The model 12 is a dual mono version of the Model 10. Inside are no differences that I am aware of except that all circuitry is doubled up and divided over 4 chassis instead of 2. The model 10, 12 and 112 were the first amps in which the new LM3886 IC's were used in place of bipolar transistors. These IC's not only carry out the amplification but also allow extremely accurate bias and temperature control and also occupy very little circuit “real estate,” dramatically reducing capacitive and dielectric storage effects, as well as simplifying the overall signal path.
Also novel is the application of a so called Power Buss in which positive and negative DC current is transferred to each output device by dual polarity. Within these buss bars, opposite phases are carried side by side, the two signal halves separated by a tiny 9 mil insulator. These bars can be easily identified as the bright red/orange metal bars running across the inside of the amp. One common question is whether the output section of the amplifier is biased into Class-A operation. Technically, the answer is “yes,” as the exceptional linearity of the output section design achieves the advantages of pure Class-A operation. Using the “Intelligent Power Transistor with Gain” system keeps the output section properly biased at all times to eliminate crossover distortion caused by the output transistors during turn-on and turn-off.
Although I haven't heard the 112, I still have a pretty good idea of what it should sound like as my Model 10's switched power supply broke down and no matter what the importer tried, couldn't be fixed. In the end the amp went back to Jeff Rowland after which the man himself installed a linear power supply in place of the problematic switched one. The inporter first didn't tell me but I immediately noticed the difference in weight when I lifted the power supply. And it wasn't only the weight that had changed: the sound was also completely different. I wouldn't say worse, but comletely transformed nevertheless. At the time I had a problematic room and very early B&W N804's that had slow and boomy bass. The original Model 10 was perfect in tightening the bass andf providing a nice speedy and rhythmic sound. The modified Model 10 sounded much more like the early Rowland amps: full, warm, colourful and a bit thick and slow in the bass. Although I now found the amp more natural sounding and in fact amazing with symphonical music, I found the rhythm, drive and speed seriously impaired so I returned the amp. After that I got Model sixes and they were again at least as speedy as the Model 10 was and even more rhythmic, with the added benefit of greater dynamics and more involvement while maintaining fluidity and smoothness as well as the sublime soundstage layering.
Model 12
1999-2004
new 21990 euro
Mystery model
The rear panel of this mystery model is interesting because both model 10 and 12 have the IEC power inlet on the power supply unit, not on the same unit that houses the amplification. Also it was the 20 amp version, not the 16 amp version as pictured.
The inside picture is interesting because the model 10 never had a linear power supply. The 112 does, but there it is situated on the other side.
The model 10 is the stereo version of the Model 12. Inside are no differences that I am aware of except that all circuitry is halved and divided over 2 chassis instead of 4. The model 10, 12 and 112 were the first amps in which the new LM3886 IC's were used in place of bipolar transistors. These IC's not only carry out the amplification but also allow extremely accurate bias and temperature control and also occupy very little circuit “real estate,” dramatically reducing capacitive and dielectric storage effects, as well as simplifying the overall signal path. Also novel is the application of a so called Power Buss in which positive and negative DC current is transferred to each output device by dual polarity. Within these buss bars, opposite phases are carried side by side, the two signal halves separated by a tiny 9 mil insulator. These bars can be easily identified as the bright red/orange metal bars running across the inside of the amp. One common question is whether the output section of the amplifier is biased into Class-A operation. Technically, the answer is “yes,” as the exceptional linearity of the output section design achieves the advantages of pure Class-A operation. Using the “Intelligent Power Transistor with Gain” system keeps the output section properly biased at all times to eliminate crossover distortion caused by the output transistors during turn-on and turn-off.
The model 10 I owned was sonically a mixed bag. I loved its fluid, velvety highs and nimble bass. But somehow it always sounded unrhythmic. Although it was fast and accurate, it was also rounded off in a sense, giving a slow impression even though strictly speaking it was fast. No matter how many cables or components I swapped it would just not come to terms with my B&W N804's. These speakers are not the fastest guns around, nor are they easy to drive, but when I later bought the model sixes, all was immediately solved. Now the sound was quick, fast, dynamic. But luckily the Rowland magic was retained. In conclusion I feel that the model 10 is somewhat of an exception in the rowland line of amplifiers, sounding offbeat somehow. It may or may not be coincidence that it was phased out after being sold for only a couple of years.
Model 112
1999-2011
New 7490 euro
A simplified version of the model 10 in which the switched power supply has been replaced by a linear power supply (toroid transformer and capacitors). The model 112 was amongst the first amps in which the new LM3886 IC's were used in place of bipolar transistors. These IC's not only carry out the amplification but also allow extremely accurate bias and temperature control and also occupy very little circuit “real estate,” dramatically reducing capacitive and dielectric storage effects, as well as simplifying the overall signal path. Also novel is the application of a so called Power Buss in which positive and negative DC current is transferred to each output device by dual polarity. Within these buss bars, opposite phases are carried side by side, the two signal halves separated by a tiny 9 mil insulator. These bars can be easily identified as the bright red/orange metal bars running across the inside of the amp. One common question is whether the output section of the amplifier is biased into Class-A operation. Technically, the answer is “yes,” as the exceptional linearity of the output section design achieves the advantages of pure Class-A operation. Using the “Intelligent Power Transistor with Gain” system keeps the output section properly biased at all times to eliminate crossover distortion caused by the output transistors during turn-on and turn-off.
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Model 10, 12 and 112
Model 10
1999-2004
new 10990 euro
used approx 3000 euro
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