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First One - mosFET amplifier module

Source is mainly a dedicated PC into Xmos > Ian's FIFO with Crysteks > Buffalo 3 > Owen's MOSFET I/V. A preamp is not strictly essential as I/V stage runs at 50mA and has low enough output impedance to drive headphones; internal volume control in 9018 is also spectacular. So, the preamp is mainly used for analogue compatibility. My old pre is built around a 6H30 fixed bias stage, fed from a Salas shunt and a tube rectifier. It is qiute transparent but does not stand a chance in a bypass test.

Speakers are an extensively modified pair of ProAc EBS (similar to ATC SCM50) with external, rebuilt crossovers.
 
Listened for a few hours with both FO mono's in place last Thursday and Friday evening. Quite a bit happened to the sound from new. On Thursday I was thinking about some modifications to my DAC/Preamp, to "tune" the sound to chance it in a way I like it more. It was a bit "thin" sounding... The last 2 hours on Thursday evening I let it play, but wasn't sitting directly in the sweet-spot for listening.

On Friday it was sounding really, really good even from the first minute. I was shaking my head from disbelief SEVERAL times during the whole evening. I didn't expect to get THIS good sound from my current set ever! It's really exceptional sound quality, not only relative for it's price, but also when compared at an absolute level. The NAD M2 I've owned before, doesn't even come close...

I can't wait to test my "better" set of loudspeakers in the setup, but there is still work to do on the X-over... (upgrading)

L.C. You'd better called it "Last One" in stead of "First One"! ;)
 
Listened for a few hours with both FO mono's in place last Thursday and Friday evening. Quite a bit happened to the sound from new. On Thursday I was thinking about some modifications to my DAC/Preamp, to "tune" the sound to chance it in a way I like it more. It was a bit "thin" sounding... The last 2 hours on Thursday evening I let it play, but wasn't sitting directly in the sweet-spot for listening.

You've just experienced burn-in period and how important it is in forming amp's sound. First One needs app. 50 hours to say it will sound properly. ;)

On Friday it was sounding really, really good even from the first minute. I was shaking my head from disbelief SEVERAL times during the whole evening. I didn't expect to get THIS good sound from my current set ever! It's really exceptional sound quality, not only relative for it's price, but also when compared at an absolute level. The NAD M2 I've owned before, doesn't even come close...

Again, for all newcomers, the First One with SMPS1200A400 in dual mono configuration is a world class in absolute term of quality. There are not many amps on the market that can reveal more from music reproduction, again speaking in absolute terms. :)
 
DC sense PCB kit

Hi LC, Any news regarding DC Sense board ?

Hi Theo

DC sense PCB-s are here, 96 pcs. available at the moment, will be produced more if any interest. :cool:

They'll be sold as a small PCB kit, including:
- DC sense PCB, 1 pcs.
- optocoupler, 1 pcs.

The rest of the passive materials should be provided by the user, nothing special few resistors, diodes, capacitors.

DC sense PCB triggers the optocoupler at more than +/-1 V DC on the speaker output, which closes its output darlington to very low Uce_sat, thus close the circuit from shutdown pin to GND of any SMPS. Switch Imax=100 mA.

Price 8,00 EUR for one DC sense PCB kit. :)

GB starts bellow. ;)

Regards, L.C. :cheers:
 

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