dpm309 wrote:
I happen to have a Hammond 125E laying around and was thinking of using it for the OT. I was looking at several posts on the 18watt site and the general opinion was that the 125E would work without losing any appreciable sound quality. Has anyone tried a 125E on a Lightning? I am trying to save some $ and I could replace the OT in the future if necessary. Also, would I have to drop the voltage on the 272DX PT (300-0-300) if I use the 5AR4 rectifier? Would a 5U4G be a better choice?
We tested Hammond transformers in the past and found their sonic quality to be lacking. You can use an 8K PP OT and get the amp to work, but be prepared to put in a better OT in order to get the best quality sound.
As far as PT goes, you need to drop that AC/DC voltage. 290-0-290 is the max recommended with that circuit and the EL84s are already at max. You can use a less efficient Rect tube but I think only the 5Y3 would drop enough. Keep in mind, the rectifier current maybe up to 3A.
You can use our VRM to drop the DC, or a simple Zener Voltage Dumper from CT to ground to do the same within reason (i.e. no more than 25V drop). viewtopic.php?f=12&t=3218