2nd amp from scratch: Low NFB- FET front end - BJT OPS

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Stereo experience

Finally, electonics are as good as finalised. Some mechanical work to complete the enclosure has to been done and is work in progress.

I recently bought a second hand PS-audio trio P-200 preamp as my audio-furniture in the living room has been installed. Sofar I did use a mixing panel to adjust volume.

I'm verry happy with the sound.

Below some pictures from current status.
 

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I'm waiting on the front panels to be ready. In the meantime, both amp's and new speakers (Sonus Faber venere 2.0) are burning in.

On the outside not 1 bolt or screw will be visible. Side-, back- and front panel are made out of 13mm thick HPL material. This material is very very nice to cut, drill and to cut thread in.

Top side is from 6mm clear glass, always nice to have a look on the inside.

I'm also happy how the internal wiring has come out. Rather clean inside. I was not able to twist PSU cables between PSU and Output stage PCB as they are 4mm² thick and less that 10cm (4") in lenght.
 

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Great interior! Is there enough airflow for power amps?

Thanks all for the comments.

Well, the dissipation per amp is approx 80W. Inside the furniture are quite some ventilation holes, from bottom to the slotted holes pattern on the topplate, which are also used to put the speaker cables trought.

Heatsinks are idling at arround 55degrees C, a bit to must to my taste. Possibly I will change the 1000va 2x38v toroidals to 2x30v in the future together with the necessary other components on the PCB.s. I can live with smaller Max output wattage, but I certainly would like to keep those 12wrms.
 
Hi Marti,

Sounds interesting, were are you located?

Meanman,
After your visit and findings, I have played with speaker positions and read quite some documentation regarding this.
Left speaker is moved 1,2m away from the corner side wall. Both speakers are move away from the rear wall, about 25 cm between speaker and wall, more is not possible due to furniture dimensions.
Bass had improved clearly.
 
Thanks!


Now the thread is active again: some listening experience.

1)
During the Christmas holidays, I left the two amp's on 24/7 this for about 2 weeks. = +-300hours. I wanted to verify whether the sound changes during break in. To be honnest, I was sceptical about break in.
Experience: after a couple of days I starting to notice difference (even my wife did!) The first week I even got the impression that it sometimes sounded even worse!?
At this point, both amp's (monoblock's) sounding more open: the sound is more in the room instead of closer to the speakers. Also with very low volume, it sound very enjoyable.

2)Mid''s were a bit to much, for guitar or female vocals I had the feeling to use the equalizer on the bluesound streamer and lower the mid's. This was when using a QED audio 40 Reference interlink between preamps and amp's. I had the change to perform some listening test with different interlinks: MITterminal 3 , Oelbach NF214, QED 40 standard, audioplan, Grimm TPR.
Finaly the Grimm TPR interlink remained and I'm very happy with the sound.

Two weeks ago I had a listening sesion with one of my friends. He is not a DIY'er but has quite some listening experience with tube amps, Sansui SS amps, B&W and Dynaudio speakers.
He was exited about the sound, especially the base was of an other level he was used to. But the sound was a bit to much "in your face", he liked more laid back sound. Is personal preference offcourse.
 
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