Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: gerry113377 on April 18, 2021, 04:24:45 pm

Title: Issue with amp build
Post by: gerry113377 on April 18, 2021, 04:24:45 pm

{continued from here (https://el34world.com/Forum/index.php?topic=25582.0)}

Hi,

I built my first tube amp. A KLD DC30 clone. It works on channel 2 but channel 1 makes a humming sound. I double checked everything, I also, removed everything and rewired it all. Still get the same humming. I disconnected channel 1 from the effects loop and the humming went away and then only had channel 2. Here is a youtube video of the humming, all schematics and a pic. If you need any more pics of a certain area let me know. Thanks.

 Gerry

Title: Re: Issue with amp build
Post by: shooter on April 18, 2021, 04:41:33 pm

Quote

I disconnected channel 1 from the effects loop and the humming went away

did you jack IN some audio at CH1FX to see if it works downstream?

Title: Re: Issue with amp build
Post by: Latole on April 18, 2021, 05:22:54 pm

Seeing these long unshielded wires, I'm amazed that the amp is silent on channel 2.

Title: Re: Issue with amp build
Post by: gerry113377 on April 18, 2021, 06:12:10 pm

I am 100% sure the unshielded wires are not the cause of this problem.

Title: Re: Issue with amp build
Post by: sluckey on April 18, 2021, 06:50:19 pm

Have you reviewed your thread from last year about this same problem?

Title: Re: Issue with amp build
Post by: gerry113377 on April 18, 2021, 07:16:56 pm

Sorry yeah, had a bunch of other projects so it's  been over a year, I decided to rewire the whole thing. Same problem, if you want  delete this and post I'll post there again, I wasn't sure to post there after a year. Guide me yoda. The old build had shieldef wire, I just ordered rg174.

Title: Re: Issue with amp build
Post by: PRR on April 18, 2021, 10:20:15 pm

Let's just drop a link to last year's progress:
https://el34world.com/Forum/index.php?topic=25582.0

Title: Re: Issue with amp build
Post by: gerry113377 on April 19, 2021, 05:58:17 am

Anyway, I should have never picked such a difficult amp kit in the first place from an unknown company. My bad for even asking and wasting every one's time. Moderator just please delete both these posts.