Friday, February 26, 2010

Slow Internet connection

You got to pity the people of Libya. They must have what is likely the slowest connection to the Internet...

november 29, 2009: The Swiss vote to ban minaret construction

february 26, 2010: Gaddafi calls for jihad against Switzerland for banning minaret construction

Wednesday, February 24, 2010

A red cMoyBB

Today a package containing parts arrived. I now have all the parts to finish the B1 buffer preamp except the case. The cMoyBB is nearly finished, I'm waiting for the Alps pot to arrive.

The cMoyBB got hooked up this evening to check voltages. The LED lights up and the rail voltages are half the supply voltage. That's good! It means the TLE2426 rail splitter works. I played with two different values for R_LED. The default value is 24K, I tried 33K too but found the 24K a better choice.

Monday, February 22, 2010

Bottle nipple

OK, I'll have two of those please. With milk? No, milk is for cows you silly twat! I'll have mine with Glenrothes Single Malt Whisky. :-)

Sunday, February 21, 2010

John Mayer

I was in record shop recently and there was music playing I didn't know, but I liked it a lot. A very distinct voice. Now where did I hear that voice before? Then I got a hunch it might be that bloke who sang Daughters, a great song IMO. Wasn't that John Mayer? It was indeed John Mayer and they were playing the Battle Studies CD in the shop. Since then I really discovered John Mayer much to the dismay of my wife. I've been playing Continuum almost non-stop the last week... The John Mayer Trio (with Pino Palladino and Steve Jordan) is high octane blues! Recommended listening.

Saturday, February 20, 2010

B1 buffer progress

The B1 buffer is progressing slowly. I soldered in the signal path capacitors. I bought Mundorf M-Cap 250's. I also soldered a small 0.01µF MKP1837 in parallel. From the 2SK170 FETs I matched yesterday I picked two pairs with near identical Idss. One channel is 8.47mA and 8.45mA, the other channel 8.46mA and 8.44mA. The lower value Idss goes in the CCS spot. It took some searching on diyAudio.com to dig up that bit of information.

Next up: the large 10000µF caps, inputs, outputs, a case and then it's time to wire it up.

Friday, February 19, 2010

Opamp rolling

I adapted a AD8066 in SO-8 package to fit in a DIP socket this evening...

The good: it worked right away!

The bad: soldering SMDs is a real challenge!

The PCB is a mere 10x10mm, I bought it here.

B1 FET matching

I received my order for some B1 parts today. I now have the 1µF and 10µF caps, the source switch and the Alps Blue pot. I also got 26 2SK170BL FETs. For optimum performance the two FETs per channel need to be matched for Idss. Not a difficult job if you know how to do it. It just takes some time. So I'm looking for two matched pairs. I asked the knowledgeable forum members at diyAudio.com for assistance in selecting the pairs.


I went to my local electronics shop today to get a TLE2426 for my cMoyBB. I also asked about the Alps pot I need. I came home with just the TLE2426. Bummer. This means I'll have to look elsewhere for the pot.

Thursday, February 18, 2010

cMoyBB PCB


A large yellow envelope from the USA in my mailbox today. Upon opening I found a Packing Slip and a small anti-static plastic bag thightly folded over a couple of times. Aha that must be the three blue LEDs I ordered. But where is the PCB I ordered? I looked into the envelope again. No PCB. I opened the anti-static plastic bag and out came the three LEDs and the PCB. I knew it had to be small but I didn't expect it to be that tiny. It measures a mere 40x47mm. 

Wednesday, February 17, 2010

Nasty buzz

My PX-100's. Love 'm. Really nice headphones. Nothing high end though. Very decent headphones for an iPod IMO. Better than supplied crappy earbuds. I noticed there was a rather annoying buzz in the right channel though. Especially when there's deep bass in the music. Damn, I don't want to have to buy a new pair. I took off the foam pad and looked at the driver. Nothing abnormal. Just a clear diaphragm. I blew a few times onto it and while looking at it with a bright light I saw something lodged in there that wasn't supposed to be. A hair. Carefully I managed to remove the hair. An eyelash to be precise. And now? Mission accomplished. No more nasty buzz. PX-100's sounds like it should again.

I found a Barkleys mints tin in my locker at work today. Mints expired a year ago... They didn't smell like they are supposed to. LOL.

Saturday, February 13, 2010

cMoyBB

I'm gonna make myself a cMoyBB headphone amp... I ordered the PCB yesterday (a red one, because everybody knows red PCBs sound way better than ordinary green ones).

Now it's parts sourcing time.

I'm gonna use a mints tin to house the amp. Everybody and his dog uses Altoids mints tins for this. Unfortunately there's no Altoids to be found locally. I can however lay my hands on Barkleys mints tins. I'm gonna use an empty red "Cinnamon" tin if the PCB will fit inside. First thing at hand is to eat the mints.

I've been playing with the cMoyBB Frequency Response Calculator. Nice Java tool to visualise the frequency response while you alter component values.