01-20-11: Pani
3. Symphonic line amplifiers are extremely conservative in their ratings. They put out loads of current. My amp is a full dual mono design with a current capability of 60 amps per channel and stable to 1 ohm. It is class A/B but is biased high in class A mode. It is possible that you may not have come across this German amp because they are not popular in US.
Pani, the info written by you re. the RG1 Mk4 is not correct. The RG1 Mk4 is a 130W/ch amplifier, it is a strictly class-AB design & it is not "biased high in class-A mode" - the heatsinks of that size simply do not support that kind of thermal dissipation. Further, your amp uses 350VA-400VA transformers with something like 32-35VAC secondaries. Thus, these transformers are able to support only 12.5Amps of current. There are 3 BJTs for push & 3 for pull. So, your amp is limited in how hard a speaker load it can drive. It might very well be sufficient for your needs but it is not outputting 60Amps of current per channel! You would smoke those output transistors as you'd stray out of their SOA + the power transformers cannot support that sort of current.
Also, the RG1 Mk4 is not stable into 1-Ohm. It is certainly not cited by the manuf & I know this to be a fact! Where did you make up this info??
The RG1 Mk4 is an entry-level power amp. A very good entry level product but do not bloat its capabilities to what they are not. Thanks.
And, the Symphonic Line of power amps are reasonably well-known in the USA - more than what you would normally think.