# Practice Headphone Amp



## JamieJ (Oct 19, 2021)

I have been looking for a quiet practice solution for a while and my first attempt is at a DIY option using the MXR headphone amp that @PedalPCB was kind enough to send me a couple of to test out. I added this to the unicab PCB. 

The unicab is a brilliant board. I wanted to add a switching jack to be able to use it with my amp as well and not just the headphone amp PCB.

My favourite settings on the unicab are the 2x12 Tweed, 1x12 open backed and the small blues combo setting. I took the picture on my iPhone but for some reason they look really crappy quality, sorry for that.


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## spi (Oct 19, 2021)

Cool, would love to see this offered as a single PCB!

edit:  I added it to the wish list


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## SillyOctpuss (Oct 22, 2021)

Wow I've just seen this and it looks awesome.  How are you getting on with it Jamie? Have you tried running any drive pedals into it yet?


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## SYLV9ST9R (Oct 22, 2021)

Missed this on Tuesday. Great job Jamie, looks awesome! 
Good thinking using the switching jack.


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## JamieJ (Oct 23, 2021)

@SillyOctpuss - great so far! It’s great to play at night without the worry of waking the kids. I have only tried stacking with a BD-2 and a  zendrive so far and it sounded good with those two. The headphone amp knob is actually a gain control instead of a volume control, so with gainer sounds you can lower the headphone amp gain. I’m only being let down by using it with iPhone headphones. I think with a good pair of head phones it would sound even better.
Thanks @spi and @SYLV9ST9R


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## SillyOctpuss (Oct 23, 2021)

JamieJ said:


> @SillyOctpuss - great so far! It’s great to play at night without the worry of waking the kids. I have only tried stacking with a BD-2 and a  zendrive so far and it sounded good with those two. The headphone amp knob is actually a gain control instead of a volume control, so with gainer sounds you can lower the headphone amp gain. I’m only being let down by using it with iPhone headphones. I think with a good pair of head phones it would sound even better.
> Thanks @spi and @SYLV9ST9R



Excellent stuff.  Makes sense about the gain/level


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## Barry (Oct 23, 2021)

Schweet!


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## ADAOCE (Oct 25, 2021)

spi said:


> Cool, would love to see this offered as a single PCB!
> 
> edit:  I added it to the wish list


I’m currently building a unicab, Mxr headphone amp (GGG), and the 4 channel mixer (GGG) into an enclosure. 

Glad to hear these two boards are working well for you. 

The mixer I’m adding will allow an auxiliary input and another 1/4 instrument input. Hope to have this done soon. I’d love to see a combo board of all three circuits but the headphone amp and unicab at the least would be awesome


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## JamieJ (Oct 25, 2021)

@ADAOCE - that sounds awesome. I’m looking forward to seeing a build report. Having the aux in makes it a much better practice solution.


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## almondcity (Oct 25, 2021)

forgive me if I missed it somewhere, but which headphone amp board is that?  I've been thinking of going this route myself


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## ADAOCE (Oct 25, 2021)

JamieJ said:


> @ADAOCE - that sounds awesome. I’m looking forward to seeing a build report. Having the aux in makes it a much better practice solution.


Hope to have it done in the next week or so. My wife is 38 weeks preggo so the pedal shop will be closed for a short time soon lol


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## zgrav (Oct 25, 2021)

ADAOCE said:


> Hope to have it done in the next week or so. My wife is 38 weeks preggo so the pedal shop will be closed for a short time soon lol


lots of incentive to be set-up to use headphones with your guitar and pedals


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## Harry Klippton (Oct 25, 2021)

ADAOCE said:


> Hope to have it done in the next week or so. My wife is 38 weeks preggo so the pedal shop will be closed for a short time soon lol


Good luck!


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## ADAOCE (Oct 25, 2021)

zgrav said:


> lots of incentive to be set-up to use headphones with your guitar and pedals


Exactly!


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## ADAOCE (Oct 27, 2021)

JamieJ said:


> @ADAOCE - that sounds awesome. I’m looking forward to seeing a build report. Having the aux in makes it a much better practice solution.


Boards are done. Gonna do some enclosure drilling and off board wiring this weekend. Hopefully I’ll have a report soon.

These GGG boards are good quality and nice and small but you sacrifice the nice layout that you get with PPCB. I can knock all the resistors and film caps out so quick on PPCB.


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## JamieJ (Oct 28, 2021)

Awesome. That gorva enclosure looks so good.

Are you going to omit the foot switch and wire them as always on?

Congratulations on the little one arriving too!


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## JamieJ (Oct 28, 2021)

almondcity said:


> forgive me if I missed it somewhere, but which headphone amp board is that?  I've been thinking of going this route myself


These aren’t on the site yet but I think they will be soon. I think they were part of a test batch. If you are in a rush GGG have a MXR headphone amp board.


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## ADAOCE (Oct 28, 2021)

JamieJ said:


> Awesome. That gorva enclosure looks so good.
> 
> Are you going to omit the foot switch and wire them as always on?
> 
> Congratulations on the little one arriving too!


Thanks man!

Yes I’m wiring it with two mini toggles that allow me to bypass the cab sim and switch from amp to headphones.

Thought about using the cabsim in the loop of the headphone amp but then I can’t use with my amp


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## ADAOCE (Oct 28, 2021)

Also not looking forward to 10 solder pots ….


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## ADAOCE (Oct 29, 2021)

@JamieJ can you explain the routing scheme here? I have a switched Jack I could use. I’m trying to figure out the best way to setup my bypass and amp switching


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## Paradox916 (Oct 29, 2021)

ADAOCE said:


> Hope to have it done in the next week or so. My wife is 38 weeks preggo so the pedal shop will be closed for a short time soon lol


Congratulations and good luck!  A good silent rig  is the way to go.... I haven’t used a cab in over 2 years... nap time and bedtime isn’t just about rest it’s also about daddy’s sanity when you are the stay at home parent.🤣


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## ADAOCE (Oct 29, 2021)

Paradox916 said:


> Congratulations and good luck!  A good silent rig  is the way to go.... I haven’t used a cab in over 2 years... nap time and bedtime isn’t just about rest it’s also about daddy’s sanity when you are the stay at home parent.🤣


Haha thanks man! Yeah I’ve been putting this build off for too long! I hear you on that. My wife and I split child care duties pretty evenly because she works some nights and I can only imagine being home all day. I have all respect for SAH parents


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## Harry Klippton (Oct 29, 2021)

It's not always successful but I try to play music with my 6 month old daughter as much as possible. I bought her a pair of hearing protection earmuffs for when I want to turn up a bit too


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## ADAOCE (Oct 29, 2021)

Harry Klippton said:


> It's not always successful but I try to play music with my 6 month old daughter as much as possible. I bought her a pair of hearing protection earmuffs for when I want to turn up a bit too


A for effort. My son at 6 months was scared of it. Now he’s 2.5 and I let him turn on whatever pedal and turn any knob he wants when I play. He gets some pretty wild sounds sometimes 🤣

@JamieJ sorry for hijacking this thread a bit. Your  build has been the kick in the ass I needed to get this one finished though


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## Paradox916 (Oct 29, 2021)

@ADAOCE oh and just my two cents, don’t skimp on headphones.


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## ADAOCE (Oct 30, 2021)

Paradox916 said:


> @ADAOCE oh and just my two cents, don’t skimp on headphones.


I got a pair of Sony MDR7506 that work great


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## JamieJ (Oct 30, 2021)

No worries @ADAOCE - glad to hear it had helped you encourage you with your project.

I have this wired: normal input jack > unicab > switched jack either to an amp or if no jack is inserted it goes to the tip of the headphone input jack. The headphone input jack > headphone amp pcb > insulated jack for headphones. Hopefully that makes sense.


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## ADAOCE (Oct 30, 2021)

JamieJ said:


> No worries @ADAOCE - glad to hear it had helped you encourage you with your project.
> 
> I have this wired: normal input jack > unicab > switched jack either to an amp or if no jack is inserted it goes to the tip of the headphone input jack. The headphone input jack > headphone amp pcb > insulated jack for headphones. Hopefully that makes sense.


Okay yeah that makes sense. Only difference with mine is the mixer. I’m putting the amp/HP switch after that. The mixer will always be in the circuit that way though which gives me some pause. This really shouldn’t be a permanent fixture in my board though so maybe I shouldn’t worry about it


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## Paradox916 (Oct 30, 2021)

So you have it wired like an FX loop between the cabSim and Headphone amp?


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## Diynot (Oct 30, 2021)

I love this headphone amp idea and you guys have executed beautifully!
   When my first was born I tried doing the little Smokey and little gem amps and they were always lacking in the clean department. @ADAOCE congrats on the impending “you don’t really know “rock your world” until you’ve had children” phase of life! Many wishes for a safe delivery. My 4 kids all love music in one form or another (piano, guitar, French horn, ukulele, drums, amongst other instruments) and they have all had a go at the wah pedal!
   So does the MXR have any clean room without sacrificing volume? Been looking at a kit from DIYre, the HC1 high powered headphone amp. It uses a 2x5532 ICs in a parallel config to drive each channel. Problem is, it’s a little too big to fit in a 1590bb or xx along side the unicab. I could do the little gem mkII, but would have to strip board it. That and there is no master volume.
   Sorry to ramble, last question, is using the emu preamp into the unicab redundant?


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## Robert (Oct 30, 2021)

__





						Practice/Headphone Amp Project
					

I'm starting this thread for feedback, suggestions, and ideas for an upcoming practice / headphone amp project, and so we can continue the discussion here instead of taking over Jamie's build report thread.   :ROFLMAO:  Here's the work-in-progress flowchart so far.




					forum.pedalpcb.com


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## jimilee (Oct 30, 2021)

ADAOCE said:


> I’m currently building a unicab, Mxr headphone amp (GGG), and the 4 channel mixer (GGG) into an enclosure.
> 
> Glad to hear these two boards are working well for you.
> 
> The mixer I’m adding will allow an auxiliary input and another 1/4 instrument input. Hope to have this done soon. I’d love to see a combo board of all three circuits but the headphone amp and unicab at the least would be awesome


I did this with a 2 channel mixer. The person for which I built it, wanted a way to learn and play along with songs.


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## JamieJ (Oct 31, 2021)

Paradox916 said:


> So you have it wired like an FX loop between the cabSim and Headphone amp?


Yep, so I could add in reverb between them if I wanted it. Also I wanted to be able to use the unicab in isolation with my amp as well (which sounds awesome).

@Diynot - the headphone amps control is a gain control so that just backs off the grit rather than being a volume control so it is plenty loud enough. I haven’t build the emu and don’t know much about it but I assume one can sim is all that would be needed.


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## taxfree (Nov 1, 2021)

Hi, Would it be possible to demonstrate how the connections in your circuit were? I built a Tonemender followed by a Unicab and would like to include an auxiliary input (to play the Backing tracks) and one and more input without both going through the unicab. I also wanted to have a headphone output that could hear the three input signals. I made an approximate diagram (see image). I don't have much knowledge of electronics and the implications of these connections.


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