|
Posted by Romy the Cat on
09-01-2007
|
|
What would I do if I move to a much larger room and the power of Milq’s full 6C33C would not be enough? Surely it would be possible to go for transmission tubes but they all high plate impedance and high voltage.
If I parallel all my bass drivers and have around 1R load impedance then it will be a transformer with zillion turns… Also, I am not a big fun of the transmission tubes’ bass.
Adding more drivers in bass array look promising but not necessarily effective or practical. So, it would be interesting to find a high current tube that might be sitting in Milq’s bass channel socket. Since I so like the sound of 6C33C it would be worth to mention that the 6C33C has a bigger brother: 12C42C
The 12C42C was a next tube in the succession or 6C19C, 6C41C, 6C18C/6C33C. The 6C41C had one plate the 6C18C/6C33C were two plated and the 12C42C was simialr tube to the 6C33C but with 3 plates!!! It is not enough to be become purring – look at the 6C33C data:
Filaments: 12.6 and 5A
Anode voltage: 120V
Anode Current: 1A
Plate impedance: 65R
Maximum Anode dissipation -120W
|
|
|
|
Posted by morricab on
11-16-2007
|
Hi Romy,
Have you ever thought of trying to build or have built for you a SE OTL? You know that there is one on the market from the company transcendent sound using multiple 6C19PI output triodes?
Perhaps a few of these 12C42C tubes would make for a great SE OTL of about a few watts, which should be enough and perhaps it doesn't get any purer sounding.
|
|
|
|
Posted by Romy the Cat on
11-16-2007
|
|
Nope, I am not a big friend of OTL amps generally… BTW, I have seen (did not heard) one Japanese amp that use 64 x 6C19P tubes. For whatever reasons Russians consider that 6C19P as very good sounding tube - the younger sister of 6C33C. It was not my experience and I actually did not like how this tube (in classic SET application) sounded when I tried it. Perhaps in OTL application it might do different – I do not know. I bought a few year years 400 of them for $70, sometimes I would need to use them up…
|
|
|
|
Posted by Romy the Cat on
04-04-2008
|
|
Whonna to drive dead woofers with single ended triode? Get the Bell Laboratories 320A tube.
The 320A Vacuum tube was designed for use as an oscillator, modulator, or amplifier at the higher power levels
and high frequencies.
Filament ratings: 35 volts at 435 amperes
Average thermionic emission: 90 amperes
Characteristics at 18 kV plate voltage and 8 amperes plate current:
Amplification factor: 30
Plate resistance: 965 ohms
Transconductance: 31,100 micromhos
Maximum plate voltages: 12.5 kV modulated, 18 kV non modulated, 20 kV RMS AC
current: 15 amps DC
dissipation: 150 kilowatts
Maximum grid dissipation: 2 kilowatt
If somebody build anything around it… please let me know – it would be worth to fly over… :-)
|
|
|
|
Posted by Romy the Cat on
05-30-2009
|
|
fiogf49gjkf0d There was a cool Russian-made tube GU-48. It is high-gain, high power pure direct heated triode with 300W on plate and 10A on carbonized tungsten cathode. I did not hear but it looks like something in the class of RCA 833 tubes. I think Japanese sell the 833 amps for 200-300 thousand dollars. The GU-48 is around $50-$60 and I do not think that it would be worse; in fact I think it might be even better…
http://www.goodsoundclub.com/pdf/GU48.pdf
 The Cat
|
|
|
|
Posted by drdna on
05-30-2009
|
|
fiogf49gjkf0d  Romy the Cat wrote: | | There was a cool Russian-made tube GU-48... I do not think that it would be worse; in fact I think it might be even better… |
|
Wait, Romy, you think a RUSSIAN product might be better? That is a surprise!
Seriously though it looks interesting. If you have a circuit to suit it, maybe I will build it.
Adrian
|
|
|
|
Posted by Romy the Cat on
05-30-2009
|
|
fiogf49gjkf0d
Nope, the Russian tubes generally much, in fact much worse than western equivalents. There were however some exceptions. Those options were due to various reasons. The tubes like GM70, YO186, 1P24B, 6E5P, 6N30P, BO188, GM57, UB180, 6C33C, 6N6P, M457, ТО-143, YO104 were very-very good. The GU81, GU48, GU29 were generator tubes and they are presumably OK; I did not hear any good-made amps with it. The GM70 is transmitting tube as well and it is exceptionably good tube also, way more superior then 211/845 tubes but it is kind of not used yet tube as no one so far made any decently sounding amp with it, at least among those that I heard. So, the Russian transmitting tubes from the GU line might be fine tubes. To make an amp with them is a totally different subject…
What surprises me however is why you have expressed an interest in the high power tubes? You are with horns and even you LF sections have over 100dB sensitivity. What will you do with 120W SET?
Anyhow, I do not have a circuit for this type of amp. The circuit is not a problem, to know how to get sound out of those tubes is the problem and I have no knowledge about it. In the world of transmitting tubes the tube never was a problem. The right output transformer is the problem. It might be VERY expensive to make it properly and it might be very unnecessary due to the existence of DSET concept. Still, to hear a 120W SET over a few days might be a fan experience … The Cat
|
|
|
|
Posted by drdna on
05-30-2009
|
|
fiogf49gjkf0d | Romy the Cat wrote: | | What surprises me however is why you have expressed an interest in the high power tubes? You are with horns and even you LF sections have over 100dB sensitivity. What will you do with 120W SET? |
|
The subwoofer still needs a substantial power source. Right now it is being driven by a solid state amplifier. It would be interesting to see what impact the SET could have here if any.
Adrian
|
|
|
|
Posted by Romy the Cat on
05-30-2009
|
|
fiogf49gjkf0d
| drdna wrote: | The subwoofer still needs a substantial power source. Right now it is being driven by a solid state amplifier. It would be interesting to see what impact the SET could have here if any.
|
|
I see, I did not know that subwoofer needs a substantial power source. If so then sure it might be interesting. To make from GU-48 a powerful LF DSET would not be difficult. The output transformer will be very simple as well. The high voltage transformer for transmission tubes usually screen up HF as they need excessive high voltage isolation but for LF only DSET it would be no brainer. Make 500mA transformer with larger lamination you will be able to found and coils with 3000V-4000V isolation. I think if you find somebody why would make it large enough to get 5Hz-7Hz at FULL POWER then it will be around 500-700 transformer. Everything else will be relatively easy if you can talk like this about an amp hat will have 1.5kV on plate. BTW, the GU-48 has high gain, so who know it might be even a single stage amp… The Cat
|
|
|
|
Posted by Romy the Cat on
02-28-2010
|
|
fiogf49gjkf0d
I keep thinking about power and how much extra power and gain I would need in a new room, Sure, it is not difficult to raise a white flag and do for SS amplification but I so would like to stay with SET amplification for my bass channels! I am looking at the Milq bass channel and breaking my head thinking how I can get more power and gain. I do not have the exact numbers how much in shortage I will be but my current that my current Milq will not be able to handle nether power nor gain. In my current room I have a perfect match between room volume, sq of transducer and amplification:
http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=6057#6057
I have a feeling that if I have extra 6dB of gain and 4 times more power then I might be able to deal with new room. Sure, the only measurement in location would show. What I know is that I VERY much willing to preserve my SET bass but to get more POWER!
Rgs, Romy the Cat
|
|
|
|
Posted by Paul S on
02-28-2010
|
|
fiogf49gjkf0d
Maybe use +/- same design (with boosted/own PS, if necessary), but fuse the 6C33C plates together for 3 dB, or double-double for 6 dB. Might be closest thing to a known quantity.
Best regards,
Paul S
|
|
|
|
Posted by Romy the Cat on
02-28-2010
|
|
fiogf49gjkf0d | Romy the Cat wrote: | | I have a feeling that if I have extra 6dB of gain and 4 times more power then I might be able to deal with new room. Sure, the only measurement in location would show. What I know is that I VERY much willing to preserve my SET bass but to get more POWER! |
|
The only hope that I have is that I might add two more driver making my array 8 driver per channel. This would give me 3dB. I truly hope that I will be able to pick up an extra 3dB-6dB from the fact that my 8 feet tall arrays develop a truly cylindrical wave from let say 12’ distance. It means I will be able to have more bass gain in relation to MF channels then I have now. This will (might) take care about gain but it will never address the subject of power. Melquiades can’t work in A2, absolutely can’t not. Even if I beef up current from Melquiades’ driver stage then the re-polarization of the coupling capacitors and the A2-dead IDHT in output stage will screw the things up.
The caT
|
|
|
|
Posted by cv on
03-01-2010
|
|
fiogf49gjkf0d
Consider a triode connected 13E1. 95W dissipation, will probably work beautifully with the existing OPT if you adjust the gap down and if you can rewire your arrays to present a somewhat higher impedance.
Something like 400V-450V / 200mA-ish will give you a plate impedance of about 300 ohms, and it probably wants to see a load of around 1k5.
|
|
|
|
Posted by Romy the Cat on
03-01-2010
|
|
fiogf49gjkf0d | cv wrote: | Consider a triode connected 13E1. 95W dissipation, will probably work beautifully with the existing OPT if you adjust the gap down and if you can rewire your arrays to present a somewhat higher impedance.
Something like 400V-450V / 200mA-ish will give you a plate impedance of about 300 ohms, and it probably wants to see a load of around 1k5. |
|
Yes, CV, I might very much look in those B7A tubes. I have seen a few of them at MIT fleemarket but I never tried them. I am taking about all of those CV2377, CV6045, 13E1, VX6094. I think if I driver them with low voltage that I have in Milq (240V) but will use high current then I will drive the plate impedance down and will be able to use them. The all have 4.5 times amplification that is considering slightly higher plate impedance will be competitive to 6C33C. I think I will be able to get out of those beam tubes 35W. Will it be enough – hard to say and I do not know how much power I would need in new place.
My biggest concern with those tubes is not power but that they run at relatively low bias voltage. The 6C33C can run at 80V-90V that with 32 times of driver stage amplification would make a sub 3V allow on the amp’s input. That is good. However, those beam tube run at 30V bias that would make 1V one the amp input to switch the output tube into A2 operation. Yes, I understand that those tubes might be fine to run with positive bias but I do not know if I want to go in there. The coupling capacitor in Melquiades will be changing polarity – very ugly for Sound. The 6E5P driver will begin to battle the grid currents. A tube that runs in A2 effectively stops to be a triode - something that I would need to consider. The most important – it will be bass channel and the tube will be running almost all time on the right side into deep A2. All the amps that I have heard, when they are in A2 kill bass’ quality first (because multiple reasons). So, I think it need to be very careful evaluated if the bass from the beam tube family on the B7A socket is worse to pursuit.
Rgs, Romy the Cat
|
|
|
|
Posted by cv on
03-01-2010
|
|
fiogf49gjkf0d Man would I love to visit the MIT fleamarket... only a few thou miles away alas.
Well, I'm not advocating A2 in any way. The 13E1 will happily run at lower anode voltages but you won't get enough A1 power out, which is a shame cos you'll need a new power supply. But at around 400V, they will bias at around 80V or more, and I think you could probably reuse the rest of the amp - driver, iron, etc...
I'll email you some curves so you can draw some loadlines and figure out the power. There are also some discussions online suggesting that Ultra-linear is the way to go with these for max output, still, I think a combo of more line array and a few more watts from 13E1 may suit you well.
|
|
|
|
Posted by RennieB on
03-14-2010
|
|
fiogf49gjkf0d Hi Romy,
Great site, got lost here for a while now searching WE13a after building a WE91a 300B set, quess have to reconsider sell and wil look in to the Melq's for the near future... Also it even got me a little in to horns...
For now i have a question i might be able to ask here, if not, please remove or delete.
Got a pair of (Mundorf/Holistic sound devices) AMT 2510c from a local distributer and would pair this with the PHL 1220 in MTM config.
Would it be possible to make 2 x 2 channel amp. DSET for it? Would be around 93 dB HES.
While you are comming to the Netherlands soon you can visit me and discuss... ; )
Fishbowl...
http://home.tiscali.nl/fishbowl.amping/experimenten.html
TB3- 2000 _ UMG 48
Ps. Not my amp... And also not the one you would fly over for... Sorry.
|
|
|
|
Posted by Romy the Cat on
03-15-2010
|
|
fiogf49gjkf0d You can build DSET for anything. DSET concept does not imply any topology but recognition of purpose and accommodation of a topology for the purpose. Generally the 93dB sensitivity is not something that I would attack with SET, unless you use SET around that monster transmission tube. But here is again where my concept of price per solution kicks in. If you are willing to surface yourself by going for DSETs with over 1000W plate dissipation and 30A on filaments then can you aim for better speakers than MTM with PHL direct radiators and AMT tweeter?
The Cat
|
|
|
|
Posted by RennieB on
03-15-2010
|
|
fiogf49gjkf0d Hi Romy,
Thanks a lot for your reply! Very helpful but there is some misunderstanding...
I personally have a WE91A 300b Clone, no ambition to build something with the tb3-2000....
There is a guy building one though... ( I would if i could!)
My problem is that i read www.timebanditaudio.com/300b/WE91A.pdf and knew the way was HES with SET.
So build a transport, nos dac and amp. With some result... Only no HES speaker yet so it's not what i was aiming for.
My next thought was to build an MTM PHL/AMT for the reason to be able to build DSET in the future and build > 100 dB HES when time and money
are on my side again...
Could you point a solution for HES > 100 dB for something of 3500/4000 Dollar? Klipsch La Scala II Perhaps?
Thanks a lot!
RennieB
|
|
|
|
Posted by Romy the Cat on
03-13-2012
|
|
fiogf49gjkf0d
There is a tube out there might be a good candidate to drive ULF from DSET
http://tubedata.tubes.se/sheets/127/7/7242.pdf
It is a low voltage triode with 100W on plate, 9 times gain and 80R plate impedance. 3 of them might form a very nice near 100W ULF DSET and it will not be too hard to make it. Did anybody have seen/heard the SETs built around 7242? With total sun 30R on plate the ultra-high current DSET OPT will have just a few turns and it might be very interesting…
The Cat
|
|
|
|
|