crossover for 604B

[toneranger1]

Has anyone built the Doug Sax - Mastering Labs xover for the 604's? I need to know what the tweeter potentiometer is set at.

[Jim D]

First of all the mastering lab xover is intended for the 604E. The B, if original, has a different cone and a far better HF horn. Some of the comments I have heard is that the Mastering Labs xover is rather odd in circuitry and the later 604 H and K units worked as well although they are 8 not 16 ohm units. I have also heard the on line schematic is not quite as originally built and some people who tried them could not get the attenuators to work. We know of another crossover made especilly for a 604 modified with the 604E cone. Jim

[toneranger1]

Jim,

Thanks for the response. These are 604B's that have just been reconed with the original kit by Great Plains Audio. Do you have any suggestions. I have the original Altec xovers, but I really desire something better.

[Twodawgz]

My personal opinion is that active crossovers run circles around passive ones. I had the original Altec passive jobs on my 604e's for many years and later replaced them with another passive model (don't even remember which one). I had been running 2 Mac MC-60's. I happened to run across a Mac MC-225 a couple of years ago and decided to bi-amp. Got a Marchand Electronics XM-26 active tube crossover with the MC-60's powering the bass and the MC-225 doing the horns. What an incredible difference. Best upgrade I ever made to my system. I will never go back to passive crossovers. You may want to check out Marchand's website. Find them on Google or another search engine.

[toneranger1]

I really wish it was that simple. My problem is that I am using a Korneff 45 tube integrated amp that does not have pre outs. I love this amp and just want to hear it through the 604B's at their best. Hmmm, maybe I've been going in the wrong direction & should find out if my amp can be modified. Thanx dawgs, you may have steered me away from a kevorkian moment....