Biamping Question

Thanks for the responses everyone. I much prefer the passive biamping approach based on the information so far.

Jsadurni,

I am using Spendor 1/2e speakers. Sensitivity is 88db and nominal impdedance is 8 ohms. The tube amp has adjustable gain: 27db (1.2V input sensitivity, 0.7db damping, 19db feedback), 32db (0.8V input sensitivity, 1.5db damping, 14db feedback), and 36db (0.4V input sensitivity, 2.5db damping, 10db feedback). The solid state is I believe somewhere in the 30 - 37db range for gain, 0.8V input sensitivity, and zero negative feedback.

I have tried the tube amp alone and even with a passive preamp (K&K TVC) the high and medium gain settings don't let me get too far up the volume control (9 - 10 o'clock) before the sound is too loud. The low gain is most flexible, but also has the most feedback which I would prefer to keep at a minimum. The designer prefers the medium gain setting. The solid state lets me get a couple more clicks in, to around 11 - 12 o'clock.

I do have a pair of EVS Nude attenuators lying around I can also employ if this would help me balance the gain in the amps. How would I go about employing the attenuators and how could I tell if I achieved the right balance. I'm considering sending my TRL D-225 back so I can have an input volume control added to it, but that would only be as a last resort.

Thanks

Hello Clio09,

I guess the simplest thing (if you havent tried it yet) would be to put the tube amp on the medium gain setting which is the same gain as your SS amp and just connect them to your preamp output with a Y connector, speaker cable of the tubes to the highs and SS to the lows...
How does it sound?

If they dont match...too many highs for instance try lowering the input sensitivity on the tube amp again to 0.4V setting....and viceversa.
If you need some fine tunning then use the attenuators, here´s a couple of links that can help with the instalation of these.

http://www.nutshellhifi.com/dact-apps.html
http://www.10audio.com/passive_pre.htm

Once you have a good setting with the attenuators you can put good quality resitors of the same value you settled on and just enjoy..... Audiophile accepted solution if you use Caddock or Vishay!

I am worried about biamping though since the Xover point of your speakers is pretty high, 3 Khz its like your speakers have 2 tweeters (they should be very resolving on mids), usually it is best to biamp at lower frequencies, say 100hz to 800hz, but do give it a try!!!

If you get away with it your system will have beautifull ease and power...

Cheers

Jsadurni,

Thanks for the information and links. Yes the Spendors are well known for the midrange. The EVS attenuators use a 10K nude Vishay. I also have a pair of Endler attenuators that use a 4k Yageo resistor. I can hook these up to the inputs of the of the tube amp to attenuate any excess gain. It should at least give me an idea if biamping will work.

both amps need to have the same sensitivity for output or one section of the speaker will play louder that the other .usually when people biamp it is with the same amp