Here are my comments about the 845 SET amplifier.
My system includes the following components:
SONOS digital music source with Audio Horizons power supply upgrade
Audio Horizons TD 3.0, upgraded by Joseph in various ways including a chip set that upsamples to 192kHz
Audio Horizons TP 2.0, upgraded by Joseph in various ways.
Audio Horizons cables: digital single ended SONOS to DAC; balanced DAC to preamp
I used single ended cables to the amplifier prototype because it was not wired for balanced inputs yet.
Coincident Super Eclipse Mk II loudspeakers (28Hz- 35kHz; high impedance; 92 dB)
The power tubes were 845s; the driver tubes (initially) were 6L6s.
After letting the equipment warm up, we began by playing the reference quality recordings which serve me as a baseline for comparing component performance. Immediately a difference appeared. From the first deep bass notes, resonances came from a nearby window frame. I resealed the window and adjusted a curtain. The low frequency energy was powerful but in balance with the mids and highs. I had not played an amplifier that got such a deep, full response out of my speakers before - not even solid state amplifiers. This amplifier has 4 ohm and 8 ohm output taps. We used the 8 ohm tap.
For about 30 minutes we listened to various recordings, trying to cover the gamut of music types and ensembles. The only boundary of the soundstage was the room itself. The depth was very good. I was struck by how well positioned instruments and voices were. Recordings which, with other amplifiers had tended to be too forward or too recessed, were not so with this one. This sound staging was excellent
The music was big, powerful when appropriate, tonally balanced, but to my ear had an unwanted tightness in the frequencies of the female voice. We paused to discuss that issue. Joseph heard it, too. Joseph suggested that we substitute EL34s for the 6L6s as driver tubes.
The improvement was immediate and exactly what was wanted. The voice opened up completely. Imagine Renee Fleming in your listening room singing "Chi il bel sogno di Doretta" from La Rondine (Fleming, The Beautiful Voice). That is what I seemed to hear. It was wonderful!
I cannot speak about rap music because I have none, but the orchestral, instrumental, classical, jazz, country, American standard, blues, rock, etc. sounded great through the amplifier.
Which amplifier do I prefer - the EL34 low power SET or this more powerful 845 SET? I'm not sure yet. Like Joseph's other products, both amps are very responsive to tube selection. Maybe the question will hinge on how loudly I want to play my music. To me 90dB is loud. Both amplifiers played that loud in my system - the 845 could have played much louder in my system. For people with less efficient speakers than mine, the 845 would make good sense.
These amplifiers do credit to Joseph. I think they are excellent products and I certainly will buy one or the other of them when they come to market.
My system includes the following components:
SONOS digital music source with Audio Horizons power supply upgrade
Audio Horizons TD 3.0, upgraded by Joseph in various ways including a chip set that upsamples to 192kHz
Audio Horizons TP 2.0, upgraded by Joseph in various ways.
Audio Horizons cables: digital single ended SONOS to DAC; balanced DAC to preamp
I used single ended cables to the amplifier prototype because it was not wired for balanced inputs yet.
Coincident Super Eclipse Mk II loudspeakers (28Hz- 35kHz; high impedance; 92 dB)
The power tubes were 845s; the driver tubes (initially) were 6L6s.
After letting the equipment warm up, we began by playing the reference quality recordings which serve me as a baseline for comparing component performance. Immediately a difference appeared. From the first deep bass notes, resonances came from a nearby window frame. I resealed the window and adjusted a curtain. The low frequency energy was powerful but in balance with the mids and highs. I had not played an amplifier that got such a deep, full response out of my speakers before - not even solid state amplifiers. This amplifier has 4 ohm and 8 ohm output taps. We used the 8 ohm tap.
For about 30 minutes we listened to various recordings, trying to cover the gamut of music types and ensembles. The only boundary of the soundstage was the room itself. The depth was very good. I was struck by how well positioned instruments and voices were. Recordings which, with other amplifiers had tended to be too forward or too recessed, were not so with this one. This sound staging was excellent
The music was big, powerful when appropriate, tonally balanced, but to my ear had an unwanted tightness in the frequencies of the female voice. We paused to discuss that issue. Joseph heard it, too. Joseph suggested that we substitute EL34s for the 6L6s as driver tubes.
The improvement was immediate and exactly what was wanted. The voice opened up completely. Imagine Renee Fleming in your listening room singing "Chi il bel sogno di Doretta" from La Rondine (Fleming, The Beautiful Voice). That is what I seemed to hear. It was wonderful!
I cannot speak about rap music because I have none, but the orchestral, instrumental, classical, jazz, country, American standard, blues, rock, etc. sounded great through the amplifier.
Which amplifier do I prefer - the EL34 low power SET or this more powerful 845 SET? I'm not sure yet. Like Joseph's other products, both amps are very responsive to tube selection. Maybe the question will hinge on how loudly I want to play my music. To me 90dB is loud. Both amplifiers played that loud in my system - the 845 could have played much louder in my system. For people with less efficient speakers than mine, the 845 would make good sense.
These amplifiers do credit to Joseph. I think they are excellent products and I certainly will buy one or the other of them when they come to market.