Gretsch Junior Jet Controls Upgrade

I’ve had a Gretsch Junior Jet II G2220 short scale bass for several months and like it a lot. However, I was less than thrilled with the control layout of single volume and tone and a selector switch (bridge, neck or both).

I decided to do something about it.

This would give me a volume for each pickup and a master tone control - like a Jazz or PJ bass. Since the Gretsch has “mini humbucker” pickups, I went with 500K pots and a .022 uf cap. I also decided to upgrade the output jack to a Pure Tone full contact jack. Genuine Gretsch knobs are readily available online.

When I popped the cover off I realized that the CTS pots would be a significant upgrade over the cheesy little mini-pots I found. I guess that corners must be cut somewhere on a $300 bass.

As can be seen above, the pots are really tiny compared to a CTS pot (which I included for reference). The good news is that there is plenty of room in the cavity for the larger pots.

This was the scary part - the holes needed to be enlarged a bit for the new pots, and unlike other basses with the controls in the pickguard or a metal plate, the holes are right in the body.

If there is one takeaway from this post this is it. Do NOT try to enlarge the holes with a drill; use a tapered reamer ($10 from Amazon) instead. Otherwise you risk chipping the finish around the hole.

I temporarily mounted the pots in a piece of fiberboard to hold them in place while I did the wiring.

I wired it just like a jazz base, for which there are a gazillion wiring diagrams available online.

I used a 25 watt soldering iron I had on hand which was barely adequate for the job. It was fine for soldering wires together but had difficulty attaching the ground wires to the pots. If I ever do this again I’ll use at least a 40 watt iron.

All wired and tucked in! As can be seen, there was plenty of room.

All done, and everything works as expected. Now I can get the tone I like by turning the neck pickup volume most of the way up, and turning the bridge pickup up just enough to give it a little bite.

15 Likes

Nicely done job :musical_note:

3 Likes

Very tidy job @spidey9 and a really good write up :+1:

3 Likes

Excellent job, @spidey9 . . . :+1:

And excellent post . . . :slight_smile:

Cheers, Joe

3 Likes

Hello! beautiful installation… I can’t wait to get my toggle switch replaced for a blend just like you did here.
I have the exact same bassguitar, and am getting this sorted out end of January.
I’m struggling finding “the correct” pots, or knowing which pots to go for really.
Would you mind posting a list with the new pots specifications and such?
Thank you in advance for any type of response.

2 Likes

@Sebasstian

Actually it’s not a blend control. The problem with a blend is that one pickup is turned down as the other is increased - there is no way to run both pickups wide open. Blends only really work for active setups.

What I have is like a Jazz bass. What used to be the master volume is now the neck pickup volume, and the pot in the switch hole is the bridge pickup volume. The tone control location is unchanged. The wiring is identical to a Jazz bass.

I used 500k CTS audio taper pots. Conventional wisdom is 250k pots for single coil pickups and 500k pots for humbuckers. The Gretsch has “mini-humbuckers” plus the original pots metered at 422K.

From Amazon: Set of 4 CTS 500K Short split shaft audio taper potentiometers

(I ordered 4 in case I screwed one up. :smiley: )

Likewise conventional wisdom is to use a .047 uf capacitor for single coil pups and .022 uf fpr humbuckers, so .022 uf it is: .022uf / 200v 715P Orange Drop Capacitors - Pair

Ordering two turned out to be smart - I fried one soldering it in.

I found OEM Gretsch knobs on Reverb. I googled to find a Jazz bass wiring diagram.

I also replaced the output jack with a Pure Tone Full-contact Output Jack. This is optional but it provides a more secure connection and since I already had it apart . . .

Hope this is helpful.

5 Likes

Thank you very much for the informative response!
I obviously don’t know near as much as you do about pots and electronics in (bass)guitars in general.
How about a follow-up question then, If I plan to install TV Jones Thunder’Blades (expensive pickups on a cheap bass, I know, don’t ask me why please)
would you have changed anything about the parts from what you installed then? or will this be good even with that?
Thanks again, you’re the forum-poster every Googler is dreaming of.

3 Likes

There is nothing wrong with this idea :slight_smile:

5 Likes

+1 !

5 Likes

+1 :grin:

3 Likes

The TV Jones Thunder Blade is a dual coil (humbucker) pickup like the original pickups so I wouldn’t change anything.

I considered doing this, but decided against the expense, not because the Gretsch is a cheap bass, but because the stock pickups sound pretty good.

I have DiMarzio pickups on my Squier Affinity Series PJ. :roll_eyes:

3 Likes

Hello again.
My friend is helping me do the same to my Gretsch Jr Jet 2220 as you did to yours.
I’m curious about what your guys thoughts are about combining LIN with LOG pots, and which to go where, and why?
Should I go with all LIN pots? all LOG pots?
LIN volume LOG tone(x2) or vice-versa? any thoughts and ideas are welcome :smiley:

Here is a thread you may find interesting, @Sebasstian . . . :slight_smile:

HTH and all best, Joe

2 Likes

@Korrigan any ideas? I hear you’re the man to talk to about this sort of thing on this forum.
:smiley:

I used audio (log) taper for all controls. Audio seems to be the consensus for volume controls, and my volume controls smoothly increase from minimum to max.

Opinions online are all over the place as to what should be used for the tone control, but my audio taper pot seems to work fine.

2 Likes

Pot taper is a matter of preference, there’s not really a right or wrong. My preference is log (audio) pots for both volume and tone… usually… :slight_smile:

3 Likes

Great idea and nice post. I would like to do the same but I am confused about the black wires that go to the pickups. I don’t see two wires on the pickups. How do wire the black leads to the pickups to the volume pots? Typically, the black lead would solder to the pot case ground, and the white wire would solder to the middle pin on the middle pin of the pot (but I see no white wire)? Is the black pickup wire like coax?
Thanks for help.

@Fuey: You hit it exactly right. The black wire seen coming from each pickup is actually a shielded cable. The white center lead of the cable attaches to the center terminal on the respective pot, while the shielding is connected to ground, most likely at the pot case.

I was able to unsolder the leads and resolder them to the new pots without having to do any cutting or stripping of the pickup wires.

2 Likes

Great post. Appreciate the pics and the links. I’m planning to do this exact mod since my old bass is set up this way and I just prefer the versatility, and your post is the most helpful one I’ve come across so far.

I noticed in the pics that you replaced the stock bridge. What bridge did you choose, and have you noticed any benefits in sound, or is it mostly just aesthetic?

Any other mods?

2 Likes

Welcome to BassBuzz!

The bridge is a brass high mass bridge from Performance Sound.

Precision-Machined Brass High Mass Bass Bridge

A nice feature of the Junior Jet is that it uses a standard 5 screw Fender bridge, so there are lots of options available.

The Performance bridge looks good and seems to help sustain, which isn’t the greatest on the JJ (or any short scale for that matter).

I also added a Hipshot Xtender drop D tuner and fitted it with La Bella Deep Talkin’ Bass flatwound strings.

2 Likes