Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Mike_J on March 08, 2021, 02:56:17 pm

Title: Rearranging the Hoffman LTP resistors for ecap placement purposes.
Post by: Mike_J on March 08, 2021, 02:56:17 pm
In the Hoffman layout the row normally given to grounds on a Hoffman chassis are given to the LTP resistors so they can have a little extra length. Planning on moving the resistors back a row which will make them shorter. Also will allow more room to give some distance between the last ecap and the .02uF cap between the treble pot wiper and the entry to the LTP at V3-2. Don't know exactly how much room I would need between them but I think I could come up with about 1/2" which I think should be enough. A picture to give an idea of what I am talking about is attached.


Thanks
Mike
Title: Re: Rearranging the Hoffman LTP resistors for ecap placement purposes.
Post by: Mike_J on March 08, 2021, 03:13:57 pm
Not so sure this system couldn't be modified a little so every ground could end up connected in the appropriate space according to Aiken and Merlin and wind up grounding at the chassis near the input jacks and only at that spot. This seems to be a solution Merlin likes a lot. Any comments would be appreciated.


Thanks
Mike
Title: Re: Rearranging the Hoffman LTP resistors for ecap placement purposes.
Post by: acheld on March 08, 2021, 03:53:45 pm
Maybe I have misunderstood, but I always thought that PI grounding went along with the output section . . .
Title: Re: Rearranging the Hoffman LTP resistors for ecap placement purposes.
Post by: Mike_J on March 08, 2021, 05:47:57 pm
Quote from: acheld on March 08, 2021, 03:53:45 pm
Maybe I have misunderstood, but I always thought that PI grounding went along with the output section . . .
If you look at the 5f6a layout the presence pot which is the part of the tail resistor for the LTP is connected to the buss bar the preamp uses and is grounded at the input jack. Has had me confused for at least a week and maybe longer. Pretty comfortable now though thanks to help from pdf64 and others along with some reading that was recommended.


Thanks
Mike