If you live in the USA call Richard Gerberg of Modern Audio Consultants, the US distributor of ProAc speakers at (410) 486-5975 or e-mail ProAc at www.proac-loudspeakers.com
He will give you all the info you need regarding amplifier requirements for the 3.5 and D38. I've owned both ProAc 3.5 and 3.8s. In a recent conversation with Richard it was my understanding that the D38 is easier to drive than the 3.8s. He also told me that the D38 is supposed to be more dynamic with better bass than the 3.8. Incidently in owning a pair of 3.8s for 5 years I found them to be more dynamic with much better bass than the 3.5--a better sounding speaker all around in my opinion.
He will give you all the info you need regarding amplifier requirements for the 3.5 and D38. I've owned both ProAc 3.5 and 3.8s. In a recent conversation with Richard it was my understanding that the D38 is easier to drive than the 3.8s. He also told me that the D38 is supposed to be more dynamic with better bass than the 3.8. Incidently in owning a pair of 3.8s for 5 years I found them to be more dynamic with much better bass than the 3.5--a better sounding speaker all around in my opinion.