Posted on Sunday, 4th October 2009 by Auw Jimmy

To simplify the answer, Bleeder Resistor is used to “short” the positive and negative rail on your High Voltage (B+) circuit. The main reason is safety. Without Bleeder Resistor, your capacitors will store some amount of electricity after your system turned off. This may result of hazardous shock if touched, accidentally off course

This time, I change the old Bleeder Resistor (no brand metal film) into Kiwame Carbon Film Resistor with 5W rating. Here you go.

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Tags: bleeder, Kiwame, resistor
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Posted on Sunday, 23rd August 2009 by Auw Jimmy

Never ending tweaks and mods? Yes I think so. Actually, my Aikido Pre-Amp already sounds good. But as a DIY, I think the journey never ends. Tomorrow always comes with another mods. After completing the PSU mods with Mundorf MCap Supreme 3.3 uF/800VDC and ASC X386S 40 uF/440 VAC here, I decide to go further with some other components.

First, I still hear small hum. This is mainly caused by the Filament/Heater Center Tap of my DIY transformer is not exactly on the center. So the 1/4 B+ isn’t injected on the correct Center Tap position. The only solution is to create a Virtual Center Tap with a pair of 100 Ohm resistor. I use 100 Ohm 5W Kiwame. Some people may say that you can use any cheap resistor for this purpose, but I always choose the best price/performance. At US$ 2 each, Kiwame fits this job perfectly. Make sure you use an accurate resistor (metal film should fit best, carbon film also ok).

I fire up my Aikido and ta-da… no more hum, even when my ear next to the speaker! But I need to confirm later with high-gain amplifier. With a normal/standard gain amplifier, the hum is usually less noticeable.

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Tags: Aikido, DIY Audio, Duelund, Kiwame, mundorf, preamp
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Posted on Wednesday, 24th June 2009 by Auw Jimmy

I will continue my journey assembling the Mini Regulator. Now it’s the time for easiest part, the resistors and capacitors. To be honest, it’s not that easy – I mean, not as easy as I thought before

After around 1hour, I finish my job. Ta daaa… as below

I start to learn that DIY is not a matter of good sound, but also “eye catching” appearance. Well, I start it now. I “polish” the heatsink so it shines a little bit (rather than “dull” appearance). Then, I continue with picking colorful components. To be honest, it’s a little bit overkill to use Black Gate NX Series in this application. But I love the color combination and I believe you to. So? Just put it all down there.

The components are combination between Black Gate FK, Black Gate K, Black Gate NX, Black Gate N, and some resistors from Kiwame on most parts and one red one from PRP. Those Kiwames are carbon film, while PRP should be metal film. I pick PRP (despite of its red color) because this position is to set the maximum current of this regulator. Since PRP should be the regeneration of Holco, the most famous precision metal film resistor, so I do really can count on him. Oh, I also use old “dull color” green LED. This “dull color” LED should produce less noise than the newer “bright” LED.

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Tags: Black Gate, Kiwame, Mini Regulator, PRP
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