Sanders 10B Electrostatic
Clio09 Is the Sanders a 1 ohm load? If yes, do you know across what part of the musical spectrum? What is your opinion on 200 + WPC tube amps? Say Audio Research REF 250W mono blocks or Atma-Sphere 200W mono blocks? Do you think they are up to task for Sanders? |
Given what is written here: http://www.dagogo.com/sanders-sound-10b-floorstanding-speaker-review a pair of Atma-Sphere M-60's or the previously mentioned Music Reference amps should do the trick. If what I read in the review is correct the bass section of the 10B has it's own amp and electronic crossover. So the tube amp only has to power the panel section. |
I heard the Sanders speaker at this years T.H.E. Show in Irvine, and I've been lusting for a pair ever since---I loved 'em! With Sanders, Ralph Karsten, and Roger Modjeski, you have three very good designers, each of whom will give you a different opinion on an amp suitable for driving them. Sanders can be ruled out for your friend Albert, as he's a SS man. Karsten will of course recommend one of his amps (nothing wrong with that!). As for Modjeski, in his Forum he wrote that the common wisdom of an OTL being a good match with electrostatic loudspeakers is, in actuality, incorrect. Roger has designed OTL's (a really good one manufactured and marketed by Counterpoint in the 80's), and will build you one now. However, he points out that the interaction of the impedance load of an ESL with the high output impedance of an OTL amp makes them very much incompatible. That the legendary pairing of the original Quad with a Futterman or NYAL amp produced wildly inaccurate frequency response, as well as ringing and instability in the amp. I'll bet one reason Sanders would recommend a SS amp is, for one thing, precisely because of their generally low output impedance. |
8-31-15: AlbertporterAlbert, I wrote this before but I don't think anyone read it OR if people read it, they didn't understand. So, I'm writing this again: as far as the power amp is concerned, these ESLs can be modeled as a huge capacitor. This means that at low freq, the load impedance is high. At high freq, the load imp is low. Plus, for a capacitor the current leads the voltage by 90 degrees. This means that current & voltage are not always provided to the speaker at the same time (unlike conventional box speakers or even planar magnetic speakers). This means that the amp can potentially go unstable. How many times have you heard & read that the power amp failed into a high capacitance load? We've even read this for high capacitance speaker cables (like Alpha Goertz). The other thing to note (since these ESLs behave like capacitors) is that these speakers are voltage driven devices (rather than current driven devices like conventional box speakers & planar magnetic speakers). So, the power amp needs to have a very high DC power rail. It's no surprise that both Sanders' amps are 400W/8 Ohms & 500W/8 Ohms where the DC power rails are +/-80VDC & +/-90VDC. And, they also provide a gobs of current. What's happening here is that as the speaker impedance increases at lower freq, any amp would be pushing current into this higher load impedance & the output voltage will rise quickly. If the DC power rail of the power amp is not high, the output voltage will clip & you'll get distortion. A high DC power rail (such a 80VDC or 90VDC) will tend of avoid this output voltage clipping. You were suggesting an ARC REF 250. If this is a 250W/ch, 8 ohms, I calculate the DC rail voltage to be 63VDC. That seems reasonable but I surmise that the output voltage might get close to clipping if the volume is turned up. It's hard to say; best to get a home/dealer audition with these amps. Just a quick calculation: usually the first watt is where most of us listen but I don't know how loud your friend likes to play his music. Suppose that he cranks up the volume such that the amp is outputting 5W into the speaker. If the speaker presents a load of approx 800 Ohms anywhere in the 200Hz-20KHz region (the bass is taken care of by conventional woofer) then the output voltage will hit 63VDC & will clip. Will your friend crank it up to 5W output? Hard to say... I would not go below 250W/ch 8 ohms & try to look for something even higher in wattage (just to get that higher DC power rail voltage). Hope this helps. Thanks. |
