Forumsee logo
Forumsee » Consumer Electronics » Home Audio & Video » Read message
RSS: Subscribe to RSS

How much ripple in B+ and other supplies?

Tube Audio | Audiokarma Home Audio Stereo Discussion Forums - audiokarma.org
I am trying to isolate a 60hz hum issue in a Eico ST-70. I have replaced all of the electrolytics, coupling caps, I have even tried a new rectifier tube. I have verified all of the wiring is correct. I am seeing about 23VRMS ripple on the DC supplies. I know the electrolytics are low values as far as filter caps go. I used the JJ cans and I even pulled them back out of circuit to make sure nothing had gone bad. What I am seeing is DC supplies W and Y have higher voltages than they should have where Y should be 230 and W should be 165 but I am seeing 275 and 274 respectively. Y supplies the pre-amp stage and W supplies the line amp stage. If I remove W from the line amp stage I don't hear near as much hum. I not using any input signal. I have checked and checked and checked and to be honest I am starting to get frustrated because I cannot figure it out. Bob provided good advice over in Eico Place and I hope I don't wear out my welcome on here trying o get to the bottom of this. There are no open plate resistors on any of the tubes so why the higher voltages? I know these supplies are being loaded. What am I missing? I have worked on this late every night this week. Thanks for any help I can get.

 
Date: Jan 13, 2018   


Last videos:

When History repeats in Video
When History repeats in Video
Happy on SYFY
Happy on SYFY
apple fired a engineer
apple fired a engineer
How Sony TV's are made
How Sony TV's are made
Life Videos Youtube
Life Videos Youtube
Songs that ROCK--give us the vid
Songs that ROCK--give us the vid
New Dirac enabled Lexicon AVRs
New Dirac enabled Lexicon AVRs
Gotta respect CRTs
Gotta respect CRTs
Cars · 
Mobility · 
Hardware · 
Motorbikes · 
Travel · 
Boating · 
Aviation · 
About Forumsee · Contact · Privacy policy · Request content removal
production-frontend
We use cookies for navigation analysis and personalized advertisement. By using our site, you agree to our use of cookies.
Accept  ·  Learn more