Posted on Wednesday, 12th October 2011 by Auw Jimmy

Still remember the first chapter here? I have transferred the paper mockup into digital format. It didn’t take long time to do that

Just need to send (or print) this format and send to the manufacturer. I’m quite sure they can make one for me.

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Tags: Aikido, power supply, preamp, Prototype
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Posted on Sunday, 9th October 2011 by Auw Jimmy

As my chassis has done few days ago, now it’s time to design the placement of the parts. I have mentioned before that the dimension was quite tight, so I wasn’t sure that I could fit all the parts on it. But without doing some prototyping, I couldn’t confirm that. So let’s start doing that.

My new chassis contains 3 chambers. One for the main transformer, one for the power supply section, and one for signal section. The size around 40×40 cm, more or less.

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Tags: chassis, design, layout, power supply, prototyping
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Posted on Sunday, 18th September 2011 by Auw Jimmy

As  my Sowter Choke Input was acquisitioned by my friend. Then I have to consider some replacement. Actually my friend was interested with Hashimoto or similar, but as most of the Choke Input was designed for power amp, instead of preamp, so the specification and requirement (especially for minimum current demand) were different.

Luckily, as my preamp uses quite big current, then I can consider some Choke Input for power amp usage. One of them is the Hashimoto C-25-150CH. This choke is designed for Input application, rated at 25 H and 200 mA maximum current. DCR is claimed around 205 Ohm. Spec wise, it’s all very good to best. As material, Hashimoto is quite confident with its Orient High B core (forget Permalloy or Amorphous). Internally, this choke should be a C-Core type, with extra electrostatic shield. Oh, Hashimoto also put extra work to make this choke as a magnetic shield type. I think they do understand that Choke Input could radiate enough flux and/or electromagnetic things. Definitely, a magnetic shield design will be a nice addition. Build quality of this choke is also quite superb. With around 2.4 Kg weight, this is a heavy weight championship (remember, this is only a choke!)

The second one is a Tamura A-4004. Although it’s rated only 10 H and 200 mA maximum (or 2.5 H at 400 mA), this choke only around 10% lighter than Hashimoto Choke Input above. Physically size, this Tamura also a little bit smaller than the Hashimoto. Before, I was considering A-4006 (Amorphous) also. But due to some other consideration (as my Aikido Preamp already has Duelund CAST Ag Silver Capacitor inside), then I think non-Amorphous core will give a nice combination with it. Right or wrong? We shall prove it later…

Tags: Choke, Choke Input, Hashimoto, power supply, Tamura
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Posted on Tuesday, 30th August 2011 by Auw Jimmy

One of must have software when simulating power supply is PSU Designer II or PSUD II. This amazing freeware could simulate your power supply behavior, before you start to assembly your circuit. Off course, not all looked good means good for ears, but at least we can try

Below is my current Aikido PreAmp power supply circuit. The rectifier actually should be RGN, but I can’t find it on the list. So let’s roll with similar one, the common 5U4-GB.

The chokes are various from Sowter, Electra-Print, and Lundahl. Plan to take another amorphous one from Tamura, but we’ll see. Capacitor also varies, with V-Cap, Jensen, ASC, and the last minute acquisition, Black Gate WKz.

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Tags: power supply, PSUD, tube
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Posted on Saturday, 27th November 2010 by Auw Jimmy

When it comes to high current and high efficiency, actually we don’t have much option rather than using switching based power supply. For most of consumer electronic equipment, this kind of power supply probably one of the best choice. But for audio, I would like to avoid it – really avoid it.

But again, the option to go high current with non-switching based power supply probably would introduce another issue – heat or thermal dissipation. We are talking a high current regulated output. Bear in mind that switching based power supply is quite stable. So if we plan to replace them, make sure we have a quite stable solution also. Not much choices available, rather than go to the regulated one.

Not many regulator could handle high current. Quite easy to go up to 1A with classic 78xx/79xx based regulator – although the sonic performance is mediocre.

Better solution we can pick LM317 probably up to 1.5A or the bigger brother, LM338 up to 5A. This one is sonically better than 78xx/79xx based regulator.

Another high-end approach is to use LT1083/84/85/86. This one could handle up to 7.5A with some limitation. Probably one of the best, but I doubt we can push the limit for this kind of regulator.

I would try another cheaper solution, LM723 with extra pass transistor to provide enough extra current (we can go up to 10A with this, and the heat will be well shared to the pass transistor rather than on single chip).

Actually we can go with 0.5 Watt of resistor, but I go with the 2 Watts for all when available.

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Tags: 3055, high current, LM723, power supply
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Posted on Monday, 25th October 2010 by Auw Jimmy

Today, I design the power supply module for my tiny amplifier project (check here and here for detail).

The power supply are divided into three modules. One is for the 4x TBA820 (I stack 2 bridge diode to provide 3A current), the other two are for the tube “high voltage” section and the MP3 Player (source). The power supply for the MP3 Player should be regulated with LM317. I will add this one later.

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Tags: power supply
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Posted on Friday, 18th December 2009 by Auw Jimmy

I have a short free time at the afternoon, and it’s time to test my Power Supply for my Gainclone. Powered by Talema dual secondaries, each rated at 18VAC/6.3A

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Tags: Black Gate, gainclone, power supply, talema
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Posted on Saturday, 28th November 2009 by Auw Jimmy

Finally, with the help from my girlfriend, I manage to get the Nuvotem Talema Transformer on hand within a week. It’s rated at 6.3A with 2x18V output or about 225VA. Not bad for my LM1875 huh…

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Tags: power supply, talema, transformer
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Posted on Sunday, 15th November 2009 by Auw Jimmy

It’s a cool weekend, we are entering rainy months. I continue soldering my Ultimate Power Supply. Today, I solder 8 pcs of MUR860 and 70 pcs of Black Gate F Series. Done in 3 hours, not bad huh.

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Tags: BlackGate, diode, mur860, power supply, rectifier
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Posted on Saturday, 14th November 2009 by Auw Jimmy

Some of you have emailed me asking to finish the Gainclone – Black Gate Power Supply project, and well, I’m about to complete it with some modification. Here is the “sneak-peeks”

The rectification section is made dual, total 8 pcs of MUR860 will be used here.

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Tags: BlackGate, diode, gainclone, MUR, power supply, rectifier
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Posted on Sunday, 25th October 2009 by Auw Jimmy

I’m the middle of laziness… Actually I want to finish my Gainclone LM1875 project, but it will consume a lot of my brainpower But I don’t want to waste this weekend doing nothing. So I just test my Mini Regulator for my TentLabs XO2 Reclock Module.

Luckily, I still have old transformer, rated around 1A with 15 VAC output (tested around 15.3 VAC).

I connect the Mini Regulator to the transformer and check the VDC output. The green LED lit means everything is OK The VDC measured around 11.83 VDC. A little bit lower than my expected 12 VDC output but this should be fine. I will try with higher transformer later (16-18 VAC).

Tags: power supply, regulator
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Posted on Sunday, 11th October 2009 by Auw Jimmy

Still remember my other “stupidity” here? After several hours of investigation, I finally decide that the Jensen Copper Foil Paper Tube is not a good capacitor for bypassing purpose. The music will lose most of its detail. YMMV, this is based on my investigation. Feel free if you have other opinion.

On the other side, I still have the “Classic” Jensen Copper Foil Aluminium Tube. Surprisingly, this capacitor works better on the High Voltage bypass section! The price of this capacitor is only 1/3 of the Paper Tube. I will give some more listening test, but so far I would stick with this “Classic” Jensen on the bypass section. This “Classic” capacitor gives warmth sensation without losing the details.

Tags: Bypass Capacitor, Capacitor, jensen, power supply
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