A lot of us want to build our own amps, but the prospect can be daunting and it can be expensive buying high quality kits or parts.
A lot of us want to build our own amps, but the prospect can be daunting and it can be expensive buying high quality kits or parts.
(sound of huge rabbit-hole opening)
I love vacuum tubes. They are fun to play with. They will, briefly, sustain a huge overload of a magnitude that would make the magic smoke come out of solid-state devices.
Just be prepared to deal with a lot of superstition and woo from vacuum-heads who don’t really know whereof they speak. There are audiophiles out there who rave about the tonal qualities and “sound stage” of the 6X5GT rectifier tube, which is best known amongst antique radio fans as being prone to inter-electrode shorts that will burn out the power transformer, most of which are made of unobtainium.
I’m not an electronics expert, except for 1970’s automotive technolgy. I did build a few Heathkit and Radio Shack kits on cold winter days.
I must say however that if you’ve ever heard a circa 1950’s Zenith Radio with vacuum tubes, or a Wurlitzer juke box powered by same, there was a richness in the sound that is hard to duplicate with solid state.
Many years ago (1976??) I walked into a second hand store and auction mart on River Street in Moose Jaw. It was later in the evening, quite dark, and the owner was alone in this huge room, sitting in an old rocking chair, and listening to a cabinet style circa 1950’s Zenith tube type radio. Solid hardwood and one large single speaker. One of the best sounding radio’s I’ve yet to listen to. The sound seemed to go right through your heart. Back home I had a solid state Zenith Stereo with ”Allegro” speakers. The richness of the old Zenith tube type radio however could not be matched.
There was even a specific odor that came out of a device after the vacuum tubes got hot. Correct me if I’m wrong, however I believe DeForest type tubes gave off ozone that accounted for the clean odor..
A lot of hams prefer the older tube radios. There are a lot of them on the second-hand market and they still work well. They tend to be more robust than the solid-state radios.
Since many of those rigs are bulky and heavy, they’re referred to as “boat anchors”. In fact, a few months ago, I listened in on a ham net dedicated to them.
Unfortunately, most of the North American companies that built them are now out of business. Solid-state rigs became available in large numbers over 40 years ago, mainly out of Japan, but those firms didn’t or couldn’t change their product lines. One reason was that the amateur radio market is rather small and re-tooling would have been quite expensive.
You know well of what you speak … the rabbit hole is a never ending trip to infinity. And yes, I am an analogue tube enthusiast. And yes … there IS a tonal difference between SS and tube equip. … and yes, there are significant differences in tube sound. With most agreeing that vintage English Mullards are quite magical … for reasons beyond my limited understanding of electrical engineering … something about the size/shape of the “getters” and whatnot. All I know is that I have a very reliable and sensitive set of ears that can detect subtle differences in recording and playback. I have a rather impressive collection of top-end vinyl … OMG … yes there is a massive difference in the quality of recordings and pressings. And a massive difference in the analog playback equipment. I am currently enjoying my latest $ 2K moving coil cartridge (needle-for the laymen) … only because my wife would divorce me if I purchased the $10K model. And I won’t bother bragging about the price tag of my turntable … as it was purchased well-into my one-way trip into the audiophile wormhole
http://www.diyaudio.com/
A fairly good example of the DIY electronic community. And yes, I am a prior customer of The Tube Store.
Yeah, there are guys that wax poetic about the tonal quality of…rectifier tubes. Which do nothing but rectify alternating current from the HV winding of the power transformer into a few hundred volts Dc to energize the plates and screens of those tubes that do handle the sound.
Seriously, if were to build a vacuum tube audio amp to be as perfectly perfect as humanly possible, there would be no rectifier tube. There would be big honking batteries for plate current, and smaller batteries for screen grids, and more batteries to keep the heaters hot. If there’s no AC going into the damned thing, there will be no hum. And big batteries would have enough punch to drive the output tubes into the kilowatt range, if they could take it.
Of course, you’d have to use oxygen-free copper speaker wires, with that kind of power on tap…
diyaudio…one of the greatest repositories ever built on the web. Can’t count how many hours I’ve spent in there….
In the late 80’s I used to frequent the Brittany Inn, a small pub in downtown Winnipeg. They almost always had great live bands. One evening this guitar player walks on stage with an amp roughly the size of two milk crates and plugs in, and I think to myself, really, that’s it?
I was blown away. After the show he explained to me that it was a hotrodded Mesa Boogie tube (cant remember Mk 1 or 2) with a 12″ Celestion. Most amazing sound I have ever heard from a guitar amp.
Years later I decided to pick up a SS 100W Marshall with a 4×12 cabinet. Price was right. Had it for two weeks then sold it. My tube 50W Fender Twin with 2×10″ simply sounded better, had better punch, felt louder and refused to meltdown when I pushed it over the edge.
When it comes to guitar amps, tubes win. No contest.
Tube amps are great but heavy. I have a Fender Super Twin Reverb from the seventies which is capable of clean tone way up the volume scale but it weighs a ton. I played in a swing band for 8 years and preferred a little solid state Polytone with a single 12″ speaker. Almost as clean and warm as tubes but easily packed up and carried by it’s user after a late night gig. I usually practice with SS amps too as I hate heating up the tubes for a short time period.
This thread struck a chord with me. (Pun intended) I’ve always been bemused by the myth that audio equipment must be “broken in”. Not to mention Mapleshade’s claim that speaker cables must be elevated from carpet by trestles to avoid electrostatic contamination.
If anything breaking in audio gear is an exercise in confirmation bias.
Agree with one of the posters here – audio recordings (whether analogue or digital) are inconsistent at best. A decent audio processor is a must
Just my $0.02 worth.
Came across the tube store on the internet and then discovered it’s about ten miles from my house. Great folks.
There is a huge amount of voodoo thinking regarding tube amps and tone. They do give great guitar tone, but it pays to ignore a lot of the fine wine babble that sometimes takes place – although I only use tubes that have been made in Russia by chinese folks.
too bad you don’t live 10 miles from me, I’m chucking out a shit load of VT’s, and selling a 6 band, about60 year old, VT radio
I got my Bachelor of Science in Electrical Engineering degree in the late 70’s and worked towards a Masters degree until I could not stand the university politics (and resumed working with a good rock band). I am currently self employed fixing guitar amps for rock stars (mostly in their own mind). There is surely a “golden ear” crew that claim, for example, that they can tell the difference in sound from their guitar effect pedal when using Duracell as opposed to Energizer. More power to them, as they help sustain my business, and I am glad I do not have their ears, as I would never be satisfied.
There is, in truth, a valid reason to use vacuum tube rectifiers in guitar amps. The tubes are very inefficient, and as significant power is drawn though them, the supply voltage tends to sag. This results in a temporary reduction in the power output, but as the power chord signal from the guitar starts to die away, the supply recovers and provides an automatic “sustain” (maintenance of a certain volume) effect.
Current production trends in musical equipment make tube systems more expensive, especially since digital signal processing can mimic the tonal characteristics of any number of amps, using a reliable solid state output. My masters research involved copying analog signal processing using digital equipment (although at a much higher power output level – about 45 million watts per channel), and I can assure you that there is still a difference.