trinityamps.com

Hi team, joining the fray here to celebrate after what's been a crazy foray into instrument and amp building by a physics luddite.

I've wrote about my building experience here...
https://jimhaswords.wordpress.com/2015/02/19/2015-resolution-1-build-two-amps-trinity-tramp/

Spoiler alert is that I haven't fired it up just yet (explains more in the blog post); I'll post more here after I fire it up.

Some good words there jim! we're with you for start up! ring out those connections, check your grounds.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Results in!

First, I'm glad I made my sweep through because I'd swapped the .047uf for the .47uf and had the input in the wrong turre going into to the pre-amp.

However, I fired it up and it plays (almost!), no smoke, and some nice tweed tone.

Here's the odd stuff:

1. Low pre-amp plate voltages:
184.4 @ pin 1
173.3 @ pin 6

Most other voltages seem fine:
B+ max VRM: 408V
6V6 cathode: 29.4V
R8/C8 junction: 338V
Pin 3 12AX7: 1.7V
Pin 8 12AX7: 1.85V

2. Volume knob only works past noon-ish of the sweep (maybe related to #1?)

3. High-pitched squeal in 'tude mode when vol, vrm, and master cranked to max.

Tone controls work fine, as does thin and fat.

Any suggestions?

Still, I'm pretty amazed! It's a functional amp.

Update again!

Regarding the Gain sweep, it was actually because I had my cap turned around and the amp can be just that quiet. It also seems like 184V at pin 1 and 173V at pin 6 on the pre-amp tube aren't too uncommon from the other threads. Curious why this would be?

So, the only remaining knit to solve is the high-pitched hum in 'tude mode when cranked.

Otherwise, it is a really, really sweet sounding amp, quiet, and with a lot of character in all modes and toggles.

This is almost 100% a lead dress issue. Chopstick v1 connections to the board and move them around and see what changes make by moving them. Then Shorten all the wires to V1 as much as possible. You may need to use more shielded cable too.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

From what I can see based on the one pic on your site showing the finished amp I would suggest making the shielded wire going from the Tweed/Tude pot to the socket as direct as possible. Don't bend the wire around the chassis, take it on a diagonal path straight to the socket.

You could also try shielding the MV's wiper connection and the NFB wire. Earlier Tramp's did this.

But try coco's suggestion first and "chopstick" your amp.

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http://pdfelectronics.com

Thanks all for the suggestions.

I had a chance to poke around V1 with a chopstick and it somehow just stopped, which was nice but somehow unsatisfying. Hopefully it lasts, if not, I will shorten the wires, do the above again, and see what goes on.

What a fun amp!

Great to see a couple of new Tramp builds popping up on the forum here lately. Congrats on a nice looking build!