new issue for me [solved]

[ee]

In the beginning the amp checked out. I had an occasional light static/pop both channels with the left more often than the right after firing it up. It wasn't bothersome or anything and not often. So yesterday I decided to re-solder the speaker terminals. I upgraded them at the time of initial build. They are the rhodium plated type and kinda hard to solder to me. Since I wasn't totally confident I had a good joint there I re-soldered and file off some the rhodium to get to the copper. I was careful to remove shavings. I also rewet safety ground, output power output transformer lug, both OT-2 ground lugs, IEC entry E, L, and N. Since I was there thought it was a good idea. However, when I powered it back on the right channel was out and the right 2A3 was cold. I stared at it a couple of minutes and noticed the right channel began to have a bit of sound and the tube was getting warmer, not glowing filaments though. They got redder over several more minutes but did not match the right in sound or functioning. Here's where I may have messed up more. I tilted up the amp with music playing checked terminal strip 8 (ground)  (black lead of volt meter) to terminal strip 1 (red lead volt meter). No good reason to go there first, should have done tubes first perhaps.  When I made lead contact the 2 LEDs on B side of board went out and came back on when I removed meter leads from 8 and 1. Power level  dropped and the left and right channel were equal but about half as loud. Turned amp off. I removed the safety ground lug and scraped under it because originally I had spray painted the top and there was a very small amount of that made its way to the back. I removed solder from from safety ground lug and re-soldered those 2 connections. Turned the amp back on and both 2A3 heated up equally but vol still diminished. I turned it off and let it set for a few min. Turned it back on and right 2A3 was slow again to heat up. I turned it off and back on and it heated right on up, vol still diminished. I put in a new 12AT7 to try but still diminished vol and so far the 2A3 have heated up equally but haven't measure voltage yet to see if they should be getting more which I would think would help the volume issue.
I'm at work till later so I'll do volt and resistance checks when I get home. 2A3 first thing. I was just hoping for some direction as to what I may have cooked or hurt that caused the volume to drop in half. I still have the occasional pop/static so yay 
Thanks
Eric

[Paul Birkeland]

If you have a 2A3 that isn't glowing, the red/black twisted pair of wires that run to that tube are where to start.

In particular, the connections on the power transformer lugs can take a fair amount of heat to solder properly, so I would start there.

-PB

[ee]

So what I think did. I perhaps sent to ground the cap at terminal strip one with the music playing leading to the LEDs going out on that channel temporarily while the leads were on.  Not real sure about the 2a3 not coming on good. But it's continuing to come on properly now. I measured some voltages a few minutes ago. Both 2a3 are 2.45v so that makes me feel good. I checked some others also at the acitve load pc board. All checked out. Thanks for your help. Sounds great as it did.
Side note- For this build I started using distilled water on the sponge for cleaning the soldering iron tip and it's been spotless. When I was practicing before this build I used regular tap water and the tip was really hard to keep clean and didn't last too long.

[Natural Sound]

Side note- For this build I started using distilled water on the sponge for cleaning the soldering iron tip and it's been spotless. When I was practicing before this build I used regular tap water and the tip was really hard to keep clean and didn't last too long.

Hmmm... interesting... I have pretty hard water here at my house. I don't have a problem with tip life. In fact I've been using the same tip on my Hakko 936 for about 10 years. But I'm going to give this a try anyway. Couldn't hurt. Thanks.

[ee]

experience wise I'm more like 10 weeks. bow bow. Doing a better job of tinning the tip probably helps too.

[ee]

So this is a great post following my "soldering for 10 weeks" comment. I have resoldered the PT and OT terminals at a bit higher temp. Today it dawned on me, while tracing stuff in my head , that I had wired in the 2 180 ohm resistors parallel instead of series to get 360 on the ps board. And and I soldered in a 1.5k + 100 ohm resistors below the active load board in parallel to get 1.6k. Neither of those of course would add up to the desired number in parallel. Embarrassing for sure so I hope someone learns from my mistake. It was a resistor upgrade but note soldered in the way I did it initially. A bit of surgery I and it's good now. That also explained a funny resistance I was getting but couldn't convince myself the number was right. Still sounded nice though.
Thanks
Eric

[Paul Joppa]

Booyah - I know it's a pain at the time, but I totally LOVE it when someone makes a blunder and then figures it out for themselves. It's real learning, the kind that will stay when the memorization has failed, and as long as we can help make that happen I feel pretty damn good!

[ee]

HaHa that's awesome! Good thing is I didn't beat myself up over it and it was nice to realize. It was funny looking back at it and how precise i was trying to be symmetrical with the wiring and placement of them too.