Input sensitivity on passive bi-amp of RM 40's

zybar · « **on:** 22 Dec 2003, 12:08 am »

If I passively bi-amp the RM 40's with tubes on top and ss on the bottom, how close does the input sensitivity of the two amps need to be?

If the tube amps are more sensitive, can the pots handle that?

If the ss amp is more sensitive, I could use a passive preamp to adjust.

I have hanging around an old Adcom GFA 555-II. This puts out 325 watts at 4ohms and has an input sensitivity of 1.75V. I don't kow for sure, but I think my Kora Cosmos Reference Monoblocs will be more sensitive.

GW

ekovalsky · « **Reply #1 on:** 22 Dec 2003, 01:58 am »

Input sensitivity isn't a very consistent specification. Some rate for full output power, some for 100w, some for 1w.

A better indicator would be gain, which most manufacturers specify. Most SS amps are 26-32db, many tube amps are significantly lower.

I've never tried bi-amping with two different amps on the VMPS speakers. When I had my Apogees (biamp mandatory with electronic crossover) I always got best results when two identical amps were used, even when gain was perfectly matched.

zybar · « **Reply #2 on:** 22 Dec 2003, 02:00 am »

Thanks Eric.

Too much idle time till I get the new nuts for my binding posts...

GW

Horsehead · « **Reply #3 on:** 22 Dec 2003, 02:02 am »

The "nuts" are driving you "nuts"

ekovalsky · « **Reply #4 on:** 22 Dec 2003, 02:07 am »

George,

Have fun with your post and nuts

Horsehead · « **Reply #5 on:** 24 Dec 2003, 02:29 am »

So George- How are your nuts? Did they arrive today?

zybar · « **Reply #6 on:** 24 Dec 2003, 02:50 am »

NUTS!!!

My nuts didn't show!!

Friggin UPS screws me again

Although Brian did absolutely ship the package overnight, the UPS website says there were mechanical problems in Louisville and my package never made it. I hope it gets here tomorrow.

More importantly, I have presents for the family arrivng tomorrow (including the wife's).

Luckily, all of them are coming via FedEx.

I just asked Brian about using electrical tape to secure the bananas. if he says I am ok, it will be music time.

GW