I have, essentially, both. The DR-2 was Classe's first product. The DR-2 uses Motorola power Darlington transistors on the outputs and no driver transistors. The DR-3 uses Motorola power transistors with drivers. The DR-2 has regular 5-way binding posts while the DR-3 has monsterous silver or gold plated connectors that will accept bare wire or spades only. The DR-2 & DR-3 have big, thick bus bars for grounding, and both amps are dual-mono and bridgeable. The DR-2 is a simple, elegant circuit with a minimal amount of capacitor bypassing and tantalum input coupling caps. The DR-3 has alot of capacitor bypassing and film input coupling caps. The DR-3 is an all-out high-end design; there is nothing in the design and construction that has not been scrutinized and overbuilt. The DR-2 is a bit more humble, but still extremely well designed and well built.
Sound-wise, I can't exactly speak for the DR-2, but I can come close: The DR-2, like all of Dave Reich's designs, has a very natural, yet highly accurate sound. There is a touch of warmth, but not like tubes. The sound is extremely balanced with no frequency range standing out any more than another. The DR-3 has similar characteristics, but with even more detail and resolution. It is my opinion that the DR-3 does not have the same bass as the 2. The DR-3's bass is very relaxed and effortless, but seems a touch slow. I once described the DR-25's bass as "oozing out of the speakers with no sense of urgency", and I might describe the DR-3 the same way.
Now, please take my words with a grain of salt. I have never actually heard a DR-2, but I do own and use it's predecessor, the Eleson PCA-100. This looks exactly like a DR-2/3 without the big, engraved faceplate. This amp is the reason Classe came to be (Class A - Classe, get it?). There is no available schematic for the DR-2, but I recently found a picture of the inside of a DR-2 that confirms that the Eleson and Classe circuits are the same. The only major remaining difference between my Eleson and the DR-2 may be the transformers. FWIW, Dave Reich said that the Eleson could be considered a DR-1 when I spoke to him last October :-)
I purchased an early DR-3 (there was also a DR-3B) just last weekend, so I'm still comparing the two amplifiers. I'm presently using a pair of dynamic monitors (I have no planars or 'stats) so I do not have the full frequency range of larger speakers. I am also using a DR-5 preamp.
FWIW, I noticed that both of these amps have a high DC turn-on transient that will push your drivers out as far as they can go! I recommend being careful with smaller speakers as these amps can vaporize your vioce coils in a fraction of a second (ask me how I know). Also, these amps run hot - they're burning over 150 watts per channel at all times. Keep the amp ventilated, but do not use forced-air (fan) to cool the amp.
Cheers,
-JamesW-
Sound-wise, I can't exactly speak for the DR-2, but I can come close: The DR-2, like all of Dave Reich's designs, has a very natural, yet highly accurate sound. There is a touch of warmth, but not like tubes. The sound is extremely balanced with no frequency range standing out any more than another. The DR-3 has similar characteristics, but with even more detail and resolution. It is my opinion that the DR-3 does not have the same bass as the 2. The DR-3's bass is very relaxed and effortless, but seems a touch slow. I once described the DR-25's bass as "oozing out of the speakers with no sense of urgency", and I might describe the DR-3 the same way.
Now, please take my words with a grain of salt. I have never actually heard a DR-2, but I do own and use it's predecessor, the Eleson PCA-100. This looks exactly like a DR-2/3 without the big, engraved faceplate. This amp is the reason Classe came to be (Class A - Classe, get it?). There is no available schematic for the DR-2, but I recently found a picture of the inside of a DR-2 that confirms that the Eleson and Classe circuits are the same. The only major remaining difference between my Eleson and the DR-2 may be the transformers. FWIW, Dave Reich said that the Eleson could be considered a DR-1 when I spoke to him last October :-)
I purchased an early DR-3 (there was also a DR-3B) just last weekend, so I'm still comparing the two amplifiers. I'm presently using a pair of dynamic monitors (I have no planars or 'stats) so I do not have the full frequency range of larger speakers. I am also using a DR-5 preamp.
FWIW, I noticed that both of these amps have a high DC turn-on transient that will push your drivers out as far as they can go! I recommend being careful with smaller speakers as these amps can vaporize your vioce coils in a fraction of a second (ask me how I know). Also, these amps run hot - they're burning over 150 watts per channel at all times. Keep the amp ventilated, but do not use forced-air (fan) to cool the amp.
Cheers,
-JamesW-