trinityamps.com

Trinity Amps Guitar Amp Forum
It is currently Thu Mar 28, 2024 7:09 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Fri Dec 21, 2018 6:07 pm 
Offline
Experienced
Experienced

Joined: Wed Sep 12, 2018 5:17 pm
Posts: 374
Location: Shawnee, OK
Completed install of VRM in Trinity Tweed and there was a lot more hiss (at high volume and when the tone control is turned up) :bugeye: than before (some, but not objectionable) :) . VRM was installed per layout with 1M resistors on pin 2 and 7 of V1. Also there is a 1M resistor on each of the inputs per layout. Sooo, 1) Are the 1M's necessary/required in both positions (inputs and V1)? 2) What do the 1M's do on V1?

Also read in documentation that replacing carbon comp resistors w/ Metal Film will help tame the hiss. I don't want to go overboard with the MF resistors. Should I replace the 820R cathode(?) or the 2 100K plate(?) resistors or all three? And will Carbon Film's do the trick (have those in 100K; the 820R will need to be ordered if needed)?

Thanks for any additional information provided.

Edit: Reread the VRM docs and it answered most questions. The 8-16 uF 450V capacitor is added between HVIN terminal and power ground, this is correct? And regarding the resistors to the plate, good/bad idea? :hmmm:

_________________
"The only problem with being retired is you never get a day off"


Top
 Profile  
 
PostPosted: Wed Jan 02, 2019 1:18 pm 
Offline
Friend
Friend

Joined: Wed Sep 19, 2018 12:47 pm
Posts: 21
My install was on a TC-15 so maybe different but...
I did take the resistors off of the input jacks.
My instructions said something like "move the 1M resistors from the input jacks to the grid."
And I do believe Stephen said something to me about a hum if you don't make this move
So I don't have the 1M resistors in both places.


Top
 Profile  
 
PostPosted: Wed Jan 02, 2019 11:35 pm 
Offline
Experienced
Experienced

Joined: Wed Sep 12, 2018 5:17 pm
Posts: 374
Location: Shawnee, OK
Thanks for the reply! PS Were you on the AX84 forums? I joined AX84 ,but haven't kept up for about 10 years. Work interfered, but retired now. Back to fun!

_________________
"The only problem with being retired is you never get a day off"


Top
 Profile  
 
PostPosted: Thu Jan 03, 2019 3:21 pm 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7519
Location: Canada
1M should be on the tube if you have a VRM installed. Not in both places.

Read the section called "Introduction to Vacuum Tubes and Common Terms" in our manual. It will tell you what the resistors do.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps


Top
 Profile  
 
PostPosted: Thu Jan 03, 2019 6:28 pm 
Offline
Experienced
Experienced

Joined: Wed Sep 12, 2018 5:17 pm
Posts: 374
Location: Shawnee, OK
Stephen, thanks for the definitive reply on my VRM question! I built the Tweed first and added the VRM after the Tweed was running and playing REALLY well. Will make a note in build docs so I won't repeat this mistake again.

_________________
"The only problem with being retired is you never get a day off"


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group