Moving from 120 VAC to 220 VAC operation on Krell monoblocks

Just read an interesting article from MBL regarding audio benefits for operating power amplifier at 220 VAC on dedicated electrical circuit.
Also read on the Gon that Dan d’Agostino has voiced the sound of the FPB amp series by operating them at 220 VAC. 

I currently own a pair of Krell FPB-350 MCX monoblocks which operate on 120 VAC dedicated circuits (14 gauge wire). Contacted Krell and they indicated dip switch positions for operating the amps on 220 VAC. The MBL paper suggests to wire 220 VAC dedicated circuit using 10 gauge wire to reduce electrical noise and amplifier modulation of electrical circuit.

While the theory seem to be valid and before rewiring my dedicated circuits, I would like to have some Krell amp owners comment on the benefit of going to 220 VAC operation for those who have performed the mod.

From what I understand make of this what you will.

For 220V, a 110v transformer is installed in the power box with 110-0-110 secondary windings - with 0V (centre tap) tied to earth. This gives you 2 phases (0, 180) which = 2x 110V.

I don’t know how legal or safe it is, just move to Australia we have 230v here all the grunt you need, that's why our systems sound better than yours,width=178,height=178/winking-...

Cheers George

Hi George,

Thanks for the invite, but I love my Canada. Well, if your gear sounds better ‘down under’, good for you guys and say hello to Crocodile Dundee 😎 on my behalf. We get 220 VAC coming in the electrical box on 3 wires with two phases ( 2x110 VAC). I will communicate my findings sometime next week when I’m done.


I had (stupidest thing I have ever done, selling it) a Krell KSA-250 power amp. Used it in Europe on 220V/50Hz and in the USA 110V/60Hz and can't honestly say I noticed any difference in sound quality. How I miss that amp!
Thank you Schubert for your accurate description of Canada. FYI, we will have our audio show in Montreal this weekend (Place Bonaventure hotel).

With current USD/CAD exchange rate, our american friends should come visit our great city.