cost to service and update an M3 or M100 amplifier

[Juan]

What is a usual cost for having a functioning but all original M100 amp serviced/updated by a Hammond tech including usual expected parts? (but not including tubes or transformers)

[enor]

Not sure what you mean by "update" - I'm not aware of any common updates for the above units

[muckelroy]

The biggest cost is labor (or, it should be, if the tech is worth their work.) That varies greatly from tech to tech.

A bone stock M100 amp needs a new power cable at minimum, and a fuse. The rest is determined by testing. Sometimes, the can caps test fine, sometimes they don't. Sometimes, techs will replace the can caps and other electrolytics even if they test strong, sometimes they don't. Some techs test every single resistor and capacitor individually, replacing if out of a certain % spec. Some don't. Not every tech is equipped to completely test every capacitor in a way that is accurate, and will shotgun replace all of them. Tubes should be tested and replaced only where needed, not altogether. It's absolutely impossible to give a "usual cost" on this forum.

[Juan]

I will check with a local tech.

[David Anderson]

Like muckleroy says, not all techs agree (as you can read sometimes on here) on exactly what needs to be done to refurbish a 50 year-old amp. There's a lot of risk calculation that goes into it. In other words, "If I don't replace this original part, how likely is it to cause trouble down the line?"

Some techs are extremely conservative, only replacing things that are obviously bad. But then what happens in a year? Other techs might want to replace every part, but that's usually unnecessary, not to mention time-consuming and expensive.

You will rarely find total agreement.