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Wednesday, February 25, 2009

The beauty of Vacuum Tubes...

It has been a long time I left my Audiophile hobby.. It all started when I was still studying and built my first solid-state audio amplifier based on the Motorola MJ15004 transistors.

Then, after listening and playing with it for quite sometimes, it was sold to a friend which is now a long gone friend.. lost contact. I started again but not with solid-state.... I have build my first vacuum tube amplifier based on EL34 tubes configured in single ended mode. Wow.. that was my first vacuum tube audio amplifier. However, it did not last long too.. this time, the output transformer gone kaput. The primary winding open circuit due to the bias current is to high.. It was waste as the output transformer is given by 9W2ECG. The output transformer made by TDK Japan and it's no longer in production. I shouldn't have thrown it away though...

Unable to enjoy my own audio system at home is really boring again... I build another one.. this time using KT88 tubes.. but in push-pull design using Hammond output transformer... and configured in ultra-linear push-pull. But i was a disappointment as it doesn;t sound as good as what I have before... sold it to a friend again...

Then built a 12W single ended using 300B tubes and paired with Audio Note output transformer. I actually build the Reichert 300B circuit, housed in a mirror finish stainless steel casing. All the parts used is premium.. Kiwame resistor, Blackgate audio grade capacitors, Audio Note copper foil coupling capacitor and poin to point circuit. NO PCBs!

This time, the 12 watter amplifier push me to the ground!! The fat lady sang! with a sweet warm and clear sound driving my midrange JBL speaker. NO! it's not enough yet.. my JBL speaker cant deliver what the 300B is supposed to have... frustration again... I've been conned by a man who promised me to sell this amplifier at his shop.. 3 day after I sent the amplifier to his shop, he claimed that it was stolen.. what the heck!! He supposed to compensate me but that was just a promise.. up to today.. I only receive 2% of the money... so.. that was it.. I quit! After all, I have to move to Penang to work and I dont have a proper place... Sold all my other equipments... Then all became a grand father story... LOL

A few moons ago, I started to have the itch again... Then, 9W2ECG have the solution for me... this time with a 1.2W single-ended 6EW7 tubes...with a double C-core output transformer...
It is now singing happily in my room driving a pair of extinct driver.. a pair of CORAL 8A-40, 93db/w/m full range driver planted in a TQWT enclosure... yeah baby yeah!! 1.2W with a full range driver is enough.. loud enough if you want it to be loud... forget those with 100W or 300W or even 500W... this little baby is giving out 1.2W r.m.s.... not those peak output or p.m.p.o kind of output.. it's RMS!! But my CD player cant do justice to it.. I need to get another good CD player to deliver those good recordings...

Have you listened to a 2 watter driving a 104db/w/m speaker? Well, that doesn't fit my bills but I did have a chance to listen to it...

1 comment:

M.Zaifful said...

Dear 9W2DTR, i like to know about audio amplifier using thermionic valve or electron tube, but it' all long gone technology.can you teach me or perhaps built one for me and including the best price you can offer.Thanks de 9W2MZY