Hi to all....nice and funny thread....
I love tubes very much, but I also run my rental company.....so I must say that such amp would be just very impractical for live gigs. Big, heavy, hot as hell, very expensive to build and expensive to maintenance.....Of course if you want to work proper and be reliable. What will happens if you have gig for 1000 people and amp suddenly burns out....That's the reason why is always batter to have more amplifiers to drive sound system. For an example. If one of my 30 amps died I wouldn't notice at all......And what about the human labor. My amp racks weight some 70 kilos containing one Carver PT2400, one PT1800 and one PM950. Total output power is some 6KW at clipping. I must tell you that even such power/weight ratio is funny and stupid compared to some modern amplifiers from Crown, Powersoft.......which produce some 10KW from just a few kilos......I know what I'm talking about When heavy racks need to be dragged in some club in the basement, or even wore dragged out again in the morning when party is over and everybody are drunk and sleepy.....And one more scenario. What will happen if such big and heavy amp falls from 1m to the floor? I suspect that it will cost a lot and gig won't happen at all. I don't want to go in to details containing high voltage spikes in OPT and all things which may happen if you short the output or unplug the cable at the full power......
So my advice is don't do it. From practical reasons. If you want to do something almost the same than it is still better to clone some old Phase Linear 700b.....called Flame Linear or even Blaze Linear.......some years ago I have such idea and will be happy to send you some files.....pcb-s.....info...of course if you still insist to have heavy and dangerous amp for professional use. Of course very nice sounding........But I can't help myself to like your idea at the other side
Best wishes and regards, Taj
I love tubes very much, but I also run my rental company.....so I must say that such amp would be just very impractical for live gigs. Big, heavy, hot as hell, very expensive to build and expensive to maintenance.....Of course if you want to work proper and be reliable. What will happens if you have gig for 1000 people and amp suddenly burns out....That's the reason why is always batter to have more amplifiers to drive sound system. For an example. If one of my 30 amps died I wouldn't notice at all......And what about the human labor. My amp racks weight some 70 kilos containing one Carver PT2400, one PT1800 and one PM950. Total output power is some 6KW at clipping. I must tell you that even such power/weight ratio is funny and stupid compared to some modern amplifiers from Crown, Powersoft.......which produce some 10KW from just a few kilos......I know what I'm talking about When heavy racks need to be dragged in some club in the basement, or even wore dragged out again in the morning when party is over and everybody are drunk and sleepy.....And one more scenario. What will happen if such big and heavy amp falls from 1m to the floor? I suspect that it will cost a lot and gig won't happen at all. I don't want to go in to details containing high voltage spikes in OPT and all things which may happen if you short the output or unplug the cable at the full power......
So my advice is don't do it. From practical reasons. If you want to do something almost the same than it is still better to clone some old Phase Linear 700b.....called Flame Linear or even Blaze Linear.......some years ago I have such idea and will be happy to send you some files.....pcb-s.....info...of course if you still insist to have heavy and dangerous amp for professional use. Of course very nice sounding........But I can't help myself to like your idea at the other side
Best wishes and regards, Taj
Sweet, me too. We used to use these X2159 (early 8974) as RF amps at pppl.gov. 73
Hi to all....nice and funny thread....
I love tubes very much, but I also run my rental company.....so I must say that such amp would be just very impractical for live gigs. Big, heavy, hot as hell, very expensive to build and expensive to maintenance.....Of course if you want to work proper and be reliable. What will happens if you have gig for 1000 people and amp suddenly burns out....That's the reason why is always batter to have more amplifiers to drive sound system. For an example. If one of my 30 amps died I wouldn't notice at all......And what about the human labor. My amp racks weight some 70 kilos containing one Carver PT2400, one PT1800 and one PM950. Total output power is some 6KW at clipping. I must tell you that even such power/weight ratio is funny and stupid compared to some modern amplifiers from Crown, Powersoft.......which produce some 10KW from just a few kilos......I know what I'm talking about When heavy racks need to be dragged in some club in the basement, or even wore dragged out again in the morning when party is over and everybody are drunk and sleepy.....And one more scenario. What will happen if such big and heavy amp falls from 1m to the floor? I suspect that it will cost a lot and gig won't happen at all. I don't want to go in to details containing high voltage spikes in OPT and all things which may happen if you short the output or unplug the cable at the full power......
So my advice is don't do it. From practical reasons. If you want to do something almost the same than it is still better to clone some old Phase Linear 700b.....called Flame Linear or even Blaze Linear.......some years ago I have such idea and will be happy to send you some files.....pcb-s.....info...of course if you still insist to have heavy and dangerous amp for professional use. Of course very nice sounding........But I can't help myself to like your idea at the other side
Best wishes and regards, Taj
This is true, and the reason class D became so popular in the PA business first. Still, here in the US one can always get an SVT+fridge for rental. The general solution is to slave these for more power if needed.
Clamp diodes help, but can't prevent the sorts of faults that can happen on the output. The Champ amp I've estimated to weigh around 80 kilos, so it's only practical on a dolly and with a couple of strong backs if needed, or a fixed installation.
Moinsen,
Nice work, but how do you get 1000W output from 4x125W (500W) plate dissipation ???
Did you measure the 1000W ?
Best,
Nice work, but how do you get 1000W output from 4x125W (500W) plate dissipation ???
Did you measure the 1000W ?
Best,
Tube manual seems to support it:
Push Pull AF Power Amplifier & Modulator - Class AB1 (ICAS)
Plate Voltage ................................. 2500 V
Grid No. 3 Voltage ............................ 0 V
Grid No. 2 Voltage ............................ 750 V
Grid No. 1 Voltage ............................ -95 V
Peak Grid No. 1 Voltage........................ 180 V
Grid No. 1 Current ............................ 0 mA
Plate Current (Zero Signal) ................... 50 mA
Plate Current (Maximum Signal) ................ 290 mA
Grid No. 2 Current (Zero Signal) .............. 2 mA
Grid No. 2 Current (Maximum Signal) ........... 54 mA
Driving Power ................................. 0 W
Load Resistance ............................... 19K Ω
Power Output (approx) ......................... 490 W
Regards, KM
The answer sure is solid state when it comes to costs and less weight,
but a powerful tube amplifier is the goal here according to CSlee.
It's not the easiest way, but why always go the most common way?
At home I prefer tube amplification when playing loud.
It should work on a larger scale too. A tube amp for P.A. to me is something special.
I guess it's quite an experience, no matter how it turns out.
but a powerful tube amplifier is the goal here according to CSlee.
It's not the easiest way, but why always go the most common way?
At home I prefer tube amplification when playing loud.
It should work on a larger scale too. A tube amp for P.A. to me is something special.
I guess it's quite an experience, no matter how it turns out.
If I would want something similar than solid state for subs and tube for mids and highs would be my choice. I see something like ,,too much power is almost enough.....,, and it is true. Especially when you drive subs and the program is some electronic, drum and base.......For event with 1000 visitors you will need much much more power than ,,only,, 1 KW for subs. Some 5 KW is more likely to satisfy people with huge desire to hear 125dB......And after you find out that than you will discover that some 300-500W for mids and 100W for highs would be enough......There was legendary amplifier from Mcintosh, MI350 which was used at Woodstock in 1969.......but it has very complicated output transformer.......maybe is worth to try reverse engineered that beast......if you want tubes. I was studying this transformer some years ago......
I made sound system here in Ljubljana for small bar called BI-KO-FE. I use 400w solid state amp for subs and small EL84 amp for horn loaded mid/highs......Bi-Ko-Fe
About class d amplifiers. I hate them because they don't sound as should. Especially when you drive them to the limit. Almost all become aggressive what is really unpleasant in combination with modern narrow line array speakers......but almost all factories use them even on highs where only some 50w is required.....uf
And about 813 amp. Of course it is possible to get some 500W of output.....look at the phillips QB2/250 datasheet. It is the same tube ......
It is also possible to get 100W from 2 EL34. Of course in B class.
Best regards, Taj
I made sound system here in Ljubljana for small bar called BI-KO-FE. I use 400w solid state amp for subs and small EL84 amp for horn loaded mid/highs......Bi-Ko-Fe
About class d amplifiers. I hate them because they don't sound as should. Especially when you drive them to the limit. Almost all become aggressive what is really unpleasant in combination with modern narrow line array speakers......but almost all factories use them even on highs where only some 50w is required.....uf
And about 813 amp. Of course it is possible to get some 500W of output.....look at the phillips QB2/250 datasheet. It is the same tube ......
It is also possible to get 100W from 2 EL34. Of course in B class.
Best regards, Taj
Well, it does say on that page that John Chambers measured 1015 watts from the prototype. He has an excellent track record, so I'd be inclined to believe him.
Yes, the Mullard book supports this but also says only 69 watts from a pair of EL37s even though they are both rated at 25 watts anode dissipation. I always wondered about that.
Barry
Moinsen,
Sorry but thats all theoretically data, i gues.
I have measure a 200Watt Amp with four EL34 at 800V anodevoltage. The Amp reach 200Watt, but he has also 20% of THD at that point !!!!
Best,
Sorry but thats all theoretically data, i gues.
I have measure a 200Watt Amp with four EL34 at 800V anodevoltage. The Amp reach 200Watt, but he has also 20% of THD at that point !!!!
Best,
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Moinsen,
Sorry but thats all theoretically data, i gues.
I have measure a 200Watt Amp with four EL34 at 800V anodevoltage. The Amp reach 200Watt, but he has also 20% of THD at that point !!!!
Best,
What type of feedback did you use? Or no feedback at all?
Ah, i think you dont understand me right...
This 200 Watt amp with four EL34 was not my tube amp! It was a Echolette build in the 70tes. I only repair this amp for a friend, i don t know exactly how the NF was. I guess it was from the sec. winding of the output transformer to the first ECC83 and it was round about 20dB or so.
By the way my friend change the old Valvo EL34 for a new quad of chinese ones, the tubes exploited by the first switching in. Do not use chinese EL34 at 800V anode voltage...
Best,
Moinsen,
Sorry but thats all theoretically data, i gues.
I have measure a 200Watt Amp with four EL34 at 800V anodevoltage. The Amp reach 200Watt, but he has also 20% of THD at that point !!!!
Best,
Theoretical data? I'm pretty certain the manufacturers of these tubes don't make up theoretical data for their manuals. In short, the data I posted is direct from a tube manual under ICAS conditions... so I'm quite certain under those conditions I can get 490 watts output.
If it's mostly theoretical data, exactly what would you propose be used for specification data?
Regards, KM
Let me put it in the "right" way. Maybe manufacturer's data should be a better description... The description are more for advertising.
Sure you can get 490 Watt out of two tubes of 125 Watt plate dissipation and sure you can get 200 Watt with four tubes of 25 Watt plate dissipation.
BUT wat for? You can not use thees amps for audio amplification as we use amplifier today, because 10% harmonic desperation are not "state-of-the-art"...
Best,
Valve amps are mostly used by guitarists to get a good colour into the sound so at least 10% distortion is good point.
If you just want a good amp then get a class AB or D and solid state.
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OK, let me explain, 10% K2 are good and make of course a warm tubesound that i like too, see my amp.... But 10% K3 an you can not use the amp for anything but making heat.
There cant be a "good" amp. A amp can only be good for a specified task.
Best,
Just google the "phillips el6471" this monster runs on 230 volt mains, has a 3000 volt anode and weighs in at just over 350 pounds. Not exactly portable but it just shows that it can and has been done. True this is a monoblock so you would need 2 of them but hey, go big or go home right? She sure is pretty though. Phillips, disturbing the peace since 1953.
He he.....monster amp but I suspect that it is a little impractical for mobile ,live, club/touring......application.....what was the first question ...
But really interesting. I have Phillips tube data book...for tetrodes and pentodes, transmitting tubes.....and some of giant metal water cooled tubes were also intended for use as af amplifier/modulator....
Nice reading.
Regards, Taj
But really interesting. I have Phillips tube data book...for tetrodes and pentodes, transmitting tubes.....and some of giant metal water cooled tubes were also intended for use as af amplifier/modulator....
Nice reading.
Regards, Taj
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