trinityamps.com

Trinity Amps Guitar Amp Forum
It is currently Thu Mar 28, 2024 11:47 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: Voltages too high
PostPosted: Mon May 18, 2020 5:00 pm 
Offline

Joined: Mon May 18, 2020 4:12 pm
Posts: 7
Just completed my OSD build. It is working but not properly. To start I the amp does work without any abnormal noises but have noticed a couple issues which may or may not be related. Overdrive level and ratio don't seem to do anything, and the volume is lower than it should be.

When back and checked the voltages and found most of them to be too high.
Without tubes the voltage on each of the red Main transformer wires is 400V and B+560V

With the tubes in: B+513V
V1 pin1 209V, Pin 3 1.7V, Pin 6 215V, pin 8 1.6V
V2 pin1 145V, Pin 3 2.8V, Pin 6 221V, pin 8 1.7V
V1 pin1 348V, Pin2 43V, Pin 3 70V, Pin 6 338V, Pin7 44.5V
V4 & V5 Pin 3& 4 515V

My concern being the high B+ , V4 & V5 voltages. Also low voltage on V2 which likely explains the volume.

I am a novice builder and am looking for help as to how to trouble shoot this and any help is greatly appreciated.

Thanks


Top
 Profile  
 
 Post subject: Re: Voltages too high
PostPosted: Mon May 18, 2020 7:20 pm 
Offline
Expert
Expert

Joined: Sat Dec 04, 2010 3:42 pm
Posts: 519
Location: Qualicum Beach, BC
Hi, welcome to the forum!

Just the usual troubleshooting advice:

Make sure all the parts are the right values and are in the right places.
Make sure all your solder connections are good on the board and the tube sockets.
Make sure all your wiring is correct. There are lots of controls and relays in this amp. It's easy to get things mixed up.

Verify that everything that's supposed to be connected is actually connected. Check both visually and using an ohmmeter. Put the probes on the component leads or terminals rather than the solder connections so you are checking the continuity of the solder connections, too.

Some people make a copy of the layout drawing and use a highlighter pen to mark the wires and components as they check.

V2a voltages are low. Check all the wiring to V2 and its socket.
B+ is high. Make sure the power transformer is wired properly for the voltage coming out of your wall.


Top
 Profile  
 
 Post subject: Re: Voltages too high
PostPosted: Tue May 19, 2020 10:48 am 
Offline

Joined: Mon May 18, 2020 4:12 pm
Posts: 7
I will continue checking as you suggested.
I was wondering if there was perhaps a way to isolate the problem of at least eliminate some of the circuit to find the problem?

Thank you


Top
 Profile  
 
 Post subject: Re: Voltages too high
PostPosted: Sat May 30, 2020 5:54 pm 
Offline

Joined: Mon May 18, 2020 4:12 pm
Posts: 7
Ok, one issue solved and on to the next. Not sure of the exact cause, just reflowed my connections and no more high voltage readings.

unfortunately now the voltages are too low.
with the tubes in:
B+1 417
B+2 413
B+3 403
B+4 271
B+5 263
The concern being with B+4 and B+5

AC in at 120VAC and 325VAC on each or the red leads from the power trans before the diodes.


Top
 Profile  
 
 Post subject: Re: Voltages too high
PostPosted: Mon Jun 15, 2020 12:06 am 
Offline

Joined: Mon May 18, 2020 4:12 pm
Posts: 7
Well got it working after finding an issue with the layout that Stephen helped me work though. Still some low voltages but right now it just wants a guitar plugged into it. And just like the build there is so much more to learn about its operation. With every nob and switch playing off of each other creating a new cornucopia of tone. May need to tweak it a bit but best to work in and get to know my new girl friend:) hope my TC15 isn't jealous:)

But the OSD seems to be happy in its new home driving a 12" Eminence Cannabis Rex I had laying around.


Attachments:
IMG_1820.jpg
IMG_1820.jpg [ 834.32 KiB | Viewed 4611 times ]
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 12 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