Combined AC30 Schematic

[randalp3000]

Got this killer book awhile back from England called
A Service Engineer's Guide to the Vox AC30 Valve Amplifier
by Stephen Grosvenor
http://www.thevoxac30guide.com/

so I made a combined schematic of the different models without the trem channel.

I tried to attach the jschem file but I guess they are not allowed...


Update, put the cut circuit in the correct location

[rock_mumbles]

Nice!

It would be nice to have the editable schem ...

[10thTx]

It would be nice to have the editable schem

Here is a SCH editable schematic that you can edit to more appropriately match Randalp3000's schematic.

They're not quite the same currently.

With respect, 10thtx

[Masco]

At least one channel should be routed to the unused PI input, IMO. I prefer using EF86 channel for this and eliminating the 220k mixing R as Vox did for the AC-30/4. Others that want all channels in-phase for input jumping can route the TopBoost channel instead to that input.

[Masco]

Got this killer book awhile back from England called
A Service Engineer's Guide to the Vox AC30 Valve Amplifier
by Stephen Grosvenor

so I made a combined schematic of the different models without the trem channel.

I tried to attach the jschem file but I guess they are not allowed...

What a great idea. That JMJ fella does an amp like this with power scaling.

[chief mushroom cloud]

Got this killer book awhile back from England called
A Service Engineer's Guide to the Vox AC30 Valve Amplifier
by Stephen Grosvenor

so I made a combined schematic of the different models without the trem channel.

I tried to attach the jschem file but I guess they are not allowed...

What a great idea. That JMJ fella does an amp like this with power scaling.

[Masco]

Can't blame him Chief MC, if I think he's the right person, he just picked up a JMJ-30 from someone that let it go on TGP. Looks to me like it's about to become a platform for tweaks

[chief mushroom cloud]

Can't blame him Chief MC, if I think he's the right person, he just picked up a JMJ-30 from someone that let it go on TGP. Looks to me like it's about to become a platform for tweaks

NOOOOOoooooooooooooo!

[renshen1957]

Got this killer book awhile back from England called
A Service Engineer's Guide to the Vox AC30 Valve Amplifier
by Stephen Grosvenor
http://www.thevoxac30guide.com/

so I made a combined schematic of the different models without the trem channel.

I tried to attach the jschem file but I guess they are not allowed...


Update, put the cut circuit in the correct location

Hi

I purchased a copy of Ebay, several years ago, killer book on AC-15, AC-30/4, AC30/6 treble, normal , and bass variants.


Cheers,

Steve

[randalp3000]

Can't blame him Chief MC, if I think he's the right person, he just picked up a JMJ-30 from someone that let it go on TGP. Looks to me like it's about to become a platform for tweaks

These comments have been haunting me for some time and I couldn't figure out where it was coming from. But now I get it, duh...

Yes I did have the pleasure of purchasing a JMJ30 awhile back as part of my vox quest(it is by far the best one I have by the way). Please be assured gents that no harm will come to this beautiful amp. This amp needs no tweaks and I have plenty of my own builds to tinker with.

So whoever built this amp , thanks much. A TW size version would be killer, maybe with 2 channels.

rp

[Masco]

Can't blame him Chief MC, if I think he's the right person, he just picked up a JMJ-30 from someone that let it go on TGP. Looks to me like it's about to become a platform for tweaks

These comments have been haunting me for some time and I couldn't figure out where it was coming from. But now I get it, duh...

Yes I did have the pleasure of purchasing a JMJ30 awhile back as part of my vox quest(it is by far the best one I have by the way). Please be assured gents that no harm will come to this beautiful amp. This amp needs no tweaks and I have plenty of my own builds to tinker with.

So whoever built this amp , thanks much. A TW size version would be killer, maybe with 2 channels.

rp

Guilty.
It sounded like you were going to do some experimentation w/ coupling caps Glad you're enjoying it as is. There's quite a lot of tonal options in those 3 channels for single coils and humbuckers. Every channel has it's own thing going and covers a lot of AC-30 ground.
Cheers!

[M Fowler]

Off subject but still AC30 I like the way this guy built his chassis and mounting.

http://www.youtube.com/watch?v=XaJx9buy_TY

[Masco]

I like that chassis, but I prefer my EL84s upward vertical instead of upsidedown. I've done upsidedown in other builds and they tend to rattle, especially if you use modern manufactured EL84s.

Here's my traditional style chassis: http://img594.imageshack.us/img594/8900/jmj30upper.jpg
http://img580.imageshack.us/img580/5743 ... bottom.jpg

Power scale control on the far right.

[randalp3000]

She's a beaut clark.. looks familiar, wish I had the new pull boost.

side topic

What output transformers have you tried and what are your faves? I have a couple amps with different Mercury's and they all sound great. I have a build with a Hammond vintage ac30 copy that sounds really good. I also have a well known AC style amp with a Heyboer ac30 ot that just sounds like ass no matter what I do or what update mods the builder sells me. This amp is too bright/harsh and too bass heavy. I even replaced the linear taper pots in the tone stack with correct audio taper so my settings are where they should be.

[randalp3000]

Off subject but still AC30 I like the way this guy built his chassis and mounting.

http://www.youtube.com/watch?v=XaJx9buy_TY

I like the built in fan. I noticed on my hot summer gigs that my Z Wreck would start to loose headroom and sound a bit week and crappy after it got really hot. So now I have a kinda big, ugly, white clip on fan that I use all the time and my amps run nice and cool and sound more consistent.