My pair of J2s have been running perfectly since early-Nov., 2014, with the channels paralleled...
Paralleling channels of a J2.
...driving my 97dB-sensitive Serenity Acoustics Super-7s. This week I dragged my old Audio Physic Avanti IIIs out, connected the MR/treble to the mono'd J2s and the bass ends to a pair of plate amps.
First and early conclusion was that the 60-Watts-into-4 J2s had, and still have almost a week later, plenty of power for the 87dB-(in)sensitive Avantis. Because the Avanti x-overs include no HP filters* for the MR drivers, I added a high-quality cap to the input jacks of the J2s to create a 190Hz filter, then changed it to a 130HZ and then an about-90Hz filter. As the input caps and the Avantis haven't operated for several years, they're still breaking in, but the system is sounding better and better. My golden-eared buddy, when I told him I was surprised the amps sounded as good as they did driving the power-hungry speakers, told me he thought the J2s were the best-sounding amps I've ever had in my system, and that includes a LOT of often-expensive amps.
I'm really pleased with the sounds of the new system and very happy I bought that pair of J2s.
More later.
August 15 update. The speakers still sound excellent, and I believe the amps are the best sounding I've ever heard.
* because I removed them
Paralleling channels of a J2.
...driving my 97dB-sensitive Serenity Acoustics Super-7s. This week I dragged my old Audio Physic Avanti IIIs out, connected the MR/treble to the mono'd J2s and the bass ends to a pair of plate amps.
First and early conclusion was that the 60-Watts-into-4 J2s had, and still have almost a week later, plenty of power for the 87dB-(in)sensitive Avantis. Because the Avanti x-overs include no HP filters* for the MR drivers, I added a high-quality cap to the input jacks of the J2s to create a 190Hz filter, then changed it to a 130HZ and then an about-90Hz filter. As the input caps and the Avantis haven't operated for several years, they're still breaking in, but the system is sounding better and better. My golden-eared buddy, when I told him I was surprised the amps sounded as good as they did driving the power-hungry speakers, told me he thought the J2s were the best-sounding amps I've ever had in my system, and that includes a LOT of often-expensive amps.
I'm really pleased with the sounds of the new system and very happy I bought that pair of J2s.
More later.
August 15 update. The speakers still sound excellent, and I believe the amps are the best sounding I've ever heard.
* because I removed them
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I've since improved the Avanti IIIs a bit
1. I replaced the LP choke driving the lower-MR driver with a 12g. version (v. the original 20g. version) to get a little more lower-MR energy from the system, and...
2. Replaced the already-wrong* 3rd-order HP filter for the tweeter with a single-order filter, that being a huge 6.8uF SoniCap Platinum (Teflon-film-and-tinfoil) cap.
Now we have a little more warmth and cleaner treble, and I'm even happier with them.
LOVE those J2 amps!
* I had already replaced the hard-sounding ring-radiator tweeter with a B-G Neo-3 PDR mag-planar driver, which improved the quality of the treble substantially.
1. I replaced the LP choke driving the lower-MR driver with a 12g. version (v. the original 20g. version) to get a little more lower-MR energy from the system, and...
2. Replaced the already-wrong* 3rd-order HP filter for the tweeter with a single-order filter, that being a huge 6.8uF SoniCap Platinum (Teflon-film-and-tinfoil) cap.
Now we have a little more warmth and cleaner treble, and I'm even happier with them.
LOVE those J2 amps!
* I had already replaced the hard-sounding ring-radiator tweeter with a B-G Neo-3 PDR mag-planar driver, which improved the quality of the treble substantially.
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