High voltage circuit testing: out of spec reading 190-190.2V DC [resolved]

[Rabco]

Hoping everyone’s Thanksgiving was great.

Doc, PB, your opinion(s) please regarding my high voltage circuit testing readings:

6U= 126.6-126.7; 16U=129.3 which fell within the acceptable range.

My B+ Reg TP on the PC board= 190.9 which is high. FWIW if memory serves, my original Moreplay build had a just out of spec high voltage circuit reading which was thought to be acceptable when I reported in. Also, I had a slightly chipped resistor body that I went ahead and left in place on the Moreplay Upgrade board, after checking in with you all.

Your recommendations please.

 

[Paul Birkeland]

Could you post a photo of your upgrade board build?

 

[Rabco]

I can now.
Sorry my photography skills are,,,,,,mediocre.
Does this show what you need?

 

[Paul Birkeland]

The solder joints on the zener diodes need a lot more heat.  If you can turn your iron up all the way, that might help. 

Are the voltages coming out of the low voltage board looking good? You should see about 6V at the H1 and H2 sets of pads. 

 

[Rabco]

Paul, I'm getting 6.31 V at H1, and 6.33 V at H2.

Hmm, I'll be OK putting 899 degrees on the Zeners?

My usual MO has been a 4-5 count while the iron is applied to the object and board attachment point at ~710 degrees. Much lower than that and I was not getting any flow. Brand new Hakko with Hakko tips.

I don't need to dismount the board to solder from "underneath"? Dumb question I guess, as I assume doing aggregates all at once are just an efficient time use, right? In other words I can solder from the top as in the picture I sent?

I try to assume nothing.

 

[Paul Birkeland]

I solder at 899.  Do double check the instructions for raising the temperature if you have a Hakko station.  It's easy to think you are raising the temperature when you're actually in the calibration menu, and increasing that lowers the tip temperature.

 

[Rabco]

Excellent suggestion.

I'm new to this Hakko machine and that's a great tip.

Once I've tried again, I'll remeasure, and if I'm outside spec, I'll post up again.

I reread my last post. My apologies. I wasn't trying to flash attitude. Your help is appreciated.

 

[Paul Birkeland]

Yeah when I got my 888, I immediately wanted to turn it all the way up, then it wouldn't even melt solder.  I guess peak maturity for me is at least opening the manual before sending it back, and then the inevitable operator error was discovered.

 

[Rabco]

Paul,

Back again.

I dialed the Hakko up to maximum. Soldering this way was just like metal on metal soldering with a torch, which I did plenty of in a prior lifetime. I made it to a mental 1001 count and the solder flowed.

Did the zeners again.

Unfortunately, my measurements look, in essence unchanged.
6U--126.9V
16U--129.2V
H1--6.33V
H2--6.31/v
B+ Reg TP--190.1V

How now?

 

[Paul Birkeland]

Can you measure the voltage on each banded end of each zener diode? 

 

[Rabco]

Paul,

ZD1–186.3V
ZD2–140.3V
ZD3–93.5V
ZD4–46.6V

With the common on the volume pot.

 

[Paul Birkeland]

I don't see anything particularly concerning there, I think you're good to go.

 

[Rabco]

Thanks Paul.

I appreciate the trouble shooting and guidance.

Especially on the weekend &/or after business hours….truly above and beyond the call of duty.

Scott

 

[Rabco]

Paul,
Just a quick note to let you know my initial impressions of my completed upgrade.
Nothing but good news…..
I don’t know if there may be some break-in time involved, but I certainly can hear the improvement in my systems’s sound right away…..and therefore the affect on the Moreplay was as intended, I believe.
Your suggested improvements from stock are plainly evident to me, and definitely worth the price of entry.
If I had to broadly describe it, it makes my speakers sound as good as my headphones, which in my book is the ultimate compliment. I can now hear it all with my speakers.
I’ll post up soon with more happy audiophile speak.
Nice work!
Thanks for the help and your patience..
Scott