VTL MB125 MonoBlock Power Amplifiers $7,187.50 VTL MB125 MonoBlock Power Amplifiers are all about smaller chassis with a more Massive power Supply. The MonoBlock form factor allows VTL to take advantage of this form factor. 100 Watts Tetrode and 50 Watts Triode in Tube Power is plenty for most speakers. Dimensions HxWxD: 7x16x12″. Weight: 45 lbs. NOTE: Pricing is $7187.50 / pair.