pauln

The first thing that happens to the AC power input is that it gets converted to DC to run the rest of the circuits. If you were starting from scratch, you would specify the required DC values up front in the design and use a battery; the conversion of AC to DC is just to account for the common source of power availability. (Some tubes use AC heaters, though) So... at what point does a seriously wealthy audiophile forgo using AC power and switch to battery? The elegant and effictive solution would be to bypass the AC line power and provide dead clean battery power directly to the circuits. How much would that modification cost? I think it would cost less than some of the more expensive AC power cables? Deep cycle marine batteries are not expensive and act to separate you from the problems of the AC source, even though they use the AC source to charge...

FYI, the Pro-Ject Tube Box MK II (phono preamp) is avaiable from needledoctor.com or sumikoaudio.net for $449 The one on the list is not the MK version... both retailers use the pictures of the MK version but all call it Tube Box II. I found a review where the guy said he paid $399, calls it the Tube Box II, but shows the MK version in the picture. Hope that helps... specs: here or here http://www.needledoctor.com/Pro-Ject-Tube-Box-II?sc=2&category=401 http://www.sumikoaudio.net/project/products/tubebox2.htm review

Here is what I get using P=V^2/R and I=V/R Watts ohms Volts Amps 2048.000 8 128.00 16.00 1024.000 8 90.51 11.31 512.000 8 64.00 8.00 256.000 8 45.25 5.66 128.000 8 32.00 4.00 64.000 8 22.63 2.83 32.000 8 16.00 2.00 16.000 8 11.31 1.41 8.000 8 8.00 1.00 4.000 8 5.66 0.71 2.000 8 4.00 0.50 1.000 8 2.83 0.35 0.500 8 2.00 0.25 0.250 8 1.41 0.18 0.125 8 1.00 0.13 0.063 8 0.71 0.09 0.031 8 0.50 0.06 0.016 8 0.35 0.04 0.008 8 0.25 0.03 0.004 8 0.18 0.02 0.002 8 0.13 0.02 0.001 8 0.09 0.01

Hey Dave! I have a Stanton L720EE cartridge with a DD71-EE stylus, and a second stylus (big fat one) designed for tracking 78s, both virtually unused. I'll drop it by some evening soon and let you see if suitable for anything. If so, I'll just give it to you for keeps. As a B&O man, I don't know quite how the fittings work, but the cartridge has a rectangular rear end with a hole through it sideways, and there is a separate adapter for whatever you call that mounting where you hang the thing from two screws. Paul

I got a pair of some of the last La Scalas I's made in Feb of 2005. They have the new drivers and came with the AL-4 networks. They sounded fine. I put in type A's and they sounded far better to me. I play records only, use 2A3 amps, no subs, have yet to push more than one watt through them. Totally amazed every time I sit down to listen to music! There was nothing really "wrong" with the AL-4's, I can see why many would like them, especially loud listeners. But to my SET loving ear, they sounded a little too "Hi-Fi" with maybe a slightly exaggerated upper and lower frequency extension, a tiny bit artificial or synthetic - just not dead absolute real compared to the A's. The A's sound much more real to me. I know their gentle low order slopes are a potential problem for very loud listening, but I don't do that. They work the best for the listening level I prefer. They are more open, clear, transparent, invisible, all those things that match well with the SETs and vinyl approach. As far as all the other network possibilities, I don't know if there is a network that sounds as good at loud volumes as the A's do at moderate volume.

For those wishing to know the procedure for discharging the power supply caps before working inside a tube amp (rewiring, mods, putting bias measuring circuits in place)... Make an insulated lead wire that has an alligator clip on one end and a 10K resistor on the other. Make it so that the leg of the resistor at the end connected to the wire is insulated either with shrink wrap or electrical tape, and leave the terminal free leg bare. ----[ 10Kohm resistor ]================================[alligator clip] After pulling the power plug, remove the power tubes and if there is a stand-by switch, set it to "On". Connect the alligator clip to the chassis, then hold the other end of the wire by the insulated part, and use the resistor's bare terminal leg to make contact with all the pins in one of the power tube sockets. Maintain contact for about 30 seconds on each pin. Don't touch anything else conductive. Only one of the pins is the one that will discharge the PS caps, but doing them all will insure that you get the right one. This only has to be done for one of the power tube sockets. Be cautious. Use one hand.

"Pauln, you have absolutely no knowledge of my elec. experience or previous exposure to high voltages. Just because I have not Biased a tube amp does not make me inadequate to do so. Since I have worked with high voltage (CRTs for one) for 25yrs with first the USAF/ANG as s sensor systems specialist and then as a high voltage electrical service provider, I am certainly no stranger to electricity or high voltage. "even when the amp is unplugged" on a tube amp? I don't thinks so, as vacuum tubes bleed themselves off immediately when power is removed, right pauln? Maybe I should be warning you sir about the dangers of high voltage." I beg your pardon. You must agree that "101" is the designation for the very first beginning instruction class and using it in thread titles is the common way of indicating one is not knowledgable on a subject and requesting basic information. I have no knowledge of your experience because you did not introduce any, you used the label '101" and I told you the most important knowledge - the danger. I posted because a "101" level inquirer might not be aware of the danger of the caps (even when the amp is unplugged). People have died from not knowing the dangers of an unplugged amp. Since you demonstrated that you didn't know about that, my post served its purpose. Since you were so kind to ask me directly; no, you are incorrect, it is not the vacuum tubes that bleed anything (except heat for a few minutes), it is the power supply caps, and they may continue to hold a lethal charge for weeks if not discharged using a shop procedure. They certainly do not immediately do so when the power is removed unless the manufactuer has deliberately installed a resistor to do that. The discharge procedure is used even when the resistor is present to avoid the risk of it having failed and the charge remain.

If you have mono blocks, why not connect the amps directly to the networks with ultra-short cables of a few inches? It would be like not even having speaker cables or any of their supposed defects. Is this better than the $50K cables?

The bias procedures for tube amps is very dangerous and can kill you, even when the amp is unplugged - not something a novice at the "101" level should consider attempting themselves. Find someone to do it for you that is well experienced. Some single ended designs use a self bias circuit that does not need adjustment. In general, you cannot predict the correct bias for a circuit until the measurements are done, and those measurements vary among tubes of the same design.

"I lost the stylus (am at a loss how...it just wasn't there one day)..." Prediction: When you find the stylus the hum will go away.

If you play bass guitar through the woofers that came out of you La Scala, expect to destroy them pretty quickly...unless you are planning to do this for "bedroom practicing" at a very low level. The designed physical response of bass guitar musical instrument speakers as the power goes up is: Linear, then non-linear, then overdriven (they are designed with plenty of reserve so they can operate in non-linear forever without damage and will tolerate considerable overdriven operation without guaranteed damage - they are tough and designed to be driven hard; but if you keep going up in power then they may be ultimately damaged. The designed response for high-fi speakers is: Linear, then a bit of non-linear, then overdrive damage. (They are not designed to be driven hard). They do not have the design reserve to ease into non-linear but for the briefest of moments and that thin reserve is very much closer to the overdriven level at which any extended operation at that level may destroy them.

Dave, was thinking about you just the other day. Count me in! Paul

My favorite kind of thread! Let's examine the possibilities. Otherwise you might be using them upsidedown...![] If they just isolate, then not only do they prevent vibration from entering the component, they prevent vibration from exiting the component. If they just conduct vibration out of the component, they also conduct vibration into the component. If they both conduct and isolate, perhaps differentially as in the mechanical diode theory, then the theory would imply that the dominant direction of conduction would be one way and the dominant direction of isolation would be the other... so let's examine which direction these might be. There are 17 possible ways for the cones to operate on vibrations as far as direction is concerned: These things either just "isolate" vibration non-differentially in both directions towards and away from the point, or they just "conduct" vibration non-differentially in both directions, or they isolate differentially based on the direction of the vibes (two possibilites based on the favored direction polarity), or they conduct differentially (two possibilites), or both just isolate and conduct non-differentially, or isolate non-differentially but conduct differentially (two possibilities of the later, so three total), or the above case visa vera (three possibilites, see previous above), or both isolate and conduct differentially (four possibilites, you do the math). All that without yet considering any possible frequency changes. There are 16 possible ways for the cones to operate on frequencies as far as direction is concerned: These things all pass, high pass, low pass, or band pass going toward the point and/or all pass, high pass, low pass, or band pass going toward the base. This looks like 272 possible ways these cones might operate, and I used simplified categories of possible mechanical operation. Now lets see what the polarity might be for those cases where the magnitude of the conduction or isolation (or both) of vibrations through the cones acts differentially depending on the direction. Does the cone shape act like a horn and make the vibration increase going from the point to the flare (and reduce in the opposite direction)? Or, does the greater flare base area take a given magnitude of vibration and increase it (concentrate it) when vibration goes in the direction toward the point (and visa versa for the opposite direction)? That is, which might be the conducting direction and which the isolating direction? Since the typical geometric orientation for the use of footer cones is for the points to point down, it seems that the mechanical operation assumptions would be that the cones act more as conductors for vibration traveling in the down direction (to "bleed off" vibes from the component), and act more as isolators for those vibrations going in the up direction (to block vibes from entering the component). Depending on the theory of mechanical operation, one might also assume that the theory would have the cones acting as vibration magnitude concentrators in the down direction (acting as an energy "sink" or absorber/damper at the base end of the cone), and as magnitude reducers in the up direction (mechanical impedance mismatch/vibration diffuser). I can almost imagine that they actually work, the question remains, if they are doing something, what is it, and how? Anyone have some cones, a test source, and a scope?

Interesting. But don't most people increasingly allowcate their funds out of the stock market and into fixed instruments as they approach retirement to avoid the potential problems with a market down turn? Someone in their 70's with money at risk in the market is going against the usual and accepted recommandations offered by almost all financial planners.

I have one, it is the early version of the WPL that is encased in the chassis of a WPL10V (so it has two channel volumes labeled "Volume" and "Balance") because George didn't have the new chassis yet. I use it with Wright 3.5 SET monoblocks and LaScalas for two channel vinyl listening exclusively - absolutely wonderful! The Wright phono preamps are "active" in the sense that they have gain and push a pretty good level to the power amps. This does not work with all types of power amplifier. They seem to prefer pushing a lower gain power amp rather than providing a more passive signal for a higher gain power amp to drive. Some professional reviews seem to have discovered the same thing.

So glad my home is a "digital free zone" My turntable and records have served beautifully for 33 years, no end in sight.

What are you calling analog sound? Do you have an analog source or are you comparing digital inputs/outputs, some of which may have various A/D or D/A conversions?

I have a Carver M-500t; for those not familiar with it... 250W/ch @8ohms 350W/ch @ 4 ohms 500W mono bridged (diagram for how to do that screened on the back panel) Two very large watt meters on the front face that may be callibrated inside with a plastic screwdriver and a known source (but the lights for them went out years a go) Magnetic Field power supply I could probably find the rack handles if I looked around for them Of the few sand amps I have heard, this one is the nicest sounding, very strong and quiet. I've been going the other way for years (SET), so if someone is looking for a big old Carver to play with, let me know.

Oh, you think you're done? It has only begun, my six string friend! Once you fall in love with guitars and guitar playing its never done, so much to hear and explore. Good luck on the start to a long rewarding passion.

You won't do so well unless you read the instructions or happen to notice that the cannon has a red bar indicator that occilates in length - that is the instantaneous power of the shot, so you need to catch it when it is at maximum.

Kitten Canon

But Artto is correct about the time problem - the time delay of the correction means it lags the very point in the wave it meant to correct. The correction is always behind and correcting the "wrong" part of the signal. Which creates a lessor additional error. For very steady constant sounds this may not be such a problem, but for quickly changing sounds or complex sounds that change the wavefrom irregulary, the correction will not really ever catch up to totally match phase with the error. Since the correction is a loop, the mismatch between the correction and the error first time around becomes a second error which subsequently misses it's correction match the second time around, and around and around til the level of correction for the orginal error is diminished to nothing.

Apex center forward was meant to refer to how you point the cube with a side edge most forward toward the front center. No one is addressing my fundamental question - how do you tell if the sound comes from the front or the back with two ears? Only if you already know how different a sound will sound whether it bounces or deflects in or off the ear at different orientations would the final signal coming from that ear have any chance of indicating the front back source direction (or above/below - really the whole ventral plane). Of course that might be possible if the asymmetric outer ear masks the high frequencies a lot for sounds coming from the back and amplify those from the front, but then; does that mean a four mic and four speaker system would need to apply the low pass to the back channels and play the fronts louder? Try putting you hands against the sides of you head like two giant ears, but place them in front of your ears so they point as if you had them on backwards - facing to the rear. Front sounds still sound like they come from the front! Even with the low pass operating in the wrong direction?

Aw hucks, I don't really know anything... You're thinking of the "pinna", the latin for feather. Actually, the 180 degree limit boundary of you mics would make quite difference with the orientation you use having an apex center forward.

Just guessing, but the courts go by what you have in writing, not so much by what is said, right?