• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Rectifier rolling in Eico ST40

Dandy

Dandy

Addicted Member
Inspired by another thread about subs for 5AR4 rectifiers, I did a bit of rectifier rolling in my Eico ST40.

I liked the sound of the 5V4G (in while I'm typing now) and a recently bought 5R4GYB. Both of these give more body to the sound. But as this amp is self biased, I am wondering what voltages to check in case I'm pushing the 7591s too hard. Different value cathode resistors?

Sorry, I should know the theory, but I don't. I'd value advice please.
 
Register to hide this ad
Those rectifiers have larger voltage drops than the 5AR4 (especially the 5R4) so they may be easier on the 7591 tubes when they reach the steady state...but the 5AR4 takes longer to warm up for a nice smooth slow start.

Watch out for some of the rectifiers like the 5U4 that have higher filament current draw (3A vs 2A for the 5AR4).
 
You must log in or register to reply here.
Back
Top Bottom