First One - mosFET amplifier module

[Lazy Cat]

a20h juste arrived yesterday. after 24h burn-in, i m listening it since one hour and cant stop if you see what I mean... for the time being that's just an amaizing good investment and amaizing value for money. also it has xlr so I ll try in coming weeks a FO balanced/bridge config (as I have 4 module with 2smps) as you suggested in later post in may. stay tuned

maxi please spread the word in the head-fi forum, they are thirsty of any new info about this DAC.

Gustard A20H DAC (Dual AK4497EQ, analog preamp, headphone amp, all in one)

Shame they're listening with the headphones only.

 

[maxlorenz]

Small notice to all having SMPS1200A400 in FO M amp, add two 10mF/63 V per channel and enjoy the bass. Cap Bank from FO L clearly showed the benefit.

I already bought the caps I am just waiting for the last modification (second PS plus cables) to settle or burn-in, since I feel subtle changes in sound on day to day basis...silver plated OCC copper cables are my present choice for internal wiring.

Cheers,
M.

 

[fluid]

Stereo Amp finished

Hi Guys,

I have just finished my new First One 1.4M build with SMPS600 from Cresnet and some capacitor boards that I got very cheap from Taobao, 4400uF per rail extra United Chemicon KYB from Mouser, less than US$2 each when you buy 10, and very low ESR and high ripple when paralleled.







One thing for anyone who might want to add extra capacitance to an existing Cresnet supply. The extra capacitance tripped the Over Current protection at start up, with advice from Cresnet all it took was 1 resistor to be added in parallel and the problem was solved.



Next in line is the rebuild of my 1.2 modules into a 6 channel amp with individual power supplies.



I have found another SMPS from Taobao that is very well made for a very low price, I have tested them and so far work very well and sound excellent. They drop around 5V under load and on 240V AC give 55V when loaded with a First One at idle. These are strictly 220 to 240V only though.



As I needed to buy 6 the shipping was making other options very expensive.

 

[Finnogangela]

Fluid, great pics and advice, thank you.

 

[fluid]

Fluid, great pics and advice, thank you.

No problem

 

[poseidonsvoice]

Fluid,

Wow. Excellent work. It's obvious you take enormous care in your builds.

Best,
Anand.

 

[poseidonsvoice]

LC,

Please, where is First One S V1.4? If not, kindly advise on what power levels we can expect the M version to produce at +/- 40VDC?

Thank you,
Anand.

 

[ClaudeG]

Interesting read Fluid, and nice pix!

Will be interested in your findings and recommandations re more affordable SMPS à la Cresnet or Taobao, aswell as additional cap boards.

Have a nice WE

Claude

 

[Lazy Cat]

DIY at its best!

No problem

Congratulations on fantastic build, enjoy.

 

[Lazy Cat]

LC,

Please, where is First One S V1.4? If not, kindly advise on what power levels we can expect the M version to produce at +/- 40VDC?

Thank you,
Anand.

First one S is next, planned to start in Jan 2017.

At PSU voltage +/-40 V, FO M is able to deliver 75 W/8 Ohm, 140 W/4 Ohm.

 

[poseidonsvoice]

Is there any advantage that First One S has over First One M if the latter is configured with +/- 40V supplies? I assume that the S version should have similar sonics but lower power.

Thanks,
Anand.

 

[maxidcx]

awaiting LC info, FO S will most likely be only 1 push pull (1 die) and therefor les expensive and potentially smaller and bias will be lower (probably half) so this will be easier to integrate in smaller case or multi amp system. may be LC will do regular keynotes
one wish for the S please LC, manage so that we can (at least optionaly) have a Signal ground, so for multi amp we dont have issues when using a common PSU (see my post http://www.diyaudio.com/forums/vend...-mosfet-amplifier-module-330.html#post4838999)

 

[Lazy Cat]

First One L preview on 6moons

Interesting reading on 6moons, Mr. Srajan Ebaen seems enthusiastic

6moons audioreviews: Ubiq Audio Model 1

6moons audioreviews: Ubiq Audio Model 1

6moons audioreviews: Ubiq Audio Model 1

L.C.

 

[Mark Verhoeven]

Hi Guys,

I have just finished my new First One 1.4M build with SMPS600 from Cresnet and some capacitor boards that I got very cheap from Taobao, 4400uF per rail extra United Chemicon KYB from Mouser, less than US$2 each when you buy 10, and very low ESR and high ripple .

Very nice build! Which casing did you use?

 

[fluid]

Very nice build! Which casing did you use?

Thanks Mark, chassis for my First One is 2U Dissipante from Modushop.

 

[Mark Verhoeven]

Andrej,

You have E-mail with an order.

Mark.

 

[Lazy Cat]

Andrej,

You have E-mail with an order.

Mark.

Thanks, sent already 😎

 

[Parap]

problem with connecting smps1200

Hello,

I started my build of the first one amp 1.4. I am using 2 smps1200a400 from Hypex for power supply.

I have a problem when connecting. I currently have iec ac connector connected to a switch, it measures 230v ok. When I connect one of the power supplies the fuse in the iec ac connector blows instantly. I tried it two times with both supplies. I am using 1A slow blow fuses.

Hope it is something simple, anybody knows what I am doing wrong?
http://www.diyaudio.com/forums/attachment.php?attachmentid=579461&stc=1&d=1478881639

 

[Theodosis O.]

Too small fuse.
Use 4A or bigger.

 

[Parap]

Thanks Theodosis. I was hoping it was something like that. Going to buy some 4A fuses tomorrow.