JojoD818 said:That was quick Tim. I would not need a tone control, just plain line stage is what I had in mind. Been searching the net for a foreplay schematic but can't find one except for a modified foreplay with 6N1P tubes.
JojoD
I don't know anything about the Foreplay so I just posted my preamp.
For a straight-up line amp you can just run the 1st triode plate on to the 2nd triode's grid. Note that V1's plate voltage biases the cathode follower!Tim
Hello,
I would recommend the preamp design published in Glass Audio by Buce Rozenblit. The article is republished in Rozenblit's "A Beginners Guide to Tube Audio Design", which is where I found it. I built it and use 5814A's. It drives a 1969 JLH 10 watt class A amp into Klipsch speakers and sounds terrific. It is also very inexpensive and simple to build (it was my first audio project).
Mike L.
I would recommend the preamp design published in Glass Audio by Buce Rozenblit. The article is republished in Rozenblit's "A Beginners Guide to Tube Audio Design", which is where I found it. I built it and use 5814A's. It drives a 1969 JLH 10 watt class A amp into Klipsch speakers and sounds terrific. It is also very inexpensive and simple to build (it was my first audio project).
Mike L.
jojo, you will not find any Foreplay schematic on the web because it is copyrighted material.
bottlehead used to sell the Foreplay manual for $35 and is a great value. send them an email if they will still sell it, and ask them to ship via USPS to save cost. if they say they won't sell it anymore, i have another suggestion -
you said "like the Foreplay", now, the Berman 76 preamp is floating on the net. the Foreplay uses the same topology. you can also look at JE Labs version of it from Joseph Esmilla's site. from that schematic, you will be able to figure out how to convert it to 12AU7, all you have to do is to put in the AU7 operating points. the good thing here is that you can actually design your own. i'm sending you all my Norman Crowhurst articles (yup, i found them) which is a good starting point.
i'm sure you are deeply in love with tubes by now and i suggest an investment on SE Amp CAD and TubeCAD will be worth while. I use them a lot to give me a starting point when building something. Let's give these guys at TubeCAD a favor by buying the legit copy for a very reasonable price more information about the software here - http://www.glass-ware.com/ online purchase and other goodies from www.tubesandmore.com
cheers!
bottlehead used to sell the Foreplay manual for $35 and is a great value. send them an email if they will still sell it, and ask them to ship via USPS to save cost. if they say they won't sell it anymore, i have another suggestion -
you said "like the Foreplay", now, the Berman 76 preamp is floating on the net. the Foreplay uses the same topology. you can also look at JE Labs version of it from Joseph Esmilla's site. from that schematic, you will be able to figure out how to convert it to 12AU7, all you have to do is to put in the AU7 operating points. the good thing here is that you can actually design your own. i'm sending you all my Norman Crowhurst articles (yup, i found them) which is a good starting point.
i'm sure you are deeply in love with tubes by now
and i suggest an investment on SE Amp CAD and TubeCAD will be worth while. I use them a lot to give me a starting point when building something. Let's give these guys at TubeCAD a favor by buying the legit copy for a very reasonable price more information about the software here - http://www.glass-ware.com/ online purchase and other goodies from www.tubesandmore.comcheers!
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