trinityamps.com

Trinity Amps Guitar Amp Forum
It is currently Sat Dec 04, 2021 9:17 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 3 posts ] 
Author Message
PostPosted: Fri Jul 30, 2021 10:10 pm 
Offline
Friend
Friend

Joined: Mon Feb 10, 2020 12:30 am
Posts: 11
Hey there folks!
I am attempting a few mods on the TC 15 and hope you can help.

I am using the Ef86 into the V3 stage and tonestack. I have the bottom (inverting side) of the PI grounded before C8

I am taking the Ef86 out from pin 6 into the input of C1. There is a lot more gain than is practical from the EF86.

I believe, and perhaps you could confirm that I need to add the 470k AC load resistor below the treble bleed cap C3

I am hoping to make the amp behave like my old Bad Cat Cub III
I will use the V2 stage for a dumbulator, and try Merlins Squish control next.

Big Thanks!


Top
 Profile  
 
PostPosted: Fri Jul 30, 2021 10:33 pm 
Offline
Friend
Friend

Joined: Mon Feb 10, 2020 12:30 am
Posts: 11
https://www.ampbooks.com/mobile/classic-circuits/matchless-pentode/
Here is a detailed look at the Ef86 circuit

I tried the load resistor and it helped greatly! The gain is a little hotter than I like, so I will go back to the stock values for r33 and r34 and try to tame it down a little.

Maybe this will save someone some nasty harsh toneā€¦. Without the load resistor the amp sounded more like a Chinese ac15 than a matchless.


Top
 Profile  
 
PostPosted: Sat Jul 31, 2021 12:41 pm 
Offline
Friend
Friend

Joined: Mon Feb 10, 2020 12:30 am
Posts: 11
I did the squish/morph mod using the spare 1meg pot. It really helped tame the gain and harshness and adds a nice compression. Photo is from the discussion on the 18watt forum.

Attachment:
C44C9001-E225-441B-BC60-3667A6837154.png
C44C9001-E225-441B-BC60-3667A6837154.png [ 1.08 MiB | Viewed 2766 times ]


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 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