Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: p2pAmps on April 03, 2020, 05:35:37 pm

Title: AB763 - One Channel - no/tremolo Project
Post by: p2pAmps on April 03, 2020, 05:35:37 pm
Hello team,

This is a project I'm just starting to play with.  An AB763 / One Channel / no-tremolo.  A few things you will see is the 1M resistor missing in the reverb circuit.  I will be adding a dwell control in place of that thus the extra set of brown and yellow twisted wire.  The 51K resistor you see is a tremolo load resistor. 

So...  I am all ears for you experts that see my short comings.  Please come fourth and tell me what I may have missed or just plain messed up.

Cheers and stay safe
Mike

(https://images.squarespace-cdn.com/content/v1/56fbe87462cd94ff6ec9d02c/1585953093338-RJ9UPA680FL0IHOANFN5/ke17ZwdGBToddI8pDm48kI92NeKnLg7XBAc64xNsWpR7gQa3H78H3Y0txjaiv_0fDoOvxcdMmMKkDsyUqMSsMWxHk725yiiHCCLfrh8O1z5QHyNOqBUUEtDDsRWrJLTmLLxGPZs9cXJqW7PQ94qJw5O9wQm9af9u3DSkF--A8RYMyAtpGhc92cTkcSDMVHln/IMG_9816.JPG?format=2500w)
Title: Re: AB763 - One Channel - no/tremolo Project
Post by: sluckey on April 03, 2020, 05:52:31 pm
Clean and neat as always. Schematic tells all.
Title: Re: AB763 - One Channel - no/tremolo Project
Post by: purpletele on April 03, 2020, 07:44:24 pm
Hello team,

This is a project I'm just starting to play with.  An AB763 / One Channel / no-tremolo.  A few things you will see is the 1M resistor missing in the reverb circuit.  I will be adding a dwell control in place of that thus the extra set of brown and yellow twisted wire.  The 51K resistor you see is a tremolo load resistor. 

So...  I am all ears for you experts that see my short comings.  Please come fourth and tell me what I may have missed or just plain messed up.

Cheers and stay safe
Mike


Mike,

What chassis are you going to use?  Are you using a Cap Board and where will you mount it?
Title: Re: AB763 - One Channel - no/tremolo Project
Post by: tubeswell on April 03, 2020, 08:40:45 pm
I did a 1-channel AB763 circuit sans verb and trem, and instead of pre-amp attenuation I changed the TS to a James TS, which is set up in such a way to give flat response with pot rotation at 50% and wide range or adjustment for treble and bass. Also has a 'raw' (TS lift) switch for really basic extra grunt.