"Building the very best amp on the green earth on the first try"

This is the road to madness, or at least inaction. I, and… can I get a show of hands here, been there.

Let’s say for the 6AH4 amp we were discussing a while back. At a guess you need

http://audioroundtable.com/GroupBuild/messages/1111.html
http://audioroundtable.com/GroupBuild/messages/1113.html
http://audioroundtable.com/Tubes/messages/665.html

Over at AA there was a long discussion on the merits of low DSR chokes, that moved on to power transformers. At first I thought the thread had promise. Well silly me.
Also it has been very hot here and with little or no AC. Perhaps I am a bit cranky.(No miserable little smile face)

So. After your very considered reply, I reread the thread. To go back to your original question, low verses high DSR. I can not think of a reason that you would want a high DSR secondary in a SE amp.

Does this mean that that the transformer with the lowest possible DSR is always the best? Good question. I have not looked at it in those terms,

Two points. First, remember, a transformer can be drawn ‘as a black box that is full of compromises’ (I rather like that one;)
Second, if you go and order ten different EI transformers with the same spec. you will end up with a collection that weighs in at say, 5lb to maybe 12lb or more and cost < $50 to maybe several hundred. Can the "goodness" be measured in DSR alone? Probably not but it may well be an indicator. Make a good green belt project for someone. .

There is much more to say on this. Such as OK John get to the point and how do you choose a power transformer.(Hint I look in my junk box first).But it still much too hot and I am starting to fade away. More later…John

My point is I do not choose a transformer on it’s DSR I find that if I choose a good transformer, low DSR usually happens.

For example, take two transformers from Hammond the 270fx Vs the 370fx. Now the 370 is set up for multiple input voltages but that is beside the point. They are rated very close 139VA for the 270 Vs 142VA for the 370. The 370 is a much beefier transformer and cost twice as much. So what’s up with that? Want to guess witch has the lower DSR?

That aside If you are trying to get close to the "rated" 150ma, which do think will run reasonably cool and not buzz like a… well you get the idea. Now if you only ask for 75-100ma the 270 may work just fine. So were dose that leave us with the DSR?

Your mission should you chose to accept it…Please let us know.;)

As to how to whatever DSR we end up with works into the filter. I need to research as well. First thoughts, model a simple filter. Say 10uf -5mh-50uf to a stepped load. vary the transformer DSR and take good notes. Maybe replace the choke with a resistor. When in doubt use 1k. I think there something on the VT52 site.
What do you say, we work this for a week or so and compare notes?…John

My point is I do not choose a transformer on it’s DSR I find that if I choose a good transformer, low DSR usually happens.

For example, take two transformers from Hammond the 270fx Vs the 370fx. Now the 370 is set up for multiple input voltages but that is beside the point. They are rated very close 139VA for the 270 Vs 142VA for the 370. The 370 is a much beefier transformer and cost twice as much. So what’s up with that? Want to guess witch has the lower DSR?

That aside If you are trying to get close to the "rated" 150ma, which do think will run reasonably cool and not buzz like a… well you get the idea. Now if you only ask for 75-100ma the 270 may work just fine. So were dose that leave us with the DSR?

Your mission should you chose to accept it…Please let us know.;)

As to how to whatever DSR we end up with works into the filter. I need to research as well. First thoughts, model a simple filter. Say 10uf -5mh-50uf to a stepped load. vary the transformer DSR and take good notes. Maybe replace the choke with a resistor. When in doubt use 1k. I think there something on the VT52 site.
What do you say, we work this for a week or so and compare notes?…John