View Full Version : Any Cheap Audio Tube Amps Out There?
06-14-2002, 04:53 AM
- - - Or even, cheap audio tube amp kits?
- While pondering a recent project that requires a 3-5 watt audio amp, I began to get curious how expensive a simple, small tube audio amp would cost, and if it would make any difference in sound quality. When I looked around though, I couldn't find any. The cheapest kits I could find were for these big home-stereo modern-art-looking things starting up around $750 (you know, where all the tubes stick up in the open, so you can see them). Preamp kits start at ~$400+.
- Now I know that tube amps are audiophile products which means they are essentially somewhat overpriced, but I'm looking at these circuits and not seeing anything exotic except for the fancy high-end tubes themselves. That does not explain why there are no cheap ones, however: not too long ago, every television had at least a dozen or so RF tubes in each one, and they all didn't cost $1000. There must still be a lot of third-world factories cranking out low-priced tubes.
----Does anyone offer cheap tube audio equipment or kits? If not, why not? - DougC
06-14-2002, 05:57 AM
A look through the archives of TNT Audio (http://www.tnt-audio.com/int.html) will throw up several tube amps in built or kit form. If cheap ones exist then they have probably reviewed them.
06-14-2002, 09:22 AM
Tube amps are indeed an audiophile piece of equipment. As such, there are not many manufacturers that make them. There's not much demand for them. Why use tubes when you can use chips is the modern line of thinking.
Most people who use tube amps are audiophiles looking to recapture that "warm" sound that vinal records used to have. Modern music is recoreded digitally and played back as such. Thus there is no ambient noise in the background. To some people this sounds artificial. So they use tube amps to introduce low levels of ambient or "white" noise in the background.
Most people who appreciate the diffrence either are using older equipment or have spent great deals of money on modern equipment. McIntosh and Denon both make Tube amps if I'm not mistaken, but their pricey.
06-14-2002, 09:30 AM
Originally posted by Skippman
Tube amps are indeed an audiophile piece of equipment. As such, there are not many manufacturers that make them.
It's been awhile since I read what I am about to relate so I don't have a cite but IIRC tubes are so expensive because practically no one makes them anymore. Mind you this was several years ago so things may have changed but the article mentioned that only Russia has anyone manufacturing tubes. In this case Russia being behind the times, so to speak, is a benefit to them.
Running with Scissors
06-14-2002, 10:03 AM
Other than the tubes, the expensive part of the amp is the output transformers. These are understandably a specialty item, were usually custom made for a particular amp, and are therefore hard to get and expensive when you can. Parts Express (http://www.partsexpress.com) carries some, but they start at $45.50 for a 20 watt model. You'd need two of these for stereo. That's for their cheapest, push-pull, 4 screw model. Potted and single-ended transformers are even more. And don't forget to add to that the cost of the power transformer.
Another reason for the expense is that they have to amortize the cost of the design of the amp (and the kit) over the relatively few units they feel they'll be able to sell.
That being said, check the Vintage Audio (http://listings.ebay.com/aw/plistings/list/all/category14998/index.html) section at ebay - there are always many people selling tube amps there, and you could probably find one from one of the less trendy manufacturers for a song (NPI). Don't count on getting a cheap Mac, Marantz, Citation or Fisher; instead look for brands like EICO (a Dynaco competitor), Lafayette (a Radio Shack competitor, they eventually morphed into Circuit City), Heathkit (although some of these are quite pricey as well) and even Harman-Kardon (I sold a tube H/K amp on ebay a couple of years ago and didn't get much at all for it).
This is, of course, assuming you're looking for a one-off. I suppose if you don't need something really powerful and are willing to do point-to-point wiring (to save on the cost of designing and matting a circuit board) you could probably build one from scratch cheaply enough. Actually, I just checked Parts Express, and even a matched quad of Svetlana 6550s is only $120. EL34s are even less. So you could probably build a decent tube amp for a relatively small amount of money, if you did it all yourself. You could probably find schematics on the web.
And if you want to go all out, you can put a tube on your motherboard (http://www.aopen.com/products/mb/ax4b-533tube.htm).
06-14-2002, 10:06 AM
As much as I hate to plug a specific company on any MB, call up Antique Electronic Supply in Tempe, Arizona and ask them. Better yet, have them send you a catalog. I'm sure that there are other tube electronics suppliers out there, but AES is the only one that I know of.
06-14-2002, 10:16 AM
Running - That may be the coolest thing I have ever seen! I'm probably going to order one of those for my new Home Theater PC.
06-14-2002, 12:26 PM
And if you want to go all out, you can put a tube on your motherboard.Now that's a real product, right? Not someone's joke picture? Just checking (sometimes, you just can't tell for sure).
06-14-2002, 01:12 PM
Antique Sound Labs has an 8 watt Monblock Amp for 99 dollars. Many people like these ( as do I). All you need to do is add a pre-amp.
06-14-2002, 04:08 PM
Originally posted by Whack-a-Mole
. . .practically no one makes them anymore. . . .the article mentioned that only Russia has anyone manufacturing tubes.
Don't have the specifics at my fingertips but there are lots of tube manufacturers in Europe, as well as China, and probably US. There is a strong market for tubes for musical instrument amps.
Now I don't want to hijack this thread but I don't think we've seen the whole argument for tube amps for audio. I don't buy the ambient white noise noise theory since audiophiles go to great lengths to avoid artificial ambient noise.
The reason guitarists like tubes is that when they distort, they do so harmonically and add richness to the tone. They (we) don't want to just reproduce the source signal with absolute fidelity, we want to make it better.
However, I would think audiophiles would want to avoid distortion at all costs, and not add anything that isn't provided by the source. I would think solid state would give the most faithful reproduction of the source signal. Audiophiles, tell me why I'm wrong.
Running with Scissors
06-14-2002, 04:13 PM
Originally posted by ZenBeam
Now that's a real product, right? Not someone's joke picture? Just checking (sometimes, you just can't tell for sure).
Surprisingly enough, it's real. That's the manufacturer's own website I pointed to.
06-14-2002, 08:43 PM
Say, anyone make an inexpensive tube amp that's surround sound compatible?
06-15-2002, 02:22 AM
First of all if you really want a cheap tube type audio amp just go yard saleing. There are thousands of old tube type phonographs out there that nobody wants.
Second there are only 2 to 4 rf tubes in a TV.They are in the tuner. They wouldn't do you much good in a audio circuit anyway.
Just curious. What kind of project do you have in mind for a tube type audio circuit?
06-15-2002, 10:04 PM
- - - What I wanted any amp for mainly was because the portable minidisc recorder I have has no line-out, and the headphone comes in quite low when run into the PC's line-in. There are numerous transistor amps <2 watts for $15 or less. I knew that big tube amps cost a fortune, but I was curious about the price of small ones.
I would think solid state would give the most faithful reproduction of the source signal. Audiophiles, tell me why I'm wrong. - CookingWithGas
- It sounds like audiophile BS but you'd know the difference if you heard it. It is a type of distortion, but it's one that hasn't been duplicated real well digitally. I was just wanting an amp; it's not like I'm advocating $2000 speaker cables or anything. - DougC
06-15-2002, 10:35 PM
Originally posted by DougC
- It sounds like audiophile BS but you'd know the difference if you heard it. It is a type of distortion, but it's one that hasn't been duplicated real well digitally. I was just wanting an amp; it's not like I'm advocating $2000 speaker cables or anything. - DougC Agreed. There's a tube microphone out there that a buddy of mine likes to use to record things with (think its called a U-47), and I can always tell when its been used in a recording because to my ears, it sounds like a cheap Peavy PA is being used for playback. Drives me nuts! I can even tell when that particular mike has been used on commercial recordings. That being said, tube amps tend to provide a more "ambient" sound than strictly electronic amps which sound "dry" by comparison.
06-16-2002, 07:42 AM
- - - The best way I can describe it is that when you use 100% digital recording/playback (especially with condenser mics), the playback sounds very sharp and harsh.
- Tube mics+tube amps add a sort of softness to it all, and there's no way that really duplicates the effect well digitally. Saturated analog tape adds a similar effect. Digital studio recording equipment was supposed to kill off analog recording equipment, but it never did, and the reason is that digital doesn't sound like the (more expensive!) analog equipment does. - DougC
06-17-2002, 08:10 AM
Seems like my point about tubes vs. transistors was transmogrified to a discussion about analog vs. digital.
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