|Wzmacniacz SPE Expert 1K-FA|
|tylko R-140 na 3 fazy o wadze 100kg daje rade nawet jak nie ma podpitej anteny i taka musisz kupić a nie stresować sie padaczkami Expertami , Acomami i innymi pżdzinami |
bo opanowało Cie jakies prześladowanie o uszkodzeniach ,padaczkach i innych przypadłościach i coś komuś chcesz chyba udowadniać
krąży po sieci informacja o głośnej i niby wadliwej pracy SPE 1,5K tylko malo kto z tych niby twierdzacych ze ma uszkodzenie w SPE bierze pod uwage to :
I think, at this point, that it is necessary to share some technical considerations regarding this noise that a couple of customers consider very annoying, imputing SPE also of inaccuracy.
With the due respect I assure that nothing is dangerous or inaccurate !!
This noise is due to the presence in the power supply of the power factor correction (PFC) which is now mandatory in the CE area and which, I believe, will soon be also mandatory in all the administrations of the world.
The use of the PFC allows to minimize the phase difference between current and voltage coming from the electric network, trying, at the same time, to keep the current absorbed by the amplifier as sinusoidal as possible.
These features are essential to optimize the efficiency of the power supply and to avoid the introduction of disturbances generated by the demand for large power into the mains.
By pure example in the CE area the power amplifiers with classic transformer at 50 Hz are now out of the norm because do not have PFC.
The PFC must therefore take into account simultaneously the momentary conditions of the mains and the momentary demands of power from the amplifier.
The external conditions are the most varied and difficult to predict (I can feel in my shack that something varies when the elevator of the building is in operation).
Also the internal conditions vary according to the power demand, a very particular situation is created when there is no absorption (reception in "operate") in which the PFC intervention is not continuous and therefore is more audible.
To eliminate this noise it would be enough to put a resistor (560 ohm 10 / 15 W) as ballast at the output of the VPA but, since in our opinion, the noise generated was minimal and present only in some circumstances, then we decided to not lose 5/6 W inside the amplifier.
SPE acquires one switching power supply designed by specialists in which the components for the PFC have been designed by major Companies ... this is the state of the art.
I asked the respective Distributors to replace the two power supplies, hoping that they are faulty ( but in the final test this did not appear).
However if the noise will still remain unacceptable for them, I will pray the Distributors to refund them the price paid.
I hope this behavior is appreciated.
73’s to all.
i temat został zamknięty i nastała błoga cisza i w PA i w sieci na ten temat , osobiscie ja tam w swoich nic nie slysze , no pracują owszem i kreca wentylki jak im dasz do pieca to cos musi je schlodzic , normalnie myślący zdaje sobie z tego sprawe ale juz nawiedzony nie do końca