Wednesday, February 26, 2014

Final tweaks of WE437A-300B monoblock

hi y'all, long time no see eh?
My humble monoblocks burnt one of pair of 300B, the filament burnt because my power transformer has bigger current rating than fi of 300B, filament only need 1.2A and my power transformer can supply 5v up to 2A without drop! what a powerful-overkill power transformer...
Sometimes overkill can kill your tube also haha..
Normally, power transformer, named high cost, high quality such Tango, Hashimoto filament supply precisely 5v 1.2A which will drop a little voltage (4.8~4.9v with filament load)
The other problem, my main voltage higher than usual, between 225-228vac, which is in Indonesia normally below 220vac.
So this time is a change to replace tubes with another. journey of my humble monoblocks that gives me a big hole in my pocket.
My choice this time is still Full Music, but different type, Full Music 300 B/n (Mesh Plate) which glow beautifully in the dark. time to order tubes from wiwitubes.
The tubes arrived very safe, double boxed, padded everywhere, and comes quick, 4 days with EMS service to my door.
Mesh Plate 300B form Full Music gives different signature from Carbon Plate, lower bass, more powerful mids energy.
At first my ears don't like so much the high frequency area, a little bit muddy.
Changes the speakers wire solve the problem, now my speakers cable is QED Silver Anniversary XT,  the highs become more airy, balance mids and tighter bass.
for the sake of longer life 300b, i decided to put 0.22 ohm in each filament supply that will drop the voltage to precisely 5v, this one also functioned as soft start filament supply.

The last tweaks, I changed no name silver-cotton tubing signal input wires to be Mundorf silver-gold wire in teflon tube 30 cm, twisted only twice, telfon tube only for return (ground) wire only.
more detail in mid-high area.
This is very good wire, i made my interconnect with this wire also. twisted every 10 cm. a little bit long time to break in, bit once break in, it can beat 600$ US interconnect.

the last tweaks?? nooo i have change one more lahh, my friend gave me pair of Blackgate 100uF/100v, why not experimenting with WE437A cathode bypass capacitor :)
at first-as peoples said about blackgate before break in- muddy! how can holy grail, most expensive capacitor has that sound signature!
but after 10-20hours, the treble start singing, the highs not as sharp before, but more musical, I can hear the differences a lot, and more balance.
After 100hours, my smiles can show off all my teeth, this is what I want.
Powerful, deep bass, normal mids, airy high.
maybe this is the last tweak... maybe...

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