I'm in the process of building a pair of 300B SE monoblocks with 6SL7/6SN7 Aikido front end. These are intended to push a pair of Klipsch rf7. The rf7s have dual binding posts intended for bi-wiring/bi-amping. My original plan was to provide two sets of banana plugs on each amplifier and just tie them together inside the amplifier (effectively biwiring) but then I started pondering bi-amping by simply adding an additional 300B and SE OPT to each monoblock.
The mono Aikido boards provide space for two coupling caps exiting the stage and John Broskie suggests using these for additional outputs (subwoofer amp in, etc.) and the coupling caps could even be spec'd differently creating a crossover network on the preamp output.
So basically, each monoblock would consist of two single ended 300B output stages driven by a single 6SL7/6AS7 Aikido input/driverstage .
Just thought I'd throw this out there and see what kind of response it gets. The two additional OPTs and 300B add a bit of cost to the amplifier, I wonder if bi-amping in this way would be worth the investment?
The mono Aikido boards provide space for two coupling caps exiting the stage and John Broskie suggests using these for additional outputs (subwoofer amp in, etc.) and the coupling caps could even be spec'd differently creating a crossover network on the preamp output.
So basically, each monoblock would consist of two single ended 300B output stages driven by a single 6SL7/6AS7 Aikido input/driverstage .
Just thought I'd throw this out there and see what kind of response it gets. The two additional OPTs and 300B add a bit of cost to the amplifier, I wonder if bi-amping in this way would be worth the investment?
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My two cents
I have been using bi-amped systems for 10+ years with different amps for tweeters and woofers. I use a single preamp with an electronic crossover feeding two power amps.
If you can afford the cost of the crossover and the extra amps the benefits are hard to beat.
Doing what you suggest may be possible. But, by the time you have variable gain on each channel and appropriate crossovers you probably would have been better off going down a more traditional route.
Steve
I have been using bi-amped systems for 10+ years with different amps for tweeters and woofers. I use a single preamp with an electronic crossover feeding two power amps.
If you can afford the cost of the crossover and the extra amps the benefits are hard to beat.
Doing what you suggest may be possible. But, by the time you have variable gain on each channel and appropriate crossovers you probably would have been better off going down a more traditional route.
Steve
Biamping may make sense. Biwiring simply puts a small dip in the speaker response at the crossover frequency, so is a waste of money unless you speaker happens to have a small rise in response at the crossover which needs correcting.
Two 300B will double the loading for the Aikdo driver, which with its CF (like) output should be able to handle it. Make sure good driver tube are used. IMHO, to make it worthwhile, you might want to make sure you have the room acoustic equipment and time to fine tune the setup. (ie: due to small difference in Bi-amp outputs, disconnection of LPF and HPF in the speaker's built in cross over and etc). I found it very hard to do it with my set of ears and not sure I want to trust my cellphone app. One more set of 300B and OPT worth while for 300B are expensive.
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These speakers still have their internal crossovers in play when connected for "bi-wiring". Most others work the same. Some (hopefully very small) advantage comes from removing the woofer's current's modulation of the voltage drop across the upper range's wiring. But would simply doubling the amount of copper and connecting conventionally be as good or better? It might in some cases.
Two more subtle advantages come from your proposed arrangement: the upper-range output stage can use a much smaller coupling capacitor, for faster overload recovery. And the upper and lower range output transformers can each be optimized for their respective gigs - not at all a trivial advantage for the very best performance. Both of these advantages can also be had with a real bi-amp, along with its many other advantages.
All good fortune,
Chris
Two more subtle advantages come from your proposed arrangement: the upper-range output stage can use a much smaller coupling capacitor, for faster overload recovery. And the upper and lower range output transformers can each be optimized for their respective gigs - not at all a trivial advantage for the very best performance. Both of these advantages can also be had with a real bi-amp, along with its many other advantages.
All good fortune,
Chris
Thanks
Thanks to all who have replied thus far. Some excellent points made here. As a few of you have mentioned, getting the crossover points right would be non-trivial. It's also hard to know what exactly is happening with the internal speaker crossover. I think If I were to bi-amp I should probably play it safe and just give both connections a full-range, unfiltered output.
On second thought, rather than committing to what I originally described perhaps I'll just build two pairs of the single tube / OPT variant.
Thanks to all who have replied thus far. Some excellent points made here. As a few of you have mentioned, getting the crossover points right would be non-trivial. It's also hard to know what exactly is happening with the internal speaker crossover. I think If I were to bi-amp I should probably play it safe and just give both connections a full-range, unfiltered output.
On second thought, rather than committing to what I originally described perhaps I'll just build two pairs of the single tube / OPT variant.
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