Headphone Amplifier?

I'm so happy to see it, been wanting one for a while. I'm watching this thread too.

My question is: if I'm running pedals straight into this headphone amp, does it need a cabsim (like Unicab) to sound good, or does it sound good on its own? Without some eq filtering, straight signals can sound crap--but maybe it has adequate EQ built in.
 
I have another Q, what exactly is the stereo 'spread'? Common trick with modellers is to delay one ear by 10-20ms but I'm assuming it's not that
 
I have another Q, what exactly is the stereo 'spread'? Common trick with modellers is to delay one ear by 10-20ms but I'm assuming it's not that
I’m guessing it does the classic stereo spread trick of changing the EQ in the two channels slightly. Cut bass and treble a tiny bit in one channel, cut upper mids in the other channel, and you’ve got a quick and easy stereo spread
 
If it's related to the mxr project that's out there, it definitely benefits from the unicab. I boxed them together recently. I also enjoy it with the rog ginger and the aion ts-50 I completed last night (build report coming when it's boxed). I'm hoping it's a departure from the mxr as it is easy to fart out with bass. Fingers crossed for some headphone beano.
 
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This one is a basic headphone amplifier.

It's not related to the MXR, it uses a pair of LM386's.

I was pleasantly surprised with how nice it sounded playing my guitar plugged straight in, but you'll likely want some sort of amp/cab sim or at the very least EQ if you're planning to do any serious practicing with it dirty.

The stereo spread was inspired by the spread effect in the DSM Simplifier which introduces a phase shift on one side. It enhances the sound enough that I can't imagine ever turning it off. :D


If you're wanting all the bells and whistles (amp sim, cab sim, true stereo, etc) you'll want to hold off a bit, but if you just want a way to drive headphones from your pedalboard for practicing quietly or testing pedal builds this should work quite well.
 
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That reminds me...I ran the Rockman into a Parenthesis Rat-only, as my rat doesn't have any clipping options...anyway....I found a pretty cool arrangement that bleeds some pretty sweet sustained harmonic toppings to the tasty treat...it took some futzing with the amp, pedals, and guitar....so probably wasn't worth it, but it sounded pretty slick.
 
@Robert Any chance you have some docs about this, still waiting for mine to show up in the mailbox and wanted to order some parts. Was wondering about some weird values or what pot to order... can't wait to try that one. Thanks ;)
 

BOM and drill template. If your order was placed before today you have Revision 1.

The only difference between the two revisions is the LED placement and a pair of 100R current limiting resistors were removed in Revision 2.
 
@Robert and others, a couple of questions on this project:

1- Would it work for a bass ?
2- Would there be a few mod to run a bass ?
3- What if I was to connect a second jack for an auxiliary input straight to in/gnd , a way to plug you phone and play a backtrack ?

Thanks….
 
1. That's what I plan to use it for.
2. I think it's meant to be polyvalent... ?
3. Good idea, myself I planned on doing it on the output for 1/4 and 3.5mm
 
1. That's what I plan to use it for.
2. I think it's meant to be polyvalent... ?
3. Good idea, myself I planned on doing it on the output for 1/4 and 3.5mm
Interesting, so you do not think the sound need to be amplified and joined to the volume control ? Any specific reason ?

I'm also thinking of a MH-M18 Bluetooth module, just not sure if the PCB located in a aluminum enclosure would require an external antenna...
 
My plan on the output is to have a dpdt to select my output ... I don't know if it's better or not, but hey, one more switch ;)
On the other hand, I'm interested in mixing an auxiliary input, but my guess is that it would need at least a blend pot... I'm not experienced enough to know how to do it the right way. :unsure:
 
But for now, I've received my missing parts to complete this PCB, only to find out... no DPDT, I'm almost sure I had a few in my cart, but maybe I removed them because I planned on restocking later for my other pending builds.
 
My plan on the output is to have a dpdt to select my output ... I don't know if it's better or not, but hey, one more switch ;)
On the other hand, I'm interested in mixing an auxiliary input, but my guess is that it would need at least a blend pot... I'm not experienced enough to know how to do it the right way. :unsure:
For the auxiliary input, I think you could control the blend by using the volume of your device. Once you have parity, the volume knob of the pedal would increase both equally if you connect the auxiliary to the input of the amp. If you connect the aux to output, then blending would have to be done each time you change the pedal output volume...

That's my thought anyway...
 
That make sense using the phone volume on the input.
I may not have been clear about my intentions on the output. I will not add an auxiliary on the output, just the ability to plug cheapo earphones if that's all I have available at the moment... wife sometime steals my good headphones.
 
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