Tube Biasing: do I have to?

Brucegel:

There are good tube designs and bad tube designs. The same goes for SS. Each has its advantages and disadvantages.

As far as digital goes, I feel that CDs are an improvement over vinyl records. It's very hard mechanically to put the signal onto vinyl, and also very hard to retrieve it. CDs don't have those problems, so it's a "less imperfect" medium. The A/D and D/A conversion is where there may be problems, but I feel they're done fairly well, and better than the electrical/mechanical and mechanical/electrical conversion done in vinyl records. The electrical/mechanical and reverse conversion done on CD is less prone to problems because you're simply looking for signal/no signal.

Tape also has electrical/mechanical and the reverse conversions. It's at a smaller scale, but you're still doing it. There are problems with this. Digital tape is more able to ignore those problems because it's easier to do signal/no signal recording and playback. Again, the A/D and D/A conversion could cause problems, but it seems to be quite good.

I'd say that the case is less clear with digital vs. analog tape than with CD vs. vinyl record. Analog tape is probably a better medium than vinyl records. It just costs more to produce which is why it didn't dominate the market.

Getting back to biasing tubes, yes, you definitely want to make sure they're biased correctly. Tube equipment has added hassles that you don't get with SS gear, and that's the price you pay for using tubes. One would hope that the benefit to you outweighs the increased hassle.

Once you figure out how to do it, it's normally quite easy. You shouldn't have any trouble with it.

Judy426>Whoa!! You are kidding right?

Not at all. The built-in distortions of vinyl are so horrible that any slight problems with CDs are rendered meaningless.

The problems with digital are curable, while the problems with vinyl are not.

I could speculate that you've never heard a quality CD setup. :-)

Euphonic distortions sell an awful lot of equipment, usually at very high prices. Vinyl, moving coil cartridges, 8W SET tube amps, very expensive car speakers masquerading as "full-range" speakers...

Then there are the purely psychosomatic effects of fancy wires and parts. Peter Belt is the logical extension of all of this. :-)

I had an H-K Rabco table at one point, then a newer H-K. My most recent is a Sherwood belt drive table that I've heavily modified for better damping of resonances.

Cartridges have been mostly Grado, but I also had an A-T and a Shure. I prefer Grado. I've also tried the Longhorn mod for the Grado carts, and I, of course, calculate the required load and change my preamp to match.

I carefully setup the cartridge using a Cart-A-Lign, and you can definitely hear the difference. A mistracking cartridge causes noticeable distortion and you can hear it as separate from the music. (Pops and ticks are also perceived as separate, so they're perhaps a bit less nasty than they could be.)

I've also listened to various audiophile turntables and cartridges. None of them did much for me. They're more expensive, but not necessarily better.

Once you do away with unwanted resonances in the table and arm, align the cartridge, and make sure it's electrically loaded properly, you're pretty much at the limitations of the medium.

The CD player or transport is not a big factor. Just choose one that has a digital out and the features you want. I have a Philips player, and it's been working fine.

My DAC is an OmegaStar from Audio by Van Alstine.

I listen to a wide variety of music, and also spend time listening to live music. (I play acoustic guitar too.)

Guitar and piano simply sound more realistic on CD than on vinyl. The dynamics are reproduced better, and there's no smearing of the decay.

The "weight" of large orchestral works also comes across better, the strings sound more realistic, and the brass comes across so much better that it's amazing I ever put up with vinyl.

Reel-to-reel tape is also superior to vinyl. It seems to have some low level problems, and it has noticeable noise. However, as with pops on records, tape noise has a different character than music, and it's fairly easy to listen past it. (It's hard to describe, but tape noise and record pops appear right at the speaker, while the music is not nearly as localized to the speakers.)

Unfortunately, with vinyl, the problems with attack and decay are not so easy to ignore. Perhaps I could best explain it as the problems with dynamics directly affect the reproduction of the instruments and music. Tape noise and pops and things like that affect the background. Does that make any sense to you?

CDs simply provide, to me, a better window to the original performance. Are they perfect? Probably not. But they're good enough that I can safely move on to the speakers and the speaker to ear interface - which is where the real problems lie in most systems.

We have a good handle on the electrical part of things. It's when we interface to mechanical systems that big problems show up. Eliminating vinyl cures on part of it. Mics are quite good. Speakers are not so good. :-)

Then we have issues with how we record a performance, and how the speakers reproduce the electical signal (and how it all reaches your ears). There are some basic flaws to stereo reproduction that are generally ignored. Binaural attempts to deal with this, but it only works if you're close to the generic model they use. Transaural is a better direction to go in.

Non-linearities and distortions in speakers can be a huge problem too.

At any rate, I feel that we now have the chain from microphones to the terminals of the speakers in a state where they're "good enough," and it's time to worry about other things.