trinityamps.com

Hi all!
I'm new to this forum, and just wanted to say hi and thank you all for a great site for learning stuff about amp building!
I want to show you my first build.. It's a Lightning with parts I got from Nik at Ceri@tone. It sounds great, and I have no hums or buzzes! Noise free!
http://www.kjetilrostad.com/PICT0257.JPG
A bit messy, but for a first timer..

I only have one problem! I made a "high cut" pot that doesn't seem to work! The pot says B220k and the cap is a .0022uF. (it's on the right on the picture). There is little or no difference when turning it.
Does any one of you see anything wrong with this?

best regards,
Kjetil

It looks like you have the .0022uf cap just soldered to the wiper of the pot; it also needs to be soldered to the open leg. Here is a good schematic of one, it is labeled tone, but functions the same way. AC10 I'm not sure if it would make a big difference, but it's worth checking. I also used a .0047uf for the cap on my cut control and it makes a very noticeable difference.

Eddie

Thanks Eddie.
As you can see I'm quite new to this.
I tried what you suggested this morning, and it now works! The cut effect is very subtle and barely noticeable, but maybe it is just what you need to take off just a little bit highs when the amp gets too brittle. I'll try a .0047uf cap later, just have to go get one..
I'm curious about why the DC30 has a .0022cap and the AC10 a .0047 cap for the cut. (larger/smaller amp??) Looks like the 10-20 watt amps have a .0047 cap and the larger amps have a .0022uf

And if anyone is interested:
Here's something I recorded with the amp just now, quick and dirty..
First just some delay, then next two with a Maxon 808
http://www.kjetilrostad.com/Audio01.mp3
http://www.kjetilrostad.com/Audio02.mp3
http://www.kjetilrostad.com/Audio03.mp3

Kjetil

Glad to hear it worked I think the reason the AC10 uses the .0047 is that it is the only tone control on the amp, so by using the bigger cap it offers more noticeable effect. Oh, and by the way, the clips sound killer

Eddie

You had it right the first time.

1. It is fairly subtle, but definitely nice with single-coils.

2. Don't forget, it's going across the PI and how effective it is depends on the position of the master. Master up, it works a treat, master down, not so much.

3. I like the cut (I added the same one to my Lightning), but am thinking of dumping the master volume. It is difficult to control, and I do notice a difference in transparency when it's not wired into the circuit. The Cut has no such effect (I guess because of the cap).

Before I dump the Master completely, I may try a different scheme--using a rotary switch and some resistors--Position 1 out of circuit, other positions with fixed resistors picked empirically.

P.

Hi,

I actually think it was a difference when I did like Eddie suggested, but it might be that I had the master more towards full when I tested it after the change.
I have also been thinking about taking out the master, but was thinking I just could have a switch to take it in and out. And if that also makes a tonal change, it would be really interesting! Could this be done with a footswitch?

For the cut control I have decided to go for a switch that takes it out, or make the cap a .0022uf OR a .0047uf. A nice option to have without being much trouble to make! (remember i'm a novice amp builder)

Another little mod I saw somewhere is to have a 200k resistor in series with the gain pot and make it switchable. This would make a nice little gain boost, don't you think? To make it practical in a live setting I'll have to figure a way to make it footswitchable without to much fuzz.. (the 200k resistor could also be a pot?!)

Eddie, thanks for the comment about the soundclips!

Kjetil

Nice work Kjetil.

_________________
PJM

http://www.diyguitarist.com