth. The soundstage is wide and deep and has a good sense of height. I believe a lot of the naturalness of the sound is due to the very simple crossover, and the coherence of sound as the woofer to tweeter transition is seamless. I elected to use the New Advent tweeter as it has a larger radiating area and more stroke than a SEAS 27 mm dome, and does not distort if played loudly with the first order crossover.
Sources:
CD Player/DAC:	The CD player is a Rotel RCD971 from 2001. This is an excellent and very well built player, fully up to the amp and speakers. It does better than most CD players in retrieving depth and hall ambience clues. I auditioned 7-8 CD players, some much more expensive, before selecting this one. Extra low output impedance makes it insensitive to the interconnects used or to the preamp it's connected to. There are five separate power supplies for different sections, and there is an elaborate filter on the line cord.
Turntable/Phono Stage:	A modified Dual 1229 is used as a single play automatic/manual TT. The platter has been modified by the addition of an aluminum plate that fits down inside the outer rim, and is bonded to the platter to gain a flat top surface and some constrained layer damping. A soft silicone rubber mat is used to give full support for LP's. The cartridge is either an AT95EX, or a Shure M75EJ II. Interconnects are a pair of Diskwasher low capacitance.
Other Source(s):	Sony CDR-W1 CD recorder. Tied into the preamp to be able to record from the system. This is a dual tray CD recorder with 4x speed. Gives very good results. Copies are used in our cars. It also is a very good player, and the two trays sound identical to each other and very nearly as good as the Rotel.
Other Accessories/Room/Misc.:
Speaker Cables/Interconnects:	The speaker cables are 12 gauge fine strand cable, precisely equal in length. The end connections are giant gold spade lugs crimped and soldered to the cable, and then very tightly clamped to the gold plated dual banana plugs on both ends. Interconnects are custom made to minimum length to minimize capacitance. RCA plugs on both ends are heavy and gold plated. The short interconnects also make a much neater backside without hanging loops of cable.
Other (Power Conditioner, Racks etc.):	Everything is plugged into a surge protector which in-turn is plugged into a second surge protector.
Tweaks:	Lots in the speakers and Dual 1229, few elsewhere, see the speaker section for details. Probably the biggest tweak was matching the components into a synergistic system, and placement and room treatments; which together are far more important than the components individually.
Room Size (LxWxH):	18 x 12 x 8
Room Comments/Treatments:	The room is fairly dead with wall to wall carpeting and a fair amount of furniture. Speaker placement is critical, and a location was found that gives the same sound from left and right speakers from my listening chair for best imaging. So I have acoustical symmetry. Center distance between speakers was adjusted to give the best sound and image. There are enough bookshelves on the walls to act as excellent diffusers of the reflected sound.
Music Preferences and Comments:
Music Used (Genre/Selections):	Rather broad tastes. Classical including symphonic, chamber music, and solos from most periods. I'm particularly fond of Vivaldi, Beethoven and Mozart. Popular, folk, and especially jazz. I love Brubeck, Ramsey Lewis, and Oscar Peterson. Over 500 CD's in all.
System Goals/Comments:	The system is about as good as the smallish room will allow. I believe in keeping it fairly simple and working on the matchups of the pieces rather than throwing money at it. Finding the synergy between the pieces is much more important than the cost. I have about $1800 invested in this system and only the CD player was bought new.
System Strengths:	Remarkable transparency and naturalness. You feel like you are hearing back through the recording chain to the original performance. The system does extremely well in reproducing the acoustic of the original performace to the extent you feel you are there. It completely overcomes the acoustic of my listening room. Put on a well recorded CD, close your eyes, and the room falls away and you-are-there. Much nicer perspective than the in-your-face, they-are-here we so often see. My best system to date in this room, and one of my best ever.
System Weaknesses:	None really, I live in a condo and have to keep the levels down most of the time. I'd like to be able to crank it up more often.
Video/HT System: Separate
TV/Projector:	46 inch Samsung with space in the supporting cabinet for components.
Processor/Receiver/Amplifiers:	An NAD C320BEE integrated amp and a Sony ST-J75 FM tuner are used for movies and when I want better sound than what's built into the TV.
Speakers (Center, Surrounds, Sub):	I use the TV's speakers for the mid-bass and on up and center fill. THe TV contains a five band EQ, and gives a nice sound, so that add on amps and speakers were not felt to be necessary most of the time. I have added a Bose AM-5 series II system to the TV for movies and certain programs. The Bose are powered by an NAD C320BEE integrated amp with 65 W/ch continuous and 3 dB of dynamic head room, plenty for this application, and with a nice clean sound. The Bose bass module sits behind the TV which sits across the corner. The satellites are wall mounted on the two sidewalls, and the two cubes are both forward firing with 45 degrees between them. I was surprised how good they sound when well set up and they provide a clarity the TV sound lacks.
Sources (DVD/VCR):	LG DVD player/recorder/VCR/CD player combo
Other HT Gear:	DVR
Comments on HT System:	When watching movies on the TV, the set's speakers provide a nice center fill and a three channel effect.
Other Interests/Hobbies/Occupation:	Retired Engineer, professional background in vibration and acoustics for 12 years of my career, car and racing fan, golf club builder/player, computers, serious photography (now digital), and I have a nice electronics bench, including a 61 band RTA and calibrated condenser microphone.