Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

RE: 5R4GY and filter cap values




I saw in your system description that you're using a pair of Motorola HS-619 mono's, so I'll assume that these are the amps in question. I did a quick search and found a schematic online that shows the amp to have a current draw of 90 mA and the voltage at the input of the filter as being 345V.

Based on these figures I ran a PSUD sim which shows that the peak current per cycle (peak repetitive) to be 350 mA using a 47uF cap at the input to the filter. This is well within the 5R4GY's safe operation envelope, since both current and B+ voltage are on the lowish side for this amp. As I had indicated in my previous post the max steady-state peak current for this tube is 650mA.

As a comparison, changing the first cap to 4uF reduces the peak current to 311mA - not that big of a drop, but also reduces the B+ at the output of the filter to 332V vs. 344V in the case of the 47uF cap, all else being equal. Hope this helps.



Edits: 03/21/17 03/21/17

This post is made possible by the generous support of people like you and our sponsors:
  Amplified Parts  


Follow Ups Full Thread
Follow Ups

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.