trinityamps.com

Trinity Amps Guitar Amp Forum
It is currently Sun Sep 20, 2020 8:57 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: VRM in my TWeed
PostPosted: Sat May 02, 2020 1:08 pm 
Offline
Friend
Friend

Joined: Mon Apr 27, 2020 1:06 pm
Posts: 14
Down to the wire! I have this done except for the VRM. I read a post saying something to the effect of “...you have an amp to build and test before you worry about things like that.” Hmmmm...what does THAT mean? Anyway, I had it in my head that the unit mounted complete in place of the stand by switch and so I have both the pot and the MOFSET soldered to the little pcb board. Then I read that I need the metal to metal contact to efficiently sink away the heat it creates. Hmmm....again? Steel better than air for dissipating heat? I’ll be googling that I thought. I wonder? They didn’t say that for no reason... So, long story longer...can I mount the VRM with the pot as I have it now or should I disassemble it and start over? There are components to add on the board to support it if I do and leads (I think) in their place if I don’t. This is the last thing to do for me I think. Thx again.


Top
 Profile  
 
 Post subject: Re: VRM in my TWeed
PostPosted: Sat May 02, 2020 2:44 pm 
Offline
Expert
Expert

Joined: Sat Dec 04, 2010 3:42 pm
Posts: 509
Location: Qualicum Beach, BC
I assume you have read the VRM builder's guide.
https://www.trinityamps.com/docs/VRMBuildersGuide3.pdf

I have never installed a Trinity VRM, but according to the builder's guide, in a Tweed amp you mount the MOSFET on the side of the chassis, external to the VRM board, and run wires between the two. Also a couple of additional capacitors are needed at the amp's inputs.

Yes, steel is better than air for dissipating the heat that the MOSFET can generate. Don't forget to place the insulating pad between the MOSFET and the chassis. This is needed to electrically isolate the MOSFET from the grounded chassis because one of its terminals is also exposed at the back of the MOSFET.

The VRM circuit is a simple one, but it has caused problems for several kit builders. That's why it's better to have the amp working properly before you install anything that messes with the B+. That way if you run into a problem, you know it's just the VRM causing it and nothing to do with the rest of the amp.


Top
 Profile  
 
 Post subject: Re: VRM in my TWeed
PostPosted: Sat May 02, 2020 3:07 pm 
Offline
Friend
Friend

Joined: Mon Apr 27, 2020 1:06 pm
Posts: 14
In “The Builder’s Guide” I see on pg 44 on the board diagram 2 caps for the VRM should they be needed in the …… fashion to indicate “possible” or perhaps “underneath”. Let’s ck the “underneath”...pg 43. No leads there. Hmmm.... Curious. Back to “The Builder’s Guide” Here online I see a ton of these circuits without metal heat sinks but I don’t trust them. Inside of an amp is pretty hot. If air would do the job it would be designed so in the schematic. Of course. Retired engineer...


Top
 Profile  
 
 Post subject: Re: VRM in my TWeed
PostPosted: Sat May 02, 2020 3:10 pm 
Offline
Friend
Friend

Joined: Mon Apr 27, 2020 1:06 pm
Posts: 14
I see the leads on the colour schematic here as well.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


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