Headphone amplifier - Veroboard?

[atech]

I need a headphone amplifier with just a volume knob, but can't seem to find any veroboard layouts for stuff like this.

Does anyone have a veroboard layout that would work?

[BRingoC]

well, it's not really vero, but I built a smokey amp on perf-board using a 100k volume pot before the first connection to the ic and connecting the two pins 1 and 8 connected to each other. Below halfway on the pot and it is sorta clean, above half and its overdrive. I use it for headphones, akg k240's, and can also drive a cabinet with it.  There are only a few parts, so making it on perf is reeeal easy, worth a try.

[cab42]

I'm quite sure I have seen a Ruby vero layout by Torchy.

However it's great fun to make your own layout. I will be happy to help if you want.

Remember that these little amps are loud! It may be a good idea to add a headphone out with lowered output. There is notes for that on runoffgroove .com

Regards

Carsten

[WhenBoredomPeaks]

What kind of headphone amp you need? The kind of stuff which hi-fi guys use which have line-in input and it is not really about the volume levels but the increased current and stuff or something guitar related?

[atech]

What kind of headphone amp you need? The kind of stuff which hi-fi guys use which have line-in input and it is not really about the volume levels but the increased current and stuff or something guitar related?

It's a monitor box for violin. I want to plug in my violin (piezo mic) into the box, run it through a buffer, and then out of the box (to the sound engineer). Then I need a 3.5mm headphone jack (for regular earbuds) with a volume control. That's it.

I've sorted the buffer part, but I'm stuck at the headphone part. 

[Jarno]

It really depends on what kind of headphones you're using, if it's high impedance stuff, than an opamp per channel will drive it, or you could two opamp stages in parallel to power one channel (left or right). There are a number of more elaborate headphone amps for diy, but most of them are not battery powered. Have you checked out the projects at headwize? More headphone amps than you can shake a stick at

[atech]

It really depends on what kind of headphones you're using, if it's high impedance stuff, than an opamp per channel will drive it, or you could two opamp stages in parallel to power one channel (left or right). There are a number of more elaborate headphone amps for diy, but most of them are not battery powered. Have you checked out the projects at headwize? More headphone amps than you can shake a stick at

It's just for regular iPod-style headphones, nothing fancy. Don't know if that's high or low impedance.

I checked out the site, but no veroboard layouts unfortunately. Also, as a beginner it's very hard to know what to go for.

I was under the impression that a headphone amplifier was one of the easiest builds?

Would a Noisy Cricket (http://www.beavisaudio.com/projects/NoisyCricket/) be able to provide me with what I'm looking for? Or is that just for guitar stuff?

[atech]

I think I found something that would work (Cmoy headphone amp):



Only thing I don't understand is what the two pots are for....is one input volume and one output volume?

Ok, so a couple of questions about the above headphone amp:

1. Will this be powerful enough to drive a pair of regular iPod-style headphones
up to volume levels loud enough for stage purposes?

2. Should the buffer circuit come BEFORE or AFTER the headphone amp? The
buffer circuit will drive the signal to the OUTPUT jack (to sound engineer).

[roseblood11]

Hi,

looks interesting -- and simple.

What kind of pot would work here? Maybe a 10k log (stereo)?

The IC is a standard dual opamp, like OPA2134, TL072...?

-If you would swap the Battery connections (and the polarity of C3 and C4) you could use jumpers instead of the two wires on the board...

regards, Immo

[atech]

Hi,

looks interesting -- and simple.

What kind of pot would work here? Maybe a 10k log (stereo)?

According to the instructions I'm supposed to use a dual ganged 10K log pot, but I'm having a hard time finding them in the UK.

[WhenBoredomPeaks]

I think I found something that would work (Cmoy headphone amp):



Only thing I don't understand is what the two pots are for....is one input volume and one output volume?

Ok, so a couple of questions about the above headphone amp:

1. Will this be powerful enough to drive a pair of regular iPod-style headphones
up to volume levels loud enough for stage purposes?

2. Should the buffer circuit come BEFORE or AFTER the headphone amp? The
buffer circuit will drive the signal to the OUTPUT jack (to sound engineer).

this is pretty powerful, it drives a Sennheiser HD555 for me. You should use metal 1% resistors for match the volume levels on both sides. Also you should use a dual gang stereo pot for volume, but i heard that the standard Alpha and similar pots are not good enough, the different sides will have different volume levels, you will need some kind of hifi pot. (that is teh reason why mine don't have a volume control, i control the volume on the computer)

I power this thing from 12V or 18V it depends on what i have on hand, i use it with a BurrBrown OPA2132. You should use some quality input caps, i used Wima MKP10s. You can use bigger caps for more extra low bass. The size of the input caps on that schematic is a joke, the wimas i used were like 12 holes long.

[atech]

this is pretty powerful, it drives a Sennheiser HD555 for me. You should use metal 1% resistors for match the volume levels on both sides. Also you should use a dual gang stereo pot for volume, but i heard that the standard Alpha and similar pots are not good enough, the different sides will have different volume levels, you will need some kind of hifi pot.

I power this thing from 12V or 18V it depends, with a BurrBrown OPA2132. You should use some quality input caps, i used Wima MKP10s. You can use bigger caps for more bass. The size of the input caps on that schematic is a joke, the wima i used were like 12 holes long.

Thanks for the input!

Problem I'm facing right now is whether to have the buffer circuit before or after the headphone amp.

Should the signal go:

violin -> headphone amp circuit -> buffer circuit / headphone jack
(split signal from headphone amp circuit, one to buffer circuit and one to headphone jack)

or

violin -> buffer circuit -> headphone amp circuit -> headphone jack
(split signal from buffer circuit, one to main out and one to headphone jack)


Another problem is that the buffer circuit only has mono input and output, so how will I split a mono signal to work with  a stereo headphone amp circuit?


These are all the connections I have to make in order to make it work:




I'm guessing I can split the signal from the VIOLIN INPUT, one going to the buffer circuit (which then goes straight to MAIN OUT)...and one going to the headphone amp circuit (which then goes to HEADPHONE OUT). But since the headphone amp circuit wants a stereo signal...?

[j-pee]

if anyone is into making this amp, I suggest reading this article...

it is extremely cool, and thorough

"How to Build the CMoy Pocket Amplifier?"   

LINK: https://tangentsoft.net/audio/cmoy/

...