Is Spatial Audio coming out with more efficient speakers?
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Mark wrote and said he posted something so I thought I would chime in. The amps are push pull 300b monos and are 27 watts/ch. Not your flea watt 300b. It has been a really fun project with Lynn Olson. If you aren’t familiar with Lynn, just google nutshell hifi. Not your traditional push pull with phase split circuits though. A different approach. No feedback. Just a single pair of 300b tubes in each amp. Drivers are 6V6 with 6SN7 input tube. Multiple power supplies in each amp. We have driven 86 dB 4 ohm speakers quite easily with them to screamingly loud levels. They are 27 watts, but seem to have the drive of a 100 watt tube amp. The prototype amps along with their matching preamp will be demonstrated at the Spatial Audio Labs room at the Pacific Audio Fest in Seattle in late June. I have even talked Lynn Olson into coming. Should be fun! No production of anything yet. Hope to get that going in the late summer or fall. Not trying to sell anyone anything here, just letting you all know what is in the works.... Mainly we are just having a lot of fun pushing the envelope a bit. I am slowly trying to retire from production of things to more projects like this one. Trying to see what is possible with a little "outside the box" thinking.
Happy Listening and hope you are all enjoying your stereos!
This sounds like a very exciting venture.
Do you prefer the LampiZator Pacific DAC with preamplifier or direct into the 300b mono blocks?
Best wishes for the upcoming audio show.
My Pacific is XLR out with no volume control so have not tried direct to amps, but I build a really good preamp so I will continue to use it. The prototype preamp is essentially a circuit that was a thought experiment of Lynn’s for a fully balanced design that has been around for years and no one ever really tried to build and perfect it. So we did for this project. Like the amps it is conceptually simple, yet has subtle complexity. It is transformer coupled on both inputs and outputs and uses the same Khozmo 64 step remote attenuator with relay input switching I have been using, but set up as dual mono. This allows me to switch a balanced signal on both channels, plus you get a balance control if you need one. Main tube is 6SN7 and it is transformer coupled to the output with custom wound iron from Dave at Cinemag for just this circuit. I have tried ECC99 and 6H6P with adapters and they also sound good, but I always pick the 6SN7 in a shoot out, so it has octal sockets. The power supply features damper diodes into a CLC and that drives a custom regulated supply which then feeds gas regulator tubes. Because of the output transformer it can easily drive RCA or XLR outputs and headphones. It has no caps in signal path and of course no feedback or anything like that. If you use the preamp xlr outs you can drive the amp input tube grids directly. It has a level of clarity that has to be heard. Quite astounding. The prototype works well and I am working on the "real" one for the Seattle show. Dave’s iron is just superb as it always is and response is dead flat from below 20 Hz to way out there beyond 20KHz. Just having fun and we will see where it all goes. Honestly I have never heard anything like this setup.... fun.
@donsachs I'm curious what is meant by this. We've been working on a fully balanced design since the mid 1980s, which started selling in 1989. Is it the use of transformers in the circuit path?
- 799 posts total