Aikido Power Supply

[dr._sleep]

Would anyone care to share their power supply designs for the Aikido Line Stage. JB has helped me with the design of an Aikido Headphone amp with dual outputs, one OTL and the other for a pair of Sowter 8665 output trannies.



Thanks,

dr._sleep

[sunrise]

Hi,
dr. sleep, Aikido has no problems with power supplies so almost any power supply will do. Just find some power supply with tube rectifier and C-L-C filter design that has on the output voltage that You require and I think You will be fine....
hope this helps and best regards


p.s. 200-0-200Vac transformer into EZ81 or similar, after that 47uF to ground than 10H inductor, than 100uF to ground and I think that You might be arround 250Vdc at the end. Off course there are much better rectifier tubes that I would like to use but EZ81 and similar are the most common ones I think..... Use whatever YOu have but watch for the first cap. (not to exceed the value recomended for the used rectifire tube)...... also You can do better than above but ...... hope this would help a little bit more).

[dr._sleep]

Thanks for the reply. The power supply doesn't seem to be problematic, although, I was encouraged by JB to use a 12v regulated DC filament supply.

dr._sleep

[sunrise]

Originally posted by dr._sleep
Thanks for the reply. The power supply doesn't seem to be problematic, although, I was encouraged by JB to use a 12v regulated DC filament supply.

dr._sleep

yes,yes - I thought that this is no question - recomended - of course...... - even if the tubes are indirect heated..... I use dc filament everywhere......LM317, LM338 the common choices for the regulation.....regards

[Bas Horneman]

I was encouraged by JB to use a 12v regulated DC filament supply.

Good advice I think when it pertains to a heaphone amp.

Even though the Aikido has built in PSRR a good psu is still necessary...but like sunrise said...a simple CLC should do the job....My Aikido is still too hummy...(think it might be the transformers)...because I just quickly wanted to whip up an Aikido...

Learning how to use psud is very handy..

[dr._sleep]

I have used PSUD to develop a CLC, but I'll need to add and additional RC to get the voltge down. My PT is a 300-0-300, 150 ma. It has 6.3v for the filaments and I'll take care of the filaments with a separate 12v filament tranny and regulated circuit.



Question: This is my first attempt at a regulated filament supply and the LM350K has 2 leads on the bottom, is the ground simply soldered to the case?

Question: Can I just cap off the 6.3 v leads separately and leave them unloaded?

Thanks, dr._sleep

[sunrise]

Originally posted by dr._sleep
I have used PSUD to develop a CLC, but I'll need to add and additional RC to get the voltge down. My PT is a 300-0-300, 150 ma. It has 6.3v for the filaments and I'll take care of the filaments with a separate 12v filament tranny and regulated circuit.



Question: This is my first attempt at a regulated filament supply and the LM350K has 2 leads on the bottom, is the ground simply soldered to the case?

Question: Can I just cap off the 6.3 v leads separately and leave them unloaded?

Thanks, dr._sleep

NOO.... look at the picture attached - when You look at the device from the bottom as shown at the picture - from Your left is adjust pin (ADJ) and from the right is Your input (IN). Output (OUT) is connected to the case.
I assume that You will take 6.3V from Your transformer for the rectifier tube filament and 12V from another transf. for the tube in Your line stage...?!
I don't understand the second question.... What You want to do with 6,3V and why. You don't have to connect them anywhere if You don't want to use them, or you can use them for the filaments for You rectifier tube...... I don't get it what You want so please explain.....
Im will make a schematic for Your power supply as I would like to do it now and post it when I am finished so please check this thread a little bit later please..... there is a better way to make Your high voltage supply than just put an resistor in series (if You need lower voltage at the end).....
regards

[Bas Horneman]

What You want to do with 6,3V and why

I think he is not going to use them because he said he was going to use a seperate filament transformer. He now wants to know if he can just leave them unconnected.

The answer is yes..you can leave them unconnected and thus unloaded...

Regards,
Bas

[sunrise]

Iout is assumed to be 20mA per channel - so 40mA. And You can use other currents for IR2 but watch not to be to high with it. I assumed 20mA. You can see that Your R1 needs to be very big so I would recomend to find another transformer since Your 2*300V is to high .....
Also be aware that You have to connect You filaments of the tubes in line stage not to ground but on some voltage because You don't want to exceed approved voltage between cathode and filament. The best way to do that would be to split R2 in two resistors so that between them You have the required voltage. If You do so, watch also not to connect Your filament supply to ground. Where You connect it to ground - connect to the voltage that You have provided with split R2.

Let us know if You understood everything.....

oh - i didn't saw that mr. Bas was quicker - if You don't use EZ81 You will have smaller voltage droppout before C1 and the voltage on C1 would be higher.......

also - if You use that schematic for one chennel than it is o.k. but for both channels i think Your LM350 would be hot. Better to run with one LM338 or two LM350 (one per channel)... My opinion...

[sunrise]

regarding the heater cathode voltage

6n1p can withstand +100V and -250V and 5687 +/- 100V . So I would recomend you to split the R2 into two resistors. Upper resistor will be 8750ohm and lower resistors will be 3750ohm. When You have them in series You will still have 12k5 and between them You will have 75V. That voltage You can simply connect where You would connect ground in Your filament. But watch not to connect that LED than to ground but on that voltage also....
if I am wrong someone please correct or ad if I have forgot something.......