Reverse engineering vintage Haz Labs pre

[AgingEngineer]

As the LHZ started life here in this forum, TB always will get the scoop on news.

RETIRING SOON: The LHZ-03 preamp is down to about a dozen units left in our shop. Once these are gone, the LHZ-04 will be the successor. The LHZ-04 is the same circuit, same components, and same tone. It's just a physical redesign to a smaller and a VERY low-profile board that makes installation much easier for those challenging spots and limited spaces. While the LHZ Shop will run out soon, Bass Direct in the UL and Ties Store in Japan still has stock.

COMING SOON: The LBCA-02 is an Active Blend control designed for the LHZ preamp. While we've been offering limited sales, we'll have full inventory listed within a week including versions for BOTH Active and Passive pickups.

ON THE DESIGN DESK: We've been working on a mid saturation control as a side project in response to inquiries from a client. This isn't a midrange EQ, this dials in a little saturation to a select range of mids to give a bit of drive that works really nice for solos and higher register work. I do not expect this to be a retail product as it is a very niche thing. I will be building a few prototype boards in the next month so if anyone is interested and wants to play with something a little... different... let me know.

 

[RedNuk]

Quick question: I'm installing the LHZ-04 in my ReBop with 2 EMG 40DCX (active) with volume + blend (LBCA-02) configuration (page 12 of the manual: "ACTIVE PICKUPS: BLEND & VOLUME (MODULAR)"). This schematic has no mention of a ground cable to the bridge.

The instructions only mention the bridge ground cable when installing with passive pickups. Does this mean I should just isolate the cable or do I still need to solder it back to a pot (like it was previously with the stock pups/preamp)?

Sorry if it's a stupid question, just unsure

 

[AgingEngineer]

Quick question: I'm installing the LHZ-04 in my ReBop with 2 EMG 40DCX (active) with volume + blend (LBCA-02) configuration (page 12 of the manual: "ACTIVE PICKUPS: BLEND & VOLUME (MODULAR)"). This schematic has no mention of a ground cable to the bridge.

The instructions only mention the bridge ground cable when installing with passive pickups. Does this mean I should just isolate the cable or do I still need to solder it back to a pot (like it was previously with the stock pups/preamp)?

Sorry if it's a stupid question, just unsure

Not a dumb question at all! For active pickups, you don't really need that ground wire. I just coil it up and tape it to the side in case I ever go back to passive pickups. Some folks feel that it helps in really noisy environments, and will solder it to the body of a volume pot or the SLEEVE terminal of the output jack.

Either way will work just fine!

 

[RasJay]

Quick question: I'm installing the LHZ-04 in my ReBop with 2 EMG 40DCX (active) with volume + blend (LBCA-02) configuration (page 12 of the manual: "ACTIVE PICKUPS: BLEND & VOLUME (MODULAR)"). This schematic has no mention of a ground cable to the bridge.

The instructions only mention the bridge ground cable when installing with passive pickups. Does this mean I should just isolate the cable or do I still need to solder it back to a pot (like it was previously with the stock pups/preamp)?

Sorry if it's a stupid question, just unsure

I just installed the LHZ-04, LBCA-02, and EMG 35P4x and 35Jx in my ReBop. I soldered the bridge cable to the sleeve of the output jack.

I went for a p/j x version of the 35DC's to get this ReBop to sound like my Spector Euro PJ with LHZ-03. I don't think I am liking these X series pickups. They have extended range and do sound less compressed as advertised. Too much piano like and too much detail in the extended highs for me. And not as pronounced mids that my Euro has. And they seem to lose the growl (overdriven) tone. A youtube video with Rodney McG goes into detail about the differences. I think I'll be asking EMG to swap them for the originals.

I played an NS2 that is at Guitar Center that has the same X pickups (actual P/J's not soapbar size) and I assume a HAZ and it sounds awesome. Not like the X I put in my ReBop. And I just watched a band with an NS2 with the same P/JX played through a Darkglass X Ultra I sold him. His sounded great as well. Neither NS2's had the overly pronounced piano like highs. Perhaps my Zebra wood is too bright for these pickups.

Other than that LHZ is the best!

 

[fibz]

The J coil is probably near the bridge. Try flipping the 35J.

 

[AgingEngineer]

I just installed the LHZ-04, LBCA-02, and EMG 35P4x and 35Jx in my ReBop. I soldered the bridge cable to the sleeve of the output jack.

I went for a p/j x version of the 35DC's to get this ReBop to sound like my Spector Euro PJ with LHZ-03. I don't think I am liking these X series pickups. They have extended range and do sound less compressed as advertised. Too much piano like and too much detail in the extended highs for me. And not as pronounced mids that my Euro has. And they seem to lose the growl (overdriven) tone. A youtube video with Rodney McG goes into detail about the differences. I think I'll be asking EMG to swap them for the originals.

I played an NS2 that is at Guitar Center that has the same X pickups (actual P/J's not soapbar size) and I assume a HAZ and it sounds awesome. Not like the X I put in my ReBop. And I just watched a band with an NS2 with the same P/JX played through a Darkglass X Ultra I sold him. His sounded great as well. Neither NS2's had the overly pronounced piano like highs. Perhaps my Zebra wood is too bright for these pickups.

Other than that LHZ is the best!

That is almost exactly my own experience with the X series pickups in my Zebrawood Rebop. I've got two other Rebops that are all within +/- 2 years of each other, each with different woods. The Zebrawood definitely has a VERY different tone than the other two.

Because I love experimenting, I tried the X series in my Zebrawood Rebop but they didn't stay there for a month before I went back to my tried and true 40P5 and 40J set. Like you, I found it too bright and clean sounding. I ended up putting them on one of my frankenbasses that has a duller tone, and they sounded great on that instrument.

 

[RasJay]

That is almost exactly my own experience with the X series pickups in my Zebrawood Rebop. I've got two other Rebops that are all within +/- 2 years of each other, each with different woods. The Zebrawood definitely has a VERY different tone than the other two.

Because I love experimenting, I tried the X series in my Zebrawood Rebop but they didn't stay there for a month before I went back to my tried and true 40P5 and 40J set. Like you, I found it too bright and clean sounding. I ended up putting them on one of my frankenbasses that has a duller tone, and they sounded great on that instrument.

Wow! Thanks for confirming Lonnie. We seem to have similar taste as we also discussed on Youtube that I found your LHZ because the EMG BQC I tried was too sterile. If your experience with the X series and Zebrawood was the same as mine, then I am not imaging it. I installed them a few days ago and already want to swap them out. I previously bought a standard ReBop that I gifted to my brother and yes the Zebrawood does sound very different to me.

So, do the original 40P5 and 40J sound like a Euro in the ReBop? My goal is to get the same or as close as tone of my Euro P/J and use the ReBop for down tuning and quickly switch between songs on stage.....and have the same volume and dynamics. I know I could just buy another Euro, however I bought the ReBop fro other plans I bailed on and decided to use it for down tuning. Plus it is a beauty.

 

[AgingEngineer]

So, do the original 40P5 and 40J sound like a Euro in the ReBop? My goal is to get the same or as close as tone of my Euro P/J and use the ReBop for down tuning and quickly switch between songs on stage.....and have the same volume and dynamics. I know I could just buy another Euro, however I bought the ReBop fro other plans I bailed on and decided to use it for down tuning. Plus it is a beauty.

To me, the only difference between a Rebop and a Euro is the bolt-on neck and the terrible model name. Build-wise, I don't know that there is much (if any) difference between a Rebop and a Euro aside from the bolt-on neck. To me, they sound and play the same when set up with the same electronics and general setup.

If I were blindfolded I wouldn't be able to tell my Rebop from my Euro. I have all mine set up with the same pickups, LHZ, and general setup. They are all REALLY close in tone aside from very subtle differences in body tone between them.

That said, the Zebrawood definitely has a different natural body tone than the others. Not enough to make it stand out, but there's a higher probability that I could pick it out of the blindfolded lineup.

 

[paskisti]

To me, the only difference between a Rebop and a Euro is the bolt-on neck and the terrible model name. Build-wise, I don't know that there is much (if any) difference between a Rebop and a Euro aside from the bolt-on neck. To me, they sound and play the same when set up with the same electronics and general setup.

If I were blindfolded I wouldn't be able to tell my Rebop from my Euro. I have all mine set up with the same pickups, LHZ, and general setup. They are all REALLY close in tone aside from very subtle differences in body tone between them.

That said, the Zebrawood definitely has a different natural body tone than the others. Not enough to make it stand out, but there's a higher probability that I could pick it out of the blindfolded lineup.

Do their sustain and note "ignition" being very similar too? Stereotype seems to be that bolt-on has snappier/faster sound and neck through has better sustain.

 

[AgingEngineer]

Do their sustain and note "ignition" being very similar too? Stereotype seems to be that bolt-on has snappier/faster sound and neck through has better sustain.

For me, I really don't notice a difference in the sustain or attack between a bolt-on or neck-thru. I DO notice differences in wood (between identical models, same setup, and same electronics), however.

I am curious what others think because I find this is another topic that people are pretty polarized about. I went down the internet rabbit hole last year watching videos trying to do objective comparisons on guitars (one luthier even built two identical guitars with the same source wood), but the differences were so minor (some in favor of bolt-on, some for set neck) that it could easily have been how hard the strings were played.

 

[fibz]

I got some samples of my 5 string Rebop, although this one is equipped with TW and DC (TW is in humbucker mode) and BTS.

 

[paskisti]

I got some samples of my 5 string Rebop, although this one is equipped with TW and DC (TW is in humbucker mode) and BTS.

Sound is perfect and I would not dream about Haz Lab anymore

I probably cannot fully get that clear and thick but still rich sound out of my Fender Jazz V even I can mimic it, in a way. Song is not easy either.

 

[RedNuk]

Gotta give some praise here: I'm getting used to the LHZ-4 in my 2010 Spector ReBop5 DLX with dual EMG 40DCX pickups... damn that sounds so good compared to the TonePump with EMG HZs.
Love the breakup when starting to dig in I'm not using it dimed but rather around 50-60% bass boost and about same with treble boost into a Markbass Little Mark Tube 800... just wow!

With my band (3 piece) we record our rehearsals and it cuts through really nicely, giving a more rounded and fuller sound... just awesome!

Thanks @AgingEngineer for the awesome work, you rock!

 

[AgingEngineer]

Gotta give some praise here: I'm getting used to the LHZ-4 in my 2010 Spector ReBop5 DLX with dual EMG 40DCX pickups... damn that sounds so good compared to the TonePump with EMG HZs.
Love the breakup when starting to dig in I'm not using it dimed but rather around 50-60% bass boost and about same with treble boost into a Markbass Little Mark Tube 800... just wow!

With my band (3 piece) we record our rehearsals and it cuts through really nicely, giving a more rounded and fuller sound... just awesome!

Thanks @AgingEngineer for the awesome work, you rock!

Thank you @RedNuk! I'm glad you are digging it!! This makes me remember when I got my first Rebop, a 2008 DLX with the same configuration: HZ pickups and a TonePump. It's a fantastic bass, but that combination of pickups and preamp did not (to me) match the quality or class of the instrument itself. It felt as if I'd bought a Ferrari, but they'd put the engine and drive-chain of a Toyota Corolla in it.

I don't play mine dimed either: I'm running about about 70% boost most of the time. For me, those knobs aren't just EQ (bass and treble) but they also determine what that "dig in" point is. It also depends a lot on the type of band I'm playing in and amp I am using. These days I think of anything above 50% boost as being in the "fun zone" now.

 

[RasJay]

50-60% bass boost and about same with treble boost

I run mine either 50% or 60% as well. 60% gives it a fuller sound without losing mids. 100% gets unwieldy and overbearing. At least in small venue setups.

 

[RasJay]

X series in my Zebrawood Rebop

EMG traded me the X series I bought for the original P/J DC35's. I can now confirm that my ZeBop sounds 90% the same as my Euro P/J. And since I am using the ZeBop for D standard tuning, I am very happy to keep them consistent.

 

[Phreaky Phriday]

I run mine with nordstrand big singles, 100% on the treble and 80%-100% on the bass. Its a wild scooped beast of a bass and i wouldn't have it any other way

 

[TK4261]

I recently installed a set of EMG PAX alnico pickups and a LHZ pre in my 30" Maruszczyk P. The sound is incredible now. I wish I would have done this to it earlier. Such a great Pre with the PAX pickups. It does not sound like a short scale Bass anymore.
There is one question that I have if though if someone could chime in. The volume knob seems to go from dead quiet to very loud with just barely turning the volume knob. I am using the EMG volume knob that came with my EMG pickup and everything is wired clean and correct. The only thing I can think of is that I did solder the bridge ground wire together with the main ground wire to the jack. I am not sure if that would have any affect. Everything looks good and there is no noise.

 

[AgingEngineer]

I recently installed a set of EMG PAX alnico pickups and a LHZ pre in my 30" Maruszczyk P. The sound is incredible now. I wish I would have done this to it earlier. Such a great Pre with the PAX pickups. It does not sound like a short scale Bass anymore.
There is one question that I have if though if someone could chime in. The volume knob seems to go from dead quiet to very loud with just barely turning the volume knob. I am using the EMG volume knob that came with my EMG pickup and everything is wired clean and correct. The only thing I can think of is that I did solder the bridge ground wire together with the main ground wire to the jack. I am not sure if that would have any affect. Everything looks good and there is no noise.

Awesome bass, and I'm glad you are getting the tone you were looking for with the LHZ!

As far as the volume pot goes, that's an odd one. The bridge wire to ground will not make any difference in how the volume pot works.
I suspect you may have gotten a defective volume pot from EMG. Volume pots for EMG active pickups should be audio taper with 25k resistance. From the marking I can see (25KA) it appears to be the correct pot, but it might have accidently been assembled with a linear taper pot.

If you reach out to EMG, they should be able to send you a replacement. Or drop me a PM with the name used on your order and I'd be happy to ship you (at no cost) one of our new prototype volume pots (pin compatible with the EMG volume pots) that we'll be selling soon.

 

[piitxu]

Here's another happy LHZ user. First of all I'd love to thank @AgingEngineer for the completely personalized experience during the whole process. In a world where everything is automated, outsourced, or min-maxed to extract the last ounce of profit, having the chance to exchange e-mails with the individual behind the final product is usually impossible. In this case, Lonnie helped with everything and even personalized my order so It would be 100% solderless from start to finish.

Also, it arrived in barely 48 hours from the US to Spain, which for me is unprecedented.

Now, to the preamp. It's been installed in a LTD Surveyor 87. Because the space is scarce and I didn't really want to modify the pickguard, I've ended up ditching the independent pickup volume pots in favor of a single pot for both pickups, so a vol-treb-bass setup. This might not be ideal for most but I play with both pikcups maxed most of the time so it works great for me. Even then, it was a bit of a challenge finding the right spot for the preamp. The space under the pickguard is pretty much the same you find on a regular Fender or Squier P. I've ended up installing it in the bottom of the cavity. The clearance to the pots was plenty, but it took me a while to fix the wiring in a way that I could close it all down without it being too tight.

As for the sound, today I finally had the chance to try it in rehearsal. We play kind of old school power metal, so a lot of 16th notes, power chords, etc. Now, I HATE mids on a bass guitar. As a principle. For me, in a band with two guitars, the bass should sit well below them, right on top of the kick. It doesn't need to cut through as if it was a third guitar, it needs to be felt. And the LHZ helps a lot there. It adds that sweet subtle distortion in the high end which is what makes you noticed in the mix, in a way that adding upper mids or highs or more distortion doesn't.

I run my bass through a JOYO Scylla compresor into a sansamp bass DI and then into a Hartke LH1000 and a EBS Neo 2x12. The fun part about the LHZ preamp is I've got a lot more of an usable EQ range now. Before, with bare EMGS or with my Spector NS pulse with DCs, I had to be quite more precise with the EQing to get the tone I like. Now, the tone is already shaped before it hits the pedals or the amp, and makes it a lot easier to adapt to the room.

Does the bass sound like a Spector? No it doesn't, nor I was hoping for it. It's a whole different beast, with a more naturally scooped sound. But it defintely added some of that "Spector growl" to the bass.

I can't recommend this enough, specially if you are unhappy with your current preamp or don't have one. In my case, I'm starting to like dig the tone I get from the NS pulse 5 with the DCs and the tonepump. What I don't like from it the absurd high output of the pickups, even with the preamp set at minimum which is cutting signal. But if I ever feel like swapping the DCs for a soapbar P/J set, I'm getting myself another LHZ preamp.