yeatzee
Member
- Joined
- Jul 21, 2016
- Messages
- 59
Decided to dive into the world of AC30's and go after my dream rig, the AC30 Super Twin (head and cab)! Long story short these don't come up often in the states so when one popped up locally I jumped at it. Was listed as all original but upon further inspection of the blurry photo's it had a few standout issues. Eventually settled on a price that gave me a buffer in case the issues were really bad and went to pick it up. Amp did not function well, no sound out of the trem channel, normal barely worked. Also had lots of pops/crackles, a weird cutout on the back of the head cab that wasn't disclosed, non-original celestion alnico silvers with one recone, etc. A slight basketcase, and that was without really seeing what was what on the inside.
Then as luck would have it, a second 60's copper top popped up locally, this time a combo which appeared to be much more original... so I bought that too. Here they are:
The end goal is to restore the super twin and make it gig-able, and potentially grab the original alnico blue speakers from the combo to complete the set in the ST. I've been dabbling with working on amps this past year, recently restored a '65 Vibrolux Reverb so I've got some reps under my belt but nothing with a vintage vox. Exciting project for sure! I decided to document the whole process on YT showing step by step, and fingers crossed when it's all done I've got a beautiful vintage AC30 of my dreams ready to go for another decade!
Here's the video kicking off the series, in it I open up the ST and show everything:
And if you can't be bothered, here are some gut shots:
Good news, mostly original and doesn't look too messed with. Bad news, replaced Power Transformer with a 70's AC30 Lemark. OT is an original albion. Top Boost appears to be a homebrew kit. According to the previous owner this was Mark Sampson of Matchless fame's amp. Who knows, but I wouldn't say the work done looks thatttt great.
The hardest part has been deciphering what is what, to me the amp is not laid out intuitively like a fender is. The grounds jump between both sides of the tag board, the tube order is bizarre, etc. And unlike a fender, there isn't a readily available layout to reference and the schematics are quite complicated due to the very crazy trem circuit which takes up like 65% of the tag boards. Eventually I found a home-drawn layout by some legend from years ago that I was able to use to cross reference and determine what's been changed and what is different on mine vs that guy's (also worth noting mine is a treble model, vs the normal model the layout is based on). I took diligent notes after reviewing everything very carefully and built out a game plan.
Direct link for zooming in
Circled in teal = replacing / questions. Black/yellow obviously notes for what is different with mine vs the layout or just general notes as I learn more about what I'm looking at. I recorded a video detailing my findings in the layout vs mine here:
After that I started my first soldering attempts. The tag boards are extraordinarily fragile so no solder sucker, the recoil will break them so lots of braid and patience.
Next up it's installing carbon comps where the resistors were swapped to carbon film to keep it as it was from the factory, and then also replacing the trim pot since it was the wrong value and the bypass caps since it's best practice to do so.
After that I tackled the screen and grid stopper resistors off the power tubes, very important on vintage AC30's as the stock values don't work well with modern voltages and modern glass. Also a very tedious job to do it right.
Been a massive project so far, not too far to go until it's done but wanted to share if there are any amp geeks on here
Then as luck would have it, a second 60's copper top popped up locally, this time a combo which appeared to be much more original... so I bought that too. Here they are:
The end goal is to restore the super twin and make it gig-able, and potentially grab the original alnico blue speakers from the combo to complete the set in the ST. I've been dabbling with working on amps this past year, recently restored a '65 Vibrolux Reverb so I've got some reps under my belt but nothing with a vintage vox. Exciting project for sure! I decided to document the whole process on YT showing step by step, and fingers crossed when it's all done I've got a beautiful vintage AC30 of my dreams ready to go for another decade!
Here's the video kicking off the series, in it I open up the ST and show everything:
And if you can't be bothered, here are some gut shots:
Good news, mostly original and doesn't look too messed with. Bad news, replaced Power Transformer with a 70's AC30 Lemark. OT is an original albion. Top Boost appears to be a homebrew kit. According to the previous owner this was Mark Sampson of Matchless fame's amp. Who knows, but I wouldn't say the work done looks thatttt great.
The hardest part has been deciphering what is what, to me the amp is not laid out intuitively like a fender is. The grounds jump between both sides of the tag board, the tube order is bizarre, etc. And unlike a fender, there isn't a readily available layout to reference and the schematics are quite complicated due to the very crazy trem circuit which takes up like 65% of the tag boards. Eventually I found a home-drawn layout by some legend from years ago that I was able to use to cross reference and determine what's been changed and what is different on mine vs that guy's (also worth noting mine is a treble model, vs the normal model the layout is based on). I took diligent notes after reviewing everything very carefully and built out a game plan.
Direct link for zooming in
Circled in teal = replacing / questions. Black/yellow obviously notes for what is different with mine vs the layout or just general notes as I learn more about what I'm looking at. I recorded a video detailing my findings in the layout vs mine here:
After that I started my first soldering attempts. The tag boards are extraordinarily fragile so no solder sucker, the recoil will break them so lots of braid and patience.
Next up it's installing carbon comps where the resistors were swapped to carbon film to keep it as it was from the factory, and then also replacing the trim pot since it was the wrong value and the bypass caps since it's best practice to do so.
After that I tackled the screen and grid stopper resistors off the power tubes, very important on vintage AC30's as the stock values don't work well with modern voltages and modern glass. Also a very tedious job to do it right.
Been a massive project so far, not too far to go until it's done but wanted to share if there are any amp geeks on here
