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

[Curranproducer]

very cool!!! I am going to work on this a bit today and then enjoy some more!! I also built a nice little headshell at work from some scrape MDF board, BUT I am not sure how to bolt the chassis to the headshell, the hammond chassis has small holes on each corner flange under the chassis, but I am not sure how to mount it up

[martin manning]

For mounting the chassis you will need some kind of captured nuts on the inside, or if the head shell is wide enough you can attach some pieces of aluminum angle to the ends and then bolt through those to mount it.

BTW, I believe the mini switches should all be on-none-on (2 pos) type.

[Curranproducer]

do I need to worry about any mind of voltage rating on the SPDT switches? or can I just use some mini switches I have here at the guitar shop?

[martin manning]

If they are the typical 1/2" mini toggles rated at 125v 6A they will be fine.

[Curranproducer]

got all the new components for the trainwreck mods, for the 50r 25W resistor
I went with a 50watt since I could not find a 25w version at my local shop. I am also changing the 100r, and 1k5 resistors on the power tubes to the higher wattage rating of the train wreck. the vox resistors are only 1watters. I am doing the PPIMV mod as well as changing up the coupling caps to .047uf from the .1 that is on the original ac30. do I remove the 100k resistors after the PI tube for the PPIMV? and the 2M2's replace them on the dual gang pot correct? I am leaving the power filter section alone with the 22k's and 10k pots between the filter caps. and I am keeping the filter caps the same as well. will this still be OK or am I going to be missing that wreck tone if I dont do the mods? I have the can multi filter caps in there right now

[Curranproducer]

I am changing the resitor/cap combo coming off of the power tube cathodes from 50r/10w and 250uf/25v for the 50r/25w and 220uf/100v .

[martin manning]

Yes remove the 100k's, they are replaced by the dual pot elements. The Rocket has 220k bias feed resistors (not 100k), so use a 250k dual pot and 2M2 safety resistors. That replicates the 220k. Do replace the 100n PI coupling coupling caps with 47n... that value goes with the 220k bias resistors to set the HF roll-off from the PI into the power tubes.

[M Fowler]

Follow this guide.

[Curranproducer]

Still goofing around with turning my AC30TB into a wreck, BUT I have another curious question. WHERE is the slope resistor typically found in a tone stack? is it usually in a standard spot in the schematic of every tone stack? or something unique from amp to amp. there are so many similarities in tube amps that I am wanting to see what the answer is

[martin manning]

The "slope" resistor is peculiar to the Fender tone stack, which Marshall and Vox copied. This network is most often drawn in a ladder form, as shown on the Rocket schematic, but it is identical to the AC30 TB. The slope resistor is R8.

[Curranproducer]

now I feel like a real dope. where does my B+3 wire go to after pulling the 100k resistors from the .1uf coupling caps? Do I just put a jumper wire between the new caps and the old B+3 connection on my circuit?

[martin manning]

Are you sure you removed the right 100k resistors? The two that go to the plates (pins 1 and 6) of the PI stay, along with the b+3 connection there. The ones that are on the other side of the 0.1 (or 0.047) PI-to-power tube grid couplers are the ones that the pot elements will replace.

[Curranproducer]

OK GOT IT!!! I was looking at the WRONG part of the layout, and I did not have a schematic to go off of!! woo hoo this website and you guys are awesome!!!

[Curranproducer]

OK finally got the time to throw something together last night at the studio!! I am out of guitar shape so be NICE!!!! This is the AC30 through a Mesa Dual rec traditional cab with an SM57 on it. it is going into an API preamp I built and then into an 1176 compressor I built(bypassed though) into my Yamaha O2R96 console and recorded with reaper DAW. the bass is my 2004 P-bass with a Dimarzio P pickup into a Sansamp bass driver through the API and with the 1176 squeezing it nicely. Drums are form my buddies at Toontrack(love the software). The guitar is my ESP 400 series 50's strat in torino red with the maple fretboard that I have aluminium foiled for noise, and re-did the radius and fret wire to for a more modern feel. 10-52's from D'addarrio, and tortex purple sharpies, the drive pedal in there from time to time is the S7G 7drive pedal that I build for Strictly 7 Guitars here in ohio. I did NOT pull out the 7 Strings for this because I wanted to offer you all something a little more traditional in sound and tone. enjoy

[Curranproducer]

sorry I posted that clip twice