The John East preamp club

[XLunacy]

Been a while since I posted here, but thought I'd give folks a peek at an install I just did with one of my ancient East preamps in a new bass.

The bass is an Acasia Non Reverse Fanned Fret Five String Thunderbird that was originally passive with Nordstrand Dual Coil 5 Pickups. The previous owner replaced the Dual coils with Nordstrand Zen Blade 5 sidewinders, which are very clean and neutral sounding pups. I had an old custom built John East preamp from the early 2000's laying around, so I figured what the heck, let's make this baby Active!

Before…
View attachment 5125521

After…
View attachment 5125522

A close up of the install…
View attachment 5125524

The custom preamp is actually a three stack dual preamp with one standard two band stacked pot BTB-01 section for the neck pickup and a MusicMan stacked pot section for the bridge pickup. The volume stack is vol/pan. The setup works great with the Nordstrand pickups with a huge range of very useable sounds easily dialed in. The 20+ year old East preamps breathed some real life into this bass.

Not showing a full picture of the front of the bass is criminal Interesting preamp design. The Zens really sing with a nice preamp powering them!

I want to get a J Retro Deluxe with the flat response option. It's out of stock at East, and no dealers seem to have that model. Is there a site that might have them?

I had ordered my Uni-Pre from this website with no issue, but it's based in Germany, and judging by the current price of the item, more on the expensive side so, depending on how much / how fast you need it:
East J-Retro 01 Deluxe Preamp

 

[Zeom]

You do both at the same time.
You set the low side from 20 to 80 hz. You set the high side from 40 to 200.
I use the high side to select the frequency I want to be centered at and then adjust the bottom to how much subsonic I want to allow in.
Keep in mind, these are gentle slopes so both affect frequency bands that are adjacent.

The best way to go about this is to play with it. Boost your bass and adjust the high side and play, going back and forth with the dial. You'll know when your in your desired spot. It behaves exactly like the mid sweep. Once you have that dialed, adjust how much low bass you want. That's it. Super easy.

Thanks for the idea, it has to be added in the manual

 

[Zeom]

Not showing a full picture of the front of the bass is criminal Interesting preamp design. The Zens really sing with a nice preamp powering them!


I had ordered my Uni-Pre from this website with no issue, but it's based in Germany, and judging by the current price of the item, more on the expensive side so, depending on how much / how fast you need it:
East J-Retro 01 Deluxe Preamp

It is a right price if you consider the currency change between the euros and pounds, glad it's available !!

 

[GBassNorth]

Not showing a full picture of the front of the bass is criminal Interesting preamp design. The Zens really sing with a nice preamp powering them!

LOL - wouldn't want to be a criminal, so here ya go, frontal shot of the Acasia Bird with the East test mule preamp installed.
This preamp was originally built as a proof of concept test back around 2005ish to see how well the Musicman voiced preamp would work in unison with a P bass preamp. After the test mule work was complete I put it in a Jaguar SS P/J bass and just recently took it out of that and installed it in the Pink Acasia…

Just for good measure, here's a shot of my custom built East preamp (the final version of the test mule shown above) that was installed in a bass I designed and built. I had John replace the volume/pan stack with a Vol/vol stack (wasn't fond of the slight volume drop at center detent of the test mule) and had him install a pickup selector (neck/both/bridge) otherwise identical to the test mule but in gold…

Finally, the one that started it all, back in 2005ish I installed a J-Retro Deluxe in my Fender Jazz Deluxe 5. Sounded great and really transformed that Jazz bass into a tone monster…

I've used many other active preamps, but I'd put East preamps at the top of the list. John is so easy to work with, all his preamps have very polished well thought out component layouts and wiring methods for a true OEM look vs some aftermarket wiring spaghetti fest that many of his competitors use. Plus they sound fantastic and to date (going on about 20 years of use) they seem bulletproof. Hats off to John!

 

[redname]

I got some new pickups and they coming with the ground and hot wire for each pickup

my prev pickups have hot and cold wires instead, so they go in the J retro pickup connectors as per the manual instruct, so how do i connect my new pickups since it only has hot wire?

i'm thinking that the hot wires still goes into the pickup connectors as they shld and then i'll solder the 2 groun wires as one and then connect into the grounding connector together with the bridge ground wire

is tht ok?

 

[Geri O]

That ground wire is the cold wire. I'm pretty sure it goes in the negative connector of the preamp.

 

[redname]

That ground wire is the cold wire. I'm pretty sure it goes in the negative connector of the preamp.

oh, so it can just go in the pickup connector? tht'll be so nice

thanks

 

[Geri O]

oh, so it can just go in the pickup connector? tht'll be so nice

thanks

Yes!

Let us know that you are up and running.

 

[redname]

Yes!

Let us know that you are up and running.

did the switch and the bass is still sounding fine

 

[Luke the Fluke]

My John east Uni pre is amazing - what's the closest floor pedal do you think with a similar sound?

 

[ctmullins]

My John east Uni pre is amazing - what's the closest floor pedal do you think with a similar sound?

A Uni mounted in a stomp box.

No, really. It's pretty straightforward.

 

[Rasca]

Hi everyone !
i have already instal a john east uni pre 4 in my bass, and i have a problem and did not find here any solution so i am asking you some help

i put this preamp in my bass with norstrand zen blade pickup and when i plug the bass there is a really weak sound in active mode and absolutly no sound in the passive mode :/

any idea of what the problem can be ?

thanks for the answer

 

[GBassNorth]

Hi everyone !
i have already instal a john east uni pre 4 in my bass, and i have a problem and did not find here any solution so i am asking you some help

i put this preamp in my bass with norstrand zen blade pickup and when i plug the bass there is a really weak sound in active mode and absolutly no sound in the passive mode :/

any idea of what the problem can be ?

thanks for the answer

My East preamp sounds wonderful with the Nordstrand Zen Blade pickups, so I suspect you'll be very happy once it's sorted out. As for your specific problem, no clue, but it's always good to install a new battery if you're having problems with an active bass output. Although, the passive function should work just fine with or without a dead battery.

 

[Zeom]

Hi everyone !
i have already instal a john east uni pre 4 in my bass, and i have a problem and did not find here any solution so i am asking you some help

i put this preamp in my bass with norstrand zen blade pickup and when i plug the bass there is a really weak sound in active mode and absolutly no sound in the passive mode :/

any idea of what the problem can be ?

thanks for the answer

My guess is wiring problem, a detailed photo will help

 

[Rasca]

Ok during playing a little bit suddenly a massive gain came, I found it was my output touching the coil paper that was causing the problem and it works great now i'am so happy !
Zen blades and John east uni pre combo is great !

do you have a little buzzz when abusing of the treble boost ?

 

[ptidwell]

Hi everyone !
i have already instal a john east uni pre 4 in my bass, and i have a problem and did not find here any solution so i am asking you some help

i put this preamp in my bass with norstrand zen blade pickup and when i plug the bass there is a really weak sound in active mode and absolutly no sound in the passive mode :/

any idea of what the problem can be ?

thanks for the answer

Well, first I would tell you to check with John. I would tell you to check the connections on the active/passive switch. I have a few uni-pre's and have had several conversations with John and diagram exchanges with a similar issue. We started with the wiring. Nevertheless, he ended up sending me a new active/passive pot, and that resolved it. John is very accommodating and he and I have an 8 hr. time difference.

 

[smeet]

I've sent a couple of questions to John, with no response. Is this normal?

 

[Zeom]

I've sent a couple of questions to John, with no response. Is this normal?

Me either, I can't get hold of him since may. :-(

 

[Zeom]

Uni-pre 4 paired with Delano quad coil are now installed in the MIG corvette $$ and fully functional (3 gigs already). Now come the time for a fine tuning. I share with you my experience and want to hear from you your personal experience and/or advice.
I started by the bass internal wheels and fix it at around 30 (low) and 60 (high), it was ok, not boomy and while dialing the medium at around 180, I get a beautiful warwick growl. With that settings, I liked the medium at these 3 frequencies, around 180 (10 o'clock) 450 just before halfway and almost 2000. So I changed my mind so I can tweek less, and opened the bass wheels all the way from 20 to 200, now I have my 180hz included and the growl stays permanently, I dial only the medium when needed at 450 or 2000. Now thinking about lowering the treble wheel to 2000 so I can keep the medium at almost halfway al the time (450), but I will miss the clanky treble in slap unless I pull the treble knob for 10k. How do you guys manage?

 

[smeet]

My favorite preamp for many years has been the Nordstrand 3-band. How does the sound of the Uni-pre and J-retro compare to that? The Nordstrand doesn't have sweepable mid frequencies, but you can switch between a couple of options, and it doesn't have the bright option. Other than that, they seem fairly equivalent in terms of features.

What I like about the Nordstrand is that it sounds and feels very natural. I can boost or cut everything by a lot, and the tones are still good and usable. It never feels "hyped". Also, the way my tech (Mo at Nordstrand) wires it, passive mode retains all the functionality of active mode, except of course for the eq.

Has anybody had a chance to compare them?