Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ToneJunkie on June 16, 2024, 08:58:40 am

Title: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 16, 2024, 08:58:40 am
Bought a mojotone kit build off of facebook marketplace for $900.  It was working and after using it for a couple months it started having intermittent issues.  I found the issue but the lead dress and general build quality was not that great soooo.  I gutted it and rebuilt it.  I have not powered it up yet but will be doing that today sometime.  Just thought I would post some pictures.  The last several amps have been a Slucky layout and this one I wanted to try the layout from Lyle @ the youtube channel Psonic Audio.  Hope there is no smoke :-)
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 16, 2024, 09:05:59 am
Larger Pictures...
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 16, 2024, 09:07:36 am
Larger pictures...
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: Lectroid on June 16, 2024, 01:09:59 pm
Very clean work.  Impressive.
Title: Re: New Two Channel Deluxe AB763 build no trem (My favorite mods)
Post by: ToneJunkie on June 18, 2024, 01:33:44 am
I usually play through other AB763 amps that I have built.  Thanks to all that have helped me here over the years!
This one fired up with no problems so I just got to tweak it from the usual Deluxe Reverb values.

First off no trem and removed all associated parts from the build from the onset so I could use the control spots for the following.
Mids control for the reverb channel (in the speed slot) and a Vox cut control (in the intensity slot).  I actually started with a variable feedback control but decided I wanted to tame the highs a little and turns out I love this mod!  I can increase the treble from the tone controls and just attenuate a the end and I think it sounds and feels better.  I'm going to put it in to some of my other amps.  I increased the NFB slightly to 1k.  I think it feels better.  I wanted to tame the reverb a little and darken it.  I removed the cathode bypass cap on the reverb driver and put a .005uf cap over the grid leak of the reverb recovery.  I also removed the 47pf and 10pf bright caps.  I think that is about it.  It sounds great and is quiet.  I think I will just play it for a while and see if it needs anything else.  Here is the last gut shot. 


Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: Willabe on June 18, 2024, 02:32:47 pm
I see an Allesandro speaker in the cab. How do you like it? Looks like their ceramic?

Tone Quest Mag loves those speakers, both the ceramic and the alnico's.

It seems those and the new Fanes and Jupiter speakers are kings of the hill these days.
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 19, 2024, 11:10:39 am
I do like it... All of my other amps use celestion G12-65 speakers.  The thing I notice most is a little more high end.   I do like the feel.  I think one of the reasons I wanted the cut control on this amp especially was due to the little more high end but with the cut control its easy to dial in.  I'm very excited to play this amp live.  My next shows are the first week in July so we will see.  Here is a video of my new band and the style of music I play.


Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: tdvt on June 25, 2024, 02:32:57 pm
..this one I wanted to try the layout from Lyle @ the youtube channel Psonic Audio.

I meant to ask when you posted this, if you have a good rendering of the Psionic board layout?

I had checked out his design from a video clip but hadn't really studied it.



PS band sounds good, nice playing & recording
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: Tone Junkie on June 25, 2024, 03:24:26 pm
Saw this and went wait when did build one of these. lol wrong tone junkie
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: mresistor on June 25, 2024, 06:40:20 pm
Looks like a chassis board plates and all from Thailand.
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 27, 2024, 11:15:17 am
Two ToneJunkies :-0  I'm not sure what the Thailand thing is about but I just took a screenshot from Psonic and mocked up my own board... moved a couple things and moved forward. 
Title: Re: New Two Channel Deluxe AB763 build no trem (Its been years since my last one)
Post by: ToneJunkie on June 27, 2024, 11:18:14 am
Here is a recording of the amp in action... I think the reverb sounds pretty good.  Still working on the whole recording a band thing :-)