| cbutterworth |
Yet another Aikido question (I apologise)
My PSU has been designed, and I have bought some surplus/used motor-run caps 1.5uF, 45uF, and 60uF.
Now, the thing is - the 45uF is huge (2.5 x 5 inches), and the 60uF is not much smaller. The 1.5uF is small enough to not be a concern.
I looked in the Antique Electronic Supply catalog, and they supply CE can capacitors that are made using Mallory specs and equipment. These are FP type cans and a multisection 30/40/80uF 525VDC measures only 1 3/8 by 3.
Capacitor size is going to have an effect on the size chassis that I eventually choose.
So, how would this FP cap sound compared with the 45uF and 60uF motor runs caps in the PSU? I would still use the 1.5uF AC motor-run for the cap-input to the first choke.
Thanks,
Charlie |
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| Eusebius |
| Use the motor runs from small to big with a couple of chokes in between and get a big chassis. I used some Mallory computer grade electrolytics once and whatever they did for computors they were complete **** in a tube PSU. Dead, slow, sluggish, dreadful. |
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| cbutterworth |
Eusebius,
Well......I'll be using the motor runs caps then!
Where in Britain are you located? I grew-up in Rochdale.
Regards,
Charlie |
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| Bengali |
Hi Charlie,
I'm starting on an aikido board. Did you finish building yours?
Did you make a preamp or amp? If you don't mind me asking what tubes did you decide on? Did you go with SS or tube rectifier?
I'm still looking for a 5ar4 tube power supply circuit. My transformer will be 234V. I think the 5ar4 drops 17volts, so I'm left with 217v. I just need 200V for the +B, 6cg7/6dj8's.
I don't know for preamp, if the +B should be regulated or non regulated.
thx. |
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| cbutterworth |
Bengali,
I just stuffed and soldered the Octal Stereo preamp board. It was really easy work. I will use four 6sn7's as I want to keep to gain relatively low.
My hunch right now is to build the PSU in a separate case to the preamp. I'll sit the PSU on the floor and run umbilicals to the preamp.
The PSU consists of Hammond 269AX (125-0-125), a bridge rectified using 1N4007's; 1.5uF cap, 10H, 155 ohm choke; 45uF cap; 10H, 155 ohm choke; 60uF cap. That will give around 300VDC. I will use a separate transformer for the 6.3VAC heaters.
What this will mean is that I can keep the noisy components away from the actual preamp.
From what I have read, the arrangement of the tubes in the Aikido really minimize on noise. I am not planning on regulating the B+.
Good luck with your Aikido.
Charlie |
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