pauln

As a musician, this is not a mystery to me. Music lovers hear things differently; hard to explain... The simple way to say it is: Some hear sound more as music, where most others, including many audiophiles, hear music more as sound. It's not black and white, but the main difference is in how it is perceived... hearing progression movements, chord types, melodic lines, harmonies, etc. from a musical recognition standpoint (as abstract internal representations with which music lovers are well familiar). This is heard in spite of the quality of the source, ... a nice system or a clock radio. To put it another way, this whole question is like two people working a math problem with pencil and paper, the non-mathematician arguing that it would be better to use nicer paper and a better pencil... the mathematician seeing through the tools themselves to the beautiful idea beyond...

You are planning to be "GRINDING STEEL" in your shop... how loud is that? I'm not a steel gringer, but I'm imagining that it makes enough noise to require hearing protection - for your ears, as well as the speakers. Glad you are thinking about it and looking out for your La Scalas... just had to ask.

If you can solder and follow a schematic you're an excellent candidate for building your own. As you might imagine, in a well designed and manufactured finished product, virtually every aspect, be it the position of components and wires or placement of controls; everything has been done with respect to a collection of principles - low noise, low hum, etc. All that stems from the technical engineering side and experience. Some manufacturers have more of that than others... When fashioning a product from a kit there is the chance that many of the specific techniques used by the industry pros will be misunderstood, poorly implemented, or just overlooked. Some of these are quite simple, but may not be intuitively obvious to the general builder. It is very important to spend some time on the kit / DIY forums to learn as much as possible about what techniques have the most influence on success.

If you build one of the Bottlehead amps, be sure you twist the hell out of all the paired wires, both signal and heater supplies, to knock down the hum. To the degree that the Belle is very similar to the La Scala, you should definitley try SET power, the 2A3 tube is plenty with a properly matched preamp and just sounds heavenly, profound, dimensional, and real. Nice to see this old thread get revived...

My experience is that in spite of placing the speakers to do their best, the greatest contributor to imaging is the type of amplification.The imaging has to be in the signal before the speakers can present it.

My point? ...oh, I forgot to make a point. Well, it could go in different directions but I guess my general point is that the fundamental design principles that many of us seek and enjoy from the big efficient Klipsch speakers may actually be best implemented well below the ultra high priced approaches that pursue different principles. If one sticks to the PWK approach to music reproduction there may not be just a diminishing return with further expense - there may be a "sweet spot" region beyond which those principles become violated and the nature of the resulting sound may depart sufficiently to be disappointing even with further expense. I don't think it would be absurd at all to audition a $100K system, then go home and discover that one's own modest system actually offers more of what one seeks in music reproduction, be it purity, musicality, liveliness, tonal feel, so whatever - it depends so much on one's preferences. If one's preferences are actualized by adherence to fundamental principles that don't manifest well when abandoned or scaled up to a mega-system, I can see how the $100K system might not be "better" at all. Just to make the point clear, even if a flawed example, I imagine that the total cost of some of the systems used in movie theaters might approach the $100K level, yet there must be many who return home and decide that the music in the movie did not sound as good as the same music played on their home system.

Those ultra-expensive systems tend to be comprised of speaker arrays that require a lot of watts, and specialized amps to deliver those watts. Speaking of "ordinary" amps, according to Nelson Pass, "Push-pull amplifiers generally operate in Class A mode up to a point where the output current is twice the value of the bias current. In the Class A region, both halves of the circuit share the signal simultaneously. Beyond that the signal is handled solely by the push (+) half of the amplifier or the pull (-) half." This means that with sufficiently sensitive speakers you may be listening in class-A even though you have a class AB amp. For example, I have a very nice old (1973) Sansui AU-6500 integrated amp. The spec bias setting is 28-32ma, so according to Nelson Pass as long as the output current is below about 60ma, I'm in class-A. If I do the calculation for how much power to which that level corresponds for 8 ohms load (about 30milliwatts) and then use the sensitivity level of the La Scalas to estimate how loud that power level is... the transition from class-A to class-AB occurs at around 90 db spl. This is one of the hidden values of ultra sensitive speakers - more of the music's dynamic range is delivered in class-A; for very moderate volume levels almost all of it.

RG59? What are you using it for? When should I use RG59 versus RG6

fini: "Wendy Carlos uses Cornwalls suspended from her studio ceiling." My records say "Walter Carlos", but maybe that was before swapping the folded horn for a port?

The question may be backwards and the comment above about the body being a great antenna more accurate. We guitar players notice this all the time and usually think we are grounding the strings by touching them to make them quiet. See this link for the current theory (bad pun) which looks at it the other way. Here Now about the cable. The line into my home goes to a splitter in the attic from which it projects and drops down into the walls in about four different places, only one of which I use. I noticed that when I played my guitar and stood anywhere near one wall with one of the unused cable outlets I got noise. I disconnected all but the one I use from the splitter and the noise disappeared. Dave, there is something you can try. Disconnect each component and measure AC volts with a multimeter between the chassis and the outlet ground screw while the component is powered on. Then reverse the orientation of the plug in the outlet and repeat the measurement, using a cheater plug if the component is a three prong plug or one of the modern ones where one blade is wider than the other. You will get two different AC volt "leakage" readings, one higher than the other like 30mv and 80mv. Mark the plug for the orientation that has the least AC volts. Repeat with each component, then plug them all in with the lower volt orientation. This gives you the lowest noise floor as a baseline for any further ground hum or noise issues to be solved. For any components using the cheater to get this orientation, just run a wire from the component chassis to the ground screw on the outlet face - it is the same as the ground hole in a three hole outlet, which is just a redundant safety ground identical to the neutral slot. Or use the cheaters that accept the three prong on one side and present a ground wire on the other to connect to the ground screw... I'm sure you already know most of this stuff above. The reason plug orientation shows an imbalance is that the power supply from the utility has a "single ended" aspect to it. The two AC 110V wires from the pole to the home are out of phase. Both are used together for 220V outlets. For 110V outlets only one of those is used and it goes to the "hot" slot in the outlet face. The "neutral" slot just goes to the ground in the breaker box. So does the "ground" hole in the outlet face. The single ended thing comes in because you are placing your component's power supply between the AC 110V "hot" slot and the grounded "neutral" slot. The convention for fused power supplies is to place the fuse on the "hot" side of the transformer primary coil, but not all manufacturers do that. Hope you get things worked out.

Can't say anything about the Forte, but the La Scala needs some room*. The sound from the three horns does not integrate into a unified presentation until you are about 12-15 feet back and it really helps to have about that much space behind and beside you as well. What some call the harshness is coming from sitting too close and hearing the pre-integration imbalance and possibly too much early reflection in small rooms. *I will say that for a couple of weeks I put my La Scalas in a bedroom (carpeted floor). I also put up a mattress on each side wall and the back wall ... sort of as a "near field" experiment... sounded surprisinly good in the highly damped smaller space even at moderately high levels PS - Come to think of it, after the baby comes you are not going to be getting any sleep so you will have unused mattresses around and a highly damped listening room would keep the sound level down in the rest of your place.

The way it is written, he has access to dealers with La Scalas, they just don't have good enough equipment to present him an audition. The implication is that the guy has good equipment at home. The best comparison, short of taking the speakers home, is to take his gear to the dealer. If it was me, I would ask the dealer if I could bring in my equipment and set up an audition. This makes more sense than requesting random reviews on the internet without even indicating what he considers state of the art equipment.

It might just be the jacks, especially on used equipment. Some RCA jacks are mounted with a "key" that prevents them from rotating; others are mounted without a "key" and may just be held on with hex washers behind the chassis. Some people like to twist RCA plugs when making or breaking contact with the jack, and over time repeated twisting may cause the jacks to become loose enough to rotate. Once they can rotate there are lots of problems that can happen; broken wires, things touching that should not touch, etc... Try pinching the external jack protrusion with your fingers and see if it is loose or can be turned. If so, you might need to inspect them from behind (inside) and see if you can re-tighten them.

I replaced my speaker wires last night with 26awg solid with thin insulation, twisting the two wires so they have about two revolutions per inch, about eight feet long. This replaced 12awg stranded inline with thick insulation. The change seems to have improved everything; even my headphones sound better.

Well, just let me say this about that... I also have been a HiFi enthusiast for about 40 years. I had Heresys for about 30 of those years, then got La Scalas. I wish I had done that many years earlier. I also tried a couple of amplifiers, including a 250W/ch Carver, but about ten years ago I got some single ended triode mono blocks and tube preamp. I wish I had done that many years earlier. To answer your question, it is impossible to say for a specific situation. But generally, my advice would be to not wait to find out.

Not high end? Please consider that Sansui made some of the best integrated amps in the world at that time. Their tuners were very highly regarded and still prized today. The tuner probably needs a service procedure called an "alignment", which is fairly complicated and requires some test and signal equipment. The amp is old enough to consider replacing some of the electrolytic capacitors and general service. You could check and adjust the DC offset and output transistor bias yourself with a multimeter. Both of those pieces are very well designed, well built. The same level of quality new today would be found after exceeding at least $1000 - this is equipment worth spending a little to have checked and brought up to original specifications. Look around the Exclusively Sansui forum section of Audiokarma.org and discover just how nice your stuff really is, and how to take care of it or contact someone who knows how to do the service. I have an AU-6500 that is just amazing. The site mentioned above has a library of service manuals, instructional threads, and many step by step examples of bringing these great pieces back to full performance. It would also be the perfect place to pose your questions or problems as the forum there is full of friendly experts (like the Klipsch forum).

Did you mean to say that the more complex networks present a flatter impedance? And that the simpler network has more variation, allowing the fatter bass? On looking at zobel, I find, "A Zobel is a filter used to stabilized loudspeaker impedance in a crossover-speaker circuit. This consists of a capacitor with a value equal to one which gives a crossover frequency at the frequency where the impedance has doubled, in series with a resistor which has a value equal to 1.25 times the nominal loudspeaker impedance. This is connected parallel to the loudspeaker between the loudspeaker and crossover." There are some zobel calculators that take the nominal impedance and the frequency at which the impedance doubles as inputs. If I tried this I'd need to know those two values... would the nominal impedance be considered 8 or 6 ohm? Which peak of the impedance is the one used to measure the impedance doubling frequency, and from which side? Or do you know the frequency at which the impedance doubles? The zobel seems to be a high pass filter which would skinny down the bass. Not sure if that is the way to go with La Scalas and SET... I like the sound the way it is and everywhere I look the La Scala and type A are praised as having a very easy impedance load. But a zobel is just a cap and resistor, so it would cost nothing to try. Is it just the FR that would be the benefit of a zobel in this case, flattening the stock +/-4dB down a bit? I wonder how much of that might impact the dynamics.

When I bought my 2005 La Scalas they came with the AL-4 networks. My feeling was that they were designed for "modern" habits - loud playing from solid state amps. They used a sixth order design with steep slopes and some designed-in frequency compensation. Testing them with loud levels using a Carver M500t (250W/ch) they sounded very good, smooth, made the Carver sound great. But, my preference is moderate levels using SET, and the AL-4 did not seem to have been designed with that in mind. They were a different direction... in fact, each of the AL-4 network boards had more components on them than are inside my SET mono blocks and tube preamp combined. I bought Bob's type A's with the GE motor run caps and knew within three seconds that I had found the right replacement networks - first order broad slopes, lower volume clarity, far superior match for the SET amps to my ear. I'll be interested to read what you think after sprucing up your originals.

I can tell you that in the guitar tube amp world, after installing and setting the bias for new tubes, most people will leave their amp powered on (not in standby mode) for a few hours to let the tubes operate hot and "get used to" that particular bias setting. Not sure what exactly might be going on there technically, but lots of techs and manufacturers recommend it to promote long term stable operation. Likewise when someone decides to change the bias of existing tubes; giving the tubes a few hours of hot running with the new operating point is thought to help the tube establish that new setting for the long term.

Dr. Who, I'm not mystifying physics; modern theory does plenty of that all by itself. When modern theory is able to explain how a point particle has mass, what charge is, how massless particles have momentum, and how point particles and massless particles have angular momentum... then I will begin to believe that physics has some fundamental understanding of these things. Until then it is just math that works and conceptual analysis that doesn't. I'm kind of interested in why you think the general ss-current and tube-volts characterization is backwards. The most common solid state power amp stage is probably the common collector or emmiter follower, which has a voltage gain of less than unity. It is certainly a current amplifier. Except for the cathode follower, which is kind of rare and not highly regarded in the audio world these days, I think most of the tube amp power stages are voltage amps. Maybe I'm missing something?

Not sure how it is for others, but my browser (Firefox) makes the "Save" button appear way out to the right of the final dialogue box so I need to scroll way out there to hit it. Maybe some folks are getting up to that point and not finding the final button to finish the download...?

In truth we know almost absolutely nothing about electricity (or the rest of physics) at a fundamental level. As others have mentioned, there are lots of theoretical equations that have been developed over the years that describe the measured behavior of electronics. The math is needed to work with those equations; for example impedance is typically characterized by using imaginary numbers in a complex number plane. Everything with waveforms uses trigonometry, and you'll need to brush up on exponents and logarithms. As far as your questions; solid state amps tend to be current amplifiers and tube amps tend to be voltage amplifiers, but both end up delivering watts (power). Speaker design is complicated by the addition of mechanical physics, which you have already noticed. Do a search on this forum for "The Dope from Hope" to find a copy of Paul Klipsch's informal newsletter collection for Klipsch dealers that covers much of this at a basic level of understanding, oriented to answering questions about amps and speakers, etc. The behavior of electrons in terms of movement depends on their situation. In a conductor (wire) experiencing a direct current each electron will be in one of two conditions at any one time. He may be bound to the outer shell of an atom, or he may be a free electron unbound among the metal atoms of the conductor. At this point one must distinguish between charge and charge carriers. The charge will travel through the conductor on the order of about half light speed, but the charge carriers (electrons) will only move on the order of centimeters per hour. There is a net flow of electrons (current), but this is quite slow and comprised of individual electrons only moving a tiny distance closer to their neighbor. Some of these movements will be free electrons, others will be bound electrons becoming unbound, others free electrons becoming bound, and bound electrons directly changing the atoms with which they are bound. In all these cases, they interact by exchanging photons (present theory) and basically pass the net charge imbalance along the conductor - kind of like a relay race where each electron runs a short distance and uses photons to hand off the charge difference to the next electron. Since the charge hand off is mediated by photons at light speed, the proportion of the relay leg that is made by light allows for the charge movement to be quite fast even though the charge carriers (electrons) are slow. In a conductor experiencing alternating current, the same thing is happening except the charge direction is reversing periodically. The charge speed is fast enough to transverse the length of the conductor, even when that length includes the power utility grid distribution system covering hundreds of miles. Yet, the charge carriers are "local" and don't have a net movement. In a bipolar semiconductor junction the charge is characterized by both charge carriers (electrons) and "holes" (an absent electron which is like a relative net local positive charge), and the semiconductor material has an impurity deliberately added to the material (called doping) which provides atoms with valence (in this case atoms with either one electron in the outer shell or atoms that just need one more electron to fill their outer shell). Electrons moving one direction are like "holes" moving in the other direction... If you look at this you will find there are PNP and NPN bipolar transistors, depending on whether the charge carrier is considered to be the electrons or the "holes". In an electron tube like a triode or pentode, there is a real flow of electrons from the cathode to the anode (plate) through the vacuum in the tube on order of half light speed.

That is a lot of records... but I still have 1600 78's looking for a good home.

The Soundstage site does distortion measurements on speakers. They don't show percent distortion because that is too general. What they do is plot across frequency and show two curves. The dB difference between the two curves indicates the distortion (in dB) at any frequency you care to check. Knowing the dB difference, you can figure the distortion at that frequency as a percentage... their explanation: Both curves are reported in dB which can be read off the vertical axis. In order to convert to a percentage one must read the top line (frequency response) and then determine the dB difference between that line and the bottom line (THD+N line). Translation from dB to % is as follows: Equal (or 0dB difference) = 100 % -10dB = 31.6% -20dB = 10.0% -30dB = 3.16% -40dB = 1.0% -50dB = <0.5% If you look around their site, they have examined some pretty high end speakers (and amps). To do a home distortion measurement might be pretty difficult. You would need to compare the signal going to the speaker with another signal derived from a microphone. The influence of your room acoustics would likely prevent any reliable conclusions.

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