DIY F5 pure class A power amp(Nelson Pass design)

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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Mon Oct 15, 2012 1:29 pm

tony wrote:
AbadSantos 7 wrote:Hi Tony,

Les is correct, All I posted is a clone chassis for Krell and Accuphase.

Measured 480X480X182 these are huge and heavy. The supplier told
me its from 15 to 20kg.

Cheers.


thanks for the info...any links or websites that we can look at?


The supplier was only referred to me by my friend formerly working in Harman Kardon.

These are their chain of local supplier when they doing some product development
for their Harman Product.

Normally these chassis are being exported to Hongkong. For this particular chassis
im negotiating to remove the label and some markings. And they will make some
hole not conforming to specs so that they can sell to me as reject. Otherwise
I still need to pay 17% Tax.

You can check Les chassis, I was able to sell him at reasonable price. However for
this kind of chassis, need this to ship by sea thus a group buy is a must.

Sorry Les for the Hijack...
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby endrik35 » Mon Oct 15, 2012 1:48 pm

Krell KSA-250 chassis! Wow! Di parin ako magpapatukso Loi! I'll try my best to resist the urge! ;)
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby bass_nut » Mon Oct 15, 2012 2:14 pm

hi kuya Endrik,

had an actual taste of Nelson Pass DIY F5 Class A power amp a few years ago. i was able to audition it through the courtesy of Ferds who DIYed it.. hooked this to my humble 2.1 home audio system.
impression: fast attacking transients amplified very well. a pair of Dynaudio C1 were adequately powered, per my listening room size/character, preferred loudness level (76~85db measured at the 'sweet spot', ~3 meters from the speakers) and preferred music genre.

cheers !!
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Mon Oct 15, 2012 2:59 pm

endrik35 wrote:Krell KSA-250 chassis! Wow! Di parin ako magpapatukso Loi! I'll try my best to resist the urge! ;)


Palibhasa kasi Doc hindi ka pumapatol sa less than 30K pesos na amp... :lol: :lol: :lol:
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby endrik35 » Mon Oct 15, 2012 3:04 pm

bass_nut wrote:hi kuya Endrik,

had an actual taste of Nelson Pass DIY F5 Class A power amp a few years ago. i was able to audition it through the courtesy of Ferds who DIYed it.. hooked this to my humble 2.1 home audio system.
impression: fast attacking transients amplified very well. a pair of Dynaudio C1 were adequately powered, per my listening room size/character, preferred loudness level (76~85db measured at the 'sweet spot', ~3 meters from the speakers) and preferred music genre.

cheers !!



Dear Kuya Fer! He he! I believe you. The turbo version at 100 watts class A can do that! A couple of guys told me that the F3 is better than the F5 composed of two monoblocks!

@Loi, casing palang niyan eh mukhang 30k na! He he!
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby bass_nut » Mon Oct 15, 2012 6:16 pm

endrik35 wrote:
Dear Kuya Fer! He he! I believe you. The turbo version at 100 watts class A can do that! A couple of guys told me that the F3 is better than the F5 composed of two monoblocks!


off topic: classmate ko si doc/atty TonyRebs kaya ang alam ko ay kuya ka namin, doc Endrik ... :tmi: :rofl:

on topic: the F5 i auditioned was housed on a China imported aluminum casing. total estimated cost way back then was ~P25k as Ferds did not charge professional fees. we scheduled 3 units from him. unfortunately, he had difficulty importing the 3 aluminum casing as the China based supplier closed shop ;(

i remember asking him if the F5 amp was bridgeable so that we may extract more power output on a mono-mono config. he told us it was only designed for 25wpc @ 4~8 ohms.
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby edrel sison » Mon Oct 15, 2012 6:36 pm

when i grow up i want to build myself my own version of the F5.. :D :D
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby endrik35 » Mon Oct 15, 2012 6:39 pm

bass_nut wrote:
endrik35 wrote:
Dear Kuya Fer! He he! I believe you. The turbo version at 100 watts class A can do that! A couple of guys told me that the F3 is better than the F5 composed of two monoblocks!


off topic: classmate ko si doc/atty TonyRebs kaya ang alam ko ay kuya ka namin, doc Endrik ... :tmi: :rofl:

on topic: the F5 i auditioned was housed on a China imported aluminum casing. total estimated cost way back then was ~P25k as Ferds did not charge professional fees. we scheduled 3 units from him. unfortunately, he had difficulty importing the 3 aluminum casing as the China based supplier closed shop ;(

i remember asking him if the F5 amp was bridgeable so that we may extract more power output on a mono-mono config. he told us it was only designed for 25wpc @ 4~8 ohms.

;)
No more worries Manong Fer, nandyan na si Loi who works in China for our casing needs. I remember doc,Tony, naging prof yata namen siya sa Legal Med! He he
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby bass_nut » Mon Oct 15, 2012 7:06 pm

endrik35 wrote: ;)
No more worries Manong Fer, nandyan na si Loi who works in China for our casing needs. I remember doc,Tony, naging prof yata namen siya sa Legal Med! He he


off topic:
kuya Endrik, si doc Solis ang prof natin sa legal med .. pasang awa nga kami ni TonyRebs sa subject na iyan :@ :rofl: :rofl:
si doc Sandy ang siguradong higit na mas bata sa atin ..no worries, i know doc Arnel Diaz is much older than both of us :lol: :rofl:

on topic: it is nice to know that sir Loi will be of great help for our needs :clap: :clap:
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby brainf » Tue Oct 16, 2012 8:23 am

Group build! Group Build!

We have here Loi for the casing/heatsinking, Edrel for the Powerplant (i.e. traffo) requirements and our resident electronics guru TonyT, all critical areas covered! :rock:
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby brainf » Tue Oct 16, 2012 8:29 am

bass_nut wrote:
on topic: the F5 i auditioned was housed on a China imported aluminum casing. total estimated cost way back then was ~P25k as Ferds did not charge professional fees. we scheduled 3 units from him. unfortunately, he had difficulty importing the 3 aluminum casing as the China based supplier closed shop ;(

i remember asking him if the F5 amp was bridgeable so that we may extract more power output on a mono-mono config. he told us it was only designed for 25wpc @ 4~8 ohms.


P25k is about correct for good parts and custom build (i.e. labor of love).

The F5 Turbo design has broken the 25W into 8ohms limitation :devil:
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby brainf » Tue Oct 16, 2012 8:31 am

edrel sison wrote:when i grow up i want to build myself my own version of the F5.. :D :D


Too funny, we're all still kids at heart (don't we love our "toys"). :rofl:
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby tony » Tue Oct 16, 2012 1:40 pm

Stuart Yaniger, SY of diyaudio designed a preamp, IMPASSE preamp, can be used for the F5, so that you can bridge two sets of amps for more power...http://syclotron.com/ImPassePreamplifier.pdf

uses a 6SN7 driving a 6dj8/ECC88/6N23P....balanced outputs, balanced inputs...
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Wed Oct 17, 2012 11:09 pm

Hi Les,

If I use TO247 type rectifier diode, what part number would you recommend for power supply for F5 Turbo V3?

Any link for the data sheet?

Cheers.
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby brainf » Thu Oct 18, 2012 12:32 pm

AbadSantos 7 wrote:Hi Les,

If I use TO247 type rectifier diode, what part number would you recommend for power supply for F5 Turbo V3?

Any link for the data sheet?

Cheers.


I recommend using the one specified in the F5 v.3 BOM :) For my build I went discrete with HFA25PB60 (had to import them) but I'm not sure if they're up to the task for V.3 though.

Keep us updated on your build and parts sourcing. ;)
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Thu Oct 18, 2012 3:41 pm

brainf wrote:
AbadSantos 7 wrote:Hi Les,

If I use TO247 type rectifier diode, what part number would you recommend for power supply for F5 Turbo V3?

Any link for the data sheet?

Cheers.


I recommend using the one specified in the F5 v.3 BOM :) For my build I went discrete with HFA25PB60 (had to import them) but I'm not sure if they're up to the task for V.3 though.

Keep us updated on your build and parts sourcing. ;)


Hi Les,

HFA25PB60 may not suitable since this is only single channel I think. PCB might be very much populated if I use this option.

Im still designing the PCB for the power supply and Im thinking for the TO247 dual type rectifier diode to go with the power PCB.

Cheers.
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Sat Nov 24, 2012 11:05 am

Hi Doc, Les,

This is my Xmas gift for the 2 of you :devil: :devil: :devil: ...Hope you like it for your future DIY build.
Complete set of F5T V3 PCB...100w Class A.
Image
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby endrik35 » Sat Nov 24, 2012 1:12 pm

AbadSantos 7 wrote:Hi Doc, Les,

This is my Xmas gift for the 2 of you :devil: :devil: :devil: ...Hope you like it for your future DIY build.
Complete set of F5T V3 PCB...100w Class A.
Image




Wow! Maraming salamat brader Loi! I've decided to keep the B1 preamp. Partner ko sa tube amp! Sana bumagay! ;)
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby AbadSantos 7 » Sun Nov 25, 2012 3:24 pm

endrik35 wrote:Wow! Maraming salamat brader Loi! I've decided to keep the B1 preamp. Partner ko sa tube amp! Sana bumagay! ;)

Hi Doc,
Speaking of B1 pre-amp. I know you heard both the Original B1 and the DCB1...Whats your take on this Papa's creation?
Oks ba? Im thinking HOT ROD Version...

Image
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Re: DIY F5 pure class A power amp(Nelson Pass design)

Postby brainf » Mon Nov 26, 2012 8:50 am

AbadSantos 7 wrote:Hi Doc, Les,

This is my Xmas gift for the 2 of you :devil: :devil: :devil: ...Hope you like it for your future DIY build.
Complete set of F5T V3 PCB...100w Class A.
Image


Maraming salamat Loi aka Santa! :)

I hope we've been good boys to deserve such a gift. :$

Hehe! Me thinks the power supply board will get used first :devil:

See you in a few weeks!

leslie
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