"WHAMMY" Pass DIY headphone amp guide

Edit: forgot to mention, I'm listening primarily with Beyerdynamic DT-880s, the 250 ohm version.

So far I've tried the LM833, MUSES8820, OPA1612 and OPA1618. The OPA1618 is easily my favorite. It has a neutral to mildly bright signature but feels energetic and reveals a lot of distinct front to back layers in the music, and in general a 3D vividness (Radiohead's In Rainbows is super fun to listen to with this one). Most importantly, it's the one where I find myself bobbing my head and getting lost in the music. The LM833 was fine but I just didn't find myself involved in the music. The Muses and OPA1612 were good but a little too warm for my taste and again, didn't involve me as much.

I know this depends on personal taste, cans used and to some extent part selection, so none of these judgments are necessarily useful to anyone else. But having tried several opamps that people like in this thread my one criticism of the Whammy is that straight out the gate, it seems geared more toward clean, hi-fi, mixing/monitoring type listening. Nothing wrong with that per se, in fact I mix music myself and it will make a great reference there. And given the ruler-flat frequency response, its' not surprising. But I had to try several op amps before I found something that was actually *fun* to listen to. Having done that legwork, I'm really enjoying the amp.

I've got the OP249 and OPA2134 on the way. I'll probably stop there as I'm already pretty satisfied with the OPA1688, but down the road I might be tempted to try one of the more expensive Muses, or a discrete op amp like the Burson V6 Vivid.
 
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Edit: forgot to mention, I'm listening primarily with Beyerdynamic DT-880s, the 250 ohm version.

So far I've tried the LM833, MUSES8820, OPA1612 and OPA1618. The OPA1618 is easily my favorite. It has a neutral to mildly bright signature but feels energetic and reveals a lot of distinct front to back layers in the music, and in general a 3D vividness (Radiohead's In Rainbows is super fun to listen to with this one). Most importantly, it's the one where I find myself bobbing my head and getting lost in the music. The LM833 was fine but I just didn't find myself involved in the music. The Muses and OPA1612 were good but a little too warm for my taste and again, didn't involve me as much.

I know this depends on personal taste, cans used and to some extent part selection, so none of these judgments are necessarily useful to anyone else. But having tried several opamps that people like in this thread my one criticism of the Whammy is that straight out the gate, it seems geared more toward clean, hi-fi, mixing/monitoring type listening. Nothing wrong with that per se, in fact I mix music myself and it will make a great reference there. And given the ruler-flat frequency response, its' not surprising. But I had to try several op amps before I found something that was actually *fun* to listen to. Having done that legwork, I'm really enjoying the amp.

I've got the OP249 and OPA2134 on the way. I'll probably stop there as I'm already pretty satisfied with the OPA1688, but down the road I might be tempted to try one of the more expensive Muses, or a discrete op amp like the Burson V6 Vivid.

I think you will really like the OPA2134 but I really do recommending giving the OPA2107 a whirl as it's made on a difet process and sounds amazing. :)
 
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Edit: forgot to mention, I'm listening primarily with Beyerdynamic DT-880s, the 250 ohm version.

So far I've tried the LM833, MUSES8820, OPA1612 and OPA1618. The OPA1618 is easily my favorite. It has a neutral to mildly bright signature but feels energetic and reveals a lot of distinct front to back layers in the music, and in general a 3D vividness (Radiohead's In Rainbows is super fun to listen to with this one). Most importantly, it's the one where I find myself bobbing my head and getting lost in the music. The LM833 was fine but I just didn't find myself involved in the music. The Muses and OPA1612 were good but a little too warm for my taste and again, didn't involve me as much.

I know this depends on personal taste, cans used and to some extent part selection, so none of these judgments are necessarily useful to anyone else. But having tried several opamps that people like in this thread my one criticism of the Whammy is that straight out the gate, it seems geared more toward clean, hi-fi, mixing/monitoring type listening. Nothing wrong with that per se, in fact I mix music myself and it will make a great reference there. And given the ruler-flat frequency response, its' not surprising. But I had to try several op amps before I found something that was actually *fun* to listen to. Having done that legwork, I'm really enjoying the amp.

I've got the OP249 and OPA2134 on the way. I'll probably stop there as I'm already pretty satisfied with the OPA1688, but down the road I might be tempted to try one of the more expensive Muses, or a discrete op amp like the Burson V6 Vivid.


Did you mention OPA1688 or OPA1618?
 
Forgot to mention I tested these OP Amps with HiFiMan HE400i headphones and a Topping D50 DAC. I used FLAC audio 96Khz 24 bit. Evanescence Synthesis album.

Hi Gaz

First, thanks for the extensive Opamp review. I also have (among other sets) a pair of HiFiMan HE400i headphones, so I'm looking forward to seeing how your evaluations match up with my experiences (RC4580IP, LM833N, LM4562NA, OPA2134PA, AD746JNZ so far).

Your mention of the Topping D50 DAC led me to doing some research on the unit, as my existing Eiderol DAC was pretty minimal quality.

Short story: I just received a D50 today, hooked it up and can only say I am surprised and amazed at the improvement. So thank you, sir, for bringing this excellent piece of kit to my attention.
 
I have a whammy with Toshiba and another with Fairchild (and I've built one with IRF...) and there's no difference in bass.

It's (the whammy) a very neutral design that doesn't editorialize at all. Changing opamps won't make much difference either. If you want more bass, I'd honestly grab a different set of headphones, or (more fun) put a Schiit Loki in front of it and EQ to your taste. :yes:

Hi 6L6:

I took note of your mention of the Schiit Loki and it pushed me over the edge in deciding to get one of my own. Turns out it is an excellent EQ for headphones, as well as my desktop system. It's also surprising how useful it is for balancing out some less than ideal recording mixes.

Of course, the Loki was an easy self-sell as I was sales manager for Audio Control in the late 1970s when our only product was a 5 band rotary control equalizer (the Audio Control 520) with optimized EQ band center points and filter Qs.

All I can say is that I feel sure Greg Mackie would also like it, and the circuit design is decidedly more hi fi than the opamps and circuit implementation used back then (40 years ago - how time flies!)
 
I still have a couple of Audio Control equalizers in my garage! The newer models with slider pots. I got them for like $7 each as surplus, because the power transformers had failed. Did I repair them? Naah, couldn't find replacement trafos easily and other projects beckoned....

Must be models built after Greg Mackie sold the company to Tom Walker in the early 1980s. Greg's product was always conservatively designed and built: +/-18V opamps run at no more than +/-15V, generous margins on the cap voltage ratings, etc., all design criteria holdovers from his days running the TAPCO pro music mixer company (sold to Electro Voice in the mid-1970s). That said, bad parts runs do slip through.
 
Do you think using a soft start with the whammy is a bit excessive? I have one of those push button switches from Aliexpress but not sure if I want to use it to switch 240VAC. 20190816_161838.jpg 20190816_162358.jpg 20190816_162411.jpg 20190816_162424.jpg
 
I often use these switches - I've never had a problem. But someone told me about an internal short circuit when mains burns PSU through led wires...
I use it in my whammy. you can use a switch, but the indicator led can be placed separately if there is a fear of short circuit.
 

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Do you think using a soft start with the whammy is a bit excessive? I have one of those push button switches from Aliexpress but not sure if I want to use it to switch 240VAC. View attachment 775579 View attachment 775580 View attachment 775581 View attachment 775582

Just a word of caution, I used one of those switches for my NAP200 build and after about 2 years it shorted and wouldn't switch off. Nothing bad came of it, just that I can't switch it off.

In retrospect it seems quite dangerous that something so cheap is tasked to handle mains voltage. Don't know how on earth they stepped it down to 12V (probably) for the LED in the switch too.
 
Just a word of caution, I used one of those switches for my NAP200 build and after about 2 years it shorted and wouldn't switch off. Nothing bad came of it, just that I can't switch it off.



In retrospect it seems quite dangerous that something so cheap is tasked to handle mains voltage. Don't know how on earth they stepped it down to 12V (probably) for the LED in the switch too.
I'm thinking about using it on another project instead.
 
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These push-button switches ("vandalism-proof switches") are not all created equal.
There are ones that are rated up to 5A at 240V, and that have 12V or 24V input for the LED. They tend to cost around 20 EUR here in Europe. I use them in most of my amp builds. Never had any problems with them so far, after a few years of use.

What I do though, is wiring a small ceramic cap (10 nF - 100nF) across the switch contacts in order to avoid erosion of the contacts through possible switch-off sparks.

Best regards, Claas