Just as an FYI, the "seller" may have not been able to describe the mod as some modders, like Steve at Great Northern Sound, do not divulge what components are part of the mod. Whereas, the Parts Connexion will email you an exact listing of all components that went into the mod.
I have had components modded by both of these companies (Resolution Audio and Sonic Frontiers) and sold the components on Audiogon within a week. I thought there was definite improvements in sound, and sold the items without losing hardly anything on the mods.
Like was stated in an earlier comment, it depends on who is doing the mod and what their expertise is in. For example, Chris Johnson with Parts Conn. once did R&D for Sonic Frontiers, so I felt more comfortable in utilizing his services on the SF preamp mod.
I have had components modded by both of these companies (Resolution Audio and Sonic Frontiers) and sold the components on Audiogon within a week. I thought there was definite improvements in sound, and sold the items without losing hardly anything on the mods.
Like was stated in an earlier comment, it depends on who is doing the mod and what their expertise is in. For example, Chris Johnson with Parts Conn. once did R&D for Sonic Frontiers, so I felt more comfortable in utilizing his services on the SF preamp mod.