trinityamps.com

Trinity Amps Guitar Amp Forum
It is currently Wed Jul 17, 2019 9:33 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 11 posts ] 
Author Message
 Post subject: Triwatt build
PostPosted: Mon Apr 29, 2019 11:56 am 
Offline

Joined: Sun Feb 03, 2019 12:59 pm
Posts: 2
I have now finished my Triwatt build and it sounds fantastic!
But I have problems with hum/buzz from V2 induced by the OD relay board.
Apart from this the amp is very quiet and the noise floor very low but the hum is louder than I think it have to be.

I have performed the following tests:
1. disconnected the 6.3 V AC heater cables from the OD PCB and powered the OD board from a 9V battery. Result same hum level as when powered from the heater supply.

2. When battery powered grounded the OD board. All hum disappears! A very low hum can be heard on full volume, same as with no OD board installed.

Conclusion:
The OD board needs some form of ground reference. But how to do this when it is powered from the heater supply?
When the OD board is not grounded the whole board acts as an antenna for hum and the cables to the front panel OD-switch are very sensitive. Whit the card grounded this is not a problem and you can touche all cables without inducing hum.

Any tips what to do? Is it verified that the new OD-board works without inducing hum?

/Bjorn


Attachments:
Triwatt.jpg
Triwatt.jpg [ 4.63 MiB | Viewed 1042 times ]
Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Tue Apr 30, 2019 8:18 am 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
Give me a little time to test this. I am workng on one right now.
We do have a seperate transformer we can send if necessary. No charge.
This is a new design.

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Tue Apr 30, 2019 8:19 am 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
Beautiful job on the build too!! :thumbsup:

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Sun May 05, 2019 10:26 am 
Offline

Joined: Mon Apr 01, 2019 11:16 am
Posts: 2
Riise, I’m in the process of building a Triwatt with the same board, does the hum exist at all times or just when the footswitch In engaged? I’m not too sure how I should proceed with my build. Does the pull switch function still work or does it still hum. Sorry about the stupid questions.


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Sun May 05, 2019 1:57 pm 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
bbrodie wrote:
Riise, I’m in the process of building a Triwatt with the same board, does the hum exist at all times or just when the footswitch In engaged? I’m not too sure how I should proceed with my build.


Give me a little time to test this. I am workng on a build right now. In a week or so There will be an answer.
We do have a seperate transformer we can send if necessary. No charge.
This is a new design.

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Sun May 05, 2019 3:05 pm 
Offline

Joined: Sun Feb 03, 2019 12:59 pm
Posts: 2
bbrodie, The hum appears when you turn up the master volume, regardless if the footswitch is connected or not. The hum is proportional to the volume setting and doubles when the overdrive gain stage is engaged and the overdrive volume is set to full.
The pull switch works when the footswitch is disconnected. There is no difference in hum level with or without the footswitch connected.
I've had no time to investigate this further. My plan is to exchange the voltage regulator and the relay for 3V versions and supply the card from only one side of the filament winding and the center tapp (grounded). I will order the components tomorrow and return with the result when tested.
I suggest that you wait for Stephens answer. I'm convinced that he will come up with a much more elegant solution.

_________________
Bjorn


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Sun May 05, 2019 4:29 pm 
Offline

Joined: Mon Apr 01, 2019 11:16 am
Posts: 2
Thanks so much for the reply!


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Sun May 05, 2019 6:00 pm 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
If we test and we have to send a small power transformer for this, it will be able to be grounded.

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Fri May 10, 2019 8:27 am 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
So we did some testing and it seems we will need to send a small relay power trasnformer. We cant get a ground reference. Although we didnt put the new board iinto an amp yet, we know a seperate transformer will work. We will send detail out shortly. Anyone with this issue should let us know to make sure we cover you. We will also look through our sales records.

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Fri May 24, 2019 8:24 am 
Offline
Holy Ghost
Holy Ghost
User avatar

Joined: Sun Mar 13, 2005 4:10 pm
Posts: 7329
Location: Brighton, Canada
All tested with the extra mini power transformer and ready to go. Will send out docs and parts this weekend to those who still need them.
Below is a picture of a current build with the new mini transformer installed at the powe end of the amp.

Attachment:
IMG_1673.JPG
IMG_1673.JPG [ 2.89 MiB | Viewed 742 times ]


Riise also developed a working solution we will try when we can get the parts in.

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


Top
 Profile  
 
 Post subject: Re: Triwatt build
PostPosted: Fri May 31, 2019 9:23 am 
Offline
Novice
Novice

Joined: Mon Mar 07, 2011 5:34 pm
Posts: 72
Nice looking build. It looks very familiar :) . Wondering if you may have seen photos of my build on posts from some years ago?


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 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