A cousin of the 12AX7 tube is the 12AU7 and just like its cousin there is a small commodity of the premium vintage versions of it left. Other versions of 12AU7 are 12AU7A, 6189, ECC82, and 5814. It can be used as a class A amplifier per triode section, preamplifer stages of high fidelity audio equipment, musical instruments, public address equipment, and broadcasting equipment.
12AU7/12AU7A- The most commonly made in the U.S. and RCA, GE, and Sylvania manufactured the most of them here. It seems like everyone wants to get their hands on the RCA 1960's version with greyplates and the getter on the side which became known as "cleartops." Although the earliest version RCA made had ribbed flat blackplates with a top getter and a white label. In the 1970's there was a RCA new logo version with a white label, like the 1940s+50's versions, greyplates, and a top getter.GE pretty much kept their model the same throughout the years always have greyplates, a topgetter, and numbers carved into the glass with a connect the dots looking pattern underneath. Tung- Sol made this very cool looking and very rare "blackglass" version in the late 1940s, like throwing tinted windows on a car you cant see inside. They changed that design later to resemble early RCA's with greyplates on the inside, yawwn.
ECC82- This is the identical European version. The run around as 12AX7 the in demand brands are Mullard, Telefunken, and Amperex. The rare Telefunkens are the smoothplates but there is also ribbed plates and all of them have a diamond shape molded into the bottom of the glass. Amperex most popular tube is the buggleboy with the logo of that little tube dude blowing a horn. Later the label goes to white with just the words "Amperex" and after that a orange logo arose with the world logo. Both Mullard and Amperex have put on your glasses small date codes etched into the bottom of the tube. Mullard longplate versions that came out in 1950's are the cream of the crop of this brand in 12AU7s, their plates were 3mm longer than the 60's versions. Some of the earliest had square getters and the later ones had halo top getters. The earlier Mullard logos just said Mullard then the later ones said IEC Mullard. Mullard and Amperex one day got together and made a baby just for the military called a CV491 longplate with a square getter.
5814- You can tell by the number code that it was a military spec tube. GE and RCA made these for broadcasting in the RCA command series and the GE 5-Star series. All of these have low microphonic because of their mica supports and a rare one to get a hold of is the "triple mica" versions. Very durable tubes and most have 5814 etched into the glass except some GE's have 1G-12AU7WA in white on them.
6189- When you can find these they are great. GE also put this tube out in their 5-star military line. Usually the military version will have 12AU7WA listed on the tube as well as 6189. The RCA version has 12AU7WA written in gold with blackplates and extra support rods. The older vintage versions also have blackplates and a "triple mica" spacer at the top.
6680-Just like the 12AU7 but it can withstand filament voltage variations without affecting its output. Originally used for two way mobile radio use. Motorola and GE being the most common to find today but there is also a rare RCA cleartop version.
ECC802-A premium European version of the ECC82 that has matching triode sections and is as rare as the bald eagle in the U.S.
B749- Another extremely rare one in the U.S. It was made by Genalex in the "gold Lion" series and has the gold lion script in gold on the glass.It also has a red Genalex decal across the bottom and has a grade A repuation for sound so as you can imagine top dollar.
Lets hear more about how they sound!
Telefunken and Siemens- Breath taking open air, t-rex large soundstage, great for adding some spunk to mono apps, the midrange is like it just got ran over by a steamroller it's so flat, and a on point bass . They can be found on the brightside though.
Amperex, Philips, Mazda, & other Holland/France New old stock tubes- does a balance of justice with a clean airy top end, the midrange has warmth, and again the bass is on it's A game. Recomended for musical uses of hi-fi equipment. Unusual for alot of European tubes these break up great when overdriven in guitar amps. French Mazda combines some of the more warm sound you get from amperex with the air you can get in a Telefunken with a dynamic punch in the sound.
Mullard & Genalex-warm midrange, the top end could be described as milky, specialize in making human voices exspecially female voices feel as if there was a ghost standing next to you singing, definately has razor sharp detail.
RCA, Raytheon, GE, Sylvania, & more USA made NOS-I recomend the RCA, Raytheon, and Sylvania blackplates out of this catergory because they are very musical and have a sparkle of air at the top end, warm midrange, and slamming bass. The RCA are great for guitar amps even in greyplates and longplates. I have heard GE greyplates called "all around nice guys" too bad nice guys finish last.
Remember that all vintage tubes producers used a chalky label paint so often labels are smeared which virtually doesnt mean anything although could be taken for poor quality when they have enver been used.
Friday, July 10, 2009
12AX7 tubes- the best sounding, the rare, and the ugly
First there are 5 different names for 12AX7 tubes 12AX7, 12AX7A, 7025, 5751WA, ECC83.
The 12AX7 is clearly the OG (original) version of this tube. This market is its all 12AX7's turf.
Almost Extinict like the dinosaurs
The 12AX7A- The majority came out around 1960's and have greyplates. RCA and GE made these for electronic organ manafactuers and the organ brand name can be found on the actually tube label in some cases. The 12AX7WA was the version made for the U.S. military and there is also a WB not to be confused with the Warner Brothers and WC. The W was military code A,B,C marked the later versions. The new peoductions of Russian and Chinese tubes have WX,WB, or WC codes on them, this doesnt mean jack so dont be fooled.
the ECC83- The European version of 12AX7 its marykate to ashley olsen if you will because they are identical. The ones in demand are Telefunken, Amperex, Mullard, and Siemens. Even more scarce in population are German made Valvo and early Holland made Philips Miniwatt and Philips "SQ." Out of Telefunken ECC83 you want to look for the smoothplate or otherwise known as the flatplate versions. Some of these Telefunkens on the market are also marked as Fisher or Dynaco which doesnt matter they are the same they were just made for OEM applications. Real Amperex and Mullard tubes have a pair of alpha numeric dates codes printed in dark grey near the bottom of the tube and may help in telling what brand a tube is if the logo is worn away. The rarest of all of these are the Amperex buggle boys with the treble clef music symbol next to the buggle boy image and or just the buggle boys are extremely rare. Older Mullard logos that look like a shield are the rarest of the Mullard exspecially with BVA written under it. Also keep your eyes peeled for Mullard 10m series of these tubes in pimp purple and gold boxes. They were screened for 10,000 hour heater life, matching internal triodes, and low noise. The Master series has gold plated pins and the Concert Series has the standard pins. They are very scarce unfortunately high in price as well these days . Mullard and Amperex earliest versions from the 1950's of ECC83 came in square and D getters which is when the little halo inside the tube is actually square or shaped like a D a fit to make the finest sounds. Watch out for fakes of the AmperexBugleboys and Telefunken smoothplates. You'll know they are fake if the label doesnt wash or wipe off, normally these labels will come off as easy as the slightest brush of your finger across them. The buggleboys will have buggleboy on the cartoon tube on the box and sometimes the Telefunken will have gold pins when they are fake.
7025- This was an industrilal version, that has a spiral wound filament. Can be good for hi-fi equipment because they have very low noise but so does premium brands and blackplates.
ECC803S, E83CC, E803CC-The S stands for special meaning a special european version of ECC83. What is so special about them? Well they were screened for low noise and matching internal triode elements. Although European this has been made into a 12AX7WA military type. Very rare in the USA but can be easiest to come across the rare Telefunken and Siemens versions.
5751- This was usually made for the U.S. Military. If you live in a animal house or your significant other likes to throw your collectiables when they are mad at you these are just the tube for you because they tend to be more durable and can take drops to the floor, not that I'd suggest one. Not just to be used in a game of hot potato they are also great hifi tubes that tend to be very close to 12AX7 just with lower gain that reduces noise and microphonics. The earlier versions which always seem to get more attention have extra support rods and an extra mica spacer on top of the plate structure as well as blackplates to contribute to low microphonics. The grey plate versions also come with the same genes and carry triple mica as well. GE came out with a series for broadcasting use as well as RCA which called them the "Command" series for all of you training your deaf jack russell terriors.
It all comes down to the sound!
Telefunken and Siemens- Breath taking open air, t-rex large soundstage, great for adding some spunk to mono apps, the midrange is like it just got ran over by a steamroller it's so flat, and a on point bass . They can be found on the brightside though.
Rough economy hint for cutting corners when moneys tight- Telefunken ribbed plates were made in the same era and factory as smoothplates and have very very discreet differences. You can also find Siemens Valvo and Lorenz for cheaper.
Amperex, Philips, Mazda, & other Holland/France New old stock tubes- does a balance of justice with a clean airy top end, the midrange has warmth, and again the bass is on it's A game. Recomended for musical uses of hi-fi equipment. Unusual for alot of European tubes these break up great when overdriven in guitar amps. French Mazda combines some of the more warm sound you get from amperex with the air you can get in a Telefunken with a dynamic punch in the sound.
Economy tip- The Philip Miniwatt series were made in the same Holland factories that Amperex buggleboy tubes were made in an can work for an solid alternative because they have identical insides, have the same factory codes, and the obvious sound similar.
Mullard & Genalex-warm midrange, the top end could be described as milky, specialize in making human voices exspecially female voices feel as if there was a ghost standing next to you singing, definately has razor sharp detail.
RCA, Raytheon, GE, Sylvania, & more USA made NOS-I recomend the RCA, Raytheon, and Sylvania blackplates out of this catergory because they are very musical and have a sparkle of air at the top end, warm midrange, and slamming bass. The RCA are great for guitar amps even in greyplates and longplates. I have heard GE greyplates called "all around nice guys" too bad nice guys finish last.
The 12AX7 is clearly the OG (original) version of this tube. This market is its all 12AX7's turf.
Almost Extinict like the dinosaurs
The 12AX7A- The majority came out around 1960's and have greyplates. RCA and GE made these for electronic organ manafactuers and the organ brand name can be found on the actually tube label in some cases. The 12AX7WA was the version made for the U.S. military and there is also a WB not to be confused with the Warner Brothers and WC. The W was military code A,B,C marked the later versions. The new peoductions of Russian and Chinese tubes have WX,WB, or WC codes on them, this doesnt mean jack so dont be fooled.
the ECC83- The European version of 12AX7 its marykate to ashley olsen if you will because they are identical. The ones in demand are Telefunken, Amperex, Mullard, and Siemens. Even more scarce in population are German made Valvo and early Holland made Philips Miniwatt and Philips "SQ." Out of Telefunken ECC83 you want to look for the smoothplate or otherwise known as the flatplate versions. Some of these Telefunkens on the market are also marked as Fisher or Dynaco which doesnt matter they are the same they were just made for OEM applications. Real Amperex and Mullard tubes have a pair of alpha numeric dates codes printed in dark grey near the bottom of the tube and may help in telling what brand a tube is if the logo is worn away. The rarest of all of these are the Amperex buggle boys with the treble clef music symbol next to the buggle boy image and or just the buggle boys are extremely rare. Older Mullard logos that look like a shield are the rarest of the Mullard exspecially with BVA written under it. Also keep your eyes peeled for Mullard 10m series of these tubes in pimp purple and gold boxes. They were screened for 10,000 hour heater life, matching internal triodes, and low noise. The Master series has gold plated pins and the Concert Series has the standard pins. They are very scarce unfortunately high in price as well these days . Mullard and Amperex earliest versions from the 1950's of ECC83 came in square and D getters which is when the little halo inside the tube is actually square or shaped like a D a fit to make the finest sounds. Watch out for fakes of the AmperexBugleboys and Telefunken smoothplates. You'll know they are fake if the label doesnt wash or wipe off, normally these labels will come off as easy as the slightest brush of your finger across them. The buggleboys will have buggleboy on the cartoon tube on the box and sometimes the Telefunken will have gold pins when they are fake.
7025- This was an industrilal version, that has a spiral wound filament. Can be good for hi-fi equipment because they have very low noise but so does premium brands and blackplates.
ECC803S, E83CC, E803CC-The S stands for special meaning a special european version of ECC83. What is so special about them? Well they were screened for low noise and matching internal triode elements. Although European this has been made into a 12AX7WA military type. Very rare in the USA but can be easiest to come across the rare Telefunken and Siemens versions.
5751- This was usually made for the U.S. Military. If you live in a animal house or your significant other likes to throw your collectiables when they are mad at you these are just the tube for you because they tend to be more durable and can take drops to the floor, not that I'd suggest one. Not just to be used in a game of hot potato they are also great hifi tubes that tend to be very close to 12AX7 just with lower gain that reduces noise and microphonics. The earlier versions which always seem to get more attention have extra support rods and an extra mica spacer on top of the plate structure as well as blackplates to contribute to low microphonics. The grey plate versions also come with the same genes and carry triple mica as well. GE came out with a series for broadcasting use as well as RCA which called them the "Command" series for all of you training your deaf jack russell terriors.
It all comes down to the sound!
Telefunken and Siemens- Breath taking open air, t-rex large soundstage, great for adding some spunk to mono apps, the midrange is like it just got ran over by a steamroller it's so flat, and a on point bass . They can be found on the brightside though.
Rough economy hint for cutting corners when moneys tight- Telefunken ribbed plates were made in the same era and factory as smoothplates and have very very discreet differences. You can also find Siemens Valvo and Lorenz for cheaper.
Amperex, Philips, Mazda, & other Holland/France New old stock tubes- does a balance of justice with a clean airy top end, the midrange has warmth, and again the bass is on it's A game. Recomended for musical uses of hi-fi equipment. Unusual for alot of European tubes these break up great when overdriven in guitar amps. French Mazda combines some of the more warm sound you get from amperex with the air you can get in a Telefunken with a dynamic punch in the sound.
Economy tip- The Philip Miniwatt series were made in the same Holland factories that Amperex buggleboy tubes were made in an can work for an solid alternative because they have identical insides, have the same factory codes, and the obvious sound similar.
Mullard & Genalex-warm midrange, the top end could be described as milky, specialize in making human voices exspecially female voices feel as if there was a ghost standing next to you singing, definately has razor sharp detail.
RCA, Raytheon, GE, Sylvania, & more USA made NOS-I recomend the RCA, Raytheon, and Sylvania blackplates out of this catergory because they are very musical and have a sparkle of air at the top end, warm midrange, and slamming bass. The RCA are great for guitar amps even in greyplates and longplates. I have heard GE greyplates called "all around nice guys" too bad nice guys finish last.
Thursday, July 9, 2009
Getting the best sound out of 6sn7 tubes
6SN7 tubes are typically used for the front end section of an amp or as preamp tube for a preamp like a 12ax7
First there are 5 different names for 6sn7 tubes 6sn7gt, GTB, GTA, and 5692. One hint to getting the best sound out of 6sn7 tubes is that the sound appears to work better when you combine different types of 6sn7 tubes together rather than having all one brand.
now lets list off the variation of sound between brands
Tung-Sol Round Plates/VT-231 or 6SN7- hands down best in everything they are clean, fast, sharp, have a huge span bandwidth need I go on?
RCA VT-231- their structure makes them rich in harmony, with sterling enhances on voicing, and a wide sound stage.
6SN7W or WGT Sylvania black plates- Can rank as one of the highiest quality tubes as well. If your system doesn't have enough balls such single ended amps this tube can give them the kick they need. There is three types of these tubes two large and one smaller with a smaller plate structure. The smaller one has better low level detail and the larger has a smack in the face to it. Overall the big and small have similar qualities.
Raytheon VT-231/flat black plates- the characteristic quality of sound produced by this tube is well balanced, compare it to the Tung-Sol just a little sweeter.
Ken-Rad VT-231/flat black plates- great bass, stellar midrange, butter bandwidth but not the best for preamps because they can get micro phonic on you.
Sylvania VT-231- wide bandwidth, well balanced, strong sound stage, and air.
Sylvania 1952 JAN-CHS-6SN7GT bottom getter- construction similar to early VT231 but sonics aren't and goes over the top the VT231 in every aspect
National Union VT-231- gentle bass with a good drive and great midrange
Tung-Sol 6SN7WGT Black plate brown base- sounds similar to the Tung-Sol VT-231 but not as clean
CBS/HYTRON 6SN7GT black plate- its the total opposite of me which means its quiet and its very musical we can call it the best of the military tubes
Ken-Rad6SN7GT black base- bass is slacking but still has a great clean ambiance and air.
Sylvania Green Label 6SN7GTB- its midrange and soundstage both pass as decent but its rich harmonic structure is what makes it
General Electric Black Plate 6SN7GTA- low level detail that gives it a smooth sound,wide bandwidth goes good as fourth tube combines with Sylvania 6SN7GTB in Atma-Sphere amps.
Sylvania Green Label 6SN7WGT Top Getter "silver top"- fresh out of the shower clean, great resolution, speed, although the midrange can get stuffy like your allergies, and the bass is a drag
6SN7WGTA Sylvania black base green label- good clean fun with some good bass
CBS-Hytron 5692- its too fast for love as motley crue would say basically what i mean is its fast with good dynamics to it and a lot of air with great timbre
RCA Red Base 5692- great for picking up voices and jazz music, generally a sweet warm sound
RCA 6SN7GTB- gives off a warm sound, with a bountiful mid range
G.E. 6SN7GTB Gray plates- wasn't designed to perfection but a good tube
Hope that helps in you picking out the best 6sn7 for your system!
information provided by tubeseller.com
First there are 5 different names for 6sn7 tubes 6sn7gt, GTB, GTA, and 5692. One hint to getting the best sound out of 6sn7 tubes is that the sound appears to work better when you combine different types of 6sn7 tubes together rather than having all one brand.
now lets list off the variation of sound between brands
Tung-Sol Round Plates/VT-231 or 6SN7- hands down best in everything they are clean, fast, sharp, have a huge span bandwidth need I go on?
RCA VT-231- their structure makes them rich in harmony, with sterling enhances on voicing, and a wide sound stage.
6SN7W or WGT Sylvania black plates- Can rank as one of the highiest quality tubes as well. If your system doesn't have enough balls such single ended amps this tube can give them the kick they need. There is three types of these tubes two large and one smaller with a smaller plate structure. The smaller one has better low level detail and the larger has a smack in the face to it. Overall the big and small have similar qualities.
Raytheon VT-231/flat black plates- the characteristic quality of sound produced by this tube is well balanced, compare it to the Tung-Sol just a little sweeter.
Ken-Rad VT-231/flat black plates- great bass, stellar midrange, butter bandwidth but not the best for preamps because they can get micro phonic on you.
Sylvania VT-231- wide bandwidth, well balanced, strong sound stage, and air.
Sylvania 1952 JAN-CHS-6SN7GT bottom getter- construction similar to early VT231 but sonics aren't and goes over the top the VT231 in every aspect
National Union VT-231- gentle bass with a good drive and great midrange
Tung-Sol 6SN7WGT Black plate brown base- sounds similar to the Tung-Sol VT-231 but not as clean
CBS/HYTRON 6SN7GT black plate- its the total opposite of me which means its quiet and its very musical we can call it the best of the military tubes
Ken-Rad6SN7GT black base- bass is slacking but still has a great clean ambiance and air.
Sylvania Green Label 6SN7GTB- its midrange and soundstage both pass as decent but its rich harmonic structure is what makes it
General Electric Black Plate 6SN7GTA- low level detail that gives it a smooth sound,wide bandwidth goes good as fourth tube combines with Sylvania 6SN7GTB in Atma-Sphere amps.
Sylvania Green Label 6SN7WGT Top Getter "silver top"- fresh out of the shower clean, great resolution, speed, although the midrange can get stuffy like your allergies, and the bass is a drag
6SN7WGTA Sylvania black base green label- good clean fun with some good bass
CBS-Hytron 5692- its too fast for love as motley crue would say basically what i mean is its fast with good dynamics to it and a lot of air with great timbre
RCA Red Base 5692- great for picking up voices and jazz music, generally a sweet warm sound
RCA 6SN7GTB- gives off a warm sound, with a bountiful mid range
G.E. 6SN7GTB Gray plates- wasn't designed to perfection but a good tube
Hope that helps in you picking out the best 6sn7 for your system!
information provided by tubeseller.com
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