Outboard EF86 channel mod for AC30s

[paologregorio]

Now here's a cool mod a friend of mine informed me of yesterday; an outboard, EF86 tube channel in a box that mounts on the rear side of AC 30s and is hand wired in. Included in the unit is an EF86 tube. The cost is £100, so get out your exchange rate calculators if you want one.

It generally mounts as follows, though if one wants to cut a hole in the upper back panel as is done for early AC30s with the add on top boost mod, the unit can be added on that way as well if desired:

Check out more about it at this link. There is no separate website so far as I know-just an email address for orders: http://vintageamps.com/plexiboard/viewt ... =2&t=83447

[paologregorio]

Interesting; I thought I'd get more looks at this one. Oh well.

[kennyhowes]

That does look cool! EF86 Voxes sound yummy.

[8mileshigher]

Which one of your AC-30 models are you installing this mod on ?

[whojamfan]

I'm on that site fairly often myself and could probably look this up, but how exactly does it install in the amp? Is a tech required?
Is it footswitchable? Can you blend it with 1 or the other or both of the stock channels?
Looks interesting, I'll have to check it out over waffles sometime

[paologregorio]

Which one of your AC-30 models are you installing this mod on ?

None yet. I thought I'd play through my AC30 HW model, which has an EF86 channel, a bit more to see if I like it enough to purchase the mod. Hey, maybe I'll bring it to our rehearsal tonight!

I usually just play through the top boost channel on AC30s, so we'll see. My friend Dan, who sent me the link, plays through the TB and EF86 channels together.

If I like the sound enough, I might end up adding it to both the CC2X and my vintage AC 30, the latter of which lacks a low power option, of course.

[paologregorio]

I'm on that site fairly often myself and could probably look this up, but how exactly does it install in the amp? Is a tech required?
Is it footswitchable? Can you blend it with 1 or the other or both of the stock channels?
Looks interesting, I'll have to check it out over waffles sometime

The EF86 channel mod is a separate channel entirely, without a foot switch, though that's not all that surprising, since AC30s do not come with a FS that allows one to change channel-s-cool idea though. One could probably pay extra to have an additional channel blend switch, as is discussed on page one of that topic thread, that would allow one to blend the EF86 channel with other channels, though that would require more wiring, as would a foot switch that did the same thing!

If one feels reasonably competent, one can solder in the leads to the amp oneself, or else leave it to an amp tech. My friend wired the unit in himself, and he's only started fiddling with amps over the last year. When the order for the unit is placed, the builder will ask what year and model AC30 the unit will be installed in, for which he will send instructions specific to that year and model AC30, for ease of installation.

Chatting about it over waffles at my place sounds great Mike; as I've said before, just park your rig in front of the house here- and the next door neighbor's, and the guy next door to him...and the house beyond that...and...

[soundmasterg]

I hope the guy who makes those is using shielded cable for the grid leads....and even with that, I bet it makes the amp noticeably hummier. Sounds like a cool mod though. One of these days I'll just build myself an AC30 with an EF86 channel, but too many other projects at the moment. The current one is that I'm making myself a modified Vox AC100.

Greg

[whojamfan]

[/quote]Chatting about it over waffles at my place sounds great Mike; as I've said before, just park your rig in front of the house here- and the next door neighbor's, and the guy next door to him...and the house beyond that...and... [/quote]

No lie on that one

Taking any AC100 orders Greg?

[soundmasterg]

Chatting about it over waffles at my place sounds great Mike; as I've said before, just park your rig in front of the house here- and the next door neighbor's, and the guy next door to him...and the house beyond that...and... [/quote]

No lie on that one

Taking any AC100 orders Greg? [/quote]

Ha.....maybe eventually, though I need to build this one first. I'll post info and pics/sounds of it when I get it done. Keep in mind this one is a modded Sovtek MIG 100U that I am making into a modded AC100. I'm keeping the single channel of the vintage AC100 mostly stock and adding a higher gain channel, and some channel switching to get channel A, B, A+B, a half power switch, cathode bias or fixed bias (to get both AC100 models) and a footswitch to do the channel switching in addition to the panel switch. I'm keeping the Sovtek power transformer because the voltages from it were very close to what is needed, but I did spring for a Heyboer vintage AC100 choke and output transformer. I did add master volumes to both channels to make the amp more useable. I also added a cut control from an AC30. Since this is in a Sovtek head it will not look the same as the Ac100, though I'll recover with Vox tolex and put my own nameplate on it. The head is about as big as a full size 100 watt Marshall head.

If I was going to build these to sell, I would use all Heyboer transformers, or Mercury Magnetics if the customer wanted to pay the extra coin, and I'd want to refine some things from my build. If anyone is interested in one after I get this done and you can see/hear the amp, then we can go from there. I appreciate the interest.

Greg

[paologregorio]

I hope the guy who makes those is using shielded cable for the grid leads....and even with that, I bet it makes the amp noticeably hummier. Sounds like a cool mod though. One of these days I'll just build myself an AC30 with an EF86 channel, but too many other projects at the moment. The current one is that I'm making myself a modified Vox AC100.

Greg

Ah interesting; the plexi palace forum thread doesn't mention any increased hum, and the fellow seems to know what he's doing wrt design, so perhaps he's included leads shielded sufficiently to eliminate the hum...then again, he might be of the same mentality as those who designed Lucas electrics, and vibrating, leaky BSA and Triumph motorycycles, so a bit of extra hum might not be of any consequence to him...

[soundmasterg]

The original Top Boost mod that added in to the back of AC30's was famous for increasing hum levels, but back then people didn't care as much since everything was tube and hummed a bit. It wouldn't surprise me at all if this add on you mentioned hums more....guess someone would have to try it out and report back.

greg

[8mileshigher]

he might be of the same mentality as those who designed Lucas electrics, and vibrating, leaky BSA and Triumph motorycycles, so a bit of extra hum might not be of any consequence to him...

Oh, Lucas electrics .... there's a nightmare Having owned both MG and Triumph sportscars in the 1970s I know all about great quality, over-priced Lucas stuff...

[paologregorio]

he might be of the same mentality as those who designed Lucas electrics, and vibrating, leaky BSA and Triumph motorycycles, so a bit of extra hum might not be of any consequence to him...

Oh, Lucas electrics .... there's a nightmare Having owned both MG and Triumph sportscars in the 1970s I know all about great quality, over-priced Lucas stuff...

Yep: "Lucas, Prince of Darkness"..."Lucas; Gentlemen do not go motoring about after dark".

AC30s definitely have their quirks of construction as well; hard wired speaker leads except for on the Korg TBX and HW models, which leads to difficulty in remving the chassis enough to service some components, as well as the wooden tray that the chassis is mounted to, which requires removal of the chassis from in order to access about half of the components of the amp-definitley not the elegant, accessibly simplicity and ease of maintenance that Fender amps have, but I love AC30s nonetheless.

Back to the hum question; I suppose one could ask the builder; come to think of it, I'll ask him myself and get back to everyone with a reply.

[soundmasterg]

LUCAS stands for "Let Us Create A Short."

I've got Smiths gauges and LUCAS electrics in my 1969 Volvo 1800S......needless to say, when I get around to restoring the car I'll be completely rewiring it.

Greg