Tube Pre-Amp 12bh7 Parallel Grounded Cathode

Bahan utama:
[-] 2 biji tabung 12bh7
[-] 2 biji socket 9 pin
[-] 2 biji resistor 16k, 1/2w, allen-bradley
[-] 2 biji resistor 430k, 1/2w
[-] 4 biji resistor 240 ohm, 1/2w, vishay-dale
[-] 4 biji resistor 24k ohm, 2w, allen-bradley
[-] 4 biji resistor 1k1 ohm, 1/2w, allen-bradley
[-] 2 biji resistor 43k, 1/2w
[-] 2 biji capacitor 0.47u/600v, paper in oil (pio)
[-] 2 biji capacitor 2u2/400v, mkp solen
[-] 1 biji potensiometer stereo 50k, TDK
[-] kabel secukupnya
[-] timah secukupnya

Bahan power supply tegangan tinggi:
[-] 1 biji tabung rectifier ez81
[-] 1 biji socket 9 pin
[-] 4 biji elco 50u/500v
[-] 3 biji resistor 2k4, 2w
[-] 1 biji trafo 275v-0-275v, 0-6v3, 6v3-0-6v3

Delay & mute:
[-] 1 biji ic NE555
[-] 2 biji transistor 2sc2335
[-] 2 biji resistor 1m, 1/4w
[-] 1 biji resistor 240 ohm, 1/2w
[-] 1 biji resistor 470k, 1/4w
[-] 1 biji resistor 100k, 1/4w
[-] 1 biji resistor 1 ohm, 1/2w
[-] 1 biji elco 33u/16v
[-] 1 biji capacitor 100n
[-] 1 biji elco 100u/16v
[-] 1 biji diode 1n4148
[-] 2 biji diode 1n4004
[-] 1 biji relay dpdt
[-] 1 biji relay tegangan tinggi

Deskripsi:

Filament Supply & B+ Supply

Rangkaian power supply untuk filament kali ini tidak di dc kan, jadi masih ac. Sedangkan power supply B+ masih sama persis dengan rangkaian untuk preamp srpp di project sebelumnya. Hanya R di pi filter yang beda, karena arus yang dibutuhkan 2 kalinya (dibanding srpp).

Pre-amp:

Kali ini menggunakan tabung 12bh7 dari General Electric.

Topology persis dengan topology pre-amp 6n1p sss, yaitu grounded-cathode tapi di paralel, 2 triode untuk satu channel pre-amp. Topology ini memiliki impedansi output yang cukup rendah, sehingga bisa drive power amplifier tanpa takut kedodoran, tetapi tanpa kehilangan nuansa murni tabung.

Uji dengar:

Untuk uji dengar kali ini, digunakan satu saja Luxman L-210 yang sudah di tweaking. Susunan peralatan:

–[Pioneer PD-4050]–[DVD Philips DVP-3146K]–[pre-amp ini]–[Luxman L210]–[loudspeaker]–

Kali ini menggunakan 3 CD referensi yang berbeda; Diana Krall, Emi Fujita dan Bad Company. Referensi DVD dipilih “Wall-E”.

Dari uji dengar dapat diambil kesimpulan, bahwa dengan pre-amp tabung double grounded cathode ini, reproduksi suara lebih tebal dibanding single grounded cathode (pre-amp 6n1p sss), detil bass jadi lebih berbobot, tetapi tidak kehilangan detil mid-low.

– salam — gustOmO –

source: www.bottlehead.com, www.john-a-harper.com, www.glass-ware.com, www.headwize.com
software: TubeCAD

1/3 Malam

Rasulullah bersabda : Pada tiap malam, Rabb kita turun ke langit dunia ketika bersisa sepertiga malam yang akhir. Maka Allah berfirman : Barangsiapa yang berdoa kepadaKu, pasti akan Kukabulkan, dan siapa yang memohon kepadaKu, pasti akan Kuberi, dan siapa yang mohon ampun kepadaKu pasti akan Kuampuni. (h.r. Malik, Bukhari, Muslim, Tirmidzi, dan selainnya)

Quran : Bila telah lewat sebagian malam atau dua pertiganya, akan turun ke langit dunia Allah Yang Maha Memberkati dan Maha Tinggi, lalu berfirman : “Tak ada seorangpun yang meminta pasti ia akan Kuberi, tak ada seorangpun yang berdoa pasti ia akan dikabulkan, tak ada seorangpun yang mohon ampun pasti ia akan Kuampuni”. Sehingga tiba waktu shubuh. (h.r. Bukhari dan Muslim)

Life Begins at Forty

(Jack Yellin / Ted Shapiro)
A Musical Monologue by Sophie Tucker

I’ve often heard it said and sung
That life is sweetest when you’re young
And kids, sixteen to twenty-one
Think they’re having all the fun
I disagree, I say it isn’t so
And I’m one gal who ought to know
I started young and I’m still going strong
But I’ve learned as I’ve gone along…….

That life begins at forty
That’s when love and living start to become a gentle art
A woman who’s been careful finds that’s when she’s in her prime
And a good man when he’s forty knows just how to take his time

Conservative or sporty, it’s not until you’re forty
That you learn the how and why and the what and when
In the twenties and the thirties you want your love in large amounts
But after you reach forty, it’s the quality that counts

Yes, life begins at forty
And I’ve just begun to live all over again

You see the sweetest things in life grow sweeter as the years roll on
Like the music from a violin that has been well played upon
And the sweetest smoke is from a mellow, broken and old pipe
And the sweetest tasting peach is one that’s mature, round and ripe

In the twenties and the thirties you’re just an amateur
But after you reach forty, that’s when you become a connoisseur
Then it isn’t grab and get it and a straight line for the door
You’re not hasty, you’re tasty, you enjoy things so much more

For instance, a novice gulps his brandy down, he doesn’t understand
Observe a connoisseur, the way he holds it in his hand
How he strokes the glass, fondles it, warms it as he should
Smaks his lips, aahhh, slowly sips, hah, boy, it tastes good

Life begins at forty
Then it isn’t hit and run and you find much more fun
You romance a girl of twenty and it costs you all your dough
But when a forty thanks you, she hates to see you go

And girls of twenty, all they want are big men
Big men with strong physiques
I don’t say that it’s bad
But you do get tired of those damn Greeks

Life begins at forty
And I’m just living all over again

Lost

I can’t believe it’s over
I watched the whole thing fall
And I never saw the writing that was on the wall
If I’d only knew
The days were slipping past
That the good things never last
That you were crying

Summer turned to winter
And the snow it turned to rain
And the rain turned into tears upon your face
I hardly recognized the girl you are today
And god I hope it’s not too late
It’s not too late

‘Cause you are not alone
I’m always there with you
And we’ll get lost together
Till the light comes pouring through

‘Cause when you feel like you’re done
And the darkness has won
Babe, you’re not lost
When your worlds crashing down
And you can’t bear the thought
I said, babe, you’re not lost

Life can show no mercy
It can tear your soul apart
It can make you feel like you’ve gone crazy
But you’re not
Things have seem to changed
There’s one thing that’s still the same
In my heart you have remained
And we can fly fly fly away

‘Cause you are not alone
And I am there with you
And we’ll get lost together
Till the light comes pouring through

‘Cause when you feel like you’re done
And the darkness has won
Babe, you’re not lost
When the worlds crashing down
And you can not bear the cross
I said, baby, you’re not lost
I said, baby, you’re not lost
I said, baby, you’re not lost
I said, baby, you’re not lost

Singer: Michael Buble