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Hello,
I'm starting a new build right now. I've done quite a few 5e3s and 5f1s as well as a few other various types over the years but I have never built a 5F2-A Tweed Princeton. So I figured it is time to do one.
I've accumulated all of the parts to do the stock circuit with MCI iron. I figured I might put in a few "surprises" as well. So in addition to the 5W OT from MCI, I got the 15W OT so I could see which one I liked better.
I am thinking about adding a switch on either the tone or volume pots (or maybe both). Right now, I have one 1M pot with a push-pull switch that I plan to use. The obvious mods would be 1) eliminate or greatly reduce the Negative Feedback and 2) change the cathode bypass on the 1st or 2nd stage (or both).
I think that the NFB mod is what I will try first - here is the dilemma.
The switch on the pot that I have is SPST and normally open. In other words, when the shaft is pushed in, the switch is open and when the shaft is pulled out, the switch closes. This makes sense but is a problem if I want to use this to either open the NFB path or insert a larger value resistor (say 100K) along with the 22K that is there.
The result of utilizing this type of switch is that the NFB will be modified when the knob is down and pulling it up will set the circuit to stock - the opposite of what I would like to do.
So, I've been looking at trying to use this switch in some other way than putting it in series in the FB loop but I've yet to come up with a way (series or parallel circuits).
It is too bad that the switch doesn't have another "throw" as in STDT - that would make it more flexible.
Anybody have any ideas on how to utilize this switch to get my desired result: knob down - standard FB circuit @22K; pull knob up to open the FB circuit or switch in a higher value resistor?
I prefer not to add any more switches or pots to this circuit. It would be easy just to add another toggle switch for the NFB but I want the amp to appear "stock" from the outside. I'm really looking for ideas on how to use the switch that I have which seems to be the wrong polarity for the job...
I guess worst case I can wire it like it is and I may end up using the amp with the FB disabled most of the time anyway...
Thanks in advance.
I'm starting a new build right now. I've done quite a few 5e3s and 5f1s as well as a few other various types over the years but I have never built a 5F2-A Tweed Princeton. So I figured it is time to do one.
I've accumulated all of the parts to do the stock circuit with MCI iron. I figured I might put in a few "surprises" as well. So in addition to the 5W OT from MCI, I got the 15W OT so I could see which one I liked better.
I am thinking about adding a switch on either the tone or volume pots (or maybe both). Right now, I have one 1M pot with a push-pull switch that I plan to use. The obvious mods would be 1) eliminate or greatly reduce the Negative Feedback and 2) change the cathode bypass on the 1st or 2nd stage (or both).
I think that the NFB mod is what I will try first - here is the dilemma.
The switch on the pot that I have is SPST and normally open. In other words, when the shaft is pushed in, the switch is open and when the shaft is pulled out, the switch closes. This makes sense but is a problem if I want to use this to either open the NFB path or insert a larger value resistor (say 100K) along with the 22K that is there.
The result of utilizing this type of switch is that the NFB will be modified when the knob is down and pulling it up will set the circuit to stock - the opposite of what I would like to do.
So, I've been looking at trying to use this switch in some other way than putting it in series in the FB loop but I've yet to come up with a way (series or parallel circuits).
It is too bad that the switch doesn't have another "throw" as in STDT - that would make it more flexible.
Anybody have any ideas on how to utilize this switch to get my desired result: knob down - standard FB circuit @22K; pull knob up to open the FB circuit or switch in a higher value resistor?
I prefer not to add any more switches or pots to this circuit. It would be easy just to add another toggle switch for the NFB but I want the amp to appear "stock" from the outside. I'm really looking for ideas on how to use the switch that I have which seems to be the wrong polarity for the job...
I guess worst case I can wire it like it is and I may end up using the amp with the FB disabled most of the time anyway...
Thanks in advance.