Hi all, has anyone tried the EF91 tubes on the MkIII? I found a matched pair of Telefunken ones and wonder what difference in sound would the EF91's made compared to the stock ones.
Thanks in advance!
I have actually had quite a bit of experience rolling the EF91 family. The thing that differentiates the EF91 family of tubes from the stock EF95 family is that the former draws a lot more current (300mA on EF91 compared to 175mA on EF95) and from the higher current comes the ability to handle higher gain and in fact the EF91 stays linear across a wider bandwith than the EF95.
In English, the EF91 sounds more linear and more 'airy' and extended in the top end. Telefunken of course is one of the best manufacturers in the business and is well known for the neutrality of its tubes. If you want to hear things in your favorite record that you haven't heard before, IMO the EF91 is the way to go.