I thought I’d take a few minutes to go through the progression of updates to the LHZ preamp since it’s inception in 2022. I laughingly tell people that I’ve “accidently started a business.” It’s framed as a joke, but the reality is exactly that: this was a personal project and I’d never considered selling them until I kept getting ask to sell “just one” to someone.
It’s been a journey of learning all around. Not just in how to set up a business, but how the end product has evolved. That evolution centered around one thing: learning from my customers!
As an engineer I suffer from the same myopic focus as most engineers: I will zoom in on solving THAT ONE THING that I am trying to achieve and lose sight of the practical things I could do. Basically, I figured out how to do the right thing by doing all the WRONG things first….
LHZ-01 PREAMP: FIRST RELEASE
I was single-mindedly focused on making a “mini HAZ” that would fit in my Rebop. That was it. So in my mind, it shaped up like this: Make the same circuit, with the same components and connections, but just make the pots external.
No problem.
With a lot of help with folks on the TalkBass forums, the LHZ-01 Rev 1.6 was born. In my mind, it solved the problem: connect the pots and pickups and power and output, and good to go.
HOWEVER, after a few players wanted to buy one, and I realized a few things:
- Soldering 26 tiny wires to a PCB is a special kind of torture only us electronic geeks enjoy. Hey, some people fish, some needlepoint, and some play golf. I put on a loupe and solder tiny bits of wire together. What can I say? We like what we like.
- Why is it SO HARD to find pots that fit European Spectors? Seriously???? No-one can find them. I can’t find them. But that’s OK because…
- Most folks just wanted to wire the output from their existing volume pot into the LHZ.
OK, that’s easy to do: I wish I would have thought of that. Instead of using all the VR1 connections, just two wires into the VR3 connector and we’re golden. Great! But… - What about all the folks who have modular EMG controls? Is there some way we can plug those in instead of soldering them?
LHZ-02 PREAMP: SECOND RELEASE
This update modified the layout slightly so I could add DuPont pin headers. I also gave up on trying to find pots and found a manufacturer that would custom build bass and treble pots that matched the original ones used by Spector® on the Euro and Rebop basses.
By this time, I’d found it was a LOT easier on all of us to just ship the preamp with the pots pre-wired.
Problem solved, right?
Well, sort of.
We now have the LHZ-01 which us being ordered by technicians and electronics geeks like me, and the LHZ-02 which is being ordered by everyone else. But… a LOT of those LHZ-02 customers had soldered pots. They realized it was easier to get the LHZ-02 and use a few quick disconnect cables with flying leads solder the wires to the pots and plug it in.
They were still soldering, but they MOVED the soldering activity to a far less critical spot.
Duh. (facepalm) I should have thought of that! Of course.
So now I am shipping the LHZ-02 with a kit of connectors with flying leads. This is when orders went through the roof. You see, I’d never intended on this being a business. I was building preamps for fun and enjoyed connecting with fellow players and tone hounds. It took a few months to scale the assembly and testing process to keep up before I had time to even think about improvements again.
However, I was always listening to comments and feedback. I took a lot of notes whenever a client had a question. The LHZ went into a LOT more basses than I ever thought it would. While it was small, the vertical connectors would often come up against a component in the cavity. The wires for the EQ pots were always in the way. A large percentage of clients were nervous about electronics and had questions.
Folks were marking the pots B and T so they could figure out which one was which because…. why did I label those VR4 and VR5 instead of BASS and TREBLE?
As orders kept increasing I did a time study and found that most of my time was spent bending resistors into unrealistically small forms (they do NOT make any tools that bend resistor leads close to the body like I do!) mounting pin headers, and making cable assemblies.
LHZ-03 PREAMP: THIRD RELEASE
This was the opportunity to fix all those things.
After a LOT of testing I settled on a new layout that used 90 degree pins and moved all the inputs to one side, the output on the other side, and the eq wires out of the way at the bottom. Relabeled everything so it makes sense: no more VR4 / VR5… It’s now BASS / TREBLE.
I tested a lot of component changes and found that tight tolerance thin film surface mount chip resistors have no measurable difference to the sound than the metal film resistors I was using. I also found a cable manufacturer that will now be building all the kit parts for me instead of my cobbling them together.
Those two changes saved me considerable frustration (although my wife will miss me cursing like Yosemite Sam when I goof up bending resistor leads!) and allow me more time to support clients and take on new challenges…
LHZ-03 REVISION 1.9B: FORTH RELEASE
It seems like some sort of life axiom. Whenever you think you’ve gotten everything buttoned up and have a little breathing room and can relax a little, life has a way of pulling the Joker out of the deck and throwing a whammy at you.
My whammy: counterfeit chips! And a tidal wave of orders.
I’ll do a write-up of the counterfeit chip misadventure in the near future (it is a book in itself) but the short version is this: the stock that I’d had quarantined turned out to be fake. With orders running at four times the rate that they’d been at the end of 2023 I had less than a month of chips left.
Thankfully, I’d already completed opamp evaluations and settled on the TL1464 and MC33172 opamps for the next preamp update. The TL1464 is a drop-in replacement for the existing boards, and I already had boards designed for the MC33172 opamp.
The new board design features the MC33172 opamp. This is the same opamp used by Hazlabs since 2021. We’ve also moved the the non-critical caps to SMT versions to make the board more compact.
I’d planned on executing a slow transition from the old opamp to the new one. While I was confident from 4 months of testing that the new opamps were sonically indistinguishable, there is significant brand loyalty. And yes, internet hype and misunderstanding. Which is why I put together a blind opamp comparison video to illustrate the differences.
So, is now the time I get to rest on my oars? Or is the next shoe about to drop?
The only constant in life is change. I am currently working on new products based on requests from clients over the last year, and am planning on release them in the Fall. One in particular has great potential: a blend control for dual-pickup basses unlike ANY type of blend that is (or has been) on the market. This is an original design and concept, so I am not going to release any information about how it works until I have units out of beta testing. But I am VERY excited about this one!
Anyway, old guy rambling is done now. I know all the young’un’s TLDR’d or fell asleep after the first 3 sentences, but I’m glad the rest of you stuck it out with me. This has been a journey of learning, and there is still more to come!
Cheers, mates!