"The amazing thing is, before the top of the amp used to get hot (hot air having less density always rises up), now there is a hot breeze from below while the top remains cool. This means effective cooling is taking place".
Tend to disagree with you here ........
In a still atmosphere, where there is no air movement, whenever there is a heat source (in your case, the heat sinks and few transistors) natural air convection currents set in. 'Heat transfer' makes the heat source transmit the heat to the immediate surrounding air, which gets hot and naturally rise above. The ampflier is so designed that the air vents are placed on top of it, whose role is to throw out the 'lighter' hot air from the amplifier top, thus creating a negative draft within the amplifier, which inturn invites the surrounding ambient cooler air to enter the equipment from whatever 'other' inlet ports given. You say, such ports are there on the bottom of the amp .... right? It is for this reason your amp used to get hot on the top .... as all amps do. But, thats how is has been designed !
What you have now done is to force outside cool air inside. You have made this into a 'forced' blow-thru unit ..... which might prove counter-productive. Why so, since many components which may not be attuned to ever get heated would now continuously get a stream of warm ... maybe, hot forced air .... might be detrimental in the long run.
What I would suggest, is that you reverse the fans and make it into a draw-thru operation. In other words, pull the hot air from the unit top. This would create a strong negative draft inside the unit ..... which would bring in outside cool air continuously .... and keep the unit in its original format. You would now find a steady stream .... sorry, blast of hot air blow from your amp top. Coooool ... thats how the Japos have designed it.
Obviously, the Calcutta heat (air) would also get carried in and end up getting hotter than usual blast from the top outlet..... which would make matters bad in a non-airconditioned listening room ...