Good analysis of the situation Sheldon. Civilisations die very quickly when they ignore the warning signs. Unfortunately history shows that the warning signs are rarely headed, and jlsems attitude shows us why.
But back to the more interesting issue at hand. I read a long thread today about the diyparadise Charlize. There were quite a few people there saying that it was sufficiently superior to there expensive valve amps that they were sold. There was even one comment from a person who had already sold his 300B amp and was buying an upgrade to his valve preamp with some of the cash he realised. The great thing is that this is still very much an infant technology and as far as i can tell - the skys the limit. If that is the case then sentiment will be the only thing which will justify the building of valve amps. Of course I could be very wrong.
That is one of the few encouraging things about the times we live in, technology can find many of the solutions to energy conservation - but it needs the time to develop them. I don't think 20yrs is long enough and that is why we need to save energy to give ourselves the breathing space to let science develop technologies which will allow us to live sustainably with the minimum drop in comfort levels.
Shoog
But back to the more interesting issue at hand. I read a long thread today about the diyparadise Charlize. There were quite a few people there saying that it was sufficiently superior to there expensive valve amps that they were sold. There was even one comment from a person who had already sold his 300B amp and was buying an upgrade to his valve preamp with some of the cash he realised. The great thing is that this is still very much an infant technology and as far as i can tell - the skys the limit. If that is the case then sentiment will be the only thing which will justify the building of valve amps. Of course I could be very wrong.
That is one of the few encouraging things about the times we live in, technology can find many of the solutions to energy conservation - but it needs the time to develop them. I don't think 20yrs is long enough and that is why we need to save energy to give ourselves the breathing space to let science develop technologies which will allow us to live sustainably with the minimum drop in comfort levels.
Shoog
Ah but don't discount sentiment entirely. Part of the utility in building valve amps is the notion of keeping alive some interesting knowlege of the past. It's good for us to have keep links to the past. New technologies divorced from lessons learned may solve immediate problems and leave us with new ones that are worse.
Those old radios may not have been very energy efficient, but they weren't designed as disposables either. My parents were born in the depression and my grandparents lived through it. They viewed consumptive frugality as a virtue - not a popular notion today. In response to fears after the Trade Tower attacks, our president suggested that it was in fact a virtue to continue to shop and spend as before. It ain't just him, because this attitude was largely accepted. So we got a ways to go, but the problem is not genetic it's cultural. And that we can change.
One more thought, and I'll drop this and go back to audio. For a long time now, it's been accepted wisdom in our culture that the best way to overcome limitations is to grow our way out of them - find new resources, new land, frontiers, expand production. We are not going to grow our way out of this one. It's going to be a real sea change to come up with a new definition of what constitutes "more" and "better". Let's start with more and better music.
Sheldon
Those old radios may not have been very energy efficient, but they weren't designed as disposables either. My parents were born in the depression and my grandparents lived through it. They viewed consumptive frugality as a virtue - not a popular notion today. In response to fears after the Trade Tower attacks, our president suggested that it was in fact a virtue to continue to shop and spend as before. It ain't just him, because this attitude was largely accepted. So we got a ways to go, but the problem is not genetic it's cultural. And that we can change.
One more thought, and I'll drop this and go back to audio. For a long time now, it's been accepted wisdom in our culture that the best way to overcome limitations is to grow our way out of them - find new resources, new land, frontiers, expand production. We are not going to grow our way out of this one. It's going to be a real sea change to come up with a new definition of what constitutes "more" and "better". Let's start with more and better music.
Sheldon
With NYC (and much of the rest of the country) sitting around 100deg today, i was thinking about a related topic: a cooler-running tube amp. My PP 6bq5 is definately not too welcome today. My hope was to build something more reasonable. I considered something biased close to class B, perhaps using tubes that didn't need much heater power, like the 6V6. This would seem to me to help both in heat waste and power consumption, since most of the time my amp is just loafing along. The problem is that i do not know much about amps biased this way, and haven't yet seen projects with this goal. How does one design a power supply for this? How does one deal with (what i assume is) increased distortion? and a bunch of other things that probably haven't occurred to me... anyone care to share tips or perhaps a successful design for a "summer amp"?
Go to www.davidberning.com and look at his class B amp designs (the BA150, the EA230, EA2100, and EA2101). I've adapted many of his ideas- high perveance sweep tubes, screen drive, very low idle current. The combination really does work, and my "big" amp runs very, very cool with quite low distortion.
I've pondered the use of a (bio)diesel/veg oil driven generator for a while..why not add a heat exchanger on the exhaust,and cooling system? You could get heat and hot water also.
Slap an A/C compressor setup from a car on the engine,and have A/C for the summer too.Make your own bio/veggie fuel and be set for cheap energy year round.
Add some batteries if you like,then you wouldn't have to run the generator all the time. Tag on some solar panels,and/or a windmill genny and you're good to go..plenty of excess energy to "burn" on tube amps.
I must admit,sometimes in the summer I become a SSinner,and turn the tubes off. Too much extra heat.
As for lower consumption?
Smaller amps,and more efficient speakers.
Tubes just aren't that efficient,there's no way around it..The heater/filaments have to glow in order for them to work. There's x Watts per tube 'wasted' as heat,intentionally!
(Ack! darn typos...)
Slap an A/C compressor setup from a car on the engine,and have A/C for the summer too.Make your own bio/veggie fuel and be set for cheap energy year round.
Add some batteries if you like,then you wouldn't have to run the generator all the time. Tag on some solar panels,and/or a windmill genny and you're good to go..plenty of excess energy to "burn" on tube amps.
I must admit,sometimes in the summer I become a SSinner,and turn the tubes off. Too much extra heat.
As for lower consumption?
Smaller amps,and more efficient speakers.
Tubes just aren't that efficient,there's no way around it..The heater/filaments have to glow in order for them to work. There's x Watts per tube 'wasted' as heat,intentionally!
(Ack! darn typos...)
I tried this too, after SY told me about it. It works. A pair of 6AV5's running on the edge of class B can put out 80 watts. The distortion at 50 watts is 2.5% without any feedback. The amp's efficiency (not counting filament power) was over 75% (80 watts output for 105 watts DC in).
All of this is not without problems. Conventional audio tubes distort a lot (crossover distortion) when you try to bias them near class B. High perveance sweep tube in screen drive work well. Sweep tubes tend to draw more filament power than an equal sized audio tube. Screen drive needs a lot of drive voltage. These are solvable problems.
I am sure that someone on an energy budget doesn't need an 80 watt amp so something smaller that gets similar plate efficiency, but consumes less filament power would be cool. A quick look through an old tube manual reveals several sweep rated pentodes that might work here. The 6CW5 (EL86) or the 6EM5 (there are plenty of other choices) draw 5 watts or less for the filament. The 6EM5 even has screen drive curves. If 75%, or even 70% could be obtained, a 10 WPC amplifier that runs on 50 to 60 watts of electricity should be possible. This is the energy consumed at FULL POWER. The average power consumed with music will be far less.
The filament power is constant say 23 watts (4 X EL86 + 2 X 12AX7) Idle plate power will be very low 10 watts or less (2 X 5 mA for drivers and phase splitters, and 2 X 10 mA for outputs at 300 volts). Say 35 watts at idle, and 60 watts at full power. Power consumption averaged on music will depend a lot on the music, how loud you play it, and the efficiency of the speakers, but 45 watts is probably close.
This is a big improvement over the average SE amp that eats 100+ watts of power all of the time. Due to the filament power required, a tube amp will never be as energy efficient as a SS or chip amp. I believe that a reasonable tube amp could be made, such that the increase over a chip amp will be "in the noise" compared to other energy draws in the house.
That's a good analysis. Let's look at a class B screen drive amp in the 30W class. 4x 6JN6, like the EA230. 30W for the heaters. Idle outputs at 400V, 3 or 4 mA, that's another 5 or 6 watts. Source followers to drive the screens, and the FETs can have very low idle current, so add another 5W for the screen drive. 6 watts for the driver tube anode currents, 8W for their heaters (you need four driver tubes). That's 55W at idle, probably going to 100W at full tilt for two 30W channels. Pretty efficient.
If there's any interest, a Dynaco ST70 conversion to class B screen drive might be a fun article.
If there's any interest, a Dynaco ST70 conversion to class B screen drive might be a fun article.
Before banning class A or SE tube amps, why not give active crossover a try?
Active 2 way system can achieve equal clipping headroom as a passive one with much much smaller amps. Here we can see 1+1>2.
Now I'm using 6C45 single stage less than 0.8W for mid-high, which consumes 20some watt. 4.5W 300B for bass, which consumes 80some watt. They consume slightly more than 100W in total, just like a conventional TV set.
Yes I know the efficiency is low. However the total consumptions are not very high. either.
2 low wattage amps can give me the satisfaction that a big one can not. I doubt an amp with about 100W consumption can give the same level of clarity, control & smoothness.
Overall performance in sound is what we want, not numbers.
Active 2 way system can achieve equal clipping headroom as a passive one with much much smaller amps. Here we can see 1+1>2.
Now I'm using 6C45 single stage less than 0.8W for mid-high, which consumes 20some watt. 4.5W 300B for bass, which consumes 80some watt. They consume slightly more than 100W in total, just like a conventional TV set.
Yes I know the efficiency is low. However the total consumptions are not very high. either.
2 low wattage amps can give me the satisfaction that a big one can not. I doubt an amp with about 100W consumption can give the same level of clarity, control & smoothness.
Overall performance in sound is what we want, not numbers.
Yes, active crossover systems can help. The main reason I like valves is for their midrange and treble. In a two-way system, the dome tweeter is typically twice as efficient as the accompanying driver, so, use a small Class A valve amplifier for the tweeter and a rather bigger Class AB SS amplifier for the bass.
My next loudspeakers will be three-way. I intend to use a switching amplifier for the bass (probably a Tripath - I've heard them and liked them), a 4W Class A valve amp for the (101dB/W) tweeter, and... ...and something will have to be done about the valve midrange.
It behoves us all to reduce our unsustainable squandering of the planet's resources
My next loudspeakers will be three-way. I intend to use a switching amplifier for the bass (probably a Tripath - I've heard them and liked them), a 4W Class A valve amp for the (101dB/W) tweeter, and... ...and something will have to be done about the valve midrange.
It behoves us all to reduce our unsustainable squandering of the planet's resources
Sy's and Tubelabs ideas sound good and workable, but someone would have to sketch out a circuit for us lesser diyers to work with. I have a rake of EL86's (which supposedly sound very good) which I was planning on building a self phase splitting amp with.
Unfortunately an active crossover dual amp approach is a dead end for me because I go fullrange with a super tweeter which barely tickles the main driver.
Shoog
Unfortunately an active crossover dual amp approach is a dead end for me because I go fullrange with a super tweeter which barely tickles the main driver.
Shoog
I'll see if I can dig out my PCL86 design - a nice little 6 watter in purest class a - its a pentode output though, and CF too, so a little odd in design, but I liked it when I built it (its now parts again).
the ECL86 is a curious beast - its a NN AX7 combined with an effective EL84 in the same envelope - as it is, if you're not careful, you end up with too much gain - the rest of designing with it is very simple - I seem to remember using them in PP with a triode CCS on a concertina phase splitter (very very nice) driving the pentodes, and also in the 'odd configuration of the nn ax7 sections driven from a 1:1 cheapo audio transformer (in my case I used a very small (2VA) torroid isolation transformer) with thier voltage gain, and using the el84 section for current gain as cathode followers to output. Once again a nice, and unusual design, that's simplicity itself to design...
So some food for thought there
Owen
the ECL86 is a curious beast - its a NN AX7 combined with an effective EL84 in the same envelope - as it is, if you're not careful, you end up with too much gain - the rest of designing with it is very simple - I seem to remember using them in PP with a triode CCS on a concertina phase splitter (very very nice) driving the pentodes, and also in the 'odd configuration of the nn ax7 sections driven from a 1:1 cheapo audio transformer (in my case I used a very small (2VA) torroid isolation transformer) with thier voltage gain, and using the el84 section for current gain as cathode followers to output. Once again a nice, and unusual design, that's simplicity itself to design...
So some food for thought there
Owen
I think using biodiesel to run a genny is a bit of a waste. I have thought about using waste food oil (suitably filtered) for central heating use. An unmodified diesel burner should work if you preheat the oil going in. The whole fag of making biodiesel puts me off.Not only is it an involved process, its not without risks to health. Also the raw materials are quite heavily taxed in ireland.
I have a beef farmer next door to me, I have toyed with the idea of making a biogas plant for cooking gas. The only thing with it is that biogas is only produced effectively at about body temp (36 degrees) and our ambient temp is 22 degrees in the summer and 10 degrees in the winter. When the temp drops you need to put in as much energy as you generate in biogas to keep the process going. I thought of adding a solar panel and burying it in the ground to keep the temp stable. Still the end result is marginally viable at best.
I think the correct approach is insulation first, then solar hot water, then alternative heating and only finally a wind turbine-solar panel combination for electricity. This follows the path of most potential energy savings.
Shoog
SY said:
SY, i'd be totally interested. Screen drive is a bit beyond my design ability, which doesn't go much further than a grounded cathode, so i'd love to learn. I checked out Berning's stuff, and it looks very elegant, but a bit complex and light on explanation (i can't blame him, he's running a business).
I have seen an article on a complee DC coupled SE screen driven xL509. It looked very nice and straightforwarded. Geek also commented somewhere that once you listened to a screen driven amp you maybe wouldn't go back to anything else. So, I am all ears!!
And, off course, I would surely build a borg collective for it
Erik
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