Nelson Pass F5 Turbo - In progress (Page 2~3)

[narayan]

Good wishes on your project caloy

[carbondated]

The capacitor that packs a wallop!

[AbadSantos 7]

Good wishes on your project caloy

Sir Obet,

Thanks.

Cheers.

[AbadSantos 7]

The capacitor that packs a wallop!

[camotecue]

Just to update for the 1st part of the BOM.




The SCR 47uf and the GAD 10uf/630V.

The 47uf is so big..para syang granada...

Use the 12AU7 as reference for the size.

Next time ulit..

Grabe ang laki nito! must be expensive.

[AbadSantos 7]

She...Maybe the Beauty or the Beast
Maybe the famine or the feast
May turn each day into a Heaven or a Hell
She maybe the mirror of my dreams
The smile reflected in a stream
She may not be what she may seem inside her shell....

Got Her NOS Behind Enemy Lines......


With Box


With Certificate


Para syang baby 300B ang shape..ang laki pala.

Cheers

[AbadSantos 7]

It has taken me 3 weeks to search for this Transformer that will serve as my OPT.

Its has same specs with Kevin's use at 15K primary and 600/500 ohm secondary @ 8mA.
Frequency response is a little higher on the lower range.

I thought searching this transformer is easy and cheap...but when I found it, I nearly
have a heart attack and nearly forget my name.

Anyway just closing my eyes and hoping this project become success. My funds were
totally drain....

Cheers.

[AbadSantos 7]

Hi All,

Its been a while to comeback after a full drain funds acquiring the UTCs.

Next I was able to get the vintage HP Power Transformers.
With specs at :

Input: 220~240V AC
Output: 5V / 6.3V / 320-0-320V AC

Specs should be a perfect match for the 5AR4 Rectifier Tube.
However, Im thingking to go for AZ1 German tube. So just to use
a resistor to reduce 5V to 4V Filament Voltage for the AZ1 should be ok.

Cheers.

[amandarae]

Natapos mo ba 'tong project mo sir?

[tony]

Hi All,

Its been a while to comeback after a full drain funds acquiring the UTCs.

Next I was able to get the vintage HP Power Transformers.
With specs at :

Input: 220~240V AC
Output: 5V / 6.3V / 320-0-320V AC

Specs should be a perfect match for the 5AR4 Rectifier Tube.
However, Im thingking to go for AZ1 German tube. So just to use
a resistor to reduce 5V to 4V Filament Voltage for the AZ1 should be ok.

Cheers.

your traffo looks like it is a 60va one which is more than enough for your preamp...

for your rectifier, make that 2 resistors 0.39 ohms 3watts per side and you are okey...
the AZ1 matches your 26's in looks, haven't seen one, much more held one.....swerte mo...

[amandarae]

"Tony", ikaw yung nag post sa "Type26 Preamp" thread sa DIY Audio na Tony? Thanks ulit! Okay yung AZ1 sir, preferrably yung Telefunken. Like what you mentioned, took 5V, then I installed 0.5 ohm per heater leg okay na.

Abe

[tony]

"Tony", ikaw yung nag post sa "Type26 Preamp" thread sa DIY Audio na Tony? Thanks ulit! Okay yung AZ1 sir, preferrably yung Telefunken. Like what you mentioned, took 5V, then I installed 0.5 ohm per heater leg okay na.

Abe

Hi Abe, yes it is me...member since 2003...

[amandarae]

"Tony", ikaw yung nag post sa "Type26 Preamp" thread sa DIY Audio na Tony? Thanks ulit! Okay yung AZ1 sir, preferrably yung Telefunken. Like what you mentioned, took 5V, then I installed 0.5 ohm per heater leg okay na.

Abe

Hi Abe, yes it is me...member since 2003...

Cool! Natapos ko na yung 26 preamp sir, napag palit ko lang pala yung dalawang GND nung floating na filament raw DC supply kaya umingay. Okay naman tunog!

[tony]

"Tony", ikaw yung nag post sa "Type26 Preamp" thread sa DIY Audio na Tony? Thanks ulit! Okay yung AZ1 sir, preferrably yung Telefunken. Like what you mentioned, took 5V, then I installed 0.5 ohm per heater leg okay na.

Abe

Hi Abe, yes it is me...member since 2003...

Cool! Natapos ko na yung 26 preamp sir, napag palit ko lang pala yung dalawang GND nung floating na filament raw DC supply kaya umingay. Okay naman tunog!

that's nice to hear...you may also want to try Broskie's CCDA amp using the Russian 6H23 for comparison...

i have some VT67 dht's and 80 rectifiers to try...

[amandarae]

"Tony", ikaw yung nag post sa "Type26 Preamp" thread sa DIY Audio na Tony? Thanks ulit! Okay yung AZ1 sir, preferrably yung Telefunken. Like what you mentioned, took 5V, then I installed 0.5 ohm per heater leg okay na.

Abe

Hi Abe, yes it is me...member since 2003...

Cool! Natapos ko na yung 26 preamp sir, napag palit ko lang pala yung dalawang GND nung floating na filament raw DC supply kaya umingay. Okay naman tunog![/quote]

that's nice to hear...you may also want to try Broskie's CCDA amp using the Russian 6H23 for comparison...

i have some VT67 dht's and 80 rectifiers to try...[/quote]
Okay sir, hanapin ko 'yon!

[kabubi]

mga idol,

nabasa ko na ang 26 tube is notorious for its harmonics and noise. ano po ang ginagawa niyo para alisin yung harmonics/ingay?
salamat!


k

[amandarae]

mga idol,

nabasa ko na ang 26 tube is notorious for its harmonics and noise. ano po ang ginagawa niyo para alisin yung harmonics/ingay?
salamat!


k

K, yung microphonics, kailangan suspended yung 26 tube sa chassis o kaya decouple yung chassis sa rack. Kung suspended gusto mo, pwedo kang gumamit nito http://www.mcmaster.com/#vibration-damping-grommets/=mdb7ht. Yung preamp ko, sinubukan ko munang i-decouple sa rack yung chassis, okay naman result. mayroon din namang 26 na hindi masyado "microphony" (try ST type instead of the Globe, corny nga lang hehe...)

Yung noise naman, di na issue ngayon yun. gamit ka ng Shunt Regulator sa B+ (try mo sa PSUD yung LCLC with current draw ng 32mA, make sure na at least 50Vdc higher ka kesa sa voltage na output ng regulator), sigurado walang hum. Sa filament supply naman, gamit ka ng filament regulator and operate mo ng filament bias yung type 26(about 10v sa cathode). hanapin mo schematic sa DIY Audio, o kung di mo makita, may kopya ako. As long as you have a floating raw DC supply per channel, and if you are using two chassis approach eh nag terminate yung ground sa main chassis lang, tahimik pare, guaranteed! Try to read more about "Rod Coleman" regulator, madali lang bilhin then assemble mo na lang. Combination ng CCS saka gyrator yata yun. Walang noise sa filament pare, tahimik, parang nung na knock out si Manny P!

Abe

[tony]

mga idol,

nabasa ko na ang 26 tube is notorious for its harmonics and noise. ano po ang ginagawa niyo para alisin yung harmonics/ingay?
salamat!


k

that is why this tube is a challenge.....

kevin kenedy or kevinkr at diyaudio made this amp which i think is the model for Louie and it is a good design.....

i speak to him on a daily basis in our own moderator's threads and we can talk about anything, technical support is no problem...

common cathode tube amps produces mostly 2nd harmonics and tubes in general does not produce higher order odd harmonics that is why the difference in sound between ss amps...

and at audio output levels of say 2 volts, (enough to drive most amps to clipping) running tubes at say 90 volts plate ensures that harmonic distortions are indeed very low.....2 volts is only 6volts peak to peak so that there is more than enough room in the tube operating point to worry about distortions (6 volts when compared to 90 volts is very very small)....

[AbadSantos 7]

Been a while and I put this project on hold since I sold all my tube amp last January.

So zero tube amp for me...

So thus I changed the title....

Anyway, I was inspired by Leslie aka (Brainf) about the NPass F5 project. Since this is Class A, I believe
this will be a good project to venture in...

I go for F5 Turbo version 2. 50W in 8 ohms.

I started getting all the parts.....primary set-back about this DIY project is the availability of genuine 2sk170/2sj74
since this jfets were already obsolete...including the MOSFET for fairchild FQAs.

Just yesterday, my jfets have arrived....I ordered this from Singapore which takes me about more than 2 months to arrive.

I started on chassis...I think I posted already this is pinoydvd sometime Jan....




Just started also some drilling and tapping....Im quite nervous since this is my first time work with DIY including with aluminum...


Im quite an amateur...so I need a special tapping tool to go for M3 tap. Very difficult indeed....


To be continue about the progress...wish me luck.....

[tony]

good luck......