building a Vox AC30 from the Tino Zottola book!!!

[Reeltarded]

Hey! Look! Someone built an amp around here for a change. lol

[Curranproducer]

Yeah I build for Jim Lewis of S7 Guitars, and yes I had to bolt, my lovely wife was starving for Delmonico steaks on the grill(and so was I !) i am going to do a video thingy tomorrow with my S7 pedals on the front end for some fun!!! man I thought that red/yellow WAS my CT for the entire tranny. so glad I figured it out though. NOW I want to try doing the plexi jumper move with the inputs

[Curranproducer]

I am loving it. I could never afford to buy an AC30 for my studio but since I have started this little DIY adventure I have an amazing new amp in the stable!!! Dual Rec, Mesa MKIV, Hand made marshall jcm 800, 5watt plexi/Epi Vjr, 1watt marshall Jcm800, Peavey JSX, and a soldano hotrod 50. NOW I get the Tom Petty tone as well!!! and I think this will actually sound better than a production amp from any company out there. Getting to snob it up on the orange drops seems really nice! any info on doing a POST PI MV for the amp?

[M Fowler]

https://tubeamparchive.com/download/file.php?id=28257

[martin manning]

That's the ticket, but this thing is cathode biased, so the blue wire from the bottom of the MV pots that is shown in the drawing (going to a dead-end on the board, which is actually the bias supply) will go to ground, at the bottom of the cathode resistor.

[Curranproducer]

OK, I am at my studio getting ready to record some audio and post it up for you guys, when all of a sudden the amps volume drops down to whisper level!!!! no sparks, no smoke, just super super quiet sound. it happened after I was tapping on the map chassis to find a harmonic ringing that is occurring in the signal chain. so I discharged the caps with my wire wound resistor/alligator clip setup and checked to see if any wires are touching the chassis in the master volume/ tone stack part of things and it all looks good or if I am grounding out some where else. any help or ideas would be great. I have been playing through it fro about an hour or so into my Mesa recto cab and loving the hell out of it. this JUST happened, all the Filaments are good, and the trannies are all cold to the tough

[martin manning]

Some point in the signal path could be grounding out, or something could have gone open due to the shaking you've given it by playing. Since you had no fireworks or smoke, it is likely to be a signal issue. You just have to start narrowing it down... Try swapping tubes just to rule that out, and I like to get voltages at all tube pins to see if the DC operating points look reasonable. Is the problem on all inputs? if so then the problem is likely to be after the point where they are mixed.

[M Fowler]

Here is a layout a tag member posted I really should people's names on these so they get credit. FOUND IT
https://tubeamparchive.com/viewtopic.ph ... verb+combo


PPIMV in cathode bias amp

[Curranproducer]

yeah it is on all four inputs. so I will go and check the dc voltage's on all the pins correct and report back

[Curranproducer]

SO i have been sifting through the trainwreck pages and found a post that says the trainwreck is really just the top boost part of the ac30 with some little tweaks don to it. IF this is true awesome! and if so what are the wteaks and could anyone put up a list to show me. I was planing on building a trainwreck next BUT if my top boost home brew is close then to heck with it i will do some tweaks!

[Curranproducer]

I also found my problem with the sound cutting out, Love the chop stick poke test. found a cold solder joint on the terminal board. Discharged the caps and put some new solder flow on there and BAM!!!! AC30 tone for days!

[rock_mumbles]

SO i have been sifting through the trainwreck pages and found a post that says the trainwreck is really just the top boost part of the ac30 with some little tweaks don to it. IF this is true awesome! and if so what are the wteaks and could anyone put up a list to show me. I was planing on building a trainwreck next BUT if my top boost home brew is close then to heck with it i will do some tweaks!

The Trainwreck Rocket is Ken's take on a (simplified) TopBoost AC-30

[Curranproducer]

DUDES......................... after serious review and major busy schedule at the shop and the studio, I finally have some time to plan out the THREE mods I need to do to make my AC30 into a trainwreck. NOW I am ready to pop some video links and clips for the amp, I am going to do this over the coming days I guess, and then I am going to mod it into a trainrocket. I am also going to pop in the MV. In the post up above with the MV verb rocket there are what appear to be some mini switches on the amp. are these all three way mini's? or two way mini's. just a little hard to tell. Thanks again for all of the help and infi

[M Fowler]

Look like two are SPST, the other look like SPDT.

[martin manning]

I make it three are SPST and one is SPDT. I added in the missing wires from the green "lugs" to the appropriate ground points. Just get a bunch of SPDT and wire them as needed.