Again, many thanks.

I used to subscribe to a audio hobbiest magazine called Antique Radio Classified. There was a guy in there who was big into theater tube amps. Actually, antique audio systems, radios and short wave is a very big hobby!

Vacume tube sound systems are still very popular and are on the high end of the audio market. My Carver C.D. player had vacume tube outputs. McIntosh, Marantz and other vacume tube amps from the 1950s-1960s are considered treasures whose sound quality is still a force to be reconed with. Consequently, they are worth $1000s!

There was a major parts distributor called The Parts Connection who has all the stuff needed to restore your equipment. Porcelain tube sockets, fancy connectors and wiring. Foil Caps etc,etc. New 6L6s should still be aviable.

One design change I may recommend. Conrad Johnson uses both a red and green L.E.D. across each tube to let you know if plate currents are correct. Eliminates the need to align currents on an oscilloscope. They warn that you can tweak the tubes to get a "better" sound, but misaligned currents will decrease tube life.

Also, when running tube amps, cleanliness is very important! Vacume tubes radiate a lot of heat and collect a lot of dust! Dust traps heat resulting in reduced tube life! Enclosed cabinets and towers are also bad for tube amps as they trap heat and dust. On the high-end audio market are "designer" racks that are open, allows equipment to breath! These are expensive, but check them out so that you can build your own. It would also not hurt if you purchased some micro fans from Radio Shack and ran them across your tubes.

I have been interested in tube audio for a while now, mainly after my experience with working on the sound system at the Newtown Theatre in Newtown PA. They continue to use the original IPC AM-1011 amps there with a solid state Altec for backup. Formerly there were 2 Simplex something projectors and carbon lamphouses, but since one rectifier went bad, they have changed over to Christie xenon, and a platter system, making running a bit more boring. Those IPC amps still continue to perform flawlessly though. I know on amps this age, the electrolytic caps degrade, and should be replaced, and on any older electronics, it is good to power up slowly with a variac. I have a miscellaneous pile of tube amps, including a very nice Western Electric 124D, which I have been told can sound fantastic, and is worth a good deal. I am looking forward to getting a real matched pair of amps up and running!

Get the high end oil filled foil caps.

Also, disconnect at least 1 lead from each of the components and test them to be sure they are ok. Resistors can also go bad over time--and other stuff also. Go to Radio Shack or an electronics store and get electronics cleaner.

Contact the folks at Antique Audio Classified. I believe that the collector I mentioned is in New York(?). Also double check with them about replacement components. I am not sure, but I have been told that sound/performance can change depending on the GRADE of component used, irregardless if the VALUES are the same.

One of the reasons Tubes are popular is because of the smoothness of sound they produce--it has to deal with even and odd harmonic distortion. The differences between transistors and tubes can be seen on an oscilloscope. But many of the high end audio magazines actually present charts and graphs with their reviews.

Wise decision to use the Variac--smart thinking!

One thing to remember: Quality tubes, while harder to find as time goes on is the only way to go. Stick to USA-made 6L6GC's GE, Sylvania, (both still somewhat available but the prices are rising) or if you want to spend the big bucks, RCA blackplates. Avoid the Chinese tubes at any cost,(very poor quality control and extremely short lifespan compared to US and premium Russian types) and the only Russian tubes I can recommend are the Svetlanas. The 'Sovtek' '5881' is neither a true 5881 nor a 6L6, it is a rebased servo amplifier tube with similar (but far enough off to not be optimum) characteristics to a genuine 6L6.

Recapping, as Will mentioned is almost universally required with many 50+ year old tube equipment. Antique Electronic Supply http://www.tubesandmore.com carries many of the twist-lock electrolytics and axial electrolytics that were common back then, as well as thousands of tube types. The Variac is another good idea, if you can get one. An alternative to the variac is to rig up a cord with a 100 watt light bulb in series with the amplifier, and if the bulb dims or goes out upon powering up, its a safe bet that there are no shorts in the power supply transformers or capacitors., Still the Variac is the best way to accomplish this.

Good luck and happy listening

Aaron

P.O. Box 2, Carlisle, MA 01741.

They also have a web site under their name.

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One of the fanciest pair of home audio amps that I saw advertised on the new market was as follows:

Each channel had a seperate chassis. The power supply also had a seperate chassis. The chassis were all granite w/insulating feet. All hand wound solid silver wired transformers. All solid silver hand soldered wiring. Porcelain tube sockets, etc,etc. Cost about $100,000.

Remember, audio systems of yesteryear were very efficient. They only needed 15-50 watts to power speakers. I had a friend who had a very low wattage and very efficient sound system that could blast the hell out of any high wattage system today--beautiful sound and no distortion!

The difference between hi-end audio and mainstream audio. Hi-end relies on hi efficency and hi quality components, manufacture and design. The philosophy is to get the sound from the source to the speakers as directly as possible. Hi-end systems (amps) only have an on-off switch) Pre-amps have a volume control, radio, c.d., l.p, tape selection and maybe a trebel/base switch. Rarely do you find any type of complicated equalizer in hi-end systems!

Many people think that hi wattage makes the system. This is

Check out some of the hi-end magazines and stores. The only thing that I hate about these folks is that they can be very snobbish, or so my experience has been!

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