Can tube amps give true high end bass?

It's so hard not to generalize here. I've heard a lot of systems where the bass did seem a bit bloated or sluggish with tube gear, but, when that is certainly not the case with all tube gear. All of the very best sounding systems I've heard were driven by tube gear and of all different sorts -- single ended, low-powered pushpull (particularly based on Western Electric components), and OTLs.

I don't know, and don't really care if the bass went super low or if the system was capable of really prodigious output, what I do know and care about is whether the tonal quality of bass instruments is right. A lot of systems touted for their bass quality actually don't deliver properly tuneful bass.

Jmaldonado, can you please explain why you feel a tube amplifier needs at least 40wpc to good bass?

I know that statement is patently false as I have seen published numbers of a Decware 2wpc amp going down to about 10Hz at –3db, but I would like to hear your spin on how you correlate frequency response to output power.

Regards
Paul

T_bone, as amfibious said, I was talking about damping factor. This has been one of the big discussion themes since the 70's, but apparently it keeps being ignored by most audiophiles. Regardless, it will always be important because it predicts how good is the amp's ability to generate a bass fundamental without the speaker circuit altering its amplitude. Why this happens? The question has to do with the current vectors created in a third order (or bigger) circuit, such as that found in all speakers. It's pure math, but you can measure it and of course listen to it. It manifiests itself as a "boomy" bass at a certain favorite band of frequencies which depends on how the speaker was designed, and how well (or bad) the amp can control it.

Why do I think solid state amplifiers have the advantage? Transistors are low-voltage, high-current devices, whereas tubes are the opposite, i. e. high-voltage, low-current devices. Virtually all speakers in production today are low impedance transducers, varying from 8 ohms down to 1 ohm. THEY NEED CURRENT TO WORK! By nature, they work best with transistors due to their lower output impedances, and better damping factors. Besides, in order to equal a solid-state amplifier current capability, you would need a battery of 30 or 40 tubes in parallel (remember Julius-Futterman OTLs?). That's why most tube design depend on an output transformer in order to compensate for the disparity between tubes and speakers. However, IMHO transformers bring even worst evils than they cure. They introduce even more coloration, hysteresis distortion, they attenuate the lower bass, they introduce phase-shifting, etc. The situation is just hopeless.

I have no doubt that somebody will say "But I like the bass of my tube amplifiers better than a solid-state's. They really kick in ________ recording!". That's OK. It's just a personal preference, a very romantic one... ;)

Regards,

Jmaldonado, thanks for the clarification. I guess I now have an explanation for why I like my tube amps vs others that I have tried on the relatively efficient woofers of my even more efficient speakers. I have thought about powering the woofers with solid state, but have thus far avoided it.

Another question back at you would be... how much tube power (watts vs output impedance) would one need to adequately power an 8ohm 96db woofer? say, the way a 40W solid state amp might...

+++Audiobb, I am surprised the 300B sounded better than the Cambridge consider the fact that you were using B&W 602+++

You shouldn't be.Tubes will give better mids and treble in variety of speakers.Regardless of impedance curves.We tested with few B&W (from 601 to 801D),Tannoy,Focal JM,Dynaudio etc.

+++Had you been using appropriate speakers, you may find your 300B capable of the same (or better) bass than the Cambridge.+++

I agree that,coupled with more tube-friendly speakers(8 ohmstable,93 db+),300B will improve in bass.But,according to our tests,Cambridge gives out more tight and precise bass.In my book,better and more linear bass.This is primarily caused by 2 things:

1.DAMPING FACTOR-Cambridge has couple times higher than SET amps.This can be improved with output trans.
2.PEAK AND RECOVERY TIME-Transistors are better than tubes there.Best are bipolar transistors.This is not my opinion,but plain fact.

For bass output,we have found transistors sonically better.BUT even better result still can be achieved with tubes-but it probably will cost sky high.See the previous post of Jmaldonado.But it still would never catch transistors in Peak and recovery time - which means not enough fast start and stop of bass driver.And for me it is essential.