"WHAMMY" Pass DIY headphone amp guide

[rikiheck]

FYI, there are 'boutique' regulators you can get from Parts Connexion if you want to try that sort of thing. I've used the New Class D's, and they are very good.

 

[sp33ls]

FYI, there are 'boutique' regulators you can get from Parts Connexion if you want to try that sort of thing. I've used the New Class D's, and they are very good.

Are these the ones you've used?

LC7815 +15.0V
LC7915 -15.0V

I have a pair of SparkOS that I need to use, yet. I wonder how they compare.

 

[rikiheck]

Yes, those are the ones. I've been meaning to try the SparkOS, too. Their op-amp is terrific.

 

[sp33ls]

Do you know if the New Class D regs run a bit cooler than the traditional? I could see that being a nice benefit.

 

[rikiheck]

I do not know for sure, as I've not compared them directly, but my sense is that they might. There's less heat in the ones I've built with those, though there are some other differences too.

 

[sp33ls]

Did you use them in your Whammy build, then -- naked regular configuration?

 

[rikiheck]

I used them with the standard LED configuration.

 

[Davo 1]

Did you use them in your Whammy build, then -- naked regular configuration?

Hi,

I bought the Sparkos regulators and was unsure which configuration to use, so I contacted their customer support. Andrew Sparks was extremely courteous, and after reviewing the WHAMMY schematics that I sent him, he advised me to use the naked configuration. He said that doing so it will allow the discrete regulators to reach their full potential. If you have any doubts or specific questions, I suggest that you contact him before deciding.

He can be reached at sparko@sparkoslabs.com

 

[sp33ls]

Reform caps?

Hi,
If you have any doubts or specific questions, I suggest that you contact him before deciding.

Thanks, Davo!

Looking for input on a couple more questions:

1) Thoughts on swapping out C9 & C28 to 0.01uF film caps when using naked reg config and discrete regs?

2) I ordered parts for a couple kits a few years ago and they've been sitting in a box in the closet. Do e-caps have a shorter shelf life when they're not used (i.e., no voltage "reforming" on a consistent basis)? I measured several, and the ESR ranged from ~0.2 to ~3... the small 22uF bipolars seemed to have the highest ESR.

Would I notice any benefit from following a reforming procedure before putting to use?

 

[sp33ls]

:
1) Thoughts on swapping out C9 & C28 to 0.01uF film caps when using naked reg config and discrete regs?

NVM -- Andrew suggested 100uF low ESR Panasonics. I may go that route for regulator output caps and look at 100uF Silmic II for the other couple 220uF caps.

 

[A Jedi]

Is there anything that can be done to reduce the noise floor on WHAMMY? It's always bothered me and it is too much with sensitive cans.

I've tried boutique caps, shielding the trafo, adding C2 and C7.

My rails are -16.92V and 16.75V. Offset on the AD823 is 0.1mV on the right and 0.3mV on the left. Swapping op amps doesn't make much of a difference.

Other than the few tweaks I mentioned above, it's a vanilla build using the kit parts.

 

[pfarrell]

My 4 different Whammys are all dead silent as far as noise floor is concerned. "Stock" builds for the most part. Cans ranging from 80 to 250 Ohm open backs, one set is planar.... Could you have some environmental factors? Also, aren't file source and DAC factors here?

 

[A Jedi]

That's a negative. Source is ALAC or Quobuz via Audirvana streamed to Pi2AES to Schiit Yggdrasil via AES/EBU.

And I have multiple amps that don't exhibit this behavior - Crack, Liquid Platinum, Magni 3, SW51.

I've also tried it in multiple locations/wall outlets around the house.

 

[Mark Johnson]

Y'all boahs need to do a temporary swap.

@AJedi gets a dead silent WHAMMY and @pfarrell gets a WHAMMY with bothersome noise floor. After 6 weeks, swap back.

 

[sp33ls]

Is there anything that can be done to reduce the noise floor on WHAMMY? It's always bothered me and it is too much with sensitive cans.

I've tried boutique caps, shielding the trafo, adding C2 and C7.

My rails are -16.92V and 16.75V. Offset on the AD823 is 0.1mV on the right and 0.3mV on the left. Swapping op amps doesn't make much of a difference.

Other than the few tweaks I mentioned above, it's a vanilla build using the kit parts.

You go with the LED configuration? Are you using a metal chassis?

Does the noise fluctuate when you put your fingers on the pot or chassis?

 

[A Jedi]

Y'all boahs need to do a temporary swap.

@AJedi gets a dead silent WHAMMY and @pfarrell gets a WHAMMY with bothersome noise floor. After 6 weeks, swap back.

I'd be fine with that. Not sure if @pfarrel would be lol.

 

[A Jedi]

You go with the LED configuration? Are you using a metal chassis?

Does the noise fluctuate when you put your fingers on the pot or chassis?

Yup, LED. Chassis is the Hammond with all contact surfaces sanded and pot is grounded to chassis.

Noise does not fluctuate or change under any circumstances. It's just a background "shhhhhhhhhh" that goes up and down with volume. It's not a 120hz psu noise or anything related to phones, LED lighting or anything like that. It just sounds like the amp's own noise floor.

 

[sp33ls]

I only experience that when I have the pot almost completely opened.

Before long, I'm going to try some discrete regulators and see if I can hear any audible difference (wish I had the gear to measure).

I've also seen a couple accounts of people having success with a 0.01 film decoupling cap across V+/V- on the opamp socket. Someone said they had some additional noise (more like a whine) with a Burson V6. Burson recommends this capacitor. I'm going to test that as well in the future.

 

[A Jedi]

I've also seen a couple accounts of people having success with a 0.01 film decoupling cap across V+/V- on the opamp socket. Someone said they had some additional noise (more like a whine) with a Burson V6. Burson recommends this capacitor. I'm going to test that as well in the future.

Interesting, I'll give that a shot.

 

[sp33ls]

Burson Supreme Sound (SS) Opamp 101 Part 1 (MKP cap tweak) - Burson Audio

^ For context, this tweak is from their site.