another Stereomour but a giant step for me

[Grainger49]

Shellac can be removed with denatured alcohol.  If you mess up use that on 4/0 steel wool again.

[Doc B.]

Just to clarify, I think Grainger means grade 0000 steel wool. That's about like 400 grit sandpaper. The potential for confusion is that there is not really "4/0" labeled steel wool but there is a grade 4 steel wool which is about like 30 grit sandpaper, i.e. kinda like using aquarium gravel glued to paper.

[Grainger49]

Oooo!  I didn't know that!  I'll change my responses from here forward.

[borism]

I used the shellack spray can and overall it is much smoother. A few areas had to be sanded down and when that didn't work alcohol did the trick. So, hopefully, with a few coats it will smooth out.

The input wiring is complete. It was tedious but also fun to do.

[borism]

Hi,

I need some help.
Well I completed my build, checked the solder joints, did the resistance checks and they were all fine.

Then, I put in the tubes, the fuse and powered it up. The tubes were glowing fine, no blown fuses, so I did the measurements. The AC ones were fine. Then, the DC - all are fine except for 2 terminal strip voltages and 2 active load PC board ones:

Terminal: #2       313
               #14     290

active load PC board:
               OA        317
               OB        291

Can someone tell me, what this may mean. The expected voltages in those 4 locations should all read 165-220.
I am also surprised that it seems so symmetrical.

Thanks,
Boris       

[borism]

active load PC board

[Paul Joppa]

The most likely thing is, a 12AT7 that has not been properly burned in at the factory. We are seeing quite a lot of those these days for some reason. Let it run for a while and check again. If it does not come down in 50 hours or running, we can replace it. The amp should be capable of making music right now, so you might as well listen to it for those 50 hours. You may notice some pops, scratches, and/or crackling noises, if as I suspect the cathode was not fully formed, but they should also fade out with time.

Of course if you have a spare 12AT7 and are impatient, you can substitute it to see if that changes the voltages.

[Paul Birkeland]

This is pretty unusual, did you end up measuring the Kreg voltage? 

[borism]

Thanks Paul!

I had another 12AT7 and rechecked the voltages:
       Terminal #2    190
                     #14  198
       PC board: OA   190.3
                      OB    198
So, now everything checks out perfectly. However, my wood base is drying from another shellack coat. So, I'll have to wait a little before I can listen.

Another picture of the completed amplifier.

Boris

[borism]

It's alive!

Couldn't wait to finish the base and will have to return to it this week. But music is playing and it sounds wonderful (Paul Simon - Graceland). The selector switch and attenuator, everything is working fine. What a great adventure!

Thanks everybody!

Boris

[Natural Sound]

Not bad for someone who never soldered before.    But seriously, you did an excellent job. I'm very impressed with your first kit success.

[borism]

Thanks! The instructions are very clear. I also watched all the soldering videos on youtube.

[galyons]

Congratulations! Not an easy "first timer" build! If you like it now, just wait until it has a hundred, or so, hours of burn in!!!

Cheers,
Geary

[borism]

Man this little amplifier is making some sweet music. It seems even with only a day of burn-in it is getting really good. And it turns out that it is driving my speakers that have a sensitivity of 92 (AudioKinesis Jazz Modules) very well. I rarely seem to turn the volume past 12.

Boris

[Guy 13]

Man this little amplifier is making some sweet music. It seems even with only a day of burn-in it is getting really good. And it turns out that it is driving my speakers that have a sensitivity of 92 (AudioKinesis Jazz Modules) very well. I rarely seem to turn the volume past 12.

Boris

Hi Boris.
May I ask where you are from or where you are located.
The reason why I ask, it's because I want to know how hot
does the top plate becomes when you touch it?
As you know already, I live in Vietnam
and these days the thermometer is around 35C or 90F+
I am trying to avoid using my air conditioning in my listening room
to save money to buy the Stereomour.
My Decware SE84C+ is getting very hot after just one CD playing.
I have a small super quiet fan that I would like to use to cool down the amplifier,
but I am too lazy to set it up.

Guy 13