Humbucker mod

[The Captain]

Hi ya'll. Can someone tell me what I add/ subtract for this mod? Ive trawled web but specifics are eluding me- I notice an added cap paralleled with the bright channels' 100k, is this part of it? Appreciate any help, Capt

[RickyD]

Bruce Collins at Mission Amps sells a humbucker mod for the 5E3.

[jlatrace]

Have you tried jumping the two channels and playing with the mix of the volume controls? Doing so on my 5e3 makes a substantial difference in tone when using humbucker guitars. While still very dirty, it brightens up the tone in a way that only the bright channel cannot, eliminating the "woofy" of the normal channel and the "ice picky" of the bright channel.

[The Captain]

Yes Ive tried that- it doesn't help the woofy bass, just adds more to me. What Im after is to add a ton MORE 'Icepicky' top and/ or substantially cut the bass; as even with tone at max, 1uf bypassed caps (I tried 10 and then 4.7ufs too all which, along with the .002 coupling cap redos, make absolutely no difference to the stock caps/ sound to me) and even a 680pf silver mica for the 500pf tone cap (maybe Ill try a 2000pf)- Its still a dark bass monster!

[The Captain]

Bruce Collins at Mission Amps sells a humbucker mod for the 5E3.

Yes I did notice this, but post to Uk etc and the fact that no doubt its just a an odd cap and resistor I thought it would be info folks would share around.

[jlatrace]

Replace the coupling caps with those that pass less bass. Look at the fender Blackface schematics, try .022's in both stage 1 and stage 2 instead of the .1's.

[The Captain]

Replace the coupling caps with those that pass less bass. Look at the fender Blackface schematics, try .022's in both stage 1 and stage 2 instead of the .1's.

I did this along with other cap changes mentioned above- but hear no difference really. Cant anyone tell me what the mod for humbuckers is? its my final try to rid the bass before ditching this 5e3 lark for good.

[TD_Madden]

I've built a couple 5E3s and use them with a number of humbucker-equipped guitars (actually all guitars have Seymour Duncan '59s in them). Neither of the amps seem too bassy to me (with either 12AY7 or 12AX7 in the first position)...using a RedFang in one and a Vintage-30 clone (from WareHouse Speakers) in the other. I've used other speakers as well (but decided not to keep the Celestion Blues in them...why take a chance when you play with the volume on 10 most of the time?).

The tone (and volume control range) is a bit smoother in the one that has Bruce's volume/tone mod.

I didn't care for the reissue Jensen C10Q that came with my first kit....too trebly for my taste.

The point is that changing things like speakers and preamp tubes are pretty simple mods.

[MWJB]

I seem to remember that Bruce's humbucker mod was a tone scoop filter, values evade me, as does the exact placement of the filter (before/after pots?). An "odd cap & resistor" won't cost you much, even if it comes all the way from Mission amps.

Cap parallelled with the 100k plate resistor will ATTENUATE hi freq, as will a larger (2000pf) bright cap on the tone pot.

As TD says, plug in plug out mods are cheap/easy enough..tried a 12AU7 in V1 yet?

You could also try reducing the value of the 22K preamp dropper resistor (try a couple of values in parallel) to bring up your voltages on the AX & AY (more highs & fidelity), for more front to the note try a 5V4 recto (WV have some GE's at the mo'), bigger 6V6 cathode bypas cap (100uf/100v) and first stage filter (...I'll get set upon by the 'rectifier police' if I say out loud the value I'm thinking...but 30-40uf will be fine - Waford Valves do a F&T 47uf/500v that'll fit nicely). Be aware all these mods will improve headroom, so I'd give Bruce's mod first shot.

[The Captain]

Thanks chaps for the input here. I did the plug in/out mods too, ie 12AY7 in V1, and faffed about with various bypass caps' values (even as low as a .068 on the V2). Odd thing is none, and absolutely none in any combination made a jot of difference to my ears?! it seems to me the 5e3 has the inherent tone of a cello rather than a guitar!

MJWB Im therefore eying another idea- the Princeton as a test project (with the 5e3's C12N): do you know if your little PT can be used for this? I know here is not a Princeton discussion site, but if anyone's made one & can spiel any differences to the 5e3 as a rough guide Id be grateful.

[MWJB]

The cello reference is a good one! Hard to get away from with cathode bias. Why not convert your 5E3 to fixed bias - Area51tubeaudio.com have a kit exactly for that purpose (or you could fit a terminal strip on the chassis end by the PT)? Lose your "Standby" fit the 5V4/GZ34 and replace the standby with a fixed/cathode switch on a DPDT if you want to have the best of both.

By the way, I said 12AU7 not 12AY7.

Yes, that PT could handle a push pull Princeton circuit, but B+ would be lower than any stock Princeton. If you ignore the tremolo & reverb, your amp wouldn't be that far off a Princeton (without NFB & treb & bass controls - converting to 12", non-NFB and a tone knob are not unheard of with Princetons). Non reverb Princetons can be a bit sterile.

In short, you still have a long way to go in terms of modding your 5E3 before I'd throw it out.

[The Captain]

Ah, more to ponder. 12AU7? Thats obviously a simple plan to try, but as I can hear absolutely no tonal difference between the 12ax7 and the 12ay7 as V1s..

The other ideas seem complicated and me no understand: could your PT do a single ended princeton though, like say a 5F2-A iirc? basically my 'page 1' plan is now to determine if I can, or just simply cannot, build a simple fendery sounding amp; this is what caught my eye- soundclips certainly VERY fendery, &, importantly for me using the only 'average' hammond 270fx/ 125ese/ and a simple 4x IN4007 recto- http://www.diycustomamps.com/princeton.htm

In meantime Ill bumf up on the area51.com idea and try to understand this idea- although my 5e3 does have a forsale note sketched in mind by now..
Thanks MJWB, very helpful again. Capt

[MWJB]

Yes the PT will work for a SE 5F2A Princeton, the Princeton will have a more scooped mids sound at lower settings, but drive it and you'll hear the cathode bias make itself known again. I love the 5F2A, it's relatively flexible for what it is, but you might find yourself reliving the same "problem"?

A 5E3 IS a Fendery amp...just not in the same way as a BF twin or Super Reverb. Do the fixed bias mod (don't worry about the fixed/cathode switch), it's less work than building another whole amp, which, until you have in front of you, you won't really know if you prefer.

Don't be throwing the baby out with the bath water!

[The Captain]

Sorry THIS http://jameshadfield.com/Princetone.html is the Princeton link with soundclips that specifically caught my eye, as it looks
1. simple
2. uses a hammond 270FX / 125ESE if I read right (ie not particularly high end MM trafos)
3. uses a std V.jr 8" for the sounclips (& sounds spot-on even with this bog std speaker).

[Bruce / Mission Amps]

Thanks chaps for the input here. I did the plug in/out mods too, ie 12AY7 in V1, and faffed about with various bypass caps' values (even as low as a .068 on the V2). Odd thing is none, and absolutely none in any combination made a jot of difference to my ears?! it seems to me the 5e3 has the inherent tone of a cello rather than a guitar!

Even a stock 5E3 is still quite dynamic with tone settings.
My feeling is, after the doing all the mods you've described, and it has done nothing to the tone of the amp, there is something wrong with the amp, your speaker is way too dark or your guitar is all muddy with little no tone variance.
All those amp mods should make a difference in overall tone and it seems like it isn't... so I'd be looking for other general issues/problems probably unrelated to the amp topology.
If this is one of my 5E3 amp kits, email me and I'll try and help you out with some tweaking.