Completed project, MOD 102+ amp build

[TVvoodoo]

Man I hope it sounds as handsome as it looks.
Really great project!

 

[murphy brown]

It's Alive!! ALIVE!!!!

I worked on the last of the wiring yesterday and buttoned it all up this morning before work. Powered up on the first go; no explosions, no smoke. At first I was like "shit, it’s not working" because the indicator light didn't come on. Then I remember I hadn't put the bulb in. Duh...

I didn't play it long, just enough to know it made sound. On first impression it sounds good. Definitely in the Fender tone camp. The tone controls and pull knobs are relatively subtle, but enough to hear a difference and give some good variety. I'm not 100% sure if the "mid boost" is actually a boost or if it's shifting the tone stack. I'll have to play with it more.

One thing that surprised me was the loudness. Not that it’s loud enough to keep up with a band or anything. It’s that there's not much of a taper on the volume knob. There's no keeping it whisper quiet. It's pretty much full throttle as soon as it goes past 0.5. And there's not much clean headroom. As soon as it's to volume it's already at the edge of breakup. After that it's just more saturation and the volume minimally increases.

Last thing that was noticeable on first power up was that it's pretty quiet. There's very little, if any noise through most of the volume's taper and minimal hiss as you approach full volume/saturation.

I'll report back with more feedback after I put it through its paces this afternoon after work.

Here it is in all its completed glory.

View attachment 19886

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Do you twist the wires to prevent interference/crosstalk?

 

[gearJunkie]

Do you twist the wires to prevent interference/crosstalk?

All wires carrying high current A/C should be twisted to reduce 50 / 60 cycle hum.

 

[MadAsAHatter]

Do you twist the wires to prevent interference/crosstalk?

As @gearJunkie said, it reduces hum and helps keeps the amp quiet.

 

[murphy brown]

All wires carrying high current A/C should be twisted to reduce 50 / 60 cycle hum.

I thought using an isolation transformer was the only way to do that, I did not realize that nifty hack would work also. Moreover, I previously thought that principle only applies to ethernet cable.

 

[gearJunkie]

I thought using an isolation transformer was the only way to do that, I did not realize that nifty hack would work also. Moreover, I previously thought that principle only applies to ethernet cable.

Isolation transformers reduce hum by breaking ground loops, where twisting wires with high-current A/C lines reduces hum caused by inductance.

The inductance rejection in Ethernet twisted pairs is not related to high-current A/C, but instead its high frequency oscillating signal.

 

[murphy brown]

Isolation transformers reduce hum by breaking ground loops, where twisting wires with high-current A/C lines reduces hum caused by inductance.

The inductance rejection in Ethernet twisted pairs in not related to high-current A/C, but instead its high frequency oscillating signal.

Nice comparison.

 

[MadAsAHatter]

Another way that helps reduce AC hum is to run wires as perpendicular as possible when they cross each other.

 

[murphy brown]

Another way that helps reduce AC hum is to run wires as perpendicular as possible when they cross each other.

I haven't heard of that method and that is pretty interesting.