• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Barber Linden EQ • New small form factor

#301
Real Soon said:
You might not've seen later in that paragraph where I did end up isolating pedals. I should've specified further that I've got a couple of One Spots and some other audio-grade adapters... and also noticed noise when using the Linden alone, bypassing the Darkglass and going into the B173 via hi-z input. I'll test further to reconfirm that, though.

I'm not arguing against best practices overall, mind you, just trying to clarify that I've been getting less than ideal results while also attempting to be scientific about troubleshooting. I'll end up with a proper unit by the end, but hopefully didn't damage anything in the meantime.
Click to expand...
Both pedals you think are noisy have in common that their voltage is boosted internally. They might be more picky with regards to power.

I know some digital pedals struggle with early switch mode power supplies, might be the same with charge pump pedals, not sure. Not sure what kind of technology your adapters are based on.

Charge pumps do generate noise, but their frequency is boosted to be far above audible range. Expensive pedals like Klon and quite a few praised high headroom bass pedals also use charge pumps. It's usually not a problem as long as you don't daisy chain them. Do you have a way to test it without going into the B173, no daisy chain even connected, just adapter straight into the pedal and an audio interface? Do you know anyone who have an isolated supply you could borrow to test? Important that the outlet can handle the 300mA requirement of that tube preamp though.
 
  • Like
Reactions: Real Soon
#302
Bolsyo said:
Do you have a way to test it without going into the B173, no daisy chain even connected, just adapter straight into the pedal and an audio interface? Do you know anyone who have an isolated supply you could borrow to test? Important that the outlet can handle the 300mA requirement of that tube preamp though.
Click to expand...

I was starting to think along these lines for getting the proper no-variables baseline. I actually can bypass the B173 and plug directly into the interface, and have a CS12 Pro on an ambient sounds board. I could borrow that to test against the solo One Spot for the Linden EQ, then the Particle Accelerator.

Sorry to be hijacking the thread some, though it's at least related :angel: & I can get to researching in a couple more hours.

Kinda unrelated, I'm planning to retire the Vintage Ultra as it's getting replaced by a dedicated DI box (I'm thinking RNDI). It's a v1, so just 30mA draw, but is also kind of finicky about power, and I just don't need the features once I get this new setup figured out.
 
  • Like
Reactions: Bolsyo
#303
Test setup: pedal connected to an APC good-quality power strip, then to a true-sine-wave UPS system, then directly to the wall. This took time, but I believe in science (©).

Power sources: a Jim Dunlop adapter, two One Spot power adapters (found out they're switching power supplies), one TrueTone CS12 Pro with all other pedals disconnected from power at the pedal, open circuits / no shorts confirmed.

Audio signal path: Mustang PJ bass to pedal to Focusrite Clarett 4Pre. Partway through, changed out both cables for others; here I was scientifically lazy as the change made zero difference when I did it, so I concluded the cables were okay.

Level set to a hair past 12 on the knob, Instrument level setting. The LED turned orange briefly with a good E string thump, indicating close to peak but still below.

Control level of bass directly to Clarett: ~-76dB noise floor. Volume knobs were down in all tests to take the bass out as a noise source variable. Just in case, I kept it in the same position on its stand the whole time.

The results were disconcertingly consistent: in every test scenario, the Linden EQ by itself registered an incredibly consistent -36.4dB (+/- .1dB) noise level in the DAW when enabled. Disabled, it was also very consistent, ~-53.8dB.

In contrast, the Particle Accelerator registered ~-61dB noise floor when enabled, and -~67dB when bypassed. Slightly more variance in level than the Linden, but still...that's pretty impressive for any pedal.

(note: settings used were ones with unity output level set, and with what I'll consider reasonable real-world useful settings; it's hard to get much more systematic comparing a tube and SS circuit with different EQ styles)


I need a beer.


What this tells me is that I done good in setting up my power control structure in the studio space; I invested dough in cleaning it up and it seems to be paying off.

Also, it tells me that with the Linden going into the PA, the PA is suppressing some of the frequencies that the Linden produces. As before, the noise seems to be a white-ish broad-spectrum type, and a fair bit of it is supersonic.



Well, I just remembered I've got some audio analysis tools in Ableton Live. They really upgraded the spectrum analyzer, too.

Check this puppy out:

Linden EQ.png


That's not 3.5kHz, that's 35kHz! The pedal is producing a very precise high-frequency "hum" around 36 or 37kHz, and that's what's spiking the noise floor so massively.

Here's the kicker: If I set a -12db/oct LPF at 5kHz, suddenly my resulting noise floor is around -64dB with the Linden EQ enabled.

Too bad I hadn't remembered my spectrum tools before I did all that testing! But I'm glad I did it. Now we know something about this pedal that maybe someone can test if they're curious.

I think I'm gonna go ahead and save up for a HPF/LPF pedal to get that filter action in place on the hardware side. Also, while this test shows the One Spot actually didn't do half bad when daisy chaining the pedals, I've got my eye on a CIOKS DC-7, or maaaybe a TrueTone CS7 since a couple pedals in my build are definitely low-risk with a small chain.

Thanks for your indulgence! Practice time.
 
Last edited:
  • Like
Reactions: dregsfan
#304
@Real Soon I looked at a couple datasheets for typical charge pump chips, and they usually have about 35kHz max oscillator frequency, so I'm fairly sure that's the charge pump operating at that frequency. But you shouldn't be getting much noise in the audible range. Might be something wrong with the charge pump chip or it's capacitors. You could ask David directly: [email protected]
 
Last edited:
  • Like
Reactions: Real Soon
#305
I thought I'd make sure my findings were as airtight as possible before emailing, and did some more tests using the Linden and using various LPF types to get the charge pump frequency isolated.

A) The more I learn, the more I see I don't know. Like voltage conversion being visible on the audio spectrum... I had no idea. Even if it's up past dog range, it's there. Interesting!

B) The Darkglass Vintage Ultra is a fine pedal for a lot of things, but does seem to impart a minimum noise floor of its own when used as a DI. Low enough that it's perfectly usable, and I've used it a lot with much success, but I'd always figured other parts of the chain were mainly responsible.

C) Using the Linden EQ by itself, with the LPF engaged in software (-12dB/oct, set anywhere between 5kHz and like 9kHz), I can effectively eliminate the "visible" presence of the charge pump circuit, and have determined there's no other noise to worry about. The noise floor is a tad bit lower with the Linden all by itself than thru the Darkglass VU (roughly -72dB vs the ~-67dB with the VU, negligible in the real world but good to know).


I just got a Rupert Neve RNDI in today :hyper: so will be doing some further comparisons later on, after I get a recording session done with the current chain.


All that testing work helped me conclude: trust my ears! I was expecting to hear problems due to what I saw, but the data shows the Linden is faultless. If anything, Ableton Live picking up a 36kHz signal is weird, and using the software LPF to eliminate it is a good solution.
 
  • Like
Reactions: Avalon5, Bolsyo and Roxbororob
#307
This doesn't give any solid answers to anything, but as a point of interest the switch-mode power supply (which uses an oscillator/FET/inductor/diode as opposed to a charge pump which uses capacitors) in the Particle Accelerator runs at 45.7kHz, which is well out of hearing range, and even the second harmonic will be 22.85kHz, also out of hearing range. Helps keep the audible noise down.
 
Last edited:
  • Like
Reactions: Real Soon
#308
Just read thru the last couple of pages on this thread as my new to me Barber Linden showed up yesterday. Been swapping it onto my board in place of my Particle Accelerator to compare. Loving both of them. Chain is D'Addario Tuner, LA-1A, PA or BL EQ, Quilter BB800, Berg HG410. Power is supplied by a Cioks 4. The Linden is super clean, and dead quiet in this set up. Loving the left switch to the far left for a Jazz, and to the far right (a bit of mid cut) for a P bass. Looking forward to seeing if the Barber will drive my Berg IP310.
 
  • Like
Reactions: Real Soon, Bolsyo, Low Down Brown and 1 other person
#309
Sushi Box FX said:
This doesn't give any solid answers to anything, but as a point of interest the switch-mode power supply (which uses an oscillator/FET/inductor/diode as opposed to a charge pump which uses capacitors) in the Particle Accelerator runs at 45.7kHz, which is well out of hearing range, and even the second harmonic will be 22.85kHz, also out of hearing range. Helps keep the audible noise down.
Click to expand...

In my mind, this is a very interesting thing that makes me wonder what it is that Ableton's spectrum analyzer detects.... after all, the Particle Accelerator shows absolutely no supersonic artifacts in that analyzer, and in fact, when it's engaged, it hampers the Linden's charge pump supersonic frequency's presence (the Linden being placed before the PA).

Unless there's a specific low-pass filter built into the Particle Accelerator somewhere, the way the electrical currents within those two respective methods of voltage handling interact with the audio signal is a mystery to a layman like myself, and perhaps to the engineers at Ableton.
 
#311
cosmicevan said:
Read this on another gear website:

Facebook from Dave stating that as of September 2020 their pedals are no longer in production. Sounds like an issue with finding a vendor for enclosures. He didn't say they were gone for good but it sounds like that's a definite possibility.
Click to expand...
Yeah I saw that. Devastating. Sushi Box use the same size enclosures, and it isn't an uncommon size generally so I don't know if it's price point or volume required or something else? Surely there is a solution some how?
 
#313
It sounds more like he invested in a supplier that jerked him around and there isn't the funding to pursue other options...sounds like small batches will likely happen, but no big investments to make sizeable batches of anything. The question is will the builder move on to other endeavors as a result or is this passion strong enough to put up with the nonsense.
 
  • Like
Reactions: Rocksolid
#314
The problem is that he only wants to deal with a single vendor that can do everything in-house for him (buying or making the enclosures, machining/drilling, powdercoating and printing graphics). If he rather wants to go out of business than splitting up these processes through a couple vendors, that's his choice, but I don't understand it at all. He has a low price point and could easily raise it a bit to cover any extra cost too.
Barber.jpg
 
  • Like
Reactions: cosmicevan and Rocksolid
#317
Low Down Brown said:
Man....that is a bummer :crying:

I hope they find a vendor so they don't have to shut down completely. The Linden is hands down my favorite EQ.
Click to expand...

A total shame because Barber makes such great stuff. I have a Linden and a Direct Drive v2 and would love to get additional Barber offerings. I don’t care about graphics, he can write on it with a sharpie. I’m serious. He can call them the COVID version. I’d buy.
 
  • Like
Reactions: Real Soon, Rocksolid, Low Down Brown and 2 others

Latest posts

Top Bottom
Back