I have a Fender Red Knob twin chassis. I am going to re-cap the entire amp. I was wondering if there are any changes that can be recommended/needed for reliability issues. Also I am have to change all the pots and input jacks. The pots and jacks are currently mounted to a PCB board. I was thinking of running wires to the board and then to the pots and jacks. I was wondering if this would be an issue? I can't think of any. Also wondering if anyone knows about switching the jacks from plastic to maybe a switchcraft. I am not sure if it would be a straight swap. I am just not crazy about the original plastic ones installed. I know that the amp wattage can be cut from 100 to 60 by pulling tubes. Is there a way to wire that into a switch so that the tubes don't need to be pulled? Any help will be greatly appreciated. I am looking forward to tinkering with this project.
Ad Widget
Collapse
Announcement
Collapse
No announcement yet.
Fender Twin Red Knob Re-cap and possible upgrades
Collapse
X
-
There is already a Hi/Low power switch on that amp, which is supposed to cut the power from 100W to 25W. With 2 tubes pulled you are supposed to change the impedance setting, so a simple switching arrangement will not accomplish this. With 2 output tubes you will have around 60W, 15W on low setting.
Changing pots and jacks to non-stock types will be a pain. I don't think there is a lot of room for wiring. Also the jacks will have to be insulated from the chassis and the 9pin jacks have multiple switches in them. I would recommend sticking with the stock parts, however some of the push/pull pots may not be available anymore.
I'm sure some of these amps have had non stock pots and jacks installed, but I think it will turn into a fairly time consuming job, with potential hum/noise issues due to lead dress.Originally posted by EnzoI have a sign in my shop that says, "Never think up reasons not to check something."
-
I understand that the bias needs adjustment when the two tubes are pulled. I imagine I will just pull the tubes and re-bias. There is a test point and two adjustment pots on the back of the amp. I don't think I will be able to use the 100 watts since I will use the amp mostly just around the house. From what I understand when you set it to the low power it just lowers the amount of headroom. That is the clean channel will start to break up earlier. Hope I got that right. That the hi/lo switch doesn't make the amp any less loud. The one consistent comment on this amp and most Twins is that they are are loud. I was pretty sure that it wouldn't be simple to change the input jacks to a different style when I looked at them. As for the pots I have no choice but to change them. They are all damaged. Will be less work to just resolder back to the board. I have looked around adn most of the pots are available. There is a 25k push/pull that is hard to find but I found one on all parts and ordered it last night. $20 w/ shipping. A little much but the only other place I could find one was through an electronics distributer and the minimum order was 250 pieces or something crazy like that.
Comment
Comment