Note that there were several manufacturers of solid state plug in substitutes for common small signal audio triodes like the 12A*7 series tubes. They don't sound at all tube like IMLE.. IIRC They went by such trade names as "Tubester" etc. Rectifier tubes in most cases have current plug in solid state replacements available - need to buy ones that don't overvoltage supply capacitors and the like during warm up.
AFAIK there were no replacements available for power tubes or any specialized RF types. I expect good ones would have cost more than the tube they were meant to replace.
In some cases suitable arrangements may be put together with high voltage mosfets and jfets - getting the exact right characteristics in a given circuit may be more trouble than it's worth.
Guitar amps are very poor candidates for these sorts of mods, as are IMHO most hifi gear. So knowing what you are talking about would be helpful.
Many common types of tubes are reasonably cheaply available on eBay.
Depending on where you are it might make more sense to sell the item in question and replace it with a solid state unit.
AFAIK there were no replacements available for power tubes or any specialized RF types. I expect good ones would have cost more than the tube they were meant to replace.
In some cases suitable arrangements may be put together with high voltage mosfets and jfets - getting the exact right characteristics in a given circuit may be more trouble than it's worth.
Guitar amps are very poor candidates for these sorts of mods, as are IMHO most hifi gear. So knowing what you are talking about would be helpful.
Many common types of tubes are reasonably cheaply available on eBay.
Depending on where you are it might make more sense to sell the item in question and replace it with a solid state unit.
Tubes aren't all that expensive as a rule. Transformers are though. Some rare tubes are a bit spendy but you can often modify for less expensive options. Can you be more specific about what you are trying to do? Are you trying to replace a tube in an existing piece of gear or are you wanting to replace the whole thing?
Tubes to Circuitry
Hi Mashaffer I have a meazzi concertorama amplifier about 30w output. It is sounding alot of noises crackling sounds. I changed one preamp tube and it became a little better but I don't have another cause there are two preamps as read and other small four. So I would like to change to circuitry if possible just leave it to plugin too. Hope you understood what exactly I want.
Thanks
Hi Mashaffer I have a meazzi concertorama amplifier about 30w output. It is sounding alot of noises crackling sounds. I changed one preamp tube and it became a little better but I don't have another cause there are two preamps as read and other small four. So I would like to change to circuitry if possible just leave it to plugin too. Hope you understood what exactly I want.
Thanks
Oh man, please don't junk the innards of that nice ol' sound machine...you said it basically works, but sound quality is lacking. That means that most likely the transformers are still good. I bet the tubes themselves are not the problem either. With equipment of this age, especially (all) capacitors will need to be replaced, which need not be that expensive at all. I bet this amp can be brought back to like-new sound quality with just a little tender love & care. I checked on the net and found a pic of the preamp stage; looks like it'll be pretty easy to trace a schematic of the amp and use it to restore it to good condition.
Alternatively, you could rip out the innards and stuff in a simple chip amp. Won't cost an arm and a leg and it's a very easy project. But it'd be the heartless thing to do, and instead of owning a vintage piece of equipment in working condition, you'll be left will a queer old box with some cheap and uninteresting electronics in it (i.e. a worthless pile of junk).
Oh and btw, tubes are not expensive. They are if you want to buy NOS-bugle-boy-gold-pin-whatchamacallit-fancy-audiophool-black-plate-side-getter-etc. types, but most types used in 1950s consoles like yours can be found for a couple of euros.
Alternatively, you could rip out the innards and stuff in a simple chip amp. Won't cost an arm and a leg and it's a very easy project. But it'd be the heartless thing to do, and instead of owning a vintage piece of equipment in working condition, you'll be left will a queer old box with some cheap and uninteresting electronics in it (i.e. a worthless pile of junk).
Oh and btw, tubes are not expensive. They are if you want to buy NOS-bugle-boy-gold-pin-whatchamacallit-fancy-audiophool-black-plate-side-getter-etc. types, but most types used in 1950s consoles like yours can be found for a couple of euros.
Meazzi
Hi Mastodon thanks for response I was not going to touch from circuitry but just do an add-on to the pins. This amplifier works cause sometimes I plug my synth to it but just for home not to play in audience cause as said when it heats up crackling sounds will be heard. If you're sure that these are because of caps it would be no problem cause I have others but have to be sure.
Thanks
Hi Mastodon thanks for response I was not going to touch from circuitry but just do an add-on to the pins. This amplifier works cause sometimes I plug my synth to it but just for home not to play in audience cause as said when it heats up crackling sounds will be heard. If you're sure that these are because of caps it would be no problem cause I have others but have to be sure.
Thanks
Start by replacing all electrolytics. Also check if there are bad contacts anywhere or fried resistors. Odds are that some resistors have drifted quite a bit from their original values. Drawing up a schematic and doing some measurements would definitely help figure out what's wrong.
As for replacing the tubes with silicon-based subcircuits: sounds like a very cumbersome and time consuming solution. It's much easier to troubleshoot the amp as it is!
As for replacing the tubes with silicon-based subcircuits: sounds like a very cumbersome and time consuming solution. It's much easier to troubleshoot the amp as it is!
I/ve replaced tubes because of crackling over the years, but I think now that wasn't the problem. In the dark, after my recent recap of my tube PAS2 preamp, I could see blue sparks between traces on the PCB. (printed circuit board). This was a kit, and I don't suppose the guy that built it in 1961 did much flux cleaning. In high humidity, flux on parts will cause arc over. Marine electronics engineers try to leave 1/2" distance for 500 V, that is obviously violated by the tube socket. The repair is a wet paper towel and a lot of scrubbing. Check every piece of metal before you touch it that it is under 25 VDC, and if not discharge it following the instructions in "HV for newbies" at the top before you touch any metal. If you have a "carbon track" where something is obviously burned, wire brushing or replacement is required, because carbon is not soluble in anything cheap.
As in the previous post, sometimes crackling is caused by poor contact of the grid pins of the tube with the socket, especially if the socket was exposed to household dust. Again, measurement to prove safe, then cleaning with a pick or a welding torch tip cleaner is useful.
As in the previous post, sometimes crackling is caused by poor contact of the grid pins of the tube with the socket, especially if the socket was exposed to household dust. Again, measurement to prove safe, then cleaning with a pick or a welding torch tip cleaner is useful.
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Tube gear is so big that it is easy to add transistor circuits under the chassis. I've done this to enhance a few tube rigs. It wouldn't be too hard to replace an entire (small signal) tube stage with a transistor circuit. The filament voltage can be rectified and filtered to power the transistors. The hard thing is to directly replace just the tube with no modifications to the chassis.
We may have to take these measures someday when tube supplies dry up.
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We may have to take these measures someday when tube supplies dry up.
Fortunately not too much danger of that happening in most of our lifetimes for the more common commodity audio tube types. Competition for dwindling supplies of rarer "exotic" NOS types is driving costs up, in some cases spectacularly, but even very early NOS WE tennis balls can still be had for a price. A very few exceedingly rare types used in certain German tube microphones (Telefunken and Neumann amongst others) are probably amongst the biggest concern..
Not at all: they can be easily replaced by better tubes manufactured later, like 6J1B, 6J2B, 6J32B, and similar. However, some people believe that they would sound like, say, Frank Sinatra, if they sing in a microphone with authentic tube inside, that drives prices up.
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