Sluckey's AC4

[Kev-W]

Hi, funny old world as I joined here the other year to thank the guy for his Dual Lite drawings so am back to thank him again :D, I'd been looking for similar for the AC4 and saw mention he had posted drawings so had a crack at building it, I plagiarised Sluckey's rotary tone control switch too, added his intensity mod and swapped out the trem cathode bypass cap & resistor for an LED.

It's in a Hammond 10"x6""x2" chassis that had had one of my 2 RobRob Deluxe Micros and using a 250 0250v pt & an Aliexpresss 5w ot, only snag was a low B+ (248vdc on the plate) but I changed the first dropping resistor from 1k to 150 Ohm to hit the 270 B+.

Nice sounding amp so I (hope) i linked a clip.

The name's a joke name btw not an entity.

[SEL49]

Congratulations! You may be the first to build this amp.

[Kev-W]

Congratulations! You may be the first to build this amp.

I'd found a few mentions of the amp on this site and a disclaimer he'd not built it, but having built his dual lite was confident it'd work, I'm not a tech but work with my hands so look for builds with both a layout & schematic, I altered the layout here so I could put the filter caps on the board as I already had some caps and I was using a smaller chassis, that's made a few hook ups longer than I'd have liked, and the valve bases aren't perfectly spaced as there were 2 holes drilled already, the ot also is hanging on it's side on a bracket as that was the only point I couldn't hear it with headphones.

It was tempting to not do the intensity mod as I had 3 previous pot holes drilled already but a faceplate's good for hiding things  and as it was untested I didn't know if it'd work, and as amateur builds are detective work, I did notice Sluckey mention to a poster (a few years back) who was trying to implement a part of a Fender circuit in the build and it wasn't working, that that might be why Vox didn't build it with one, which I guess had him thinking about it so he drew it up, and 'viola' there's an example of it!

My first attempt at DIYLC to get moving the filter caps in my head properly!

[Kev-W]

A couple more photos of the nearly finished amp, I've struggled with a lower than ideal B+ but I'm using a 80Milliamp ct transformer that previously ran a micro Deluxe with just a 12ay7 & 12au7, I've tried different forms of rectifier, (EZ 80 & EZ81, full wave ss diodes and a hybrid with the EZ80) but it's finished just using the EZ80 & 250v 0v 250v and a lower sized dropping resistor finishing at 7.3vdc on the cathode, 267 plate and a little under 100%mpd.

Not being a tech I've done a lot of reading about the voltages, I couldn't get a reading from either bypass cap so I changed them, but the ones I took out read ok when removed . It's been a fun build and the sound that comes out of the speaker isn't much different to the AC4 sound clips I can find on the web, tho the tremolo doesn't have that thumping noise.

The circuit board's not the usual artform you see on these boards and the new bypass cap has a long lead as a mate asked an Ai about the circuit and it criticed my work so I left the lead as so to wind it up if he asks again, there'll be a matching grill cloth on the top front of the amp when I find my stapler as it seems to be in a camouflage box.

Edit, the name plate name is humour rather than an amp building outfit, but it's where I live so puts a smile on my face 

[Kev-W]

Congratulations! You may be the first to build this amp.

The penny dropped  :icon_biggrin:Thank you for putting the drawings up! Folk like me who know a little and meddle are able to make amplifiers 'cos of stuff like that.