hi pengboon, sorry incomplete schematic 😀
the input is FR107 in bridge and raw dc is like 280V. the 330V in the schematic is a value i left during simulation- just to see if it will have the constant output that i need.
I also have another 100uF cap after the regulator circuit.
ps.
yes, add/change zener to change the reference voltage. the current zener i use are the 51V type which gives me around 220V output.
my caps are actually electrolytic, because i need the board to be real small (it's on a prototyping board).
the input is FR107 in bridge and raw dc is like 280V. the 330V in the schematic is a value i left during simulation- just to see if it will have the constant output that i need.
I also have another 100uF cap after the regulator circuit.
ps.
yes, add/change zener to change the reference voltage. the current zener i use are the 51V type which gives me around 220V output.
my caps are actually electrolytic, because i need the board to be real small (it's on a prototyping board).
thanks for great link pengboon
hey thanks for the great idea for a power supply pengboon
I had already started mine , now i think I wil change to the
supertex regulator circuit
my 12b4 is a seperate power supply design for the preamp itself
I will be milling it from a solid block of 1.5 inch 6061 t-11
aluminum somewhat looking like the nagra unit
(www.nagraaudio.com
thanks again Dave
hey thanks for the great idea for a power supply pengboon
I had already started mine , now i think I wil change to the
supertex regulator circuit
my 12b4 is a seperate power supply design for the preamp itself
I will be milling it from a solid block of 1.5 inch 6061 t-11
aluminum somewhat looking like the nagra unit
(www.nagraaudio.com
thanks again Dave
The link is from BGcap, not me. 😀
Anyway, I don't seem to be able to find the Supertex regulator rom my local RS or Farnell. Anyone knows if there is a alternative or kind enough to ship me a couple of those? 🙂
Anyway, I don't seem to be able to find the Supertex regulator rom my local RS or Farnell. Anyone knows if there is a alternative or kind enough to ship me a couple of those? 🙂
Tonight has been an interesting night... you might want to shelve that regulator idea Dave until you hear the gas regulators in my 12B4.....
Initial impressions are that the soundstage is much wider and much deeper than it was with the Thel regulator board. This may be more due to there now being a seperate regulator for each channel and I suspect similar results might be obtained with two Thel regulator boards. The bottom end also seems to be much improved and better defined than it was. There is definately alot more low level detail to be heard now than there was, even in the background in loud passages. So far the gas regulators seem the better route to go but there is more listening to do and at least another comparison of the Thel board to be done... possibly hooking up both boards we have here.
Tommrrow I gotta raid B.D.'s place to find 4 0D3's in the same bottle!
The photo is just for Choky!
Mark
Initial impressions are that the soundstage is much wider and much deeper than it was with the Thel regulator board. This may be more due to there now being a seperate regulator for each channel and I suspect similar results might be obtained with two Thel regulator boards. The bottom end also seems to be much improved and better defined than it was. There is definately alot more low level detail to be heard now than there was, even in the background in loud passages. So far the gas regulators seem the better route to go but there is more listening to do and at least another comparison of the Thel board to be done... possibly hooking up both boards we have here.
Tommrrow I gotta raid B.D.'s place to find 4 0D3's in the same bottle!
The photo is just for Choky!
Mark
Attachments
hmmm gotta admit that ghostly purple glow is cool
and the circuit is much simpler
I did find OA3s at (www,thetubestore.com)
if you dont find them loco-ly
I still havent picked up my12b4s yet
when is the best time to find davis at his shop?
Dave
and the circuit is much simpler
I did find OA3s at (www,thetubestore.com)
if you dont find them loco-ly
I still havent picked up my12b4s yet
when is the best time to find davis at his shop?
Dave
Dave,
You gotta call! Always call! I can't tell you how many times I have dropped by only to find the old man is not there.
I told you I picked up the Eico, but I also couldn't resist the blue Arcturus laying on a shelf under the Eico parts. I asked Bill about the blue glass, and he just grunted, "It was marketing crap! Supposed to enhance the performance of the tube. Crap."
But it worked on me. I had to buy that 1930 tube!
Now let's see...a blue glow, blue tube triode amp...sounds cool!
Lyndon
You gotta call! Always call! I can't tell you how many times I have dropped by only to find the old man is not there.
I told you I picked up the Eico, but I also couldn't resist the blue Arcturus laying on a shelf under the Eico parts. I asked Bill about the blue glass, and he just grunted, "It was marketing crap! Supposed to enhance the performance of the tube. Crap."
But it worked on me. I had to buy that 1930 tube!
Now let's see...a blue glow, blue tube triode amp...sounds cool!
Lyndon
Mark A. Gulbrandsen said:
I earned that! 😉
ps. You can't tell that I didn't tell you months before
Power Trans?
I'm about to order a power trans for my 12B4 project, like to get some advice here from the experienced 12B4-ers... 😀
1) My local shop has ready made 280-0-280 secondaries, or should I get 350-0-350 for the added margin for higher voltage?
2) I'm thinking of DC filaments in series, so filament voltage should be 24-0 or 12-0-12?
thanks in advance! 🙂
I'm about to order a power trans for my 12B4 project, like to get some advice here from the experienced 12B4-ers... 😀
1) My local shop has ready made 280-0-280 secondaries, or should I get 350-0-350 for the added margin for higher voltage?
2) I'm thinking of DC filaments in series, so filament voltage should be 24-0 or 12-0-12?
thanks in advance! 🙂
Those Arcturus blue tubes sure are pretty, especially the tipped ones. I have many of them that I have tried but unfortunately they are all hopeless microphonic and kinda "dark" sounding compared to newer ST shaped 27's and some of the older mesh plate jobs. Best for display or in actual vintage radios that use 27's in a visible manner.
Dave
Dave
DAVE!
that was certainly most beautiful pic I've ever seen on the net........in all categories (except family pictures,off course)
that was certainly most beautiful pic I've ever seen on the net........in all categories (except family pictures,off course)
An externally hosted image should be here but it was not working when we last tested it.
Its like porn only with tubes 🙂
Dave
Great photos, Dave!!!
I heard the same thing about them as well. You mean we can't open them up, substitute a better design, and reseal them? 😀
When I was searcing the web on these tubes, your suggestion was exactly what a German fellow did, building a nice radio with them.
I love guys like George of tubelab.com, who are constantly trying to figure out ways to use all the orphaned tubes and see if there is any audio applications for them.
I enjoy my Eico ST-40, and soon to be rebuilt Eico HF-81, just as much as my Aleph 3 and Krell Klone. Sure it doesn't have the slam, but the sound is very sweet.
Thanks again for those photos, Dave. We got a guy here in Salt Lake, Josh, of Electronluv.com who does amazing things with metal and tubes.
I heard the same thing about them as well. You mean we can't open them up, substitute a better design, and reseal them? 😀
When I was searcing the web on these tubes, your suggestion was exactly what a German fellow did, building a nice radio with them.
I love guys like George of tubelab.com, who are constantly trying to figure out ways to use all the orphaned tubes and see if there is any audio applications for them.
I enjoy my Eico ST-40, and soon to be rebuilt Eico HF-81, just as much as my Aleph 3 and Krell Klone. Sure it doesn't have the slam, but the sound is very sweet.
Thanks again for those photos, Dave. We got a guy here in Salt Lake, Josh, of Electronluv.com who does amazing things with metal and tubes.
hi pengboon,
transformer primary will depend on what you want to use for rectification for one (ss/tube), target voltage, and current draw.
you wanna follow mark with gas regulators? you will need two VR-150 at least, unless you wanna do mono-mono like him and you'll need four.
280-0-280 will give you plenty of volts with SS rectification (my cheap favorite is FR107) and just about right with tube rectification.
i forgot at what operating point mark is running his, it's something like 300V at 20 something mA. with a 6X4 -> 4uF -> 10H -> 47u -> 10H -> 47u will give you something like 340V, then feed it to two VR-150 as choky said for well regulated 300V.
DC for filaments? this is just me but i don't find DC a must for my General Electric 12B4A. Good layout *and* star grounding always do it for me. Anyway with 12.6V filaments, you will need half the current (300mA instead of 600mA) so the power transformer can be smaller, less heat.
Don't forget to specify filament winding for the tube rectifier, and it depends, 6X4 needs 6.3V at 1A and most others use 5V at some 3A (I normally overrate).
Cheers!
transformer primary will depend on what you want to use for rectification for one (ss/tube), target voltage, and current draw.
you wanna follow mark with gas regulators? you will need two VR-150 at least, unless you wanna do mono-mono like him and you'll need four.
280-0-280 will give you plenty of volts with SS rectification (my cheap favorite is FR107) and just about right with tube rectification.
i forgot at what operating point mark is running his, it's something like 300V at 20 something mA. with a 6X4 -> 4uF -> 10H -> 47u -> 10H -> 47u will give you something like 340V, then feed it to two VR-150 as choky said for well regulated 300V.
DC for filaments? this is just me but i don't find DC a must for my General Electric 12B4A. Good layout *and* star grounding always do it for me. Anyway with 12.6V filaments, you will need half the current (300mA instead of 600mA) so the power transformer can be smaller, less heat.
Don't forget to specify filament winding for the tube rectifier, and it depends, 6X4 needs 6.3V at 1A and most others use 5V at some 3A (I normally overrate).
Cheers!
