Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: nervous novice on April 15, 2010, 04:16:58 AM

Title: Foreplay 2 and anticipation question
Post by: nervous novice on April 15, 2010, 04:16:58 AM

I have a foreplay 2 that has a Hammond 369ax transformer and uses 5687 tubes. I also have a set of  Doc

Title: Re: Foreplay 2 and anticipation question
Post by: Paul Joppa on April 15, 2010, 06:25:05 AM

You will need to make some changes. Since this is a major modification of the Foreplay II, I'll need to know what the circuit values are now in order to guess what C4S changes would be desirable.

Title: Re: Foreplay 2 and anticipation question
Post by: nervous novice on April 15, 2010, 06:33:01 AM

Hi Paul, Thank you for the response.
I used the resistors that you posted a while back for using other tubes in a foreplay.

  They are:
        Voltage amplifier         Cathode follower   
   
 Tube       Ib       Rk      RL              Ib              Rk       VA

5687   0.004283 350    23,816       0.009493   5,451  19.60
I hope this is what you mean.
Thanks again,
N.N.

Title: Re: Foreplay 2 and anticipation question
Post by: Paul Joppa on April 19, 2010, 06:34:39 PM

Sweet!

The "Ib" column has the current for each section, and the C4S manual describes changing R1 to set the current. R2 will not have to change.

That was pretty terse, hope it's enough information. Post back if not.

Title: Thank you, Paul
Post by: nervous novice on April 20, 2010, 09:35:05 AM

Thank you very much. This is just one of the things that I love about Bottlehead. Not only do you have great sounding products, but the support is fantastic. I would also like to take this opportunity to thank everyone at Bottlehead, for not only producing these great kits, but, for introducing me to this hobby. I would have never attempted building these kits if it weren