[viny*loco]

Hi Roger
I have one RM-9mkII per channel driving Mirage M-1 speakers

each RM-9 have in one channel KT-88's to drive low frequencies and EL-34's to drive high freq.

the mirage m-1 have bi-wire option
the cables used are straightwire maestro to bass and straightwire virtuoso to highs.

so i check with my digital tester the impedance at the tip of the cables(speakers + cable impedance, it's OK?)
on bass cable the tester tells 5ohms
no lecture possible on high cable... out of range? (the tester have 20Megaohms at max)

what tap i should use? 2, 4 or 8 ohms

the friend who sell me the amps told me 8ohms tap... but the amps run too hot...

thanks in advance Roger!

vinyl*loco

[Roger A. Modjeski]

The tweeter input shows infinite impedance due to the capacitor in it's crossover. Digital meters measure DC resistance only. In both the woofer and tweeter the dc resistance and ac impedance are similar and you wont be far off considering them the same but the DC meter cannot see the tweeter through the capacitor. You would have to bypass the capacitor to measure the tweeter.

It is unlikely your connection is causing the amp to run hot. If the 4 ohm tap plays loud enough always use the lowest tap.

If you feel the amp is too hot take off the cage, make sure the amp gets air from beneath and reduce the bias till the LED barely lights in a dark room.


Roger

[Ericus Rex]

Speaking of the bias LED, just how bright should it get when at proper bias?  Just visible in well lit room or fairly bright?

[Leadfeathers]

I'm most curious how you use 2 different tubes to power the high/low frequencies.  If I understand correctly, you're using 1 RM-9 for each side/channel of your 2 channel system? Are you then using one of the channels(left or right) for high, and the other for low, on each side?  And if so, how do you get your inputs from your source divided? 
  Just curious.  TIA.

Jeff 

[viny*loco]

thanks Roger!
so if i use the 8 ohm tap I'm not overcharging the tubes?
the time life of the tubes will be the same ?

Vinyl*loco

[viny*loco]

Hi Jeff, yes I'm using that configuration, 2channel system
one RM-9 per channel driving a Mirage M-1 speaker
highs with the EL-34's and lows with KT-88's channel
I bought the RM-9 with that tubes, my friend (who sell me the pair of amps)told me that EL-34 have more quality mids... more detailed...
I don't know if is true...
 
someone could tell me the difference between the KT-88 and EL-34?

Vinyl*loco