Looks like John Atkinson mentioned the JTR room, but not the amplification:
Were the speakers biamped? Can anyone describe the setup?
Sorry for taking so long to post. I didn't get home until Wednesday night at 11 pm and spent two days catching up at work and two days catching up at home. Between Wednesday and today I also had two of my kids have birthdays. I've got some pictures I need to get of my media server that I'll post in the next couple of days.
I left the room for about 30 minutes on Saturday and on Sunday. John stopped by while I was out of the room. There were some nice Maraschino brochures on the table so anyone coming in would know about the amplification.
I attended RMAF in 2009 and have never been to another audio show. It was a lot of fun to bring the gear and setup the room. Once the room was setup on Thursday, the rest of show was very relaxing with listening to music all day and visiting with the attendees. I listened for about 8 hours on Friday and we watched a movie (Act of Valor
) in the room Friday night. Saturday was about 9 hours of listening and Sunday was another 7 hours. I never had listening fatigue and the system was enjoyable to listen to even at extremely high volume levels. I wasn't in the room continuously since I did go out into the hall to help field JRiver questions.
Here are some more details regarding setup. The speakers are designed and built by Jeff Permanian, owner of JTR Speakers. He brought his personal pair of Neosis 215RT (Reference Towers) with a matte black automobile finish. The 215RT's are three way speakers with a coaxial neodymium compression driver, dual 15" woofers, and passive crossovers. They are tuned to 17 Hz and were flat in room at RMAF to 15 Hz. The speakers are rated as 4 ohm and have a sensitivity of 95dB with 2V. With the Maraschino, they can exceed 120 dB of continuous output with peaks that are even higher.
My own media server was used with a Thunderbolt connection to a Lynx Aurora 16-TB DAC. The output is balanced to the Maraschino's. Balanced output with high output voltage to low sensitivity amps (3.1V for maximum output at 4 ohms) is my favorite way to go and yields the lowest noise floor. The Aurora has a maximum output voltage capability of 20 dBu (7.75V) which really matches perfectly with the Maraschino. You reduce the output headroom of the DAC when you apply any EQ in the digital realm. EQ was done in JRiver's 64-bit DSP after taking lots of measurements of the first row of seating and the center seats from other rows.
Volume control was done using JRiver's internal digital volume. It is 64-bit dithered to 24-bit for output. It is completely transparent down to about -50 dB which is orders of magnitude greater than what is ever used for normal listening. The DAC can be switched from 7.75V maximum to 1.95V maximum output. This allows one to use less volume attenuation when using very high sensitivity speakers.
A Torus RM20 Isolation Transformer was used for all all equipment. It is able to provide up to 400 amps of instantaneous current and presents an extremely low impedance to the amps' power supplies. Both 60V King Maraschino power supplies were plugged into the RM20. PI Audio Group power cords were used between the power supply and the RM20.
During setup, the Maraschino had a lower noise floor than my Cherry MONO Plus amps - no noise with ear up to coaxial driver (as close as I can get with my head in a horn
). With the Cherry MONOs there is a very slight hiss that disappears even when about an 1" away from the coaxial. The Maraschino has a little more detail in the upper frequencies. I was also shocked by the bass detail and control. I'm not sure how much is due to being plugged into the Torus RM20, but the bass sounds incredible on the Maraschino.
We received a lot of praise on the room and people couldn't believe the "little" amps that were powering the speakers. We probably had the highest speaker to amp size ratio at RMAF. Tommy did a great job on the sound quality of these amps and the looks are great, too.