Paulfolbrecht.
Thanks for the response. I've read conflicting reports on the 845Bs. Some are specified at 100 W dissipation, and some state more than 70W dissipation. As far as sound quality, IMHO the 845B sounds somewhat dirty compared to the 845M or the Cetron 845s I once owned.
I've spoken to Cary about this issue, and they claim that when you bias the 300B at 60MA, that the 845 has 100MA plate current with 950 Volts plate voltage. That equates to 95W dissipation. Strikes me as odd that a manufacturer would set up the amp to run so close to maximum dissipation as variations in line voltage or tolerance on parts values could easily push the amp beyond the maximum.
In addition, no one at Cary can tell me what happens to the plate current on the 845 if the 300B is biased at something less than 60MA. To me, it seems a poor design when you cannot bias the 845 directly so you don't ever know exactly what the dissipation is.
I was hoping that someone with Cary 805s might have had experience with some of the newer 845s such as the Sophia or the Psvane, and if so, where have they set the bias on the 300B?
Dean
Thanks for the response. I've read conflicting reports on the 845Bs. Some are specified at 100 W dissipation, and some state more than 70W dissipation. As far as sound quality, IMHO the 845B sounds somewhat dirty compared to the 845M or the Cetron 845s I once owned.
I've spoken to Cary about this issue, and they claim that when you bias the 300B at 60MA, that the 845 has 100MA plate current with 950 Volts plate voltage. That equates to 95W dissipation. Strikes me as odd that a manufacturer would set up the amp to run so close to maximum dissipation as variations in line voltage or tolerance on parts values could easily push the amp beyond the maximum.
In addition, no one at Cary can tell me what happens to the plate current on the 845 if the 300B is biased at something less than 60MA. To me, it seems a poor design when you cannot bias the 845 directly so you don't ever know exactly what the dissipation is.
I was hoping that someone with Cary 805s might have had experience with some of the newer 845s such as the Sophia or the Psvane, and if so, where have they set the bias on the 300B?
Dean