I recently found a box of old Realistic Lifetime tubes in a closet. I haven't heard of any of the tube types in the box and was hoping someone here has heard of one, some, or all of them. Basically I'm wondering what they were used for and what application are they best suited for and finally if I could use them for any DIY project whether it be a pre or power amp or whatever really. Here's a list of what I've found:
1X 6KD6
1X 21GY5
1X 6JS6B
1X 6LQ6 (6JE6C)
1X 17JZ8
1X 6Z10 (6J10)
1X 1K3
1X 10JY8
1X 4EH7
1X 6JU8
1X 4EJ7
1X 10KR8
1X 12BV7 (12BY7A)
2X 6JC6
2X 6HG5 (6AQ5A)
3X 6GH8A
Again, any information is usefu. Thanks.
1X 6KD6
1X 21GY5
1X 6JS6B
1X 6LQ6 (6JE6C)
1X 17JZ8
1X 6Z10 (6J10)
1X 1K3
1X 10JY8
1X 4EH7
1X 6JU8
1X 4EJ7
1X 10KR8
1X 12BV7 (12BY7A)
2X 6JC6
2X 6HG5 (6AQ5A)
3X 6GH8A
Again, any information is usefu. Thanks.
Binaural said:
Dude,
Learn to use TDSL and peruse the data sheets for yourself.
I strongly suspect those tubes were intended to be used in a TV receiver. For instance, the 12BV7 is a video O/P type.
Off the top of my head: the 6GH8 is a pentode/triode frequently substituted for the fast disappearing 7199, the 6JU8 is a quad diode that can be used to bridge rectify LOW current supplies up to 300 VDC, and the 6HG5 appears to be a member of the 6V6 clan. IMO, the 2X 6HG5s are of obvious interest. They can be triode wired and used in an approx. 2 WPC SE amp. Look here.
Obviously all are color TV tubes. Most of which could be used for an audio amp, but you won't find a lot of existing schematics that use them, and unlikely to find a scheme using just units off that list. So DIY is in order with these. But you better make sure they are actually working first, before commiting any money for the more expensive parts, like transformers etc.
Since the 6HG5 appear to be 6AQ5 clones, it could make sense to build something already designed around them. With only 1 or 2 quantity on the others though, it would be somewhat dubious to design around those, unless you just happen to have parts laying around to experiment. They should however be cheap to get more later though. Several tube sales are going on currently that have TV tubes for $1 each. (at that price, I would be more inclined to just select the best TV tubes suitable for a design and then just order them)
Don
Since the 6HG5 appear to be 6AQ5 clones, it could make sense to build something already designed around them. With only 1 or 2 quantity on the others though, it would be somewhat dubious to design around those, unless you just happen to have parts laying around to experiment. They should however be cheap to get more later though. Several tube sales are going on currently that have TV tubes for $1 each. (at that price, I would be more inclined to just select the best TV tubes suitable for a design and then just order them)
Don
These are all TV tubes. Many can be used in audio, but some creativity is required, schematics are not common.
The 6JS6, the 6LQ6 and the 6KD6 are sweep tubes. These can be used to build a high powered push pull amp. Unfortunately you will need 4 of the same type.
The 12BY7 is a video output pentode. They work well as an audio driver and were found in some first rate audio amps like the Citation II.
The 6HG5 / 6AQ5 is a small oudio output tube common in old radios, TV sets and a few guitar amps. They can be used in SE (1 to 2 watts) and P-P (10 watts) audio amps. They will work in most 6V6 schematics at a reduced voltage.
The 6JC6 makes a decent low level audio amp when triode wired.
As stated previousle the 6GH8 / 6EA8 can be used in several audio applications. It is most commonly found with the pentode as a voltage amp and the triode as the phase splitter.
The 1K3 is virtually useless, and the others can find use in audio with a bit more creativity. The issue that I see is that you will need at least two of a given tube for a stereo amp. You could build an SE amp with 6GH8's or 6JC6's driving 6AQ5's.
The sweep tubes bring good money on Ebay. The funds could be used for transformers.
The 6JS6, the 6LQ6 and the 6KD6 are sweep tubes. These can be used to build a high powered push pull amp. Unfortunately you will need 4 of the same type.
The 12BY7 is a video output pentode. They work well as an audio driver and were found in some first rate audio amps like the Citation II.
The 6HG5 / 6AQ5 is a small oudio output tube common in old radios, TV sets and a few guitar amps. They can be used in SE (1 to 2 watts) and P-P (10 watts) audio amps. They will work in most 6V6 schematics at a reduced voltage.
The 6JC6 makes a decent low level audio amp when triode wired.
As stated previousle the 6GH8 / 6EA8 can be used in several audio applications. It is most commonly found with the pentode as a voltage amp and the triode as the phase splitter.
The 1K3 is virtually useless, and the others can find use in audio with a bit more creativity. The issue that I see is that you will need at least two of a given tube for a stereo amp. You could build an SE amp with 6GH8's or 6JC6's driving 6AQ5's.
The sweep tubes bring good money on Ebay. The funds could be used for transformers.
Colt45 said:
You could use it to make a shunt regulator for a highish voltage line stage -- something like a 12b4 with a CCS on its plate. It is higher voltage than most glow tubes, won't (?) oscillate when bypassed like a glow tube.
Edit, it has lousy impedance specs -- an order of magnitude worse than a glow tube. Still, with constant current it could work.
Attachments
Eli,
I do have TDSL, and went through and looked at all these tubes, but being somewhat of a beginner when it comes to tubes and a total novice when it comes to designing tube circuits, i only see the pinout and type of tube as well as some stats. Most of the links don't work and the datasheets are still a bit foreign to me.
The 3 tubes that intrigued me the most were the 3 largest. 6kd6, 6lq6 and the 6js6b. The 3 "sweep" tubes. What exactly is a sweep tube? Could they be used in a single ended or push pull audio amplifier? If not what would warrant a tube for these applications? I'm doing as much research into tube "technology" i quote it because i know it's nothing new, but it's definitely new to me and fascinates me. I also like to hear people's differing opinions on circuits, tubes etc. Hence this thread!
I do have TDSL, and went through and looked at all these tubes, but being somewhat of a beginner when it comes to tubes and a total novice when it comes to designing tube circuits, i only see the pinout and type of tube as well as some stats. Most of the links don't work and the datasheets are still a bit foreign to me.
The 3 tubes that intrigued me the most were the 3 largest. 6kd6, 6lq6 and the 6js6b. The 3 "sweep" tubes. What exactly is a sweep tube? Could they be used in a single ended or push pull audio amplifier? If not what would warrant a tube for these applications? I'm doing as much research into tube "technology" i quote it because i know it's nothing new, but it's definitely new to me and fascinates me. I also like to hear people's differing opinions on circuits, tubes etc. Hence this thread!
Binaural;
The data sheets at this site are more complete and easier to understand IMHO. You can see characteristic curves for most and details of maximum values as well as typical applications. In some cases you will have to use your imagination to interpret the data for some tubes intended for unusual service but careful study of the data sheets will get you started in the right direction and then you can ask specific questions based on what you see there.
Hope this helps.
The data sheets at this site are more complete and easier to understand IMHO. You can see characteristic curves for most and details of maximum values as well as typical applications. In some cases you will have to use your imagination to interpret the data for some tubes intended for unusual service but careful study of the data sheets will get you started in the right direction and then you can ask specific questions based on what you see there.
Hope this helps.
Sweep tubes were used to power the deflection yoke mounted on the CRT's neck. A good deal of "sock" is needed to move the electron beam(s) across the phosphor face, especially at the large deflection angles that became popular. A large deflection angle allows for a shorter CRT and a cabinet that is reasonably "shallow".
2X tubes, of the same type, are needed to build a SE stereo amp.
If the mu of a triode wired 6JC6 is 40 or greater, it will serve nicely as the voltage gain device in a "flea power" SET amp. Perhaps George (Tubelab) can tell us what the mu is.
"Sweep" tubes were originally designed to "sweep" the electron beam back and forth across the face of a TV picture tube to paint the picture. It is also responsible for generating the high voltage needed to operate the picture tube using a step up transformer known as a flyback. Early sweep tubes were made out of audio tubes. One of the first was the 6BG6 which was nothing more than a 6L6GB with the plate wired to a cap on the top of the tube to better deal with the high voltages.
As TV sets got bigger, more power was needed to sweep the beam across a larger screen, and more power was needed to generate the higher voltages to light up the bigger screen. When color TV came out even more power was needed. The poor sweep tube operates at full power all of the time. "Turning down the volume" on the sweep will make the picture smaller.
The sweep tube evolved into a purpose designed power tube able to run at full power for hours at a time 7 days a week. The 3 type numbers that you have are from the end of the vacuum tube TV era and are some hefty tubes.
During the CB radio craze of the late 1970's people figured out how to make some big booster amplifiers (highly illegal) using as many as 10 of these tubes wired together. These amplifiers ran the tubes far above the published ratings leading to short tube life. This alone has resulted in stratospheric prices and limited supply of some sweep tubes.
Several audio engineers, experimenters and commercial manufacturers (including McIntosh) figured out that sweep tubes could be used to make some serious audio amplifiers. Most sweep tubes can be used to make push pull amplifiers and power levels of 50 to 150 watts can be often extracted from a pair of sweep tubes. Some sweep tubes will work in a single ended amp, and some will not. Unfortunately the only way to find out is to actually hook them up and test. I am not aware of any published schematics for these 3 tubes in SE mode, but they may be out there. The McIntosh MC-3500 used 8 6LQ6 tubes to crank out a very conservative 350 watts.
There are several users on this forum (including me) that have been experimenting with sweep tubes. Some of these experiments can be found in these this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=128533&highlight=
More sweep tube experiments are planned when I have the time, but I tend to play with tubes at the other end of the price spectrum. Some sweep tubes never gained popularity with the linear amplifier crowd, and were either not popular in the TV world (supply exceeded the demand), or extremely popular (millions made). These can be found in the tube sellers bargain sales for very low prices (sometimes $1 each). I have a few used tubes of the types you have, but I may never experiment with them due to their high prices.
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