I have a TC nova system guitar pedal. It has stereo line outs that can also be utilized to drive guitar amps. I'm not an electronics engineer - but I have many years of technical repairs and hobby projects etc. I'm looking for a miniature headphone amp PCB module that is basically mounted to a stereo 1/4" jack. I would like to tap off of the line outs L/R and parallel a signal from the line out to this headphone out module. It needs to not load the line outs in any way as well. Anyone know where I can buy a circuit like this?
Thanks for chiming in. The TC Nova pedal is pretty large compared to most board style pedals. I could likely afford a PCB sized 1.5" wide x 2" length, likely about 3/4" height for mounted 1/4" connector. Volume control could be utilized with board mount trim pot. A set and forget would work because the volume controls for the pedal circuits would be pre -HP amp. I'm using Sennheiser HD 650's. ( 300 ohm ).
Attachments
TDA2822 is happy with typical pedal +9V single supply and will drive your headphones easily.
https://electronicscheme.net/1w-stereo-headphone-amplifier-based-tda2822/
Do your shopping
https://www.aliexpress.com/popular/amplifier-tda2822.html
https://electronicscheme.net/1w-stereo-headphone-amplifier-based-tda2822/
Do your shopping
https://www.aliexpress.com/popular/amplifier-tda2822.html
No need to block anything
That is done on amplifiers/combos because supposedly you don´t want loud speakers in the room ... but you have an acoustically mute pedal or preamp.
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That is done on amplifiers/combos because supposedly you don´t want loud speakers in the room ... but you have an acoustically mute pedal or preamp.
A cute mono input solution that comes in a few different flavours: https://voxamps.com/product/amplug/
Highly regarded but perhaps not made any more has stereo auxiliary inuts: https://en.wikipedia.org/wiki/Rockman_(amplifier)
Highly regarded but perhaps not made any more has stereo auxiliary inuts: https://en.wikipedia.org/wiki/Rockman_(amplifier)
I've done some repair work with SMD - haven't built up anything from scratch - but I'm confident I can handle it.
Currently I use it in direct P.A. situations at rehearsals, as well as plugging through an Apollo interface for general at home recording and noddling using the Apollo headphone outs. I'm looking for a more portable solution for headphone noodling. Another thought for having both line outs and HP outs is for added monitoring if I want to use the TC for recording. I can live with a scenario where it's either or if needed and switched on the 1/4" jack input. The preference is that the HP circuit is just parallel off the line outs. Line outs are stereo - but plugging from just the left output : sums the stereo to mono - so not sure how that configuration would effect the HP out either.
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It sounds like you are looking for something like one of these:
https://www.jlmaudio.com/shop/headphone-amp-kit.html?display_tax_prices=1
https://diy.thcustom.com/headphone-amplifier-diy/
Connect the L/R inputs to the input of the output stage if the TC. You should be able to trace back from the line outs of your TC to the chip driving them. It's most likely opamp based. Look up the integrated circuit number to identify the pinout of the chip(s) to find the L/R signal input pins to source your signal for the headphone amp. You can simply parallel your new circuit to the existing.
https://www.jlmaudio.com/shop/headphone-amp-kit.html?display_tax_prices=1
https://diy.thcustom.com/headphone-amplifier-diy/
Connect the L/R inputs to the input of the output stage if the TC. You should be able to trace back from the line outs of your TC to the chip driving them. It's most likely opamp based. Look up the integrated circuit number to identify the pinout of the chip(s) to find the L/R signal input pins to source your signal for the headphone amp. You can simply parallel your new circuit to the existing.
If you are still searching, I made this very small and minimalistic PCB that is basically a copy of the OPA1688EVM (TI evaluation board) with optional output series/isolation resistors, 8mm diameter electrolytic caps and ferrite beads (and a Neutrik 6.3mm jack of course). It is meant to accept a balanced input signal by twisting a pair of wires and soldering them pretty much directly to the input of the differential amplifier and to the XLR outputs on the other end. There is no volume control and no output protection from DC or power on/off transients. The output isolation resistor should be chosen depending on the headphones and cable length. The SMD footprints aren't that easy to solder but no problem with a suitable soldering tip, some flux and 0.5mm diameter solder wire. If there is any interest, just let me know. 3 PCBs from Oshpark are less than 10 USD, BOM cost should be around 10USD per PCB I think.
