The obvious answer is that tube amps have higher output impedance (lower damping factor) and that contributes to total box's Q
This lends to a richer sound, given the presence of more bass
And simply solved with one resistor.
Some links to blind tests
tubes do sound better. My SX780 project has a new SS amplifier 0.003% mosfet Lichtstark from valery's revisiting the 1980's post . I replaced the M5214L with an OPA2134 op amp. The difference was minimal. using 6922 triodes in the same position yields a much wider soundstage and realism. No chance of putting an op amp back in that position.
No. Tube current is nearly proportional to Eg^1.5, while BJT's current is exponential (Is * e^(Q*V/k * T)) where Q is electron charge, V the voltage across the juncture, k the Boltsmann constant and T the absolute temeperature, Kelvin degrees). As the voltage at the anode/collector follows device current, clearly semicondutor distortion is bigger and more insupportable than VT amplifiers. Try any common SS amp (TDA2003 by example) without VFB, and the result will be a nice square wave.
I'm refurbishing my big 10W tube single-ended amp. So had to temporarily get my garage 1.5W tube SE amp so that the kids and I could continue watching Game of Thrones. Well, damn that little 1.5W SE playes SO much louder than I'd even imagined. Still getting sound levels comfortably loud for movie watching. Have of course been playing music, and it sounds so good! I imagine the 2nd harmonic is up there making a warm delightful tubey sound, but who cares, it sounds great! Of course it is compressing and the dynamics are not jaw dropping, but small can be great.
Haha I guess I aint no audiophile, just enjoy building amps and love music that's all. But I imagine a small SE class-A SS job also will sound great at low levels, again probably due to higher 2nd harmonics than usual. But that warm sound is so much easier to get with tubes. For low level listening I definately would go small tube single ended, 2A3 preferably.
Haha I guess I aint no audiophile, just enjoy building amps and love music that's all. But I imagine a small SE class-A SS job also will sound great at low levels, again probably due to higher 2nd harmonics than usual. But that warm sound is so much easier to get with tubes. For low level listening I definately would go small tube single ended, 2A3 preferably.
The audio business posters will be at it* again for pages and pages.
Thanks for the replies.
Have never built a tube amp before so have no idea in which direction to go or what to look for.
Can you please have a look at these, any good?
Douk Audio EL34 Valve Tube Amp HiFi Single-ended Class A Amplifier Board DIY Kit 8589944626153 | eBay
Douk Audio 6J1+FU32 Valve Tube Amplifier Single-Ended Stereo Power Amp Board 6409926346478 | eBay
1pcs Vacuum Tube Power Amplifier Board DIY KIT Audio Amp 131X98MM | eBay
6N2+FU32 Tube HIFI Stereo Power Amplifier Finished board 3.5W*2 | eBay
6P13P Valve Tube Amplifier Board Single-Ended Class A Stereo Amp DIY Kit 7Wx2 8589944623336 | eBay
There is a circuit diagram for one of them and the others have quite a few photos, is anything at all discernable. I want to use them for mid and treble, i already have an active sub for the bass end.
Have never built a tube amp before so have no idea in which direction to go or what to look for.
Can you please have a look at these, any good?
Douk Audio EL34 Valve Tube Amp HiFi Single-ended Class A Amplifier Board DIY Kit 8589944626153 | eBay
Douk Audio 6J1+FU32 Valve Tube Amplifier Single-Ended Stereo Power Amp Board 6409926346478 | eBay
1pcs Vacuum Tube Power Amplifier Board DIY KIT Audio Amp 131X98MM | eBay
6N2+FU32 Tube HIFI Stereo Power Amplifier Finished board 3.5W*2 | eBay
6P13P Valve Tube Amplifier Board Single-Ended Class A Stereo Amp DIY Kit 7Wx2 8589944623336 | eBay
There is a circuit diagram for one of them and the others have quite a few photos, is anything at all discernable. I want to use them for mid and treble, i already have an active sub for the bass end.
It's all wrong. The speakers should be fullrange speakers, then you can add a subwoofer for extra strenght in the lowest octave. Then, you have to spend some $$$ for the basic quality transformers & tubes etc. Push-pull is the way to go
I also think it's a combination - between the speakers( 2, 3 way, FR etc) and the amplifier type... definitely my Hiraga Le Monstre sounds nicer than other amps (tube amplifiers next on the list) at low volume (two way speakers with crossover + high output impedance of Le Monstre - generates such as "loudness curve" FR + pure class A - low crossover distortion)
We design SS amps to be optimum at certain listening level (and the range is wide if the amp can produce 200W). Nelson Pass design some of his amps to be optimum at first watts (not an issue if it is capable of only 10W like tube amps).
Class B or push-pull has issues at crossover so it has to be loud in order for this issues become small (in effect). So a fair comparison should be done only with generic SS class A.
Of course, it can be just a matter of design (tube or SS doesn't matter). I think output transistor will be the bottleneck (input capacitance in case of mosfet) if bias is less than 3A
Good mention of the Hiraga class-A! It is known and favored for it's detail (and separation of instruments)!
I fully agree that sweeping generalisations are pointless.
Still, after living for a couple of years with SS amps, thanks to a new pair of remarkable interstage transformers, my old valve amp left the closet again. Despite its modest 12W my very first surprise was the much wider range of volume outputs which sounded good compared to my SS amps. Yes, there is also the loudness effect: about 3db of lift @35Hz thanks to a highish output impedance, but clearly there is more to it.
With SS amps there seems to be a trend too: the ones with huge power supplies and multiple output devices sound the most "dead" at very low power. Harmonic spectra do not show anything.
Still, after living for a couple of years with SS amps, thanks to a new pair of remarkable interstage transformers, my old valve amp left the closet again. Despite its modest 12W my very first surprise was the much wider range of volume outputs which sounded good compared to my SS amps. Yes, there is also the loudness effect: about 3db of lift @35Hz thanks to a highish output impedance, but clearly there is more to it.
With SS amps there seems to be a trend too: the ones with huge power supplies and multiple output devices sound the most "dead" at very low power. Harmonic spectra do not show anything.
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