trinityamps.com

Hey everyone, another first time builder here and got everything together, plugged in and powered up with out burning my house down, so pretty happy about that.

Unfortunately seem to have another issue going on with the voltages, specifically everything being very low. Tests with no load, heater wiring and tube sockets seemed to measure OK, and no smoke or other major issues. However, installing the tubes and plugging in a speaker everything is very low. Basically with the VRM at max only get up to 390V at the first 50uF cap and 168 and 162 on pins 1 and 6 of the V1. Started thinking there was some power issue and the real head scratcher is at the end of the fuse only getting 51 or VAC (tried two different outlets). In the US so should be 120 right? Re did the hot and ground wires on the mains and have triple checked the fuse (not blown) and still getting the same reading. So, does anyone have any suggestions on where to start? Tried to do some searches and haven't been able to find any suggestions on something like this. Kind of glad running into some issue as it would be too easy if everything worked flawlessly the first go round right? Thanks!

Yes you should see 120 volts AC at both fuse terminals. Measured from the fuse terminals to neutral or the fuse terminals to ground. What does the voltage read at the IEC connector? You might have a bad power cord. That happened to me once. Try a different one.

Brought the amp into work to try a 3rd power source and that bumped up the voltages at both the fuse and at the IEC (measuring to ground) to 84 VAC. Didn't think about the cord possibly being bad, was guessing maybe the IEC so probably going to try one or both next and see if that helps.

On the plus side, even with the low readings everything seems to be working OK with a guitar plugged in and the amp sounds pretty damn good so happy so far. Thanks for the reply,

This may seem like a silly suggestion but how old are the batteries in your meter? Sometimes dodgy batteries can cause crazy readings.

If you measure the VAC directly at the wall outlet (you may try more than one outlet), do you got 120Vac (or between 115 and 125)? If not, Snowy may be right.

Especially if despite these low voltage measurements, the amp work great...