Cool-looking amp. Is this one of the old Headwize designs?
Actually, I've got more headamps than I know what to do with! My latest is actually one of the THX AAA designs.
For portable use, I built a modded version of Tangent's PiMETA. And one of my main amps is Tangent's PPAv2.
Back to the high-power CMoy ... no too worried about portable power. Two 9.6v NiMH should be enough.
I just want to make sure the high-power OPA is a good one. I'm willing to splurge a bit on the OPA if that's a good investment.
Actually, I've got more headamps than I know what to do with! My latest is actually one of the THX AAA designs.
For portable use, I built a modded version of Tangent's PiMETA. And one of my main amps is Tangent's PPAv2.
Back to the high-power CMoy ... no too worried about portable power. Two 9.6v NiMH should be enough.
I just want to make sure the high-power OPA is a good one. I'm willing to splurge a bit on the OPA if that's a good investment.
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The SE Class A pocket amp is my own design. It will have the same harmonic signature of a tube amp but cleaner. Absolutely no hiss/noise dead silent.
Another very good ultra low distortion opamp is the OPA1656. Use in parallel and it’s good for 200mA. Check out the insane specs.
https://www.ti.com/lit/ds/sbos901a/...=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA1656
Another very good ultra low distortion opamp is the OPA1656. Use in parallel and it’s good for 200mA. Check out the insane specs.
https://www.ti.com/lit/ds/sbos901a/...=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA1656
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Output caps
Thx for sharing the schematic.
I don't like caps (DC blocking caps) on the output or input. In all my designs, I either don't use them or servo the output somehow.
I see caps in your SE design. For the output, what are your DC voltage readings (powered up, but with no signal) if you bypassed (shorted) the output caps?
BTW:
In my own personal use, portable (= small, compact, battery pwr) are -- and have been for two decades -- for IEM use only. For non-IEMs, it's a plug-in-the wall headphone amp, diy or commercial. The Tin P2 novel planar IEM is a new device that got me interested in high-power portables. I'l lsee how that goes ... bit I have no interest in powering hd650s or beyer dt-880s with small, portable battery units.
Thx for sharing the schematic.
I don't like caps (DC blocking caps) on the output or input. In all my designs, I either don't use them or servo the output somehow.
I see caps in your SE design. For the output, what are your DC voltage readings (powered up, but with no signal) if you bypassed (shorted) the output caps?
BTW:
In my own personal use, portable (= small, compact, battery pwr) are -- and have been for two decades -- for IEM use only. For non-IEMs, it's a plug-in-the wall headphone amp, diy or commercial. The Tin P2 novel planar IEM is a new device that got me interested in high-power portables. I'l lsee how that goes ... bit I have no interest in powering hd650s or beyer dt-880s with small, portable battery units.
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Something like this, in theory, will give you 0.5W into 65R.
New Audio Op Amp - OPA1622
Max output current of the OPA is rated at ~120mA.
But probably not for too long.
And you will need a different SMPS chip than the LTC3265.
But there are quite a few around, up to 2A.
Patrick
New Audio Op Amp - OPA1622
Max output current of the OPA is rated at ~120mA.
But probably not for too long.
And you will need a different SMPS chip than the LTC3265.
But there are quite a few around, up to 2A.
Patrick
The OPa1622 is a good one and I think one of the posts that vanished was the one where I showed 8 of them parallel together. Send me a PM of you are interested, but the 8x OPA1622 has enough current to drive 8ohm speakers to a few watts. It also is very low distortion and has a pleasing sound.
This PCB had provision for AC coupling but it was bypassed on input and output as you can see the jumpers.
This PCB had provision for AC coupling but it was bypassed on input and output as you can see the jumpers.
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Just for fun, let's look at the requirements :
1W rms output, say from 32R to 100R load
Portable, so battery powered, and low quiescent current.
DC coupled, so dual voltage supply.
1W 32R means 250mA. 1W 100R means +/-15V.
You will need a dual polarity charge pump, e.g. LT8582.
A single TPA6120 should do the rest for you, as long as you do not need 1W continuously.
Said nothing about the sound.
But it fulfills your requirements.
Cheers,
Patrick
1W rms output, say from 32R to 100R load
Portable, so battery powered, and low quiescent current.
DC coupled, so dual voltage supply.
1W 32R means 250mA. 1W 100R means +/-15V.
You will need a dual polarity charge pump, e.g. LT8582.
A single TPA6120 should do the rest for you, as long as you do not need 1W continuously.
Said nothing about the sound.
But it fulfills your requirements.
Cheers,
Patrick
There was no glitch. The posts were deleted for breaking forum rules. Those who posted know why.
It's not really a dual polarity charge pump but a dual, multitopology DC-DC converter with integrated switches. It basically requires you to use 0402 components and coupled inductors on a 4-Layer PCB if you want to stick to the layout recommendations. Definitely an interesting part but not that straight forward to implement for DIY projects.
Jason Stoddard from Schiit Audio discusses how much power you "really" need for headphones (more than many think)...
Interview with Schiit Audio - Part 4: Is there a new Jotunheim on the way? - YouTube
Also the new Chinese Monoprice Liquid Gold X headphone DAC amp can output over 8w into 300-ohm:
Monolith by Monoprice Liquid Gold Balanced Headphone Amplifier and DAC by Alex Cavalli
It would be cool to see a high-power headphone amp DIY project some day.
Interview with Schiit Audio - Part 4: Is there a new Jotunheim on the way? - YouTube
Also the new Chinese Monoprice Liquid Gold X headphone DAC amp can output over 8w into 300-ohm:
Monolith by Monoprice Liquid Gold Balanced Headphone Amplifier and DAC by Alex Cavalli
It would be cool to see a high-power headphone amp DIY project some day.
Links would be helpful
Thanks!
You seem a bit upset by my comment and I apologise if I offended you. In any case, I don't really have time to search the myriad threads that have accumulated over the years. Links by you or anyone would be more helpful than "maybe you should look around a bit more" (not helpful at all!!).
Thanks!
Two tips from a youngster:
1. If you spend less time watching Youtube videos of questionable quality and value, you might find more time to identify and consume more worthy sources of information (hint: they often come in written form).
2. For a quick overview of popular DIY designs throughout the past years, just sort the threads in a subforum by popularity.
1. If you spend less time watching Youtube videos of questionable quality and value, you might find more time to identify and consume more worthy sources of information (hint: they often come in written form).
2. For a quick overview of popular DIY designs throughout the past years, just sort the threads in a subforum by popularity.
kn0ppers ....
If this thread upsets you, please move on.
BTW: I don't think there are any high-power headphone-amp threads (or projects) here on DIYA. But I will happily stand corrected.
And again, kn0ppers, I apologise if I continue to upset you -- the tone and complete lack of requested links is absent from your non-helpful replies. Instead, you reply in a preachy, vitriolic fashion.
If this thread upsets you, please move on.
BTW: I don't think there are any high-power headphone-amp threads (or projects) here on DIYA. But I will happily stand corrected.
I gave you one capable of 20w into 8ohm or 5w into 32ohm headphones earlier in this thread (8x parallel OPA1622).
There’s also this one capable of 1w into 42ohm headphones.
Simple High Performance DC Coupled Class A HPA with sub PPM THD
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