Tube amps for hi end on passive bi amped RS2.5

[Takoda]

I am bi amping passively with a Yamaha M80 on the bottom and a Phase Linear 300 series2 amp. The preamp is a Phase Linear 3000 series2. (Both the Phase Linear amp and pre were the first things I bought on credit after getting out of high school.) I like the sound I am getting but think it could get better with better amp and preamp. I have used just the Yamaha without the preamp but like the sound better with the PL products. I would like to get a new amp/s for the high end first and see what improvements I get. I have not tried tube amps with speakers like these. The tube amp I used was with Avantgarde Uno speakers and an 8 w/ch triode amp. I read all the time that tube power is different than solid state power and you can get by with lesser powered tube amps. Any information would be helpful especially if you actually have experience with the amp you suggest and these or similar speakers.

 

[whoaru99]

In a passive biamp like that the smallest amp becomes the limit of the system. So, if you can get by with what the smaller amp brings to the table it will work.

Ideally the two amps used would both have gain/level controls so that you can balance the ratio lows to mid/high.

And, no, tube watts are not different unless you count on those with extra distortion.

 

[slimpikkins]

You can also make a high pass to go in between the preamp and high end amp so that amp does not see as much of the low frequencies. This is what I do when running tubes on the top end. If you want I could hunt down a link for the formula for that. You will need to know your amps input impedance. Just takes some male/female rca plugs and a few non polar capacitors.

In my experience besides speakers the pre amp and source will effect what the end results more than an amplifier providing everything is working properly. May want to try (burrow from a friend if you can) a tube preamp or line stage if no phono is needed.

 

[Takoda]

You can also make a high pass to go in between the preamp and high end amp so that amp does not see as much of the low frequencies. This is what I do when running tubes on the top end. If you want I could hunt down a link for the formula for that. You will need to know your amps input impedance. Just takes some male/female rca plugs and a few non polar capacitors.

In my experience besides speakers the pre amp and source will effect what the end results more than an amplifier providing everything is working properly. May want to try (burrow from a friend if you can) a tube preamp or line stage if no phono is needed.

Thanks for the reply Slimpikkins, that would be very much appreciated if you could lead me to that link.

My sources are a Cary 306/200 cd and Clearaudio Performance turntable. In Missoula Montana there are not many people that have gear like that (at least people I know) that’s why Im hoping to get opinions from people that have used tube amps even if not biamped.

 

[Takoda]

In a passive biamp like that the smallest amp becomes the limit of the system. So, if you can get by with what the smaller amp brings to the table it will work.

Ideally the two amps used would both have gain/level controls so that you can balance the ratio lows to mid/high.

And, no, tube watts are not different unless you count on those with extra distortion.

Thanks for responding Whoareu99. From what I have read about these speakers the Watkins dual voice coil woofer gives a load under 2ohms that is why the Yamaha amp is driving those and it does have gain control. What is the least watts/channel you would use for top end on these speakers.

 

[whoaru99]

That's a tough call. It really depends on your desired peak listening level.

Without knowing the sensitivity, even making some predictions for actual required power is speculative.

I think Infinity recommended minimum of 100 watts for these speakers. For passive biamp that usually implies both amps are same power. Again, smaller amp can/will work as long as long as they are of a size that can support your output/crankability needs.

 

[slimpikkins]

Here's that link for the high pass calculator. https://www.the12volt.com/caraudio/crosscalc.asp#cc Just type in your input impedance and frequency. Use 1st order 6db per octave. Say your amp has an input impedance of 60kohm and you want to roll off at 80htz you get a c1 of .033. Put that in line with your high frequency amp and the preamp and there you have it, less stress on your amp...I am no expert on all this but it does work. I got the idea from owning a Vandersteen sub woofer which sort of takes this approach.

I made a bunch of them up for biamping the RSIIb. Pretty cheap to make a few up then once you find the setup you like best you can make a real nice pair with better caps.

 

[Takoda]

Here's that link for the high pass calculator. https://www.the12volt.com/caraudio/crosscalc.asp#cc Just type in your input impedance and frequency. Use 1st order 6db per octave. Say your amp has an input impedance of 60kohm and you want to roll off at 80htz you get a c1 of .033. Put that in line with your high frequency amp and the preamp and there you have it, less stress on your amp...I am no expert on all this but it does work. I got the idea from owning a Vandersteen sub woofer which sort of takes this approach.

I made a bunch of them up for biamping the RSIIb. Pretty cheap to make a few up then once you find the setup you like best you can make a real nice pair with better caps.

Thanks slimpikkins for that link I like that better than putting in an electronic cover.