Author Topic: Nelson Pass Firstwatt F5 Class A (Read 14739 times)

dBinu · « **on:** Jan 16, 2011 at 10:27 AM »

HI guys,

just want to share, the F5 Class A amp that i built for a friend of mine..

25W/8r Class A amp, dual mono setup.. with 250VA toroid and 8 x 27000uf caps per channel.. most on the parts were ordered online.. Chassis is from china..

enjoy the pix... thanks

audiojunkie · « **Reply #1 on:** Jan 16, 2011 at 10:38 AM »

wow! very Nice amp!

ATJr. · « **Reply #2 on:** Jan 16, 2011 at 07:25 PM »

congrats, glad to see your posts....

Quote from: dBinu on Jan 16, 2011 at 10:27 AM

HI guys,

just want to share, the F5 Class A amp that i built for a friend of mine..

25W/8r Class A amp, dual mono setup.. with 250VA toroid and 8 x 27000uf caps per channel.. most on the parts were ordered online.. Chassis is from china..

enjoy the pix... thanks

JojoD818 · « **Reply #3 on:** Jan 16, 2011 at 07:31 PM »

very nice build, congrats!

efren_ · « **Reply #4 on:** Jan 16, 2011 at 07:55 PM »

wow

Sir your friend will surely enjoy the sonic qualities of a class A topology. I had my share of class A amplification in the past by building designs of Hiraga, John L. Hood & Delpiane, no negative issues about the sonic qualities, but let me share this reality

:

1. Heat-no aircondition installed in the house, so everytime i operate the amp I created my very own artificial heatwave, have everyone inside complaining, even the house pets are restless

.

2. electric bill- operating a 24volt center tapped, 24 amperes tranny at full throttle when i switched on the amp at an average of 2-3hrs daily(the JLH draws an average of 3.5amps/ch) made the Meralco happy, my wife & the wives of those who ordered the amp from me mad as hell, cursing (me?) to the highest heavens

my own conclusion is unless money is not an issue, go for SS class A

kemozavi · « **Reply #5 on:** Jan 16, 2011 at 08:26 PM »

Great build, ganda ng housing!

t68kv · « **Reply #6 on:** Jan 16, 2011 at 10:00 PM »

I wonder how its sounds when this partnered with an incredible DAC

romymartinez · « **Reply #7 on:** Jan 17, 2011 at 07:45 PM »

Congrats Sir! Ganda!

pekspert · « **Reply #8 on:** Jan 17, 2011 at 08:14 PM »

Very nice amp! Pwede pang business.

BigBert-2 · « **Reply #9 on:** Jan 17, 2011 at 08:49 PM »

Napakaganda naman ng pagkagawa bro....napa-swerte din pala ng friend mo....

dBinu · « **Reply #10 on:** Jan 18, 2011 at 05:04 AM »

Thanks alot guys.. This is the 2nd F5 i've built so far and its always a treat to listen to this amp.. it really sounds great.. i like the mid and high.... Power consumption is about 140-150W..

you can read the review of the F5 here > http://www.6moons.com/audioreviews/firstwatt7/f5.html

tnx

romymartinez · « **Reply #11 on:** Jan 18, 2011 at 05:57 AM »

Hi Sir,

Yung isang amp katabi ng F5 with similar casing anu yun?

dBinu · « **Reply #12 on:** Jan 18, 2011 at 06:16 AM »

HI Romy,

thats my SymAsym 100w class AB amp.. design by AAK of diyaudio.com > http://www.diyaudio.com/forums/solid-state/154717-my-new-symasym-pcb-design-rev_1-3-a.html

tnx

dBinu · « **Reply #13 on:** Jan 18, 2011 at 06:26 AM »

here's the DAC that i've been using.. its a ESS ES9018 Buffalo II dac from Twistedpear audio..

http://www.twistedpearaudio.com/digital/buffalo.aspx

ATJr. · « **Reply #14 on:** Jan 18, 2011 at 10:18 AM »

@dbinu, saan galing yung chassis mo? any links? thanks....

blue_123 · « **Reply #15 on:** Jan 18, 2011 at 11:07 AM »

I like this

Nice ... congratulations sir!
parang MF yung design ng heatsink.

dBinu · « **Reply #16 on:** Jan 19, 2011 at 04:43 AM »

Quote from: TonyT on Jan 18, 2011 at 10:18 AM

@dbinu, saan galing yung chassis mo? any links? thanks....

Yung friend ko bumili ng chassis nung nagpunta sya sa China sir tony.. tnx

romymartinez · « **Reply #17 on:** Jan 20, 2011 at 10:29 AM »

Quote from: dBinu on Jan 18, 2011 at 06:16 AM

HI Romy,

thats my SymAsym 100w class AB amp.. design by AAK of diyaudio.com > http://www.diyaudio.com/forums/solid-state/154717-my-new-symasym-pcb-design-rev_1-3-a.html

tnx

Ah yan pala yun..

t68kv · « **Reply #18 on:** Feb 01, 2011 at 08:53 PM »

I have a chance to audition F5 last Sunday and all i can say is WOW!

You can easily distinguish the difference in terms of Highs - Lows. Its incomparable even with the reputable SymAsym "maybe because its class A" and it is good enough to fill your room with very clean and complete Bass "if you like rnb's and remixes".

I will not be bothered with any increase in electric bills if this thing can satisfy my needs

endrik35 · « **Reply #19 on:** Feb 07, 2011 at 01:52 PM »

Very nice and clean work Sir DBinu! Bagay na bagay sa first pass B1 preamp na gawa namen ni Leslie. Can I know magkano inabot nung project? Nuvotem trappos pa gamit mo Sir. Galing!

dBinu · « **Reply #20 on:** Feb 07, 2011 at 09:29 PM »

Thanks Funk... hmmmm around 25K++ .. sa chassis and toroid palang kase ubos na budget..

meron din ako ginawang Direct Coupled B1 Buffer (no in/out caps).

romymartinez · « **Reply #21 on:** Feb 10, 2011 at 08:27 PM »

How I wish I'll have the opportunity to hear these amps.