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FS: First One M v1.4 power amplifier module

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This amp is Phenomenal!

I put the FO amp into temporary service this morning in my listening room. All I can say is WOW! I thought my last amp (LM4780) added a great sense of dimension, clarity and space to the music. Well, I would be wrong. This amp is absolutely one the best DIY amps I've heard and moves to the top spot so far. I'm warming it up as I write this using my goto all acoustic instruments CD and they sound as if they were all onstage at the end of my room. It's that good. :) The strings are reproduced with fullness and clarity and the highs are effortless and smooth. Vocals are equally clear and simply pour out of the full sound-stage. And there's plenty of solid and faithfully reproduced bass as well. Actually I'm surprised with how solid the punch of bass is when it is called upon to be reproduced. And I don't have a sub-woofer hooked up to this particular rig.

Attached are pics of the wiring I finished up. It's not totally done yet, as the front panel needs a switch and other custom milling for meters. I'm using it with an Onkyo C-7030 CD player, DIY Doug Self 2012 preamp, and Energy, Reference Connoisseur RC-30 speakers. Sounds marvelous. :D Even at moderate listening levels the heatsinks are barely warm. A tad warmer around the output devices. Oh, did I say this amp - right out of the box - is super quiet and I simply hear no hum. No tinkering needed here folks - unless of course you want to. There's not much to improve on! :)

Thanks LC for an exciting new amp. You've given the DIY community an amp module that is affordable and sonic qualities that are unmatched. All you need to add is a PSU and a few hookup wires and you've got one fantastic sounding amp. More listening later today.

Link to the original post here. ;)


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New heart in old body

Hello all,

here is example how to put new heart into old body (sorry for bad picture quality). I know, it can make better, but this is good enough for me. Important is sound. Now I have true natural sound. All what is on compact disc come thru TA-E9000ES, FO 1.4 and Altec Lansing fiften into my ears. No more need to go to the opera or another concert. Thanks Andrej.

Link to the original post here. ;)


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Listening sessions began...this amp is like putting immense super-headphones! That detailed and textured it is! After listening Bartok's Violin concerto I can say: strings attacks and pizzicatti are lovely; drums attacks are fast and punchy ( You feel the leather being kicked); soundstage is huge, beyond speakers; bass is very deep but better, the images produced by the bass emitting instruments are proportionate to them; voices are fleshy...
VSSA is good but F.O. is on another league.

Thank you again, Master

Link to the original post here, ;)


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taccodude's First One experience

So , I have been listening to the New FO for a while now and I have to say that for me it`s definitiv a Keeper .It is good with all Kinds of Musik and the Bass that was missing on 1.2 is very good now. The Sound is clean,detailed and dynamic .Last Night I took it to a Friend who wanted to check it out and he was really pleased. We listend to Kodo, Misa Criola, Zaz,Billy Cobham,Chris Rea and some more , it was a long Night. He got some old B+W802 Speakers which can handle some Power and FO was enough for them.
One Problem for me is, when things get better ,I start listening louder all of the Time ,so think twice if Your Wife can handle that.:)
Happy listening DT

Link to the original post here. ;)


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My FO v1.4

Hello, here is my iteration of the 1.4. It uses two 550va EI transformers and is dual mono. I'm a relative newbie but the highs are clear and detailed. I can hear snapping where it used to be very faint. The mids are full and smooth and the bass is tight and impactful. It's been completed for two weeks now and I just wanted to let it break in. It is a very good amplifier considering everything cost me les than 500 dollars!

Link to the original post here. ;)


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I finished my FO Amp - Still Very Impressed!!!

Well after a few more weeks I finally put the finishing touches on my FO amp. I added a speaker protection board and some eye-candy meters and a custom milled front panel. Still sounding impressive with a natural and transparent sound. You can hear every note executed with precision and clarity. This amp probably needs more break-in, but it's not fatiguing to listen to at all - regardless of genre. Sitting on top is my Doug Self 2012 preamp build I completed a few years back. It's a great match for the FO. :)

For those just joining the FO party, a few inside pics can be seen in my post here.


Link to the original post here. ;)


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FO worth every penny

Hi there,
here we go, FO 1.4 is in situ in the living room and connected (biwiring) to a pair of great (but not officialy in the "hifi" range) JBL LS80 (3.5 way with 2 x8") for 3 hours ago now

what to say ... despite the nice spring wether outside, I m just stuck in the sofa. you know this feeling if you do DIY for some year : one day you plug a new component and all of the sudent, it rocks ! you cant stop putting all your CDs and you feet seems to have a direct cabling with the woofer . you see what I mean.

Well the firstone experience is even beter than that. in addition to that your body feel very proud and you smile for some minutes with a feeling of "yeess, I got it".

Yeah the firstone is just amaizing. Deep and very clear bass, no any noise whatsoever, so clear but not bright. very very good. you feel that music is just natural as it should be.

So good I m now hesitating to build a second one for biamping, as this is already amaizing good in stereo with a single hypex ! the only drawback of my config (2Ux300mm) is that temperature stabilize at 57°C and rises to 59°C at relatively loud level...

Thanks LC for sharing with us a great invention. the FO worth every penny

Link to the original post here. ;)


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Now before me I have no speakers

Hi, I greet all,
I would like also add to the lucky owners of this great amplifier.
I finished building my FO 1.4. I used all-aluminum chassis 2U 300mm, that it fits perfectly.
The temperature on the radiator near the FO module ranges from 40 to 45 ° C, it is great. :up:

Two SMPS power supply (+/-55V) are from Cresnet (thanks Sami).

Everything works perfectly. Now I just listen to music and I'm happy :happy1:

Now before me I have no speakers, but singers and instruments :) :cool:

Thanks LC :worship:


Link to the original post here. ;)


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Ok. Here we go.

The cas was born as an atlantic technologies a2000 7 channel amp. Had it for two year or so, and finally decided to do something with it. Ordered 6 modules and the work began. Because the original amp had a power supply of 60v that was the perfect choice. Ok we connected everything with no problems, just changed the amp boards. Everything worked fine but there was a horrible ground loop. Tried some things, nothing helped.

Then the roller coaster started. Took everything apart, powered everything just with the power supply, without the original boards... Still ground loops. Done a bunch of thing to get rid of it, nothing helped. Then i bought new switching power supply's. Buid it, powered it, still ground loops. Sourced the problems, and it was working good. Ordered speaker protection boards, connected everything, and again ground loops... Well i had a lot of ups and downs, but now it seems that its working fine. Im still burning it it, afted couple month i think i will redo all the wiring, because now the wires are longer to get to the modules for setting them up more easy.

My setup is an active 3 way system, something similar to JBL studio monitors. Active crossovers fully built by mu friend, Parasound 1500DAC and Xmos converter.

About the amp. I have heard a bunch of good amps, couple DIY ones like Pass Labs F5, Hiraga le monstre and others. This amp is pretty much the best one i ever had or heard. The speed of it, the clinical clarity, the mass of low end, the sound stage.. It really pushed my nerves and i wanted to throw it thru the window, but just when you push the power button and it starts to play, you forget all the nicks it gave me.













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First One module began like this..

In 2013 the first First One v1.1 module started its life in a chassis below. Lately, after reading few positive reviews my friend was finally convinced and asked me to make an upgrade. Here are some photos of job done. :cool:

Link to the original post here. ;)


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I think Lazy is right, none of us really know what we have our hands on!

Glad I figured out the Molex connectors so I can do this down the road. ;)

The Chip Amp build is Peter Daniel's (AudioSector) LM3875, the "classic" kit. The linear power supply was built according to the kit's instructions. As You can see from the photo below, is that I make it pretty hard to tweak components, as I made the chassis pretty small. :eek: I felt blessed that I got it all together! But to put the sound of this LM3875 kit into perspective, I liked them more then the Pioneer DS-1 AVR I mentioned above (which was their flagship in 1991). The Pioneer had more power but the LM3875 had a more "open" and 3 dimensional sound... ...With the First One, I get the best of both worlds, plus more. I now know what the reviewers mean by "space around the instruments" and "black background".

Yes, I should clarify what I meant by "IM distortion". When I would play Avebury at moderately loud levels with the LM3875, The bass would drown out the highs in a modulating fashion. Even at moderate levels, esp with trance music and certain movies, the bass would "mask out" the highs. At first I thought some of this was due to the streaming bit-rate, mp3, data compression and the such (as I do stream a lot here). Odd thing, is my "Cheap and Cheerful" line arrays and Pioneer CS-905s did not do that, they just sounded "distorted" (usual clicks, pops and grain) when pushed beyond the 40 watt capacity of LM3875. I was getting worried that the Avebury had a design flaw! It was really disheartening, as I put a lot of passion into that build, and for how big the system is, such a flaw would be unacceptable. But, as it turns out, the LM3875 was not the best match for this system, and its distortion signature was different. The two together Inter-Modulated! :eek: But with the First One, all such distortion is gone! :cool: And I think this goes farther then just having a bunch of watts. There is something to the First One design in how the power is put out. It can move those watts so fast and smoothly, it is like there are watts in-between the watts, like there is more "air" around the instruments! :D

Yes, very happy indeed! I consider this amp a "reference" amp, and that is almost understating it, as this amp does what it does with so much finesse. I think Lazy is right, none of us really know what we have our hands on!

Analog DAC sounds intriguing. Is there a multi-channel version?

Link to the original post here. ;)


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Today, the first time I listened to the amplifier I built based on the modules "first one amplifier". First impression: WOW !!! The class better than my another amplifier based on the modules UCD400HRX. Cool!!!

Link to the original post here. ;)


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