Posted on Saturday, 1st December 2012 by Auw Jimmy

QLS QA-660 comes with a standard PCB mount multi-secondaries transformer. This is probably not a bad transformer, but most of the time I would be more comfortable with a separate transformer for some application. We need 12V and 17V. The 12V is quite common, but 17V is rather tricky.

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Tags: QA-660, QLS, regulator, talema
Posted in DIY Audio | Comments (3)

Posted on Sunday, 11th November 2012 by Auw Jimmy

If you have a lot of old tubes, then this idea could be useful. I have planned to make this small device, but somehow quite lazy (ugh!). I think because I have Knight 600 and Hickok 539B which are quite convenient to be used.

A background of this idea is, usually an old stock tube, either NOS or not, has been kept inside the box, attic, or warehouse for years. Some could be more than 10 years. Sometime, turn it on with maximum voltage could become a ‘heart attack’ for it. Well, it’s ok if it’s a cheap $2 tube. But how about for $400 RGN?

Usually I use my tube tester, either Knight or Hickok, and set lower filament voltage first for some time before putting an actual filament voltage to this kind of tube. But somehow, I would prefer to have a simple stuff but with more function. Here you go.

The ingredients are simple. Some hole saws (lucky if have quite vary of size). A thick platform or box is nice to have for this purpose (could be acrylic, wood, or metal plate). Some rulers to measure the size. Off course you will need a drill with some extra bits. It’s always nice to work if you have a complete stuffs.

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Tags: power supply, regulator, Tube Burner
Posted in Collectible Stuff, DIY Audio, Measurement | Comments (0)

Posted on Wednesday, 27th April 2011 by Auw Jimmy

If you have read my previous entry about QLS QA-550 SD Card Player, probably you still remember that I plan to upgrade the clock. Well, finally my TentLabs Low Jitter 11.289 MHz clock has arrived. We are about to begin, but not now, not tonight!

If you ask why TentLabs. Basically I own Guido’s XO2 module before, but it’s 27 MHz version. After some confirmation with Guido, he confirms that I can just change the clock from 27 MHz to the needed frequency. Well, that’s cool!

An interesting links from Guido to understand that lowest doesn’t mean the best.

http://www.tentlabs.com/InfoSupport/page34/page34.html

Below is the clock module (XO) from TentLabs.

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Tags: Clock, regulator, TentLabs, XO, XO2
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Posted on Sunday, 28th November 2010 by Auw Jimmy

Today, I drill some acrylic and heatsink to mount the regulator PCB. What a tiring drilling job! Not too easy to drill a lot of holes on the heatsink, though (not included the wrong holes one!).

Finally, the PCB could be mounted beautifully. The pass transistor mounted on the separate heatsink on the bottom. I just need to wire them to the PCB, add the main transformer, then we can evaluate its performance.

Tags: 3055, LM723, regulator
Posted in DIY Audio | Comments (9)

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
Posted in DIY Audio | Comments (8)

Posted on Sunday, 21st June 2009 by Auw Jimmy

Although Guido from TentLabs said his XO2 Reclock Module already equipped with “enough” power supply filtering, but I insist to use extra regulator. Double filtering should be better than one (I hope so).

So here is a regulator module from Taiwan.

The PCB is called Mini Regulator. I bought it from a person named Coffin in DIYAudio.com. Nice built PCB, double layer with good layout.

I have free time this afternoon, so I decide to solder it with some components from my drawer. The first is the diodes. I use Vishay Telefunken SF5407 as primary rectification part.

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Tags: regulator
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Posted on Sunday, 29th June 2008 by Auw Jimmy

Due to parts shortage on some components, I can’t complete the assembly of my DIY project. So I just write down the idea on my scratch book. Here is the plan.

For the filament/heater supply, I plan to use LT1083 regulator. It is a good regulator for audio compared with the LM (78xx) or LM 3xx series. The first capacitor should be NOS Elna Silmic 2200uF (should be 4 or 5 in parallel). Then, a 1 Ohm/10W resistor should be place in series. Then another parallel filter with BlackGate F Series 680uF. At the end, LT1083 will do the final regulation to provide exact 6-6.3 VDC (depends on my divider resistor).

I use dual mono design for filament and also dual mono for high tension (B+). For each channel, I need around 1.6 Ampere filament power. I use custom power transformer rated at 7.5 VAC and 3 Ampere.

For high tension B+ voltage. I will have two versions.

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Tags: B+ supply, DIY-Audio, heater supply, power supply, regulator, transformer, tube
Posted in DIY Audio, Personal | Comments (4)