I am considering a First Watt F4 with 87db 6ohm speakers. As long as it's run in mono mode I should get 50 watts SE or 100 watts Balanced.
So I have two questions:
1) First Watt amplifiers play nice with very sensitive speakers but can fall apart when playing complex music with lower sensitivity speakers. Is it the lack of wattage that hurts it with low sensitivity drivers (meaning mono mode will fix this)? Or is it that the circuit is simply not designed for this load(meaning that mono mode will not help much other than eliminate clipping)?
2) How much gain is required from the preamp if I have a Balanced 4V output DAC? 2V output SE or Balanced DAC?
So I have two questions:
1) First Watt amplifiers play nice with very sensitive speakers but can fall apart when playing complex music with lower sensitivity speakers. Is it the lack of wattage that hurts it with low sensitivity drivers (meaning mono mode will fix this)? Or is it that the circuit is simply not designed for this load(meaning that mono mode will not help much other than eliminate clipping)?
2) How much gain is required from the preamp if I have a Balanced 4V output DAC? 2V output SE or Balanced DAC?
A pair of F4's run bridged will give you 100 watts into 8 ohm's. I can't imaging that not successfully driving 87db speakers, unless your listening room is really huge.
All amps, not just FirstWatt, will give variable performance according to application/use. Pick the right tool for the job. Asking a 10 watt amp to throw large volume from an inefficient speaker would be like trying to dig a mine with a spoon then complaining about slow progress.
The F4 manual advises balanced monoblocks for 87db or below speakers, with a preamp that can swing 14 volts and 20db gain.
All amps, not just FirstWatt, will give variable performance according to application/use. Pick the right tool for the job. Asking a 10 watt amp to throw large volume from an inefficient speaker would be like trying to dig a mine with a spoon then complaining about slow progress.
The F4 manual advises balanced monoblocks for 87db or below speakers, with a preamp that can swing 14 volts and 20db gain.
All that aside, my single F4, running 93db speakers in a 600sf listening room - has never failed to perform. If it has ever clipped, it was too graceful to discern. And I routinely run it hard enough to literally rumble the house.
Well hopefully you are right. I came across this thread where Nelson states that one of the Pass Labs amps outdoes the F4 for low sensitivity speaker control.
http://www.diyaudio.com/forums/pass-labs/197225-between-xa30-5-f4-sonic-impressions.html
I guess I am a bit confused where the F4 sits when compared to other uber priced amplifiers. It's not like the F4 is a dog spec wise and I get conflicting information on where this F4 mono sits against other Class A monster amplifiers.
http://www.diyaudio.com/forums/pass-labs/197225-between-xa30-5-f4-sonic-impressions.html
I guess I am a bit confused where the F4 sits when compared to other uber priced amplifiers. It's not like the F4 is a dog spec wise and I get conflicting information on where this F4 mono sits against other Class A monster amplifiers.
Thanks! From what I have been able to find the Burning Amp BA-3 can output 100W balanced too.
Any recommendations between F4 amp with the BA-3 gain stage and the BA-3 amp with the BA-3 gain stage? From what I have read there are differences but I am unsure of what that is.
Also, objectively and subjectively what's the difference between the BA-3 complementary and single ended Bias and Output boards?
Any recommendations between F4 amp with the BA-3 gain stage and the BA-3 amp with the BA-3 gain stage? From what I have read there are differences but I am unsure of what that is.
Also, objectively and subjectively what's the difference between the BA-3 complementary and single ended Bias and Output boards?
I run my Quad 988's, in a 11'x12' room, fullrange with my F4 -factory- in stereo mode. Because the room is small I can get away with it. Also, it helps that my preamp. -Supratek- has a lot of gain. Sometimes I use this set up with an amplified sw with a high and low filter set at 80 hz and it is obvious the F4 works better. The Quads have a sensitiviy of 86 db and a nominal impedane of 8 ohms. Presently I am considering either getting another F4, build one or building an F5 turbo. On the other hand, when used with my Spatial Holograms's M4, which are 93 db and 4 ohms, I can bring the house down.
However, I have tried higher power amps and one can notice the difference in their control, soundstage size and bass performance, especially with the Quads, but with less musicality meaning less smoothness, delicacy and refinement. And the soudstage might be bigger but there is less layering.
However, I have tried higher power amps and one can notice the difference in their control, soundstage size and bass performance, especially with the Quads, but with less musicality meaning less smoothness, delicacy and refinement. And the soudstage might be bigger but there is less layering.
Complementary BA output stage is the F4 minus the jfet buffer on the front end. Also, has the ability to use more pairs of mosfets for higher bias. But it's pretty much the same amp. You won't need the F4's buffer if using the BA-3 gain stage.
The single ended and push pull amps are entirely different. I haven't heard either but totally different I would imagine. With your speakers you likely want the push pull version.
I use a 25W F5 with the BA-3 gain stage as a preamp w/89 db 3-ways in a large room. If you are happy with 90db at the listening position this is enough power. If you need more volume or listen to classical with big dynamic swings you may want more. 25W can get you pretty far.
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