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Please forgive my ignorance but I'm just now starting to research SET amps.My fear is that anything smaller than the hefty Cary 805c series might not be enough for my speakers.... or my listening habits. I like it somewhat loud and dynamic but it's not really practical to change my speakers out.... or should I say, I rather keep the speakers that I presently own. They are 91db efficient Tannoy D500s with 8" drivers. They do ok with about 30wpc but they really come alive with a robust solid state amp.
Are there any worthy SET amps I should investigate that put out more than 10 - 15wpc but less than the big 50+ wpc Cary 805c?
Oh, and back to my original question. What is an SET 45 amp and how much power do they output? Thanks!
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Follow Ups:
Here are few examples from a search on the Tube DIY forum.http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=85720&highlight=811+SET&session=
http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=95624&highlight=ottoamps&r=&session=
I think the 811 will get you close to that 15 watts that you have set as a criteria for you speakers.
Aren't those old transmitting tubes? I think I remember 811's from my HAM radio days (along with the 807's that were in my uncle's homebrew 100w CW transmitter).
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Abe,Audio Electronic Supply (Cary Audio) use to offer the 811SE monoblock amp. Several years ago I demo'd a pair with my Joseph Audio RM50si speakers. I can tell you that the amp sounded great. I would describe the sound of the 811 tube as very guts. Brings a lot of life to the music. Think of the sound of a SET on steroids. One of the things I liked about the amp was the fact it used 6SN7 and 6L6 tubes. If you can find a used pair of the 811SE amps I would suggest that you try it out in your system.
A pair of PP 45s provided enough power for Tannoy Gold Monitors. In fact, the bass was quite powerful. PP gets a bad rap at times, but PP is actually more difficult to design for best sonics. A 'no compromise' PP 45 design is fantastic.
Another option is a SET based on the 845 tube (about 22-25 watts). Lots of choices out there at every price point. My own experience has been with two different Dared 845's (one modded with better caps and a bypass from the internal passive preamp). I liked them both. Happy hunting.
...that are rated at 50 Watts. Each uses a 12AX7, a 6L6/EL34 (triode-wired) driver, and one 805. I've improved them substantially and was VERY happy driving 86dB-sensitive Quad 989s with them. They'd easily generate 95dB peaks in my c. 3200CF room. E-mail me at jeffreybehr(at)cox(dot)net if you're interested.
You tube guys must be sitting around just waiting for a dump question to jump on. ;-) Just kidding, but thanks for all the responses on the 45 / 2a3 / 300B.I realize my speakers are not ideal for this, but I may try a 300B type amp just to see what 10-watts or so might do. I'm real hesitant to try anything less in terms of power. I'll let you know what I end up with and how it sounds. Like I said, I'm in my very early stages of research. Thanks for your replies.
P.S. I am not completely unfamiliar with tube gear as I have owned various 50 - 100wpc amps based on EL34, 6550, and KT88.
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Abe, hi. Typical max power for the 45: 1.6W I can tell you the quality of sound from the 45 has captivated many. Count me as one. The 45 produces a certain "rightness" of sound that is difficult to convey with mere words. If you haven't heard this tube find someone in your area with a 45 tube amp and go listen.Please keep in mind that the Cary 805c may output 50 Watts in A2 but at considerable distortion and under test conditions. The 50 Watt one tube claim is a bit over the top, I think. A single 845 is really going to do about 20 W. You could push it in extremis and get more power out of it but at what cost? Sonics? Tube health?
Still and all 20 Watts pure Class A triode tube is a lot of real world power.
The 45 tubes maximum power was rated by the RCA manual for 2 watts at 275V. That's before Roger Modjeski turned the tables with a new application and got over 4 legitimate watts out of a pair of 45's with no gimmicks.
glenz, hi. I believe RCA published data that showed 1.6 W as max single tube Class A. Later additions may have bumped it up to 2 W - but who is going to quible about 0.4 Watts? Not me.The so-called "45" that RAM labs is selling may deviate from the RCA specifications enough that it falls outside the parameters of what a Type 45 is. It should be called a "45-A" or something to make it clear it is Not a 45 but rather something akin to a 45 with higher dissipation. This cavalier attitude with specifications is just plain annoying.
Hi Elektron:
I know a little something about this tube.http://www.vt4c.com/bb/viewtopic.php?t=151 This is a 45 amp I built 3 years ago.Regards,
Hi Elektron:
Here is the RCA 45 application.......
As Single Tube Class APlate voltage 180V 250V 275V
0.825W 1.6W 2.0W
Pick your poison!
BTW What do you mean by cavalier?
If one is going to build a 45 tube it should probably meet fairly closely the parameters set by RCA who engineered the 45. That a company can make a tube which is called a "45" but has much different dissipation and who knows what other differences (heater current, inter electrode capacitance, etc.) is, in my opinion, cavalier. That is to say not paying any heed to the characteristics that would qualify the tube to be a Type 45 tube in the first place. Cavalier - showing willful disregard. Just saying a tube is a 45 or branding it so does not make it a 45. Thus my usage of the word cavalier.
Elektron:
By the way, what do you mean by a different dissipation? it doesn't have different dissipation. It's dissipation is within the guide lines set by RCA. Why would you mention that? I never did!
I beg to differ with you, and I'm not sure what kind of practical experience you have or wheather or not you have a degree in electrical engineering. However, Let me mention something that you might not know.....The application and ratings for tubes were done as a guideline for designer's(a blueprint if you will)It was not to be the end all or the holy grail for designing. This comes from the mouth
of an applications designer who had been employed by RCA fro 35 years.
By the way, how many amplifiers have you built?
glenz, hello again. You seem itching for a fight. I find that both odd and humorous. You beg to differ with me? About what? Uniform standards of manufacture of various types of electron tubes?Are you on the moon?
Elektron:
I was perilously close to calling you a "hack", but after reading your discription of globes vs ST's, I'll cut you a little slack. Still you miss the point of comparison by a very slim margin. You almost give the reason for the difference in the sound, but come up shy. A good effort though. should you want to talk further, I'll share something with you.
We were talking initially about a 45 tube(old style)and getting 4 plus watts from it. That's right. The original 45. As far as picking a fight, not really. But unlike you, I know what I'm talking about and have the background to prove it!
The craftmanship of that 45 amp is anything BUT cavalier Glenz
> smile <
[They are 91db efficient Tannoy D500s with 8" drivers. They do ok with about 30wpc but they really come alive with a robust solid state amp.]
Typically Tannoy does okay with tubes but I assume your speakers are newer ones. In many respects it isn't so much how efficent the speakers are as much as it is how constant a load they present to the amp. In any case I would say your speakers are not "SET" friendly.[Are there any worthy SET amps I should investigate that put out more than 10 - 15wpc but less than the big 50+ wpc Cary 805c?]
The 300B is in that 10-15 watt range depending on the tube used but the short answer to your question is no. If you want more than 10-15 watts you are either going to have to use multiple tubes or move into the real high voltage transmitting triode amps.[Oh, and back to my original question. What is an SET 45 amp and how much power do they output?]
SET is often taken to stand for single ended triode but should really stand for single ended topology. A 45 SET is good for about 1.5 watts. Single ended simply means one device handles the entire musical waveform. SET's typically use only one directly heated triode like the 45, 2A3, or 300B as an output tube with no global feedback (but they could use multiple tubes or even transistors withor without feedback). They are said to excel at conveying the emotional content of the music.While I am not a SET guy I do feel there is much to be said for having efficent speakers and low wattage tube amps. At present I run a push pull triode strapped 6V6 amp that is almost 3 watts per channel. I have not compared it to a Cary but I have compared to ARC and VTL monoblocks in the 80+ watt range and all have agreed the little 6V6 amp has more balls. So don't think low wattage equals wimpy sound by any means.
Russ
... a 45 SET is a single-ended triode amplifier using a 45 (or multiple, paralleled 45's) for its output tube. A single 45, single-ended is good for about 2 watts, as I recall.And they sound real good :-)
see link below...
all the best,
mrh
I assume you know that SET stands for Single Ended Triode and uses a single triode type output tube per channel. SET 45 will usually put out only 2 to 2.5 watts per channel. They are one of the lower power tubes. Wonderful sounding (some say the best, I don't have enough experience to say) but not a lot of power. If you like it loud you will want speakers that are more efficient than the ones you mention - probably 98-100+ db/m. That said, they CAN be used with lower efficiency speakers - you just won't have the volume. I built a Bugle 45 SET and, before I found some big, efficient, University speakers, I used them with a variety of lower efficiency ones. But then, I don't generally listen all that loud at home. The next step up would be the 2A3 at about 3.5 wpc and the 300B, which is usually about 8 wpc, although there are some circuits that squeeze more out of them I think. I mostly use vintage tube gear - most of which is push pull not single ended, and I get plenty of volume out of stuff that has 10-15 wpc or less. Lots of people say that "tube watts" are louder than SS watts, or it seems that way. Have you tried any type of tube amp with your speakers? I run vintage systems in the high school classroom where I teach and play music during class changes. I've run amps that are 12-14 wpc and vintage speakers that are maybe 90 db/m in a fairly large room and I've had high school kids ask me to turn it down because it's so loud. They can't believe it's so little power or that some 50 year old amp can sound so good. . . . Charlie
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