laatsch55
Super Member
Przem, if you can go with the MJ21195,96 pairs, much more robust , plus they are a dedicated audio output much quieter than the GP 15024,25 pairs.
As Don has said bias is critical when driving difficult loads. 3 ohms is not a deal breaker, but you will have to force cool it. Two things that will affect the heat, bias AND Hi freq oscillations. The oscillations are the silent killer. If you don't have a scope it's extremely hard to detect, you may feel them in the chassis or not, depends. What does your Zoebel network look like??
On the bias transistor, try a 2N5088 in place of the BC. The 5088 has better resolution and range and seems to react a lot faster to heatsink temp changes.
As Don has said bias is critical when driving difficult loads. 3 ohms is not a deal breaker, but you will have to force cool it. Two things that will affect the heat, bias AND Hi freq oscillations. The oscillations are the silent killer. If you don't have a scope it's extremely hard to detect, you may feel them in the chassis or not, depends. What does your Zoebel network look like??
On the bias transistor, try a 2N5088 in place of the BC. The 5088 has better resolution and range and seems to react a lot faster to heatsink temp changes.