Recently, we reported on a two-dimensional simulation method for the cyclic and linear sweep voltammetric response of microdisc arrays (T.J. Davies, R.G. Compton, J. Electroanal. Chem. (submitted)). Previously, only a three-dimensional simulation method had been available (H.J. Lee, C. Beriet, R. Ferrigino, H.H. Girault, J. Electroanal. Chem. 502 (2001) 138.). A key factor in our simulation was the diffusion domain approximation which effectively reduced the problem from 3 to 2 dimensions. In the present paper.. the error incurred by the diffusion domain approximation is quantified allowing for a validation. This is achieved via cyclic voltammetry with specially fabricated electrode arrays of cubic geometry in simple redox systems. Excellent agreement between experimental results and simulations is found, with the approximation resulting in less than a 2.5% error in most cases. In addition, a general method for analysing microdisc array voltammetry is reported. (c) 2005 Elsevier B.V. All rights reserved.