Netexpress,
300B, PX/4 or 45 tubes are designated for various incarnations the Cabernet and Grange. These tubes are not to be used with the Syrah. Your instruction manual that was supplied with your syrah will outline the tubes that will work with the Syrah.
What is your budget for retubing?
6f6gt works quite well in the regulator position. NOS tube rolling in the line stage has been described this thread.
300B, PX/4 or 45 tubes are designated for various incarnations the Cabernet and Grange. These tubes are not to be used with the Syrah. Your instruction manual that was supplied with your syrah will outline the tubes that will work with the Syrah.
What is your budget for retubing?
6f6gt works quite well in the regulator position. NOS tube rolling in the line stage has been described this thread.