Marvel

Exactly Duke! A good amp is a good amp, whether tubes or ss. Bruce

Here are a couple of links to folks who have done some of this: http://www.dcchomes.com/Heresy.html http://forums.klipsch.com/forums/249053/ShowPost.aspx Gregg has a page with LaScalas and KHorns too, but I can't find the link yet. Bruce

I'm using the SED EL34 in mine, and am quite happy with them. I have a new front end, so that doesn't apply (NOS 6922). I have my original 5AR4, which is still working just fine ( at 35+ years). Bruce

caffeine (kafen') , odorless, slightly bitter alkaloid found in coffee, tea, kola nuts, ilex plants (the source of the Latin American drink maté), and, in small amounts, in cocoa (see cacao). It can also be prepared synthetically from uric acid. While relatively harmless, it is the most commonly used mind-altering drug in the world. When used in moderation, caffeine acts as a mild stimulant to the nervous system, blocking the neurotransmitter adenosine and resulting in a feeling of well-being and alertness. It increases the heart rate, blood pressure, and urination and stimulates secretion of stomach acids; excessive intake can result in restlessness, insomnia, and heart irregularities. The effects of caffeine vary from person to person, as people excrete it at different rates. Physical dependence and unpleasant symptoms upon withdrawal (headache, fatigue, depression) are common in regular caffeine users.

I understand turns ratios quite well thank you. I guess I was missing that the 5AR4 is not directly heated. I hope you understand I am not trying to argue, but to understand where you're coming from in this. Bruce

Having the one horn on top looks a lot better too. Unless you are impressing the ladies with your horns. Bruce

That's great and I do it all the time. However, if you upload a pick that should be able to fit in the frame/table correctly, and it shrinks them smaller automatically. The old way wasn't really that hard to work with, and gave us a lot more options. (end rant) Bruce

This can't be right at all. That all comes off the high voltage winding and on a Mark III transformer, it only supplies about .2 amp (200 ma) on the output windings. One heater reuires more current than that. The heater on a single KT88 is eight (8) times higher than what the high voltage secondary could provide. BTW, explain what the drawings are supposed to tell me.

Dennis, Those quotes are all interesting. Dana's drivers use a polyester diaphragm (I'm sure you knew that), where most would assume the titanium for high power use. The 4591 only goes up to 9Khz (I'm sure you knew that as well). I guess one just has to trust their own ears eventually. We'll see if Dana likes his after a few weeks of listening or if it is just the 'new and different' that he likes. [] Bruce

Okay. I don't understand. First, why is the 5U4 an 'instant on' tube? Why does it conduct immediately compared to the 5AR4? I have other work to this morning, but I may have a second question later. Bruce

I have a '79 Spitfire just waiting to get restored. My son and I are contemplating a Mazda rotary engine for it. I only have about $100 in it so far. Body is in excellent shape. I would agree that the Miata would be a great car to get.

I think it was when I sold a 3/4 size Gibson hollowbody electric. Body was about the size of a Les Paul but about 3 1/2 inches deep. Brown hardshell with pink plush. $100. Or when I sold my tube Bassman head and dual JBL fender bottom. That's why I still have my '40s Gibson lapsteel. It rocks with the single coil! Bruce ... slippin' on stage. I can just imagine Duke...

Dana, What's the difference between the 4590 and the 4590P? Looking good to btw. Bruce

Actually, a resistor across a battery like that has current flowing through it. Your battery will deplete at a rate dependant on that resistance and voltage.

As my wife and I spend time at the cancer clinic at Emory, we will be praying for the family. He will certainly be missed. Bruce

I gotcha. Thanks Rick.

So Rick, are you saying that the IRCL doesn't do any good in your amp? That's what Craig said earlier. I'm not wanting to argue, but there are contradictions here. Bruce

The Allen & Heath gear is highly very underated. Built like tanks too. The new Mackie Onyx gear looks to be good, especially if you have a firewire card and software. Of course, they come with Tracktion, which is really a great piece of software. I have a version 1.x something. Once I got past the idea that the onsceen look didn't have to be the same as a physical mixer I really like it. Bruce

Amen! on all points. Prayers being offered up. Bruce

Rick, The thermistor in Shannon's ST-35 is on the 115 volt side of the power supply tranny, so it works on the whole circuit. That was the point of my quote from Rod Elliott in Australia. Even the ps tranny will get a spike at turn on because of the magnetic field being built in the coils. Very quickly, but it is there. Plus what hits the diodes can be far beyond the rating of the diodes. This contradicts Craig's earlier post. I'm NOT knockin' his work, it is exceptional, but the current limiter is CHEAP, and helps protect more that the ps caps. Perhaps, instead of the standby switch with the resistor we were talking about earlier on the center tap of the high voltage output you could just use an IRCL there. Then you would gain the benefit of a 'soft start' on the output tubes. I'll email Shannon and ask him about the idea. Bruce

Tom, Is that the 210 without the wings on it? Cool! Bruce

As is a tunsten filament in a light bulb. The resistance is very low at turn on, and quicly goes up. If not, it would burn out very quickly. Bruce

When your monster (or not so monster) power amplifier is switched on, the initial current drawn from the mains is many times that even at full power. There are two main reasons for this, as follows ... * Transformers will draw a very heavy current at switch on, until the magnetic flux has stabilised. The effect is worst when power is applied as the AC voltage passes through zero, and is minimised if power is applied at the peak of the AC waveform. This is exactly the opposite to what you might expect * At power on, the filter capacitors are completely discharged, and act as a short circuit for a brief (but possibly destructive) period These phenomena are well known to manufacturers of very high power amps used in PA and industrial applications, but "soft start" circuits are not commonly used in consumer equipment. Anyone who has a large power amp - especially one that uses a toroidal transformer - will have noticed a momentary dimming of the lights when the amp is powered up. The current drawn is so high that other equipment is affected. This high inrush current (as it is known) is stressful on many components in your amp, especially ... * Fuses - these must be slow-blow, or nuisance fuse blowing will be common * Transformer - the massive current stresses the windings mechanically and electrically. It is not uncommon to hear a diminishing mechanical buzz as the chassis reacts to the magnetic stress * Bridge rectifier - this must handle a current way beyond the normal, because it is forced to try to charge empty filter capacitors, which look like a short circuit until a respectable voltage has been reached * Capacitors - the inrush current is many times the ripple current rating of the caps, and stresses the internal electrical connections According to this, a SS rectified amp will have more of a problem, as they are instant on and the caps used for filtering aren't charged at the moment of turn on. This contradicts an earlier statement. I'm still trying to figure this out too. I pulled this off of a site that has a design for an active ICL (using current sensing, resistors and a relay, etc.). The single IRCL chips are way simpler to integrate into the design, as they just go in series on one leg of your AC mains. Bruce

The TL Audio stuff is also pricey, but maybe not quite as high as the Manley gear. The 56 input VTC runs about 10,000 pounds (made in England). Still a lot of U.S. dollars. But they make smaller units too. I've written for prices, but haven't heard back yet. Bruce

Michael, Replacement drivers for Advents: http://www.simplyspeakers.com/12diaphragms.htm Not the cheapest, but more the real deal. Bruce