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Filter Preamps - anyone compared ACG, Lusithand, Passinwind, Underhill?

Underhill is here too, I just forget his user name.

I've been very curious about the Underhill modular setup. Basically a filter preamp a la carte menu, which I think is cool. I just don't have anything to put it in right now.

I did use an ACG filter preamp once, WAY back, that I retrofitted into a 77 Gibson RD Artist for a short time. It was cool, but ultimately too much to fiddle with for live use in a fast punk band. Sold the preamp, and flipped the bass shortly thereafter.
 
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Underhill is here too, I just forget his user name.

bowthing...


I've had these over the years

Alembic Series I shorty - traded a Stingray, fretless Guild, and a nice '60s white EDS1275 that I wish I'd kept for one in '77
They're all that. I wish I'd been able to appreciate it when I had it. Had no clue how to work the filters at the time.

ACG EQ-02 - Liked it a lot. There are almost too many good sounds in it which made it a bit fiddly for me. The quality of construction is excellent and support is always available.

JTEX Distiller - Installed it in one bass, it seemed a bit shrill with that one so I'm gonna try it again in a different bass with a different pickup. I don't blame the preamp. Jerry is easy to deal with and supportive. Nice unit overall.

Lusithand Dual NFP Special - tried it in my main bass & liked it a lot. Swapped it out because I have a set of Rautia multicoils to pair with it in my ongoing winter project.

Underhill - currently in my main bass. Great sounding, fewer knobs is good for me. Was easiest of all to install. Great support from vendor both via email and in here. Many innovative choices to fit all preamp wants/needs/desires

Passinwind - I need a discrete self contained one. Gonna get one when they're released in the wild. He's always friendly & helpful to the less technically inclined

It's tough to go wrong with any of these.

This is a golden age for bass electronics.
 
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The Underhill will fit (the boards are tiny), but the Lusithand Jazz Plate is probably the easiest way to go, it drops right in.
Just an FYI, only the single lusithand NFP jazzplate fits with no mods. This gives you a single filter fir both pickups.

At least on a fender

The double NFP jazzplate requires modification ofr a sidejack.

I got the NFP single jazzplate and absolutely love it.
 
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Just to chime in here. I had a fretless a few years ago that used the ACG/East EQ02 which was the only commercially available version at the time. It had a single filter stack for both pickups along with a treble stack and a volume & blend. I agree with @kesslari - it was killer for a fretless and I only wish the EQ01 were available at the time to have a filter stack for each pickup.

I also had the EQ01 and the EQ03 preamps in a pair of ACG basses that I owned. The EQ03 was a minor update on the EQ01 @sunbeast is spot on - it is both a more polite (refined?) filter preamp and has one of the best blend controls I've ever experienced. My only complaint was that the range of the filters was so wide that it could be tough to dial in and/or recall tones.

Alan seems to have had the same thought. The ACG DFM preamp (only available in his basses) reduces the filter range by an octave and added something similar to the Wal "pick attack" option with a bump at 8k that can be adjusted by a trimmer. I'd love to try that out some day.

But my next bass is likely a pseudo Wal and I'm looking at some Turner multicoils and a Lusithand Double NFP Special. I played a Wal for a recording session long ago (about 20 years now!) and never got that sound out of my head. The Lusithand seems like it's got more of that almost gritty thing that Wals do.
 
Just an FYI, only the single lusithand NFP jazzplate fits with no mods. This gives you a single filter fir both pickups.

At least on a fender

The double NFP jazzplate requires modification ofr a sidejack.

I got the NFP single jazzplate and absolutely love it.
Does the battery fit in the control cavity, or is extra routing under the pickguard required ?
 
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Passinwind - I need a discrete self contained one. Gonna get one when they're released in the wild.

It's getting very close. My first beta test unit for the new format with a variable HPF included is coming back to my shop next week to investigate a problem that just popped up, which I'd much rather deal with now than once the full all in one PCB is done by a commercial DIY board vendor. There are a few other beta testers already trying their own builds without the HPF too.

If we're including pedals then Josh Broughton's Resonant Filter Equalizer and the DIY clone of the Anderton Super Tone Control that Pedal PCB sells deserve a shout too. I've been working on something with a full parametric mid control as well, and might actually have that making some noise by this afternoon.
 
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Just to chime in here. I had a fretless a few years ago that used the ACG/East EQ02 which was the only commercially available version at the time. It had a single filter stack for both pickups along with a treble stack and a volume & blend. I agree with @kesslari - it was killer for a fretless and I only wish the EQ01 were available at the time to have a filter stack for each pickup.

I also had the EQ01 and the EQ03 preamps in a pair of ACG basses that I owned. The EQ03 was a minor update on the EQ01 @sunbeast is spot on - it is both a more polite (refined?) filter preamp and has one of the best blend controls I've ever experienced. My only complaint was that the range of the filters was so wide that it could be tough to dial in and/or recall tones.

Alan seems to have had the same thought. The ACG DFM preamp (only available in his basses) reduces the filter range by an octave and added something similar to the Wal "pick attack" option with a bump at 8k that can be adjusted by a trimmer. I'd love to try that out some day.

But my next bass is likely a pseudo Wal and I'm looking at some Turner multicoils and a Lusithand Double NFP Special. I played a Wal for a recording session long ago (about 20 years now!) and never got that sound out of my head. The Lusithand seems like it's got more of that almost gritty thing that Wals do.
Here's my semi review.

Im no pro, but i do know what i like.

ok, so played with it a couple of hours tonight. Here are my first impressions...

(sorry long!)

i'll try to describe as best i can but some terminology i use might not be correct.

i installed it into a 98 MIA Fender jazz with seymour duncan antiquity IIs and a Badass II bridge that i drilled through to make string thru body.

quick background. i had a killer 5 string walnut wal back in the day. i loved the electronics (and many other things about it) but i'm not a 5 string player so i sold it, but i always remembered how amazing those electronics were. i figured it was just a wal thing and that's why people loved wals, but it never occured to me that this was a filter based pre-amp and not only do other manufacturers use them, third parties make them as well. instarted a thread herebasking about them and @Passinwind hipped me to a number of makers. my initial plan was and still is to put a JTEX filter in a modded bass I am working on, but that will take a while and i wanted to try them.

I was in rehearsal recently and i was wanting more articulation from my main bass a late 90s MIA jazz. It always sounds great, but you know how it is. I got home that night and stumbled in @LowEndLobster 's youtube about the lusithand NFP double jazz plate. i immediately figured this would solve both issues at once. geting more out of my jazz bass while also being able to try out a filter based preamp. i spoke to nuno at lutishand and decided on the single nfp jazz plate so i wouldn't have to make any mods to my bass. the double nfp i would have had to add a side jack.

i pinged nuno on instagram, discussed options (i went for a vol/vol my usual preference over vol/blend), i paid and it was here in like 4 days (london to dublin).

i had my guy install it today. like i said above it looked easy enough to do but it was even easier to have someone else do it.

i picked up my bass and on the walk home i was immediately feeling remorse. "this is my favourite bass. this is my main bass. i love the passive tone, what if i don't like it active." etc... I was actually scared to plug it in in case i didn't like it.

Long story short i absolutely love it.

My family was out so i was able to rock it through my practice rig (tc electronics BH250 into an aguilar GS112). When they came home i played through the headphine out on the amp.

There obviously was a marked difference between playing through speaker and headphones. More on that later.

First off, there is no tine control in passive mode, a feature i would have liked. Though the aguilar, i'm notnsure if it was my pickups or the tone control on he preamp, but the passive tone sounded great. very mid-dy and i was able to use my volume knobs to approximate tone control. However through the headphones i didn't have the fine tuning and the pasive tone sounded a bit harsh and it was more difficult to dial in a nice tone. I found some, but i didn't find MY tone like i was able to through the aggy.

then i switched it on.

through the aguilar, immediately it sounded great. i generally play with both pickups at 100% or neck 100 and bridge rolled back to taste so that is how i set it up. the range of tone out of this thing is outstanding. playing solo i was able to go from very thumpy dubby to mid elongated smoothness to harsh trebley attack and eveyrthing in between. Does it nail the Wal tone? No, it's a jazz bass, but you can definitely approximate the dude from tool or flea from BSSM with it to fool the average lsitener. You can get that thin trebley attack with the bassy undertones of tool and the kind of peaky yet smooth flea tone (if that makes sense)

When i play i like pretty much no attack on my tone. I like smooth elongated mids or deep thumpiness. this preamp delivers all three. Lots of settings i think would be good for a pick player but are useless to me generally although good to know what i can dial in if a room or amp sounds off. the range from trebley attack to dub thump us astounding. i see myself only using about 65% of the range though. there is also a push/pull for cutoff frequency that again gives you every possible JAZZ BASS tone from a to z.

Playing along to drum loops i was easily able to dial in at least a dozen very usable tones and as many again that weren't for me. it's unreal. And so easy to change sounds with just a slight twist. It sounds sensitive and complicated but it is smooth and easy and quick to find not only your favourite tone, but new tones you will love.

i am expecting my new focusrite to arrive on monday or tuesday i will figure it out and record some clips going through all the settings if people are interested.

i rate this a 9 out of 10 and will saynthe results are even better than expected.

And i did use it to track and it sounded incredible in the mix. Smooth and glassy.
 
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I was specifically wondering about the JTex, actually, since the Distiller is mostly sold as stand-alone filter circuit (at least on Ebay). One of the really cool things about the Underhill is all the different pre-assembled configurations that are available!

This is how I have my Underhill PD3 set up. One filter and adjustable Q for each PU. very versatile.
 
I was specifically wondering about the JTex, actually, since the Distiller is mostly sold as stand-alone filter circuit (at least on Ebay). One of the really cool things about the Underhill is all the different pre-assembled configurations that are available!
You can do that with the J-Tex too, you'll just ideally want active-value volume pots (or blend pus master volume) put after the filters- like 25Kohm or so. If using passive pickups you can use passive value volume pots before the filters but will lose some treble response that way
 
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Well, the control cavity in my FSO fretless Jazz is too shallow for the Lusithand filter plate, so I'm on the hunt for a place to route it out. Right now the tech at Emerald City here in Seattle may be the timeliest option, but we'll see if they can even do it.
 
I can only comment on the ACG EQ01 that I installed in one of my basses. A major thing I dislike about it is that the value of the volume/balance pots that come with this preamp are too low in my opinion. The volume won't go down low enough to completely mute the instrument, and it's the same situation with the balance control. I'm still getting signal from the neck pickup when the control is adjusted to full for the bridge pickup, and vice versa.

I haven't read all of the related posts yet, but I see that some of you have recently said that the low values are required for this sort of preamp, but I find it a major problem.

I'd like to go back to 500K pots for these controls if I could find a part that'll fit the board. Will the filtering still function correctly though? (I don't see why not.) Has anyone here tried it with the EQ01, or is there a workaround to remedy the problem with the circuit as is?
 
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I can only comment on the ACG EQ01 that I installed in one of my basses. A major thing I dislike about it is that the value of the volume/balance pots that come with this preamp are too low in my opinion. The volume won't go down low enough to completely mute the instrument, and it's the same situation with the balance control. I'm still getting signal from the neck pickup when the control is adjusted to full for the bridge pickup, and vice versa.

I haven't read all of the related posts yet, but I see that some of you have recently said that the low values are required for this sort of preamp, but I find it a major problem.

I'd like to go back to 500K pots for these controls. Will the filtering still function correctly though? (I don't see why not.) Has anyone here tried it with the EQ01?
I own/owned an EQ-01 and had neither of those problems - my volume would mute and my balance would perfectly cut off each pickup on either end.