Fender 5E3 Deluxe Build

makepeace · 2010-08-23T19:51:36+00:00

Hi guys ? Within the next few months I'm going to be building a tube amp based on the 5E3 circuit and layout, with a couple of mods. The pre-amps, phase inverter and power stage will be stock (with a 12AY7 and a 12AX7 in the pre-amp unlike the two 12AX7 in fenders '57 reissue). My aim is to substitute the single control Fender tone-stack with a two control James stack, and to use a 5Z4 rectifier to start off with (its a cheaper 5Y3 workalike). Due to the James stack, it will probably have a single channel. James Stack: For the speaker I plan to use a Celestion G12-K80 (glowing reviews from Alan and Karel) to start off with, with the prospect of upgrading to a Greenback in the future when the budget is bigger ?. I will be getting the components and speaker from Karel, who has been excellent so far with helping me out (thanks Karel ?). The cabinet I will be building myself out of laminated meranti or pine plywood board with joists on the insides of the corners (can't be assed with finger jointing..). I'm thinking about a TV/Narrow Panel cross. It'll have the TV front, but with the Narrow Panel width and height and the angled front. Either that or it'll end up as a Narrow Panel. I quite like the aesthetic of the TV, but the functionality of the Narrow Panel (angled speaker does wonders for tone) is tops. I'm afraid that an angled TV might look funny ?. Also thought about a normal TV with an angled speaker board.. Opinions on TV vs Narrow Panel vs TV Panel vs TV angled speaker board? ? I'm still debating in my mind whether to cover it in Tweed or with one of these nice imitation leather fabrics: http://www.ugfabrics.co.za/swatchBooks/hides/Default.html. I quite like that white alligator pleather :-[. I would like your guys opinions regarding the traditional tweed vs pleather. I'm quite a purist, and would never.. retro-cover, if you will - an old amp, but seeing as this is my own build, I think it could be a cool touch ? Grill cloth will be either Mojotone's Gold Striped Oxblood: or the old brown cloth (used on the TV): This will depend on what looks good with the ultimatum of the covering material story. Ok, now for my first objective question ?. Does anybody happen to know, or would anyone be able to measure for me, the inclination of the front of a Fender combo? First prize would be the '57 Deluxe (but I'm sure any angled Fender combo will do). I'm just looking for a rough measurement so I can get designing the cabinet. Cheers, Jono

Charlie4

Just a question: Where are you purchasing the cloth and vinyl from ? (Pretty much in the dark about such matters) ???

makepeace

I actually decided to leave it uncovered in the end. Rather like the stained wood finish. I did buy material though (still have left if anybody is keen on it) from U & G. Google them and checkout the hides and outback catalogues.

makepeace

o. k. I need some collective thought from the possessors of tubely knowledge out there. I have hooked my input stage up as laid out in this schematic:

(right click->view image to enlarge)

essentially what you are looking at: the bf stack replaces the 0.1uF cap that is normally before the volume control sans tone control (the bottom one).

Stuff is not working properly. :-\

If I put the guitar into the tweed input and turn up the volume, tone control at 0, nothing happens. As soon as I turn the tone control up, there is sound. The same thing vice versa, if the vol control is at 0 and the tone control is turned up, nothing. As soon as I turn the tone control up, there is sound.

If I put the guitar into the BF input (tweed controls on zero), and put all the BF tone controls at the middle and turn up the volume pot, I get nothing. If I turn up the tone control on the tweed channel (even a little little bit), I get sound.

Now I've tested the stacks individually by disconnecting each from the output to V2. They both work. The BF and Tweed stacks are not agreeing when they join at pin 2 of V2.

Does anyone have any suggestions?

:goodtimes:

MikeM

Was thinking you should try run a blender after the volumes to decouple them from each other but the pots do that naturally anyway...

makepeace

redone all the input wiring, seems i had a ground connection to the tweed tone pot that shouldn't have been there, hence the double volume controls on the tweed side. used 100k mixing resistors between each channel and the grid input.

and...

............

everything is working!

i seem to be getting more volume and drive out of the tweed channel, probably because of the higher insertion loss of the BF stack?

anyway, it sounds great and I am super chuffed. thanks Mike for suggesting the mixing resistors.

will post some final build pics as soon as 1 more thing arrives in the post ?

MikeM

Congrats ? glad its working. Yep there should be a decent vol difference when both are on max, however jumping them should produce some awesome tones?

Norman86

Any new pics? Progress?

makepeace

Norman86 wrote Any new pics? Progress?

Just waiting for some engraving to be done on the chassis, then will have some final pics. Been too busy playing (fiddling) with it to get my act together ?

In the mean time, I have a couple of questions that hopefully I can get a little help with ?

1. the mixing resistor set up: at the moment i have outputs going from the 1st tab of the volume pot of each stack into a 100k resistor each, and then tied together and connected to pin 2 of pre 2. this is the most simple (and ineffective) way of separating the two stacks, and i've read that it will most likely result in premature clipping and thus distortion of the signal (which is happening at the moment) due to impedance irregularities etc not good for an amp that has low clean headroom to begin with.

does anyone have any ideas of doing this that doesn't involve solid state components? could i take the output of each stack into an on/off/on switch? if i'm right, this will result in the stacks having zero interactivity, which isn't necessarily a good thing... any other ideas?

2. the amp is veeery quiet, but there is definitely a little bit of hum. i have tracked it down to the line coming from the blackface stack's volume pot into it's mixing resistor. if i move my hand close to it, or any other object for that matter, the hum increases in volume. when i move the guitar with its pickups right close to the line, it vibrates the house..

any ideas?

3. i found a nos general electric 12AY7 tube to substitute the new production Electro Harmonix 12AY7. it sounds really great for the most part, but its a tiny little bit hissy when using the tweed stack, either by itself, or jumped with the blackface stack. there is zero hiss when using just the blackface stack.

?

Gearhead

1. Each output gets its own cap into the next stage;
2. Have you used coaxial wire and grounded one side?
3. Not everyone saved up the good tubes for the twenty-first century. NOS tubes may be well built, but most of them are off spec since they used up the nice ones first.

makepeace

Gearhead wrote 1. Each output gets its own cap into the next stage;

Great! Does it matter what values I use? Can they be different from each other? If so, what will effect will that have?

Gearhead wrote 2. Have you used coaxial wire and grounded one side?

Nope, will try that out. Thanks ?

Gearhead wrote 3. Not everyone saved up the good tubes for the twenty-first century. NOS tubes may be well built, but most of them are off spec since they used up the nice ones first.

Cool, I thought it was the tube.. Its strange that its only happening on the tweed side though don't you think?

Thanks Gearhead :goodtimes:

makepeace

some feedback:

i replaced the hummy line with coax and i now have zero audible hum ?

replaced the mixing resistors with first 0.022uF caps and then i tried 10uF caps. the 10uF caps caused a serious drop off in low frequency response. the 0.022's seem to work fairly well, there is still some interaction between the two stacks. haven't turned it up yet though. is there another value i should be aiming for?

Gearhead

Too big coupling caps give oscillation ('motorboating'). Rather big caps give flabby bass. A bit small small caps give tight bass and too small caps give loss of low. All safe to be tried.
A combination of coupling caps and blend pot might be your solution, dunno. Maybe one day in the distant future, when this Gearhead will ascend into tube-guru-ness, I will be able to explain these things (preferrably in very esoteric ways), but for now I dunno.

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