Shask
Well-Known Member
I finally did something I have been meaning to do for a LONG time. I modded the Loop of my old 2-Channel Triple Recto. I know the Parallel to Series mod is popular, but I actually decided to leave it Parallel because I plan to use some rack units with it. I am talking about the "Loop Tone Suck Mod". When you use the loop, you lose all your bass. It is like you have to set it about 4-5 notches higher to have the same amount of bass, so when you turn on the loop it sounds all neutered. There is no bass, so it is tighter and brighter, like a different amp.
There is a badly chosen cap value on the return stage of the loop. The Cathode bypass capacitor needs to be much larger. When doing the math I found the stock value starts cutting bass at about 300-350hz. Far too high. Now it goes down to like 50hz or something. There is a 2.2uF tantalum cap that needs to be changed to 10uF.
After changing this, the amp sounds almost identical when turning on the loop. Maybe a slight less bit of presence, but that is easy to change by blowing on the knob. I actually think it sounds better with the loop on, and I don't think I would ever say that, lol. It is easier to balance the volume knobs, and my EQ pedal sounds more natural.
Anyways, just rambling, lol. Figured I would mention it since so many people hate the 2-Channel parallel loops. They all suffer from this same problem. While I had it apart I took some pics, so here are a few if you like looking at that sort of thing....
There is a badly chosen cap value on the return stage of the loop. The Cathode bypass capacitor needs to be much larger. When doing the math I found the stock value starts cutting bass at about 300-350hz. Far too high. Now it goes down to like 50hz or something. There is a 2.2uF tantalum cap that needs to be changed to 10uF.
After changing this, the amp sounds almost identical when turning on the loop. Maybe a slight less bit of presence, but that is easy to change by blowing on the knob. I actually think it sounds better with the loop on, and I don't think I would ever say that, lol. It is easier to balance the volume knobs, and my EQ pedal sounds more natural.
Anyways, just rambling, lol. Figured I would mention it since so many people hate the 2-Channel parallel loops. They all suffer from this same problem. While I had it apart I took some pics, so here are a few if you like looking at that sort of thing....