With the 300B is not too difficult to find a (good) starting point quickly thanks to plenty of published data and suggestions.
Regarding the XLS, there is already a table with some suggestions in the EML site:
http://www.emissionlabs.com/datasheets/EML320B-XLS.html
If you look at suggested operative conditions of both standard and XLS variants , including the original WE datasheet, one can notice that all suggested applications resulting in 3% THD (output stage only) run with a load+DC current combination such that the peak current at rated power = DC quiescent current, approximately.
From there one only needs to find the rest of the info from the curves without drawing necessarily the full loadline.
For example, an easy operative point from XLS curves in the link above without drawing anything could be 560V/75 mA with -120V bias approx. Then the 0V grid point at 150 mA is approx. at 140V. 560V-140V=420V and 420V/75 mA = 5.6K (Lundahl LL1623 comes to my mind first). Something like 795V peak-to-peak 142 mA peak-to-peak would result in about 3% THD and that equals 14W. According to my experience this quick guess works just fine (with good quality tubes...).
Regarding the XLS, there is already a table with some suggestions in the EML site:
http://www.emissionlabs.com/datasheets/EML320B-XLS.html
If you look at suggested operative conditions of both standard and XLS variants , including the original WE datasheet, one can notice that all suggested applications resulting in 3% THD (output stage only) run with a load+DC current combination such that the peak current at rated power = DC quiescent current, approximately.
From there one only needs to find the rest of the info from the curves without drawing necessarily the full loadline.
For example, an easy operative point from XLS curves in the link above without drawing anything could be 560V/75 mA with -120V bias approx. Then the 0V grid point at 150 mA is approx. at 140V. 560V-140V=420V and 420V/75 mA = 5.6K (Lundahl LL1623 comes to my mind first). Something like 795V peak-to-peak 142 mA peak-to-peak would result in about 3% THD and that equals 14W. According to my experience this quick guess works just fine (with good quality tubes...).
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I was just looking at the link you posted. It seems the tubes at that link have black coating on the inside of the glass. Isn't that going to increase the temperature inside the tube, since the anodes need to radiate the power dumped into them?
Without the coating some fraction of power gets transmitted through the glass to the environment, the rest gets absorbed, and then either reradiated from the glass to the inside and outside, or dumped via convection to the outside.
With the coating, more (or all) of the anode infrared radiation gets absorbed by the coated glass envelope (unless the coating is 100% infrared-transparent, which I doubt), and then reradiated to the inside and outside, and dumped via convection to the outside. So the glass runs hotter, which in turn makes the anode run hotter, which makes everything surrounded by the anode hotter.
The coating seems like a bad idea.
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The black (carbon) coating has been used in the past with no apparent negative impact. Black body is an ideal radiator as well as absorber.
Lots of 2A3s, 6V6s, etc used it in the past and are pretty easy to find pictures of.
Here is a pair of Kenrad 2A3s
Lots of 2A3s, 6V6s, etc used it in the past and are pretty easy to find pictures of.
Here is a pair of Kenrad 2A3s
Not so long time ago i was present with friends to listen to 3 pairs of 300B new production tubes. Amp was mono block version build by one friend. Very good made...
I remeber that TJ FullMusic 300B pair was very very good. There was slight differences between the brands ofcourse but not so dramatic.
Also I listened numerous times TJ FM in other SE 300B amp and it was more then decent and very good.
So for the starters I can recommend TJ FullMusic 300B.
.
Note
TJ FullMusic 300B are marked as "mesh plate". This is not true. The plate holes are just punched in one sheet-anode surface. In mesh types tubes I have had, the anode made from true "grid"...
Anyway not bad sound at all, offering much much more than the money price...
I remeber that TJ FullMusic 300B pair was very very good. There was slight differences between the brands ofcourse but not so dramatic.
Also I listened numerous times TJ FM in other SE 300B amp and it was more then decent and very good.
So for the starters I can recommend TJ FullMusic 300B.
.
Note
TJ FullMusic 300B are marked as "mesh plate". This is not true. The plate holes are just punched in one sheet-anode surface. In mesh types tubes I have had, the anode made from true "grid"...
Anyway not bad sound at all, offering much much more than the money price...
Decide what voltage, current, plate dissipation, and output primary impedance you will use.
Also, be sure to know a lot about the efficiency, and the impedance versus frequency of your loudspeakers, and room size and reflectivity.
Depending on all the above variables, you will get different results of the following:
Tube Life (reliability)
Sound level (amplitude) at the listening position
Sound character and distortion
Etc.
So many posts in this thread (146), who can keep track of the desires, suggestions, and results of all the advice given?
Pick a design, build, and enjoy listening.
(Much of my listening is done Near Field, about 2 feet;
the other listening is done further away in my living room).
Whenever possible, I use JJ power tubes, and JJ input / driver tubes.
DHT power tubes, Beam power tubes, Pentode power tubes, small signal triodes.
I get my very well matched and very well re-tested JJ tubes from Eurotubes.com (I just drive over and pick them up).
Also, be sure to know a lot about the efficiency, and the impedance versus frequency of your loudspeakers, and room size and reflectivity.
Depending on all the above variables, you will get different results of the following:
Tube Life (reliability)
Sound level (amplitude) at the listening position
Sound character and distortion
Etc.
So many posts in this thread (146), who can keep track of the desires, suggestions, and results of all the advice given?
Pick a design, build, and enjoy listening.
(Much of my listening is done Near Field, about 2 feet;
the other listening is done further away in my living room).
Whenever possible, I use JJ power tubes, and JJ input / driver tubes.
DHT power tubes, Beam power tubes, Pentode power tubes, small signal triodes.
I get my very well matched and very well re-tested JJ tubes from Eurotubes.com (I just drive over and pick them up).
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There is an operating condition within which a WE 300B will last 40,000 Hours. Both the NOS and the current WE made in Roswell will do this. With a 5 year warranty, this becomes an actually cost effective tube on a dollar-per-play-hour basis. If you would not want to go that price, the next option is a JJ 300B. JJ last solid 5,000 hours, usually more. They sound good till very near the end. Western Electric current production, or JJ, and I would suggest... definately. While truth is not determined by petition, there is a reason why so many in this thread have suggested JJ, and it is the people who really know also.
A 12AT7 can make a bit of magic driving a 300B. You might want to check into that one. It is much revered by all who have tried it is what I have noticed.
A 12AT7 can make a bit of magic driving a 300B. You might want to check into that one. It is much revered by all who have tried it is what I have noticed.
Good morning, I am running an Elekit 8600 with Lundahl and am happy with what it delivers with Electro-Harmonix 300B and even more so with the PSVANE WE300B, which is awesome. I have been given a set of TJ Full Music 300B/n and wonder if the operating conditions for these are ok in an Elekit 8600. I have read different things about about it being "mesh plate" but not really "mesh plate", and also the technical data on the web is not clear about the max anode dissipation for this tube. Has anyone tried these Full Music 300B/n in an Elekit 8600?
Thanks in advance
Thanks in advance