MartinLogan Bias Mod

[tyu]

One thing to keep in mind....all the res. put in the bias have there own sound....
so if the res...hot on the top...get a diff res....ML uses an thay sound good carbons4 1/4watt 15m ohm.5..10m ohm....some like Acoustat use1 50mohm 20watt....thay all sound diff..
SoundLab used The rat-shk...whit sand 50w...sound bad to me...but we Diy,ers need to pay a lot more time on the Bias...this is where all good sound starts an ends
Thanks for all an any info..

[Rob in Montana]

Olaf-- Thanks for sharing those measurements of the Sequel without resistors. Your measurements without resistors certainly conforms to what I am hearing.

Luckily I am using a computer based system and a Tact preamp/processor, so I can adjust for the frequency response problems. After hearing the cleanliness of the sound without the resistors, I prefer to do this and not have to put the resistors back in circuit.

I read your post that you pointed me to, where you were proposing a fix for flattening the impedance and response curve of the Sequel. I will keep that in mind. I am thinking, though that I shouldn't have a problem with low impedance affecting the response given I am using the Tact fully digital amp. If I remember right it is supposed to be stable into super low impedances. I will check the impedance of the amp, though, just to be sure.

[ticknpop]

Rob in Montana

the original 10 to 15 meg power supply output resistors were carbon film becase they handle surge and voltage breakdown better than metal films used in that circuit position - the long term reliability of your metal film resistors when used as output resistors for HV power supplies usually isn't good. Usually wire round, rated carbon films, or special high voltage power film are used.

[Rob in Montana]

Ticknpop--Thanks for the tip.