Posted on Wednesday, 24th February 2010 by Auw Jimmy

Last week, we held a DIY gathering. Located at Bintaro, Indonesia. The host was Mr. Didik F. Wiryawan and family. Around 30+ people were there, was one of the crowded gathering ever. Below is the picture of the stage. We held some Blind Test also. You will also see some fancy DIY creation here.

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Tags: Blind Test, DIY Audio, Indonesia
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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 Saturday, 15th August 2009 by Auw Jimmy

Still remember my Aikido project? Until now, I’m still using Octal socket (since most of my rectifiers are Octal based, like 5U4, GZ37, etc).  Few weeks ago, I was poisoned with RGN Rectifier. Well, I knew this tube for long time, but just that time was poisoned badly. Have no choice, got to get one at eBay.

How do I use it on my Aikido? I’m too lazy to modify the socket, I decide to create a DIY Socket Converter, from B4 to Octal.

Most European tubes use this Socket. But in this project, I will specify the usage for RGN Rectifier tubes. Most of my RGN will use 4 Volt heater, while the standard Octal will use 5 Volt. What should I do? Piece of cake, just put 2 Resistors in both heaters line. Considering the RGN will consume around 1 A current, then 0.5R will do perfectly to drop from 5 Volt to around 4 Volt (I prefer to use 0.33R each to drop to 4.3 Volt, in case my main line drop a little bit at night).

Below is the necessary parts

An empty Octal socket, B4/B5 Socket, and two 0.33R resistors.

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Tags: Aikido, B4 Socket, DIY Audio, Octal Socket, RGN
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Posted on Friday, 6th June 2008 by Auw Jimmy

I was involved in the discussion about “Good PC Power Supply“. Then, I suggested a small trick to wrap the power supply cable with aluminum foil (you can find it a local food store, usually to wrap food on the microwave).

After wrapping it with aluminum foil, I suggested to use heatshrink to wrap all the cable (and make it looked good and professional). One of my friend, Bang Rossi, tried this method on his PC. Below is the photo (hope you didn’t mind I put the photo here;). Thank you for the sharing, man!

A little bit messy (because he didn’t use heatshrink), but according to him, it worked good. Good dynamic and better sound stage. Wanna try yourself?

Tags: DIY Audio, PC, power supply
Posted in DIY Audio | Comments (2)