Practice/Headphone Amp Project

ADAOCE

Well-known member
Progress coming along. Posting this because I HIGHLY recommend waiting until this project is available rather than stringing separate boards together!!

My build report thread will have some better shots to show what I mean
 

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JamieJ

Well-known member
For those who are already working on something similar to this, how do you plan to use it?
Definitely desk based for me.

Also I caved in and bought a DSM & Humboldt simplifier on eBay recently and using the PPCB cab sim and headphone amp sounds so much better (to my ears) than using the simplifiers headphone out. So the Unicab cab sim 100% would get my vote for this build.
 

jjjimi84

Well-known member

Here is the earliest incarnation of my desk unit.

The signal chain goes fuzz to fx loop 1 to oc-2 to fx loop 2 to amp sim 1 to amp sim 2 to cab sim to fx loop 3 to reverb.

From the reverb it goes to a switch that selects whether it goes to the headphone section or to the direct out. Direct out is for recording into an interface.

The headphone section has a headphone amp and an auxiliary in.

I use it to practice and write and record and for travels. Sounds killer and works well through the jambox
 

Diynot

Well-known member
@jjjimi84 that is mad scientist level awesome!

So I have been thinking ab my personal headphone amp quest and really, I just want the option of a decent preamp into an amp that is capable of clean headroom. To that end and maybe to my folly, I ordered up an Acetylene board to pair with……? Maybe the little gem mkII, but have been toying with the idea of using a class d power amp in the form of a rehoused EHX 5mm. Is 2.5watts @ 8ohms unreasonable for headphone use? Does anybody have the schematic for said pedal?
 

Mentaltossflycoon

Well-known member
It could be buffered, or it might be removed (or replaced with a basic reverb after the cab sim)...

Initially I was imagining a simple way to switch a loop of effects in and out with one press, but at this point it's still in the air.


For those who are already working on something similar to this, how do you plan to use it? On a pedalboard?

Personally I'd be more likely to sit it on a desk in front of me, as a console-type unit, with toggle switches rather than footswitches.
I've had the ggg mxr board laying around for a while half built. I planned to use it on my couch/desk top console style with toggles like you're suggesting with a few other circuits but I may put that in a smaller travel style enclosure if you're planning to release something with more features and tabletop appropriate. I'd also be into something like that for sure.
 

DAJE

Well-known member
My headphone setup is a UniCab into one of these, a $20 knockoff of a knockoff. Works, though, and sounds good.

I have no need for the XLR sockets or the mic level pot. The mono/stereo switch is useful, though - it's for the input, so it lets a stereo input through, or splits a mono input into two outs, one for each ear.

It's not that loud - but that's a good thing, for a headphone amp. I usually have the level at about 70-80%.

Only thing I dislike about it is that it takes 12V center positive power, so I have to be careful setting up and I can't just run it off my pedal power brick.

I'd prefer toggles to footswitches, but maybe have options for either, so the builder can choose. Or at least make it so that it can be modded without much extra effort.
 

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zgrav

Well-known member
My headphone setup is a UniCab into one of these, a $20 knockoff of a knockoff. Works, though, and sounds good.

I have no need for the XLR sockets or the mic level pot. The mono/stereo switch is useful, though - it's for the input, so it lets a stereo input through, or splits a mono input into two outs, one for each ear.

It's not that loud - but that's a good thing, for a headphone amp. I usually have the level at about 70-80%.

Only thing I dislike about it is that it takes 12V center positive power, so I have to be careful setting up and I can't just run it off my pedal power brick.

I'd prefer toggles to footswitches, but maybe have options for either, so the builder can choose. Or at least make it so that it can be modded without much extra effort.
you could use an adapter cable to change center positive to center negative. do you know if it will run on 9v? or do you have a 12 feed you could use for it from your pedal power supply?
 

DAJE

Well-known member
you could use an adapter cable to change center positive to center negative. do you know if it will run on 9v? or do you have a 12 feed you could use for it from your pedal power supply?
I have both those things, but using them wouldn't be less hassle than just using the power supply that came with the headphone amp. I guess I prefer to keep center +/- far apart. I was more saying that it'd be nice if the headphone amp just used the same power as my pedals.

EDIT: I just tested it with a reverse polarity adapter, and the LED works with 9V so I'm guessing the rest of it will too. So, thanks for inspiring that.
 
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taxfree

Member
Olá, Seria possível demonstrar como estavam as conexões do seu circuito? Eu construí um Tonemender seguido de um Unicab e gostaria de incluir uma entrada auxiliar (para tocar as faixas de Backing Tracks) e uma ou mais entradas sem passar pelo unicab. Eu também queria ter uma saída de fone de ouvido que pudesse ouvir os três sinais de entrada. Fiz um diagrama aproximado (ver imagem). Não tenho muito conhecimento de eletrônica e as implicações dessas conexões. WhatsApp Image 2021-11-01 at 07.58.32.jpeg
 

G.G.

Member
I was just thinking about a headphone practice amp, how did you read my mind? 🙃

I have a Pocket Pod I've been using for years that sounds pretty good as a headphone amp, but I've noticed lately that my pedals sound a lot different through the Pod than through my Blues Jr I play for live performances (I don't use the Pocket Pod to play live, tried it and would not recommend that). Line6 made some software to edit the Pocket Pod presets but it hasn't been updated in a while and last time I tried it wouldn't run on my PC, so I don't have a way to make a preset that sounds more like my amp. It also seems like the pedals can push the pod into overdrive in a way that sounds completely different than my amp. I would really like to find something that can play nice with pedals and sound a little more like my amp. Looking forward to what you guys come up with!
 

taxfree

Member
As the unicab pcb already exists, wouldn't it be interesting to develop a pcb with just the mixer for auxiliary input and headphone output? the two pcbs could be mounted in a single enclosure
 

Stickman393

Well-known member
To add my own input...

I built a headphone amp a while back that I absolutely love, and I'm in the process of building a second one for my father. It's a community-designed circuit that AMB sells the circuit boards for called the M3. It's not a terribly expensive build, but it's certainly a bit more than an average pedal.

I've got a little collection of cans...nothing too crazy or ridiculous. It's easy to get up one's own ass when exploring the audiophile world. I tend to use mine with a pair of BLON planar magnetics or my Sennheiser HD 6xx.

Something that I really appreciate about the one I built is it's sense of "space" in the stereo image and quick tracking of low end transients. I've attached the schematic, which is open-source.


Something I've noticed over the years is that the majority of the commercial guitar headphone amps I've used have felt pretty claustrophobic and sterile, more of an afterthought and a race-to-the-bottom make it cheap cheap cheap toy than something I'd actually want to spend time with. And using one for bass...typically ends up being a smeary, unfocused mess.

So...that is to say...it would be really cool to build something with enough "oomph" behind it to drive a pair of circumaural cans competently, enough capacitance on tap to cleanly reproduce the low end transients of a bass guitar, and something that sounds more akin to the "amp in a room" soundstage than the typical "hey bud get your ears ready for this mono exploration of sandpaper and ice-pickery".

Again, it's easy to get up one's own ass when it comes to the world of audiophile headphones and amps and cork-flatulence-sniffing, BUT...there are little pieces to be snagged from that world that could be utilized to create something quite capable and FUN to use.

Granted, not everyone's gonna have $200-300 headphones to enjoy it with, but my vote goes toward "overbuild that shit".

mmm_sch.png
 

ADAOCE

Well-known member
To add my own input...

I built a headphone amp a while back that I absolutely love, and I'm in the process of building a second one for my father. It's a community-designed circuit that AMB sells the circuit boards for called the M3. It's not a terribly expensive build, but it's certainly a bit more than an average pedal.

I've got a little collection of cans...nothing too crazy or ridiculous. It's easy to get up one's own ass when exploring the audiophile world. I tend to use mine with a pair of BLON planar magnetics or my Sennheiser HD 6xx.

Something that I really appreciate about the one I built is it's sense of "space" in the stereo image and quick tracking of low end transients. I've attached the schematic, which is open-source.


Something I've noticed over the years is that the majority of the commercial guitar headphone amps I've used have felt pretty claustrophobic and sterile, more of an afterthought and a race-to-the-bottom make it cheap cheap cheap toy than something I'd actually want to spend time with. And using one for bass...typically ends up being a smeary, unfocused mess.

So...that is to say...it would be really cool to build something with enough "oomph" behind it to drive a pair of circumaural cans competently, enough capacitance on tap to cleanly reproduce the low end transients of a bass guitar, and something that sounds more akin to the "amp in a room" soundstage than the typical "hey bud get your ears ready for this mono exploration of sandpaper and ice-pickery".

Again, it's easy to get up one's own ass when it comes to the world of audiophile headphones and amps and cork-flatulence-sniffing, BUT...there are little pieces to be snagged from that world that could be utilized to create something quite capable and FUN to use.

Granted, not everyone's gonna have $200-300 headphones to enjoy it with, but my vote goes toward "overbuild that shit".

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All great points. My recent headphone amp build is limited to mono setup (fine for guitar-actually sounds quite good). For the aux input you really need two headphone amp circuits to keep it stereo and I agree that something that could drive the cans a bit more and get better quality reproduction of whatever tracks you’re trying to play along to would be good.

I want to build one of these for a buddy who plays bass at some point but I want to make sure it will work right
 
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