Signal Chain Recommendation

[FokC352]

Sup guys, first post on this forum. Been lurking for a while and I really like what I'm seeing. 

TL;DR Available at last paragraph

So I'm a big Gilmour fan, I'm trying to replicate his gear 1:1, but I'm also financially challenged which means I have to resort to digital workarounds for my tone. Currently I am using a Focusrite Solo Gen3 and several effects from different manufacturers to get my tone. However, I have this really jarring 60hz hum and a ton of imperfections making their way into my signal chain.

Lately it seems that it's developing into a hobby the way I've been interested in electronics. I know next to nothing about electronics but I am keen to learn and my computer science background should offer some skills to make my learning more facile. So I've started digging around and set it as a goal to build my first stomp box. Naturally I need to start with something easy, but also something that will be useful to me. I understand it is kind of a meme on this forum to talk about Pete Cornish so here goes:

While researching Gilmour's pedals, Cornish is mentioned a ton, and especially it seems that most of the Cornish pedals feature the tube buffer/line driver that also comes in a standalone form, the LD-1. This seems perfect for me, as I could maybe get rid of all of those aforementioned imperfections and 60hz hum that ruin my tone. Looking around some more though, there seems to be an inconsistent agreement on which buffer is the best for this sort of application.

I apologize for talking this much, I just feel the need to be exhaustive about the context and my needs, but here is a TL;DR and actual questions:

TL;DR:
My signal chain is guitar -> focusrite solo gen3 interface -> digital effects but I suffer from too much electromagnetic interference which ruins my tone. I am a Gilmour head, and also new to electronics so the first pedal I intend to build is Pete Cornish LD-1, as this is the buffer that David uses.

My question(s):
-can/should I use a guitar buffer pedal before the focusrite?
-if yes, is the LD-1 for a Gilmour tone the best option?

Thanks guys and sorry again for this wall of text lol.

[FiveseveN]

Hi, welcome to the forum!

No, a buffer is unlikely to improve anything, LD-1 or otherwise. Unless the EMI is mainly coming in through the cable and you put the buffer inside the guitar, in which case you should replace the cable anyway. Of course if you use the EMG DG20 pickups and/or EXG/SPC they're already buffered, so that's moot.

Try to find a position where there's less noise, shut down sources of interference (like a PC unfortunately ), make sure everything is properly grounded, use one of the various "noiseless" single coil systems etc.

[GibsonGM]

Hello and welcome!  Well, let's take this step by step.  What is causing "60Hz interference"?  I think that must be addressed before you go deeper with your tone quest!

Is it your playing environment? Flourescent lights, computers, things like that nearby?  Do you power your pedals with an adapter, if so, it meant for audio equipment?  Is your home/apartment properly grounded?  Any  more info you can provide will help others find the problem...

Another thing; if it's typical single coil 'hum' that is 'normal', a noise gate might also offer some help in suppressing noise while not playing...

[antonis]

Hi & Welcome..

the first pedal I intend to build is Pete Cornish LD-1

LD-1 is a good single BJT buffer and can be done better with a little thought..
But for a first build it is highly recommendend, as it is..!!

[FokC352]

No, a buffer is unlikely to improve anything, LD-1 or otherwise. Unless the EMI is mainly coming in through the cable and you put the buffer inside the guitar, in which case you should replace the cable anyway. Of course if you use the EMG DG20 pickups and/or EXG/SPC they're already buffered, so that's moot.

Try to find a position where there's less noise, shut down sources of interference (like a PC unfortunately ), make sure everything is properly grounded, use one of the various "noiseless" single coil systems etc.

I forgot to say a few words about my guitar: I have tried to clone David's black strat, so I got 3 single coils. Unfortunately I have yet to actually shield the guitar, which *should* get rid of the 60hz cycle. From guitar to interface I am using a Mogami 3368 cable which features impressively low capacitance and is also well shielded. However, in my amp sim, even with the guitar volume knob turned to 0, there is still quite a lot of noise which I assume comes from my environment, or is generated by the interface itself. This for me is the most pressing issue and I had hoped a buffer could help. I have messed around with different sockets, they seem to be grounded well enough. I use a laptop so even when I am running off of battery power, the issue remains. Thanks for the answer!

Hello and welcome!  Well, let's take this step by step.  What is causing "60Hz interference"?  I think that must be addressed before you go deeper with your tone quest!

Is it your playing environment? Flourescent lights, computers, things like that nearby?  Do you power your pedals with an adapter, if so, it meant for audio equipment?  Is your home/apartment properly grounded?  Any  more info you can provide will help others find the problem...

Another thing; if it's typical single coil 'hum' that is 'normal', a noise gate might also offer some help in suppressing noise while not playing...

My effects are entirely digital and reside on my laptop, so I'm not using any adaptors for them! Also, I have used noise gates in the past but with little success, as by the time they cut the noise off, the sustain is lessened and the highs are lost.

Hi & Welcome..

the first pedal I intend to build is Pete Cornish LD-1

LD-1 is a good single BJT buffer and can be done better with a little thought..
But for a first build it is highly recommendend, as it is..!!

As a plan for the future I do intend to build all of the pedals Gilmour uses, but I need to know if electrical engineering is for me first lol. Thanks for the recommendation

[FiveseveN]

even with the guitar volume knob turned to 0, there is still quite a lot of noise [...] I use a laptop

Yeah, that would have been useful information. All the laptop supplies I've seen are double-insulated, AKA definitely not properly grounded. You can confirm there's no continuity between your jack/strings etc. and mains earth with a multimeter. There's probably significant potential instead.

[FokC352]

even with the guitar volume knob turned to 0, there is still quite a lot of noise [...] I use a laptop

Yeah, that would have been useful information. All the laptop supplies I've seen are double-insulated, AKA definitely not properly grounded. You can confirm there's no continuity between your jack/strings etc. and mains earth with a multimeter. There's probably significant potential instead.

Any ways to fix this that you know of?

Also, unrelated but I just noticed we share the same country. Greetings from Romania!

[tootsMcgee]

Hmm, Am I understanding right that the Focusrite is producing noise even with the guitar on zero? Does it produce noise with nothing between the guitar and interface? (i.e., guitar -> interface direct)? Does it do it when you record the track straight vs into the amp sim?

I have a 2i2 Gen 2. It's surprisingly solid and I've used it on my laptop both plugged in and on battery and not observed any noise, but I mostly use it to record line level signals from sources like a looper. In general the Focusrites have great hardware and terrible drivers, which shouldn't produce noise...

EDIT: adding onto this...anywhere in proximity to a computer you'll get noise from the guitar. It should still go down with the volume knob, but there WILL be single coil noise. Even humbuckers are not immune. CPUs and GPUs current needs vary wildly depending on workload/the specific sections of the chip in use, and will abruptly change on the order of hundreds of amps. This can be audible even to the human ear ("coil whine" is when inductors/coils/other power delivery components physically vibrate in response to power needs, and you tend to hear it when the computer is busy doing heavy things with regular pauses, like realtime rendering for video games--draw a frame, wait ~15ms, draw a frame, wait, etc).

Fun fact: the difference in power draw amount and duration between types of CPU instructions, like division vs addition, can be measured through various means (audible, EMI measurements, wall socket measurements, timing) and used to deduce what information is being processed by the CPU in a side-channel attack.

If possible, keep the interface and especially the guitar as far away from the laptop as possible. You may also find that rotating on the spot while holding the guitar will produce certain angles where the noise falls off abruptly even when near the computer. Physics is weird.

[GibsonGM]

What Toots said.  When I use my strat, single coils, near my computer I pick up the digital crap it's producing.  So bad once in a while during a quiet part of recording, I have to use noise cancellation after I record unless I go 8' away from the PC (not convenient when tracking a part 50 times lol).   

If I don't use a gate and put the guitar near the tower, you can very noticeably hear all kinds of whine, buzz, clicking, which is what computers do.   And yes it changes with 'perpendicularity', same way you need to place inductors at right angles if they're in one chassis. I have a 'turn' I do when sitting here recording that brings it down to acceptable levels.  Check this stuff out!

[marcelomd]

I have a Scarlett Solo 3rd gen. Even with no instruments plugged it picks up noise from the mouse wheel turning.

[tootsMcgee]

Wow, that's pretty bad. How high up is the gain on it?

For reference, I have the gain at about 10 o'clock on both my inputs. One is on Line level and one is on Instrument. My noise floor looks like it's around -83dB. It's right next to my desktop.

I can try on laptop but you really shouldn't be able to hear anything at all from a unit just sitting there with nothing else hooked to it, unless your gain is way high...

It's better to keep gain low and boost in software if you can. If you have something like a SM57, the preamps on the Focusrite *can* use it, but you'll be pushing the gain pretty high and you might want something like a Fethead inline boost located away from the computer.

[GibsonGM]

I use a mosfet boost to give my mic's a little preamping on the way in....a few feet away from the computer, yes.

Cue Antonis making fun of my mosfet boosts...

[FiveseveN]

Greetings from Romania!

Hey, how about that!

Try this:
1. Leave laptop on batteries (PSU disconnected). This is important and might prevent a jump scare.
2. Contact a conductive part of your guitar that should be connected to ground (strings etc.) to an exposed (conductive) part of a radiator, water pipe etc. Something that is definitely connected to earth, mains earth AKA the actual ground.
Does the noise level improve?

Communist-era apartments often have earthing on a single or maybe 2 outlets (near bathroom / in the kitchen). Of course you might not live in one and it has no impact on laptops being insulated, it just makes fixing interference issues even harder.

[FokC352]

Hmm, Am I understanding right that the Focusrite is producing noise even with the guitar on zero? Does it produce noise with nothing between the guitar and interface? (i.e., guitar -> interface direct)? Does it do it when you record the track straight vs into the amp sim?

I have a 2i2 Gen 2. It's surprisingly solid and I've used it on my laptop both plugged in and on battery and not observed any noise, but I mostly use it to record line level signals from sources like a looper. In general the Focusrites have great hardware and terrible drivers, which shouldn't produce noise...

EDIT: adding onto this...anywhere in proximity to a computer you'll get noise from the guitar. It should still go down with the volume knob, but there WILL be single coil noise. Even humbuckers are not immune. CPUs and GPUs current needs vary wildly depending on workload/the specific sections of the chip in use, and will abruptly change on the order of hundreds of amps. This can be audible even to the human ear ("coil whine" is when inductors/coils/other power delivery components physically vibrate in response to power needs, and you tend to hear it when the computer is busy doing heavy things with regular pauses, like realtime rendering for video games--draw a frame, wait ~15ms, draw a frame, wait, etc).

Fun fact: the difference in power draw amount and duration between types of CPU instructions, like division vs addition, can be measured through various means (audible, EMI measurements, wall socket measurements, timing) and used to deduce what information is being processed by the CPU in a side-channel attack.

If possible, keep the interface and especially the guitar as far away from the laptop as possible. You may also find that rotating on the spot while holding the guitar will produce certain angles where the noise falls off abruptly even when near the computer. Physics is weird.

https://voca.ro/15F5aWNxNyML

I have uploaded a vocaroo recording showing the noise levels of my current rig. First sound you hear is the interface without any input plugged in, then I plug in my guitar (with volume knob to 0) and the noise goes considerably down, but it's still there and in a live gig setting would be overwhelmingly loud. Then, I start increasing the volume knob on my guitar until it reaches "10", at which point the noise is very loud. I mention that I am indeed using big muffs, compressors and no noise gate, because by the time noise gates do anything useful, they create other problems such as very limited sustain and reduced dynamics. Furthermore, Gilmour doesn't use any, so there must be a way to get rid of all of the noise in an elegant way. I also mention that my guitar is NOT shielded (I will shield it soon), but that shouldn't matter when my guitar volume is at 0. My focusrite instrument gain knob is at around 10-11 o'clock and the microphone input is disabled from the Focusrite Control software.

Greetings from Romania!

Hey, how about that!

Try this:
1. Leave laptop on batteries (PSU disconnected). This is important and might prevent a jump scare.
2. Contact a conductive part of your guitar that should be connected to ground (strings etc.) to an exposed (conductive) part of a radiator, water pipe etc. Something that is definitely connected to earth, mains earth AKA the actual ground.
Does the noise level improve?

Communist-era apartments often have earthing on a single or maybe 2 outlets (near bathroom / in the kitchen). Of course you might not live in one and it has no impact on laptops being insulated, it just makes fixing interference issues even harder.

Heh, I do indeed conduct my student business from a communist era apartment, I will try what you suggested. However, I have set up the same gig in different places (of which at least one SHOULD have actual proper grounding) and the noise problems persists. Perhaps I'm just trying to solve an unsolvable problem because I can't actually afford to splurge on proper, analogue equipment. For reference, I don't know if it helps, but you can listen to the vocaroo recording posted above.

Thanks for the answers guys!

[GibsonGM]

The level of hiss w/no guitar is acceptable in my opinion, similar to a guitar plugged into an amp. I would use a gate to eliminate it, set so low that it would not affect any playing (I mostly record into a DAW now, so it would be a software plugin).

Taking what you wrote - guitar volume down, that is also ok; that is what I am used to hearing on stage when not playing (I roll my volume pedal back between songs and like you, it goes silent).   With knob on 10 and effects engaged - that is really nasty buzz!  This suggests that the pedal chain has a 'reasonable' noise floor, based on what is acceptable to me.   But there seems to be something either mis-wired in your guitar, or there is a noise source close enough to you for it to couple into your pickups.   That is like standing near a florescent light transformer.

You have hunted for other sources of EMF nearby?

[tootsMcgee]

The level of hiss w/no guitar is acceptable in my opinion, similar to a guitar plugged into an amp. I would use a gate to eliminate it, set so low that it would not affect any playing (I mostly record into a DAW now, so it would be a software plugin).

Taking what you wrote - guitar volume down, that is also ok; that is what I am used to hearing on stage when not playing (I roll my volume pedal back between songs and like you, it goes silent).   With knob on 10 and effects engaged - that is really nasty buzz!  This suggests that the pedal chain has a 'reasonable' noise floor, based on what is acceptable to me.   But there seems to be something either mis-wired in your guitar, or there is a noise source close enough to you for it to couple into your pickups.   That is like standing near a florescent light transformer.

You have hunted for other sources of EMF nearby?

Interestingly, that sounds exactly like my breadboarded ENGL Classic Fuzz right now. It's just two opamp gain stages with zero diodes. At max gain I get some very reactive hum like that that actually peaks when I turn down the guitar volume a bit.

That suggests that it's guitar related (I've seen the same thing on the 'scope on the guitar input signal) but could it also be some weird interaction with the Focusrite?

Will have to plug it into an amp later today and see...I've only had it plugged into my interface...it's also a bit fragile so I haven't walked around with it yet.

[marcelomd]

Wow, that's pretty bad. How high up is the gain on it?

For reference, I have the gain at about 10 o'clock on both my inputs. One is on Line level and one is on Instrument. My noise floor looks like it's around -83dB. It's right next to my desktop.

Not sure if you were asking me. My gain knob usually points between 9 and 11 o' clock. I've never tried to see if playing a video or doing some heavy computation increased made any noise, though.