Posted on Sunday, 30th August 2009 by Auw Jimmy

Still curious about the different between Jensen Copper Foil Paper Tube and Duelund CAST PIO, I held another session to benchmark both capacitors. You can read previous articles here and here.

This time I visit another friend. His systems as shown below. Briefly speaking, we can see a Fostex full range speaker with extra Visaton Super Tweeter. The source are Cayin CDT-17A (fully modified on its analog stage and additional reclock module) and a turntable (VPI Scout with Super Platter and Van den Hul Grasshopper IV GLA cartridge). The preamp is Tube #26 with RGN Rectifier. The power amplifier is RS241-12E1-6J5 with RGN Rectifier also.

We compare the Jensen Copper Foil Paper Tube and Duelund CAST PIO on the position between 12E1 and RS241.

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Tags: Duelund, jensen
Posted in CD/DVD Review, DIY Audio | Comments (18)

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 Tuesday, 18th August 2009 by Auw Jimmy

After you read this, perhaps you would expect a better system to test the capacitors. So today, I visit a friend, and test the capacitors on his system. We can call him, Mr. X. Here is some brief of Mr. X audio system.

Below is the power amplifier. Powered with RS241, RE604,and 6J5. Rectifier is RGN 2504 (later we try Klangfilm RGN 4004). OT is Tango. Currently powered with Jensen Copper Foil Capacitor and old NOS Western Electric capacitors. FYI, RS241 is claimed by most audiophiles as best sounding tube amplifier (forget 300B or 2A3) – and it’s really proven, if you have chance to hear it. This is an ultimate Single Ended tube amplifier (if you really know what do RS241, RE604, and 6J5 really mean to an audiophile).

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Tags: Capacitor, Duelund, jensen, mundorf, tube
Posted in DIY Audio, Indonesia | Comments (37)

Posted on Monday, 17th August 2009 by Auw Jimmy

I just change my old “Aruki” Korean oil-can capacitor to ASC and Mundorf MCap Supreme. The configuration before is 60 uF and 40 uF Aruki Capacitor, now changed to 3.3 uF MCap Supreme and 40 uF ASC X386s.

The effect? The mid and high are getting more liquid. Background is even darker, with better separation and richer timbre. No surprise some people love the film and oil capacitor on the Power Supply section, and this MCap + ASC combination also proves such theory.

For cheaper solution, I usually go with Solen or SCR.

Tags: Aikido, ASC, mundorf
Posted in DIY Audio | Comments (1)

Posted on Sunday, 16th August 2009 by Auw Jimmy

Just what I’ve promised before, finally today I do the most awaited Capacitors Battle. Actually the “real battle” will be done within next few days. Let’s say, this is as first impression to “hear” how good they would sound

I use ELMA Switch (2 poles, 6 positions). Click here for details. The connection in details also explained there.

Here is the appearance of my jig. It’s an Aikido Pre-Amplifier. Powered with 6N1P tube in front connected to 6N6P tube as buffer stage. Rectifier is RGN 1054. The capacitor used as output coupling. Each channel has it’s own ELMA Switch. Please remember the selection is made in “perfect” mode (read here for details). Oh, I use empty CD holder as base for my ELMA

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Tags: Capacitor, Duelund, ELMA, jensen, VCap
Posted in DIY Audio, Indonesia | Comments (18)

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 Sunday, 9th August 2009 by Auw Jimmy

I have used this Vifa driver in my DIY loudspeaker for several years. Due to its pocket friendly price and also its performance. Yes, this is the cheapest Ring Radiator design (if you compare with the one from ScanSpeak).

So far, I’m quite ok with its sound. But I want to try something new: Changing its front place with a metal one. The original is made by plastic. So I order a new metal flange from my DIY friend. Click here to email him if you are interested with such project.

Here is the old plastic flange (top) compared with new metal one (bottom). I order simple flange design (no extra cosmetic on the front plate), because this is just for testing purpose. I might order a new one later – if the result is positive.

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Tags: DIY Speaker, Vifa
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Posted on Saturday, 8th August 2009 by Auw Jimmy

I bought cheap slow blow fuse yesterday. Actually, almost all of my amp or preamp could use standard fuse with no problem. But sometime, due to inrush current, I may blow some of my fuses several times. So I decided to try a slow blow one (identified with spiral like wire). This is cheap one, around $1 each. I don’t have any guts to try hi-end fuse for now. Too scare to blow my money at once

Blow the fuse = Blow your money!!!

PS: Actually, best fuse is no fuse at all. But if you are a frequent reader of my blog, then you will remember that safety is one of my main concern. So fuse is a must (at least for now).

Tags: Fuse
Posted in DIY Audio | Comments (0)

Posted on Sunday, 2nd August 2009 by Auw Jimmy

Still remember the Extreme Capacitor Battle article? Well, it’s not done yet, but we are very close on it. The break-in session has reached around 180++ hours. I can feel the characteristic from each capacitor.

To simplify (and easier) comparison session, I have prepared two ELMA switch (2 poles, 6 positions). You can see the photo below.

You might ask, why do I need two pieces of this ELMA? One should be sufficient, right? Keep reading. As you may also notice that I have a “bad habit” as a perfectionist, so this is still related with it

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Tags: comparison jig, ELMA, Sanwa, switch
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