Orpheans, Oris, Quasars and Amps (BD-Design)

by Cappy , Tuesday, November 27, 2007, 19:56 (5994 days ago) @ RichardofOz
edited by unknown, Tuesday, November 27, 2007, 22:55

As others mentioned, number of watts really isn’t the important thing to consider, once you get over a certain threshold that “lights things up”. I suppose too many watts is not optimum either, like over 40 or so, because then it becomes harder to access the all-important “first watt” in a good way. In my observations bass and lower midrange can in many cases lack density and drive if using less than about 5 watts.

What you want to pay attention to is:
1) System noise
2) System gain

Notice I said “system” and not just “amplifier”.

As far as amplifiers, I have a very high gain pentode input Lux 300b amp that is less noisy than my 1.8 watt 45 based amps. So amplifier noise needs to be looked at on a case by case basis.

The gain of the amplifier needs to be matched to the rest of the system. Some source components have high gain, others lower gain. It can be helpful to have lower gain components when using the Orpheans. But it all depends on amp and preamp gain. I have another amp, 2.5 watts using 13em7 tubes, which only has 12db of gain, and it works great with higher output sources using the Orphean. I could even stick an active preamp in the system and things would be good, maybe better.

By the way, on the subject of preamp, like Bert, I’d recommend a TVC: no gain, sounds good. You really don’t want extra gain in the preamp with horns in almost all cases. And going back to 1), active preamps add noise.

My phono stage puts out 0.65 peak volts with my current cartridge. The Twindac, to give another example, I believe puts out 0.8 volts. It's gain is a good match for a lot of amps with Orphean or Oris Horns. Standard CD output is 2 volts.

The large size of your room will also absorb some of that higher efficiency, so to speak. Also, in that size room the Ultras will stress your bass system less. I have a pretty large volume room, with additional attached rooms in open plan. I have the Compact bass, which sounds deep, detailed, explosive, and strong, but I can see where more headroom would be even better.

So in general, with your large room, and as long as you have a passive preamp, in most amplifier cases you are going to be fine with the Orpheans. Bert’s LD300bs, for example, are 1.5 volt input sensitivity, and would be a good choice. After all, he designed the Orpheans using them as a baseline.

Pentode input/driver DHT amps are a fabulous match with the Orpheans. However, if you go that route, with the higher gain of pentodes, you are going to have to watch your source gain carefully. Standard 2 volt CD output might not give you enough clicks on the volume dial.

Tags:
0