rtrott Posted December 11, 2003 Share Posted December 11, 2003 Ok, I just received my 1980 Cornwalls and thru what I have read here, tube equipment is the way to go. I am considering Edmund Lam's pre-amp and amp but I have no clue what a tube really is or does. I cant decipher the terms/model#s/etc used on this site either. Can someone direct me to a "Tubes for dummies" post so that I can figure out what I am doing? Thanks rtrott Quote Link to comment Share on other sites More sharing options...
Piranha Posted December 11, 2003 Share Posted December 11, 2003 ---------------- On 12/11/2003 10:09:37 PM rtrott wrote: Ok, I just received my 1980 Cornwalls and thru what I have read here, tube equipment is the way to go. I am considering Edmund Lam's pre-amp and amp but I have no clue what a tube really is or does. I cant decipher the terms/model#s/etc used on this site either. Can someone direct me to a "Tubes for dummies" post so that I can figure out what I am doing? Thanks rtrott---------------- Just stick around the Forum and read the threads in the 2-Channel Audio group. You'll gain a lot of knowledge about tubes that way. Quote Link to comment Share on other sites More sharing options...
garymd Posted December 11, 2003 Share Posted December 11, 2003 I know virtually nothing about tubes and I have 2 great tube systems. As long as you can pull them out and replace them with others that the forum experts tell you to use, you'll be alright. Quote Link to comment Share on other sites More sharing options...
Woodog Posted December 11, 2003 Share Posted December 11, 2003 ---------------- On 12/11/2003 11:12:36 PM garymd wrote: I know virtually nothing about tubes and I have 2 great tube systems. As long as you can pull them out and replace them with others that the forum experts tell you to use, you'll be alright ---------------- Hey Gary.... admit it... once you've been here a bit longer, you can be an expert too! This forum IS 'Tubes for Dummies' forrest Quote Link to comment Share on other sites More sharing options...
garymd Posted December 12, 2003 Share Posted December 12, 2003 ---------------- On 12/11/2003 11:55:13 PM Woodog wrote: ---------------- On 12/11/2003 11:12:36 PM garymd wrote: I know virtually nothing about tubes and I have 2 great tube systems. As long as you can pull them out and replace them with others that the forum experts tell you to use, you'll be alright ---------------- Hey Gary.... admit it... once you've been here a bit longer, you can be an expert too! This forum IS 'Tubes for Dummies' forrest ---------------- OK. I admit it but I still don't know how they work in a technical sense. I just know they sound great when they light up and you turn up the volume. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 12, 2003 Share Posted December 12, 2003 ---------------- On 12/11/2003 10:09:37 PM rtrott wrote: Ok, I just received my 1980 Cornwalls and thru what I have read here, tube equipment is the way to go. I am considering Edmund Lam's pre-amp and amp but I have no clue what a tube really is or does. I cant decipher the terms/model#s/etc used on this site either. Can someone direct me to a "Tubes for dummies" post so that I can figure out what I am doing? Thanks rtrott ---------------- Frpm one tube dummy to another, start out with a rebuilt scott, for than you can always move to higher end without too big of an inititial investment, and without a loss of $$$. I just bought a couple and sent them to Craig at NOSValves to rebuild and make perfect, if you want one just let me know Smilin Quote Link to comment Share on other sites More sharing options...
Colin Posted December 12, 2003 Share Posted December 12, 2003 ask a million questions - that is what we are here for! Quote Link to comment Share on other sites More sharing options...
Colin Posted December 12, 2003 Share Posted December 12, 2003 Things to know before a hot date with tubes If you are going to try a tube amplifier for the first time, here is what you should know: First, tube watts aint solid-state watts. A lower rated tube amplifier can sound just as powerful as a solid-state one. Second, there arent any 5.1 tube receiver or amplifiers that I know of, so you have to settle for 2 channel sound for maybe a long while. Third, if your receiver has pre-amplifier outs, you can run it as a pre-amplifier. Simply run interconnects from the receiver to the amplifier. The little babies run hot. You should never touch the tubes, especially when they are plugged in. Tubes hold current, part of the reason they sound so good, so give them 15 minutes to cool off before touching them. Each type of tube has its own unique construction (triode, pentode, etc.) and sound. 45s are typically about 1.5 watts, 2A3s about 3.5, EL34s about 10 to 30 watts, 300B are among the most powerful tubes. New handmade and vintage tube amplifiers often have hard point-to-point wiring (not thin lines on a circuit board). This is better sounding. New handmade tube amplifiers, even if made in Asia, are expensive compared to vintage amplifiers. Vintage amplifiers need refurbishing. Tube amplifiers wear out slowly the parts degrade but the amplifier keeps running. If one little capacitor or resistor goes on solid-state amplifier, thats it, you need to fix the thing. Not so with tubes. As the parts degrade, the amplifier still runs, but the sound gets worse. Tubes wear out eventually and need to be replaced. Unless you can test them, you have to assume that old tubes need replacing. If new, ask the manufacturer what the estimated useful life of the tubes is. Some new units run their tubes hot. They are more powerful, but you may replace expensive tubes every year. Typical tube amplifiers cant push around extremely low impedances of bass drivers. All loudspeaker manufacturers should make their frequency response and impedance curves easily available. A speaker that dips down to 4, or worse 2-ohms, may need a powerful tube or solid-state amplifier to really sound its best. Most loudspeakers are woefully inefficient. Super-sensitive horns are one of the few truly efficient designs that can really make the most of delicate sounding tube amplifiers. Tubes need to be cooled. Leave lots of air around them. Leave three to four feet on all sides. Tubes are sensitive to vibrations. If you are trying them out for just one night, leave them on the floor. Otherwise, place them on Vibration Isolation Platforms to dampen resonances. The input impedance of the tube pre-amplifier can make a very big difference when matching front-end equipment. Some matches do not work. You may have to experiment with higher quality front-end equipment. Tubes, and some solid-state equipment too, warms up and sounds better after about ½ hour to an hour. One of the joys of tubes is their superior imaging for relatively low cost. But this capability is for naught if your loudspeakers are not properly placed. Get them three to four feet way from front (the one you face) and side walls. Quote Link to comment Share on other sites More sharing options...
Piranha Posted December 12, 2003 Share Posted December 12, 2003 ---------------- On 12/12/2003 9:39:38 AM Colin wrote: Things to know before a hot date with tubes If you are going to try a tube amplifier for the first time, here is what you should know: First, tube watts aint solid-state watts. A lower rated tube amplifier can sound just as powerful as a solid-state one. Second, there arent any 5.1 tube receiver or amplifiers that I know of, so you have to settle for 2 channel sound for maybe a long while. Third, if your receiver has pre-amplifier outs, you can run it as a pre-amplifier. Simply run interconnects from the receiver to the amplifier. The little babies run hot. You should never touch the tubes, especially when they are plugged in. Tubes hold current, part of the reason they sound so good, so give them 15 minutes to cool off before touching them. Each type of tube has its own unique construction (triode, pentode, etc.) and sound. 45s are typically about 1.5 watts, 2A3s about 3.5, EL34s about 10 to 30 watts, 300B are among the most powerful tubes. New handmade and vintage tube amplifiers often have hard point-to-point wiring (not thin lines on a circuit board). This is better sounding. New handmade tube amplifiers, even if made in Asia, are expensive compared to vintage amplifiers. Vintage amplifiers need refurbishing. Tube amplifiers wear out slowly the parts degrade but the amplifier keeps running. If one little capacitor or resistor goes on solid-state amplifier, thats it, you need to fix the thing. Not so with tubes. As the parts degrade, the amplifier still runs, but the sound gets worse. Tubes wear out eventually and need to be replaced. Unless you can test them, you have to assume that old tubes need replacing. If new, ask the manufacturer what the estimated useful life of the tubes is. Some new units run their tubes hot. They are more powerful, but you may replace expensive tubes every year. Typical tube amplifiers cant push around extremely low impedances of bass drivers. All loudspeaker manufacturers should make their frequency response and impedance curves easily available. A speaker that dips down to 4, or worse 2-ohms, may need a powerful tube or solid-state amplifier to really sound its best. Most loudspeakers are woefully inefficient. Super-sensitive horns are one of the few truly efficient designs that can really make the most of delicate sounding tube amplifiers. Tubes need to be cooled. Leave lots of air around them. Leave three to four feet on all sides. Tubes are sensitive to vibrations. If you are trying them out for just one night, leave them on the floor. Otherwise, place them on Vibration Isolation Platforms to dampen resonances. The input impedance of the tube pre-amplifier can make a very big difference when matching front-end equipment. Some matches do not work. You may have to experiment with higher quality front-end equipment. Tubes, and some solid-state equipment too, warms up and sounds better after about ½ hour to an hour. One of the joys of tubes is their superior imaging for relatively low cost. But this capability is for naught if your loudspeakers are not properly placed. Get them three to four feet way from front (the one you face) and side walls. ---------------- Colin, Great post. Thanks! Quote Link to comment Share on other sites More sharing options...
rtrott Posted December 12, 2003 Author Share Posted December 12, 2003 Colin: I cant thank you enough for taking time out to include those extremely helpful statements. Thanks to you I no longer feel completely lost. Very informative and comforting to a tube neophyte. rtrott Quote Link to comment Share on other sites More sharing options...
arco Posted December 13, 2003 Share Posted December 13, 2003 Just go to: http://www.bonavolta.ch/hobby/en/audio/t_bas.htm Enjoy! Quote Link to comment Share on other sites More sharing options...
rtrott Posted December 13, 2003 Author Share Posted December 13, 2003 Fantastic!!! Just what I was looking for...Many thanks. Quote Link to comment Share on other sites More sharing options...
Speedball Posted June 6, 2005 Share Posted June 6, 2005 Thanks Colin......... Quote Link to comment Share on other sites More sharing options...
Colin Posted June 6, 2005 Share Posted June 6, 2005 generally, you are right! even if it is 2 years later! Quote Link to comment Share on other sites More sharing options...
Colin Posted June 6, 2005 Share Posted June 6, 2005 I posted that advice in 2003!!! Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 6, 2005 Share Posted June 6, 2005 Colin: "300B are among the most powerful tubes." Really? In what sense? Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted June 6, 2005 Share Posted June 6, 2005 "Typical tube amplifiers cant push around extremely low impedances of bass drivers. All loudspeaker manufacturers should make their frequency response and impedance curves easily available. A speaker that dips down to 4, or worse 2-ohms, may need a powerful tube or solid-state amplifier to really sound its best. " Are you shure? "Tubes need to be cooled. Leave lots of air around them. Leave three to four feet on all sides." 3-4 feet? Still, it's a nice post. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 6, 2005 Share Posted June 6, 2005 Mark: "Since there are few examples of "two identical circuits, one with PCB one is hand-wired" the opportunity to really compare sound is pretty limited, so if anyone has known examples, I'd be interested to know what they are." I know people who have built both PTP and PCB versions of Rozenblit's Grounded Grid linestage. The Grounded Grid is simple enough that a point-to-point version can and has been done with success, although I think circuit boards can have some advantages. I started gathering parts for a scratch built grounded grid, but ended up making my own version of the AES AE-1 6SN7 preamp (solid state rectified, but with a switched center tap used as a standby to let heaters warm the tubes before applying B+). The Grounded Grid kit is done very well, and I have built a few of those for others, but not one from scratch - so I can't comment on the sound personally. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 6, 2005 Share Posted June 6, 2005 Mark: "I didn't know they had two versions. Interesting. The one's you've built were PCB or P2P? To be clear, I am NOT suggesting that nice P2P units can't be built, because surely they can and are. I was just taking exception to the "always SOUNDS better" part of good old Colin's list. They might, or might not is my position. And, there is no question about some of the reliability advantages of PCB. That part is a no brainer. How's Rozenblat doing with his stuff? Did I hear somewhere he stopped offering them for a while? mdeneen" Mark -- I understood what you meant, and agree about one not sounding better than the other under all circumstances. I'm not saying he is wrong (colin)but just that there are too many variables involved to make that answer so straightforward. Again, wiring ability comes into play, and I have seen both very well done and far less well done PTP wiring of the same component; and believe that the better quality work resulted in much better performance -- mainly in terms of clarity and lower noise floor (those are important to me, but might not be to everyone). I have built a number of PCB - based amps and preamps, and I truly like doing that kind of work, and think there is far less chance of error (all things being equal in terms of soldering ability, wire stripping accuracy, and so forth.) Good point-to-point takes some practice, and Rozenblit's OTLs are examples of a design I would much rather do using circuit boards than not. I have known people who have made fairly complex OTL amps from scratch, and some had good luck, others not. Bruce only offers the PCB version, the other is available in schematic form (with parts list) in his second book. That one has to be built entirely from scratch with one's choice of chassis, etc. As far as I know, he's doing well. The last news letter I got mentioned continued work on a high powered OTL, which will also be fairly expensive, I think. I will virtually beg to not start another output power issue/thread here, but his low power SE OTLs have been pretty well received and reviewed. They are surely not for everyone, though! A high power officionado once made a joke about the low power thing (with this amp in mind)which was actually really funny! The few we had here did sound good, though. OTL amps are interesting creatures! edit - Mark: I see you mentioned some issues I also think are important re: point to point. P2P (I like that!)makes changing component types and values a little easier, I think, but I DO NOT think it's intrinsically better than PCB. Given the choice, I honestly think I would opt for PCB over the P2P, especially if I had no idea of the quality of construction. Circuit board traces can make for very short and clean signal paths, and I have seen some that are actually very sturdy and robust. However, I just finished working on an amp for friend that was PCB-based. It was something of a nightmare to work on, too. I basically figured the thing out in my head -- which works much better for this sort of thing than computers (Argggh), but found the workmanship just frightful. Good wiring and soldering ability makes a difference in both cases (IMO). Erik Quote Link to comment Share on other sites More sharing options...
lynnm Posted June 6, 2005 Share Posted June 6, 2005 Here is a link to an article that will provide a decent entry level understanding of how tubes work: http://www.anthemav.com/OldSitev1/pdf/taste.pdf Hope you find it an interesting read! Lynn Quote Link to comment Share on other sites More sharing options...
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