Timothy C’s Moreplay Build

[hmbscott]

You can do that with a Variable Output Transformer. Doesn't do any power conditioning, but you can dial in the desired voltage. See Pic.

 

[timmieec]

Thank you @hmbscott for the suggestion! I'll look into it.

I completed the heater wiring and confirmed that both tubes glow. Let there be light!

I also purchased a set of dials from AG  ;D

I'm curious what brand of tubes I've received with the kit. Anyone here able to read Russian and can enlighten me please?

 

[Larpy]

Those are Russian tubes built during the Soviet era by, I believe, Reflektor.  Good tubes.  They came stock with my Moreplay as well.  Depending on your tastes and level of curiosity, they might be all the 6V6 you need.  To my ears they sound more like old U.S. 6V6s like GE, Sylvania, and RCA than they sound like 6V6s made currently in Russia, China, and the Czech Republic.  (And I mean that as a compliment.)

 

[timmieec]

Thanks @Larpy for the information! That’s a pretty cool name, and also the name of an Arcade Fire album I think.

 

[timmieec]

Help! 

I'm failing the raw B+ voltage test. I repeated the test 3 times and got the following peak VDC read outs: 331.2, 330.7, 331.1. The spec is 280 - 320V.

I've checked all the wiring for connectivity using my DMM and it seems like everything that's supposed to be connected passes the connectivity test. I've also confirmed the polarities of the caps and diodes are correct.

Could my raw B+ voltage be exceeding 320V because, as @Paul Birkeland noted, my mains voltage is so high (245VAC)?

Or is it definitely failing the test because of a workmanship error? If it's definitely workmanship, any advice on what else I should check besides polarity and connectivity?

The cap connected across terminals 23 and 21 is rated for 350V so there's low risk to that component. But I don't know whether the components being supplied by this DC voltage will be okay receiving 331V...

Any guidance would be much appreciated!

 

[hmbscott]

Your line voltage is about 5% high, so you can expect your B+ to also be about 5% high, which means it will fall within a range of 295 - 335 VDC, and it does. So I don't think there's anything wrong with your wiring, it's your high line voltage. I can't say if it's OK or not.

 

[Paul Joppa]

So-called "230v" power grids combine/compromise the older standards of 220v and 240v, but many of the older generators are still in use. For this reason, the Moreplay power transformer can be set for 220 or 240 - but not for 230. I think that gives our customers a better chance of getting close to optimum power. That means that Timmie's voltages are only 1% high. The circuit can withstand +/-10% variation without loss of performance or reliability.

 

[timmieec]

Thank you everyone for the guidance! Good to know that I don’t need to worry about loss of performance or reliability and can proceed with the build 

Next up, audio circuit wiring!

 

[timmieec]

Audio circuit is done and connectivity tests seem to check out.

On to input wiring tomorrow!

 

[AG]

Nice and clean soldering! my hat off.
AG.

 

[timmieec]

The input wiring section was intense!

Managed to complete it though. All the resistance and voltage values checked out so I hooked it up to my Roksan K3 amplifier and started playing music through it 

Thank you everyone for the guidance throughout and helping me make my first tube amp kit a success!

May I ask what the balance knob is for? In what instances, besides DJ-ing, would one use it to make one channel louder than the other? This is the first time I've had a balance control at my disposal and it's giving me anxiety because I don't know if I've balanced it perfectly equal between left and right channels 

 

[Paul Joppa]

Four reasons for a balance control:

1) amplifiers without feedback may vary in gain by a few dB due to varying tube parameters.

2) room acoustics may enhance one speaker's loudness over the other

3) for diagnostic purposes you may want to listen to one channel alone

4) typical volume controls can deviate from matched gain, especially at low-level settings

I'm sure there are more, these are just what comes to mind this morning.

 

[Mucker]

Good job. Turned out nice!

 

[timmieec]

Thank you everyone for the guidance! Will do my best to balance the preamp using tracks with a strong centre image

 

[Karl5150]

Again, nice clean build and finish. I noticed that you are using directional RCA cables on the output and that one is reversed. Will the electrons be facing the wrong direction in that channel?
Enjoy the tunes.
Karl

 

[timmieec]

Hah thanks @Karl5150 for pointing that out! In my excitement to listen to the Moreplay, I didn’t realise I had the direction reversed  :

 

[timmieec]

Received plates with labels for the knobs from Andre (username AG) and they look great!

 

[AG]

Match perfect with the color of your choice!
Enjoy!!

Cheers from Fla.
Andre.