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First One - mosFET amplifier module

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#1,661
First One v1.4 initial THD measurements

Hi guys :wave2:

New Year 2015 will bring First One v1.4 and VSSA v1.5 based on initial 4 ppm THD 1 Wrms/8 Ohm real world measurements. :wiz:

100 Hz is well suppressed at around -130 dB. 😉

Stable output DC offset without DC servo. :yes:

Same size, same fixation holes layout, same power, same price. 😀

Stay tuned, L.C. :cheers:
 

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  • FO v1.4, 1 kHz, 1 W on 8 Ohm.png
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#1,665
Xerxes75 said:
Wow.. I am glad 2015 is just days away!
Click to expand...
Yes, agree, still a lot to be done before official launch, but I'm well railed on the track. 😀

pinnocchio said:
Any plans for upgrading 1.2 or 1.3 to 1.4?

Thanks
Do
Click to expand...
No plans in this regard, v1.4 on completely new PCB, new layout, still the same dimensions, same mounting holes layout, same power, same price.

Esperado said:
Strange: No harmonics in your graph, where they are supposed to be ...
Click to expand...
Signal harmonics hidden bellow noise level, some signal generator - sound card and PC artefact spikes present, lowering THD+noise but that's clearly avoidable with real source connection to be present. 🙂
 
#1,668
AxelFPS said:
Hi , LS!!
Parcel received, all in the best possible way.
Thank you!
Between the radiator and the transistor need to apply some insulators?
Or transistor can be set directly on the thermal grease on the heat sink?
Click to expand...

Yes you do need to put in some mica+thermal grease or thermal pads (like SIL-PAD 600 or equivalent) on the output devices but I cannot remember if the other ones are isolated or not, you can look and if it is full plastic underneath than it is isolated and will just require thermal grease.

Ciao!
Do
 
#1,673
I'm about to build a set of Linkwitz Orion 3.5 speakers and he says this about powering the woofers;
"If the two 10" drivers of the woofer are connected in parallel, then they present a low 2 ohm impedance to the power amplifier around 100 Hz. The power amplifier driving this load must be capable of at least 200 W into 4 ohm."

Will one of your 1.2 modules be ok to power 2 of the 10" woofers in parallel?
 
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