Crunch channel losing gain intermittently? Preamp Tube?

THE NEW #1. Series One Amplifiers.
Post Reply
nick_s
Posts: 18
Joined: Sat Jan 02, 2016 3:56 pm
Location: Stoke

Tue Nov 08, 2016 6:59 am

Hi guys,

My S1 45 combo is losing drive intermittently on the crunch channel only. All other channels (bright clean, warm clean, super crunch) are fine and dandy. When it happens, it's like you have someone sitting at the amp dialling out the gain knob down to minimal gain. Tiny volume drop (could be perceived) at the same time, but nothing major. It comes back again a few seconds later.

I took a look at the amp when warming up, and noted that one of the preamp tubes doesn't glow as bright as the others, so that will be the first thing to replace...what I guess I am asking is that is there anything else I should consider as a possible problem if the tube change doesn't help?

Thanks in advance.

nick_s
Posts: 18
Joined: Sat Jan 02, 2016 3:56 pm
Location: Stoke

Mon Nov 14, 2016 8:20 am

OK, a minor update. I pulled the valve that was not glowing quite so bright on one side as the others, and it was the ECC82 so no swapping around possible. That said, after inspecting (and finding nothing visually wrong) and re-seating said valve and playing for a couple of hours, the problem has not reoccurred. Regardless of that fact, I will order a new set of valves to ensure I have them to hand if needs be.

Rybow
Posts: 6
Joined: Thu Apr 08, 2021 5:19 am

Fri Jul 23, 2021 1:07 am

I’ve been finding this happening with mine quite a bit, except on mine I get a high pitched whine, and unless I strum really hard the gain channel is crackly and muted. Just discovered my 2nd stage 12ax7 gets loose from vibration.

Out of curiosity, what position is your ecc82 in? I got mine used. Looking at the back of your amp, is it 3rd from the left?

Post Reply
  • Information
  • Who is online

    Users browsing this forum: Bing [Bot], Seo-Ul-law and 46 guests