kt66 in 5f1
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JoshBernstein
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kt66 in 5f1
Hi, im wondering if it would be possible to run a kt66 in my 5f1? If so would it sound good? Thanks!
Not really
Re: kt66 in 5f1
Depends whether your PT can supply the necessary heater and B+ current and voltage. Check your output transformer's primary impedance too.
If it's a stock Champ 5F1 PT, the Magic 8-ball says "outlook not so good"
If it's a stock Champ 5F1 PT, the Magic 8-ball says "outlook not so good"
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JoshBernstein
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Re: kt66 in 5f1
Well heres the pt i have attatched. The primary impedance of the ot is 5000 ohms.
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Not really
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Stevem
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Re: kt66 in 5f1
Well your PT has plenty of B+ current ( a problem in itself )and heater current but with the plate voltage you will be running your OTs impedance is not a great match so the end result will be the same wattage output as you would have from just running a 6V6 output, plus if that's a stock 5F1 OT your gonna burn it up with the 66 driving it and the current that PT has !!
Forgive me for asking, but what does the " my name is Kendrick "
Reference to at the bottom of your posting?
Forgive me for asking, but what does the " my name is Kendrick "
Reference to at the bottom of your posting?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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JoshBernstein
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Re: kt66 in 5f1
Thank you for your help again mr stevem. "Kendrick" is a nickname given to me by one of my musician friends that a lot of people call me.
Not really
Re: kt66 in 5f1
For some reason a few of the Monotone wiring diagrams are labelled as if they delivered twice as much current as they really can. This one says 330 - 0 @ 75mA and 0 - 330 @ 75mA. What this actually means is 330 - 0 - 330 @ 75mA. As others pointed out, if it's the stock OT, it's the size of a shot glass! The winding guage is likely too small to deal with anything other than 6V6 current and even if it could, the core would saturate with more than about 25mA of standing DC current. The preamp probably doesn't produce enough AC voltage to really drive a KT66 anyway.
Re: kt66 in 5f1
IOW, you'd need a serious redesign of the power supply and a new and expensive OT to use a KT66 with a 5F1 preamp. Done well, you might get something between 7W and 15W from it. This means it won't be much louder and you probably won't exploit the tube for tone.
SE operation is about 25% efficient. In part, that explains why you get less than 5W from a 6V6 and why you'd be lucky to see 15W from a KT66.
SE operation is about 25% efficient. In part, that explains why you get less than 5W from a 6V6 and why you'd be lucky to see 15W from a KT66.
Re: kt66 in 5f1
This is exactly right, it is a 75mA PT and it will run hot powering a KT66. I would have 120mA minimum.Firestorm wrote:For some reason a few of the Monotone wiring diagrams are labelled as if they delivered twice as much current as they really can. This one says 330 - 0 @ 75mA and 0 - 330 @ 75mA. What this actually means is 330 - 0 - 330 @ 75mA. As others pointed out, if it's the stock OT, it's the size of a shot glass! The winding guage is likely too small to deal with anything other than 6V6 current and even if it could, the core would saturate with more than about 25mA of standing DC current. The preamp probably doesn't produce enough AC voltage to really drive a KT66 anyway.
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Stevem
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Re: kt66 in 5f1
Why the hell does Mojo do that with there spec sheets?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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martin manning
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Re: kt66 in 5f1
I suppose because they don't know how transformers work. How about this: http://www.mojotone.com/transformers/Fe ... OJO768.pdf AFAIK all their OT spec sheets are done this way.Stevem wrote:Why the hell does Mojo do that with there spec sheets?
Re: kt66 in 5f1
To run a KT-66 in a 5F1, the KT-66 will almost run a little cold without rebiasing. Should you rebias, the output transformer will have a very hard time and eventually blow. Sure you replace the output transformer with the correct one the power transformer will run hotter than the output tube.
Thus a bigger transformer set is required.
Old news of course.
Thus a bigger transformer set is required.
Old news of course.
Yours Sincerely
Mark Abbott
Mark Abbott
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Stevem
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Re: kt66 in 5f1
Well Jesse Sharron who looks like is doing all of Mojo's diagrams needs around of education!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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JazzGuitarGimp
- Posts: 2357
- Joined: Mon Jul 23, 2012 4:54 pm
- Location: Northern CA
Re: kt66 in 5f1
Yes, all the way around....Stevem wrote:Well Jesse Sharron who looks like is doing all of Mojo's diagrams needs around of education!
Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture
Printed Circuit Design & Layout,
and Schematic Capture
Re: kt66 in 5f1
It would probably be easier to give him a specially designed meter instead. You know...with a "half switch" that actually doubles everything and a special label that reminds you to lick your fingers before you put them inside the equipment you're about to test.JazzGuitarGimp wrote:Yes, all the way around....Stevem wrote:Well Jesse Sharron who looks like is doing all of Mojo's diagrams needs around of education!