Will I need a preamp for this?

[LetsPaul]

I'm a total newbie to pedal (and amp) building. I'm looking to put together a small headphone-only amp unit for bedroom practice. I have the PedalPCB headphone amp and UniCab boards which I plan to chain together to this end. Will I need to add a preamp, will the Unicab act as one, or does the headphone amp board not need one in general?

If I will need a preamp, are there any of the Pedal PCB preamp boards that are good for relatively uncolored sound (so I can rely on just the Unicab for color)?

Thanks!

 

[Cybercow]

The UniCab can color the sound. You should be good.

 

[LetsPaul]

Thanks for the reply, but that wasn't what I was asking (apologies If my wording was muddled).

I want to know if the PedalPCB headphone amp can use the raw "weak" signal directly from a guitar, or if it needs a separate preamp stage to boost the signal first.

I have a headphone amp from a different manufacturer (made for regular recorded music listening), but found that it can't use a raw guitar signal without preamplification (and also doesn't handle mono input gracefully), so I wanted to double check if the PedaPCB one is designed for direct guitar use.

I already know the UniCab will provide color. That's its purpose in the chain (as I understand it): to add customizable "cab tone" to the amp. I just don't know if it'll also provided preamplification if the amp needs it.

 

[Mentaltossflycoon]

I prefer to use a pre but it doesn't need one as much as other diy headphone amps.

 

[xefned]

The Unicab has a max 12db of gain fully cranked. That may be enough depending on your guitar output (active pickups?,) but it's not ideal from a signal-to-noise perspective.

I haven't built one, so I don't know for sure. (It's on my list.) Try it and let us know!

If you find it's not enough, any butt-simple booster will get you there.

 

[xefned]

For added simplicity, you can jumper pins 2 - 3 of the volume pot on the aforementioned booster for a simple 1-knob boost.

 

[LetsPaul]

Thanks! That's a big help.

I'll definitely post the results when I get it put together. Might be a bit 'cause I gotta collate part orders and design a case (I kinda want to box up the amp and cab sim as a single unit), but I am exited.

I'm pretty new to this. My only electronics experience has been doing lighting circuits for model kits, so right now I'm only capable of "paint by numbers" component assembly when it comes to this kind of thing, but I'm looking forward to learning.

*Edit* Major thanks also to those who've posted build reports of the headphone amp in the past. In the current absence of an official build doc, the gut shots have been very helpful in sussing out the finer details of some components.

 

[xefned]

You can do it! Let us know if you run into any snags.