The John East preamp club

[GBassNorth]

Thank you. I look forward to your reply.

And the answer is...
Zero hum with either pup soloed in active mode.
Zero hum with either pup soloed in passive mode.

One again East delivers the goods. I ran both active and passive tests at full volume with the treble pot dimed and the bright push/pull engaged. If it doesn't hum under those conditions it's just not gonna be a problem. Unfortunately, I realized my output jack is starting to go; got a loud pop if I wiggled the cable. No big deal, I have almost ten years on this preamp an a new jack is an easy DIY job.

Hope this helps.

 

[MrBEAR]

Okay J.E. gurus, question for you.

I have a Lairat Sirya Luxe custom.

Paul will only say it is a custom preamp from John East.

The easy parts:

On stacked knobs - Vol. & Bal.

On stacked knobs - Treble & Bass

One switch for active passive
One switch for the third knob.

Third, single, knob has a center detent.
Switch engages in active and passive.

Not really passive tone, not an obvious midrange control, switch is on/off and not coil splitting or phase related.

Have not received a response from the folks at J.E. yet but it has been awhile.

Any guesses as to what they brewed up for the third knob?

 

[J.Wolf]

Sounds like that 3rd knob is the knob off the p retro. It has a mult eq function. Don’t know much about but it definitely doesn’t sound like a u retro, uni pre or sp2

 

[MrBEAR]

Good guess but if it is, the configuration is wrong.

I was going to offer a gut shot to see if anyone recognized components.

Not happening as the wires on top are dressed and channeled so as to obscure the component modules.

I am not going to move a single wire.

 

[J.Wolf]

East stuff is made to be modular, so different components can mix and match. So it wouldnt have to have the layout of the P retro in order to have that particular tone control. I had an East with a mid knob, that I switched out for a mid stack, for example. But in reality I have no idea what it is, just guessing

 

[MrBEAR]

Oh heck.

Let the sleuthing begin.

My first observations yield:
3 White cogged wheels with arrow pointers.



Here is the topside configuration:

 

[John East]

Okay J.E. gurus, question for you.

I have a Lairat Sirya Luxe custom.

Paul will only say it is a custom preamp from John East.

The easy parts:

On stacked knobs - Vol. & Bal.

On stacked knobs - Treble & Bass

One switch for active passive
One switch for the third knob.

Third, single, knob has a center detent.
Switch engages in active and passive.

Not really passive tone, not an obvious midrange control, switch is on/off and not coil splitting or phase related.

Have not received a response from the folks at J.E. yet but it has been awhile.

Any guesses as to what they brewed up for the third knob?

Steve, I have emailed you but thought I would put the explanation here too, just happened to see your post:

Your unit is based on a UNI-PRE 3 Knob, but is a custom system for Paul Lairat, yours has a fixed mid frequency, which is the main difference:

+ Stacked Knob: VOL/BLEND (Works in Active & Passive)

+ Stacked Knob: BASS / TREBLE/ Pull for BRIGHT (Works in Active only)

+ Single Knob: MID Boost/Cut - FREQ 800Hz (Works in Active only)

+ Toggle: ACTIVE / PASSIVE

+ 2nd Toggle: (Supplied & fitted by Paul, please confirm the function with Paul)

 

[OldFunBass]

Steve, I have emailed you but thought I would put the explanation here too, just happened to see your post:

Your unit is based on a UNI-PRE 3 Knob, but is a custom system for Paul Lairat, yours has a fixed mid frequency, which is the main difference:

+ Stacked Knob: VOL/BLEND (Works in Active & Passive)

+ Stacked Knob: BASS / TREBLE/ Pull for BRIGHT (Works in Active only)

+ Single Knob: MID Boost/Cut - FREQ 800Hz (Works in Active only)

+ Toggle: ACTIVE / PASSIVE

+ 2nd Toggle: (Supplied & fitted by Paul, please confirm the function with Paul)

Does not get any better than when the man himself answers your post. Awesome!

 

[J.Wolf]

so the discrepancy lies in some confusion about the 3rd knob, which is switch activated, which Mr. Bear states doesnt act like a midrange control. hmmmm

 

[John East]

Looking the pix above, I can see that one toggle is wired to the active/passive pins on the VOL/BLEND circuit board as would be supplied by us, and the other toggle is connected to the pickup wires, appearing to be series/single coil settings.

The third knob, mid boost/cut, appears to be connected only to the main EQ circuit, in the normal way. Therefore there wouldn't be actuated by a toggle, it would seem.

 

[Dasgre0g]

 

[murphy]

I am considering putting my J Tone preamp into my Marcus Miller V bass....the original has started sucking the growl and volume from the mids since I switched pickups....not sure what went wrong with it...all knobs still function...but passive sounds bigger and growlier...possibly something got damaged in the switch
Have done it before with no problems
Either install my J-Tone or a Sadowsky preamp?

 

[Diddywah]

Got my East Uni-3 preamp today and installed it in my 2013 Warwick Jack Bruce.
Then I found this "club" on TB....so here are some pics:

The old MEC pre before ripping it out:


Finding positions for the East parts:

Finished install:

Sexy side:


My first preamp install; really easy. Just had to resolder the jack supplied with the "end of body" warwick jack and drill a hole for the active/passive switch.
The hiss I had with the MEC is gone. The East is dead quiet. And the added midrange control with the East is fantastic. It sounds great, even in passive. I will need some time to explore the possibilities here, but dialing in a good tone was very fast. Actually everything set flat and just switching to active already sounded great!
I have the Aguilar OBP3 in another bass, and the bass control on that is too sensitive. The bass on the East is very smooth and useable.

 

[J.Wolf]

nice work! Thats quite the upgrade from the MEC pre, IMO.

I'm still a little flummoxed at getting the "bass window" controls on the uni pre. Has anyone had luck getting those two wheels dialed in where you want them?

 

[Bob_Ross]

Kind of a crappy picture, but that's my 1988 Modulus Graphite Quantum-6 SPX with the ACG/East EQ-02 preamp I installed a few years ago.
Three pairs of stacked knobs:
- Master Volume & Pickup Balance
- Lo-Pass Filter frequency and ...I forget if it's a resonance control or an actual gain of the LPF output, but I generally think of that top knob as controlling the amount or intensity of the lo-passed signal
- Hi-Pass Filter frequency and...as above, I forget what the actual technical function of the top knob is, but I'm almost positive it is something different from the top knob on the LPF stack. Although I tend to use it in essentially the same way, to adjust the amount or intensity of the hi-passed signal

It's badass. Very versatile, and deliciously good sounding. Major leaps and bounds cleaner, quieter, and fuller than either the stock electronics this bass originally came with, or the EMG BTC that I had in there for the ~10 years prior to getting the ACG/East.

 

[Mr_O'B]

View attachment 2981484

Kind of a crappy picture, but that's my 1988 Modulus Graphite Quantum-6 SPX with the ACG/East EQ-02 preamp I installed a few years ago.
Three pairs of stacked knobs:
- Master Volume & Pickup Balance
- Lo-Pass Filter frequency and ...I forget if it's a resonance control or an actual gain of the LPF output, but I generally think of that top knob as controlling the amount or intensity of the lo-passed signal
- Hi-Pass Filter frequency and...as above, I forget what the actual technical function of the top knob is, but I'm almost positive it is something different from the top knob on the LPF stack. Although I tend to use it in essentially the same way, to adjust the amount or intensity of the hi-passed signal

It's badass. Very versatile, and deliciously good sounding. Major leaps and bounds cleaner, quieter, and fuller than either the stock electronics this bass originally came with, or the EMG BTC that I had in there for the ~10 years prior to getting the ACG/East.

Extremely nice bass! I have J -East Deluxe installed in my bass. Enjoy your J-East preamp!

 

[ctmullins]

East stuff is really great, but the East/ACG stuff is a whole different kind of great.

 

[mouthmw]

I cannot praise the East MM preamp enough. It did exactly what I wanted - turned my 3 band ray into a 2 band ray, and more. The mid knobs are fantastic as well, they take nothing from the signature vintage 2 band ray tone, but add great versatility. I usually bump the low mids just a bit, set my treble/bass close to flat (usually a slight cut) and that's it. Pump away.

It's paired with Nordstrand MM4.2 and it's a pair made for each other. I can never put this bass down.

 

[Funkinthetrunk]

John is awesome. I've been using his preamps many years now. I have a 4 knob Uni Pre ready for my next USACG / Warmoth build. I'll post some photos when done.

 

[Budbear]

John is a brilliant engineer and just the nicest person who delivers outstanding tone as well as some of the best customer service you’ll ever experience. I have used and enjoyed several of his pres. And the Uni pre in this self build is my favorite.