Hi folks!  I picked up a used 5E3 and I am loving it.  It was modded by the previous owner with Mercury PT and OT's.  Other than that it apears to be straight.

I have three questions though. 

1. The volume pots seem to have 3 modes, Off, Clean (1-2), and full blast (2+).  Working as designed or do I have some work to do.  i would like them to be somewhat more gradual.

2. When you are hot and come off of standby the amp makes a clicking sound.  Same thing when you come on from cold.

3. Regardless of pre amp tubes used including JAN NOS, the chassis is microphonic.  If you tap is with a metal object the sound gets amplified.

Thoughts?

Thanks Grod915! 

Mission amps looks like a great resource.   I am OK with the abruptness of the controls if they are working as designed.   I spoke with the guys at Mercury Magnetics and they say I have a ground loop.  I have exauhsted my personal tech skill at this point and am very lucky to have a very good tech in my area, Eric at Viking Amps.   I will be taking it to Eric this week.   

The tone I am getting out of this amp is nothing short of amazing.  All the roar of a tweaked marshall with the fat sassy soul only a Fender can cough up, all at once and at a volume that will not bring the cops.  I will be in amp heaven when the dynamo hum is sorted out.

All the best,
-p

The 5E3 will generally start to break-up somewhere around 3 on the Volume dial of it's channel.  And very shortly afterward, all you are doing to adding more saturation to the overdrive. 

Obviously where you have the unused Volume control affects your sound on a 5E3 and it can affect break-up a little as a result.  With the unused Volume around 6 or so, you get a lot of extra midrange, which will work against clean headroom.  With it around 10 or 11, you get the most scooped tone you can out of a 5E3, if you turn the unused Volume all the way up on to 12 most 5E3's (original or clones), it has a weird side-effect of killing much of the signal. 

Tone will also affect headroom, the brighter you turn the Tone knob the earlier the amp breaks up. 

You can tube roll to try and amp the preamp some.  The stock V1 for a 5E3 is a 12AY7 with a 12AX7 in V2 sharing duties as both the 2nd gain stage and the PI.  If you try and run a 12AX7 in V1, you'll get a lot earlier breakup.  But people have mixed and matched and found their own combos they like, which might include a 5751 or 12AT7. 

Fender built his amps for his guitars, they don't take humbuckers well, they overdrive early and get very boomy on bass (which Leo dialed in heavy to beef up single coils).  So, humbuckers will generally result in less clean headroom, P-90's can as well, just because the amp already has a lot of mid-range (which is a nemesis of clean headroom) and the Gibson-style PU's pour more on in droves.  Having that unused Volume up to 10-11 to scoop midrange is important as is using the padded input.

Make use of the padded (attenuated) input for more clean space on the Volume knob.  It's pretty much a must for humbucker or hot PU's, but it can really help when you want to play clean with traditional single coils as well. 

Don't use a Sovtek 5Y3, they are really 5AR4's in disguise and will raise plate voltages a good 40-50VDC which can push your tubes close to 100% dissipation (or more) unless the cathode bias resistor and cap are swapped to compensate.  Any good, old USA-made 5Y3 will be much better and they can be had NOS for the same price as the Sovtek, and used for less.  I recently bought 20 Tung Sol-labelled RCA-made JAN 5Y3's for $10 a pop on eBay.  Fender went to Shuguang to make their 5Y3 for their new 5E# clone, but they haven't made the tube available on the aftermarket yet. 

The Mission Amps mod is very popular, but it rebuilds the Volume controls and the Tone stack to be more like a Brownface Deluxe, so you are changing tone.

wow, that's great info Wyatt - I had noticed a change in tone when tweaking the other volume, but I didn't realise it was that sensitive. I'll try your suggested settings!

A couple of things I've done to mitigate low head room is to install a speaker with more headroom (a celestion gold in my case - 50w) for less cone breakup and use a 5V4 (if my memory serves me correctly) rectifier tube. Not sure what the technical reason is for this (something to do with voltage drop...?) but to my ears the deluxe is less compressed when above 2 on the volume and less distorted.

Otherwise mine is stock and when cracked the tone has a really great balance between clean and breakup - play gently and you have chimey cleans, dig in and you've got plenty of grit but not really super-saturated or anything... I'm liking it.

Those 5E3 amps are tiny little beasts