FWIW........I have/had an F4 and also a 300B SET (Tubelab TSE)
A 300B SET (6-8 watts output) should drive 93db speakers to a very comfortable level. I listened to that setup for years before deciding to build some 97db speakers, mainly because I had some 97db ribbons hanging around.....allowing me to not have to max out the volume knob occasionally.
In my experience you need a preamp with lots of gain to drive the F4........mine wasn't doing it for me and I ended up converting it to an F5.
A 300B SET (6-8 watts output) should drive 93db speakers to a very comfortable level. I listened to that setup for years before deciding to build some 97db speakers, mainly because I had some 97db ribbons hanging around.....allowing me to not have to max out the volume knob occasionally.
In my experience you need a preamp with lots of gain to drive the F4........mine wasn't doing it for me and I ended up converting it to an F5.
Unless you have a big room, have 93db speakers but with system impedance falling pretty low somewhere along the AF band, play them pretty loudly at ~ 100Hz or lower, while perhaps also not having or wanting powered subs, it seems hard to imagine that 8 or 9 wpc from the F4 wouldn't work quite well. So how could 14v into the F4 not produce at least 11 or 12 wpc? I would therefore expect to have great sound when these new speakers arrive. And a shootout with my stock J2 amp should also prove exciting. But I really envy you your 300B amp! Is it everything you expected?
http://tubelab.com/personal/we-have-moved/
My setup is in a pretty large room with a vaulted ceiling.....
My Tubelab 300B TSE is my favorite amp; I have 2, a 300B version and a 45 version. The 300B has been in my system for years now. I have DIY powered subs (one in need or repair now that I'm thinking about it), 300B driving mid-woofers and Poindexter's EL-34 Music Machine (triode PP EL-34) on tweeter duty using Mini-DSP. Speakers are open baffle FaitalPro 6FE200's (2x) and tweeters are fountek ribbons.
I still have the F4 stuffed boards..in case I feel like trying them again someday, but I guess I'm into the zero global feedback tube sound....lol
My Tubelab 300B TSE is my favorite amp; I have 2, a 300B version and a 45 version. The 300B has been in my system for years now. I have DIY powered subs (one in need or repair now that I'm thinking about it), 300B driving mid-woofers and Poindexter's EL-34 Music Machine (triode PP EL-34) on tweeter duty using Mini-DSP. Speakers are open baffle FaitalPro 6FE200's (2x) and tweeters are fountek ribbons.
I still have the F4 stuffed boards..in case I feel like trying them again someday, but I guess I'm into the zero global feedback tube sound....lol
Think about the factors that affect the "sound" of a 'typical' 2 stage, No feedback single ended 2A3 amplifier (if you agree that is 'typical').
One:
The input/driver tube type and manufacturer; the 2A3 tube manufacturer; the partial cancellation of the 2nd Harmonic Distortion caused by the interaction of the input/driver tube and the 2A3. And, the voltages, currents, and plate loads: on the input/driver tube, and on the 2A3 tube.
Two:
The output transformer Quality; primary impedance; primary inductance; level of pre-saturation power versus low frequencies; and distributed capacitances and leakage inductance.
Three:
The loudspeaker; the interaction of the amplifier damping factor with the loudspeaker impedance versus frequency; the room dimensions; reflections and absorptions; and the loudspeaker setup of location, toe-in, etc.
Remeber, the 2A3 amplifier is only 1 part of the complete Hi Fi Stereo playback System.
It can not be the only influencer of the "sound" of your playback system.
Expecting one part of a system to fix an un-wanted characteristic "sound", might be over optimistic.
Often, a 2A3 amplifier is most influential on the 'sound' of a System, when it is simple: A CD player; 2A3 Amplifier; and loudspeaker.
One:
The input/driver tube type and manufacturer; the 2A3 tube manufacturer; the partial cancellation of the 2nd Harmonic Distortion caused by the interaction of the input/driver tube and the 2A3. And, the voltages, currents, and plate loads: on the input/driver tube, and on the 2A3 tube.
Two:
The output transformer Quality; primary impedance; primary inductance; level of pre-saturation power versus low frequencies; and distributed capacitances and leakage inductance.
Three:
The loudspeaker; the interaction of the amplifier damping factor with the loudspeaker impedance versus frequency; the room dimensions; reflections and absorptions; and the loudspeaker setup of location, toe-in, etc.
Remeber, the 2A3 amplifier is only 1 part of the complete Hi Fi Stereo playback System.
It can not be the only influencer of the "sound" of your playback system.
Expecting one part of a system to fix an un-wanted characteristic "sound", might be over optimistic.
Often, a 2A3 amplifier is most influential on the 'sound' of a System, when it is simple: A CD player; 2A3 Amplifier; and loudspeaker.
I don’t know if anyone is still following this thread but wanted to add to some comments regarding 2A3 va 300B ‘linestages’. I have been designing DHT preamps and amplifiers for some time now and can say there is a noticeable sonic difference between the two in a linestage application. Depending on the circuit of course. My personal favorite is our 2A3 linestage as it has a bit more articulation where the 300B does have a fuller presentation just as it would be in an amplifier. The 2A3 linestage feeding one of our DHT amplifiers is sublime.
In our medium size listening room, this combination with 90dB speakers provides plenty of drive to fill the room.
As I’ve always said, “Built your system for yourself, not the critics”.
In our medium size listening room, this combination with 90dB speakers provides plenty of drive to fill the room.
As I’ve always said, “Built your system for yourself, not the critics”.