Following some discussions in another thread, I've started to think about building a Whammy with balanced headphone output (probably 4 pin XLR). I've recently bought some headphones that, optionally, come with that sort of cable, so I assume they are made for that kind of thing. (Focal Utopias, which are as good as they are made out to be!)
There seem to be four options (following here), in order of expense (or at least of work):
There seem to be four options (following here), in order of expense (or at least of work):
- Use a 4 pin XLR to separate the grounds. Probably not really a serious change, though it's said to make some difference in other posts.
- More or less like (1), but add some passive circuitry to the new negative side to make sure the impedences match (Figure 4 in the above).
- Use output transformers to do the impedence matching.
- Build two Whammy's, symmetrical balanced.
- Build a really tricked-out Whammy with e.g. Vishay Naked Z-Foil resistors, some ludicrous caps like Jantzen Superior Z-Caps for the coupling caps, etc, and do one of the cheaper options like (2).
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Hi rikiheck,
I did it (option 4) and it pays really off: Double whammy in differential mode. I can compare it with a single ended version of the whammy. I build one for my son and the double/differential whammy for myself. I'm a bit of a headphone/headamp freak because it's my 3rd headamp: I use also a McIntosh MHA100 and a Malvalve Headamp 3.
The setup is pretty simple: I go from a DAC - Holo Audio Spring 2 Level 2 - to a switch and from there to one of the headphone amplifier.
Special is in the Differential Whammy that I used a stepped attenuator (shunt) and a differentiator to get balanced signals from input RCA but I also - or better mainly - use balanced input jacks (XLR). And I'm using BB OPA627BP, two each side, a total of 4 in the dwhammy. I will add more details, stay tuned, and I hope I will be able to add some pics.
I did it (option 4) and it pays really off: Double whammy in differential mode. I can compare it with a single ended version of the whammy. I build one for my son and the double/differential whammy for myself. I'm a bit of a headphone/headamp freak because it's my 3rd headamp: I use also a McIntosh MHA100 and a Malvalve Headamp 3.
The setup is pretty simple: I go from a DAC - Holo Audio Spring 2 Level 2 - to a switch and from there to one of the headphone amplifier.
Special is in the Differential Whammy that I used a stepped attenuator (shunt) and a differentiator to get balanced signals from input RCA but I also - or better mainly - use balanced input jacks (XLR). And I'm using BB OPA627BP, two each side, a total of 4 in the dwhammy. I will add more details, stay tuned, and I hope I will be able to add some pics.
Awesome build, I wish I can understand 50% more of the wiring but Im afraid I dont have the skills to do that ... yet!
This may be too simple a question, but with option 4 (dual Whammy)
Do you need the differentiator if your input is exclusively XLR in?
Can't this simply be 2 boards, one for the left and one for the right with a common ground signal, connected to earth via a safety CAP?
Unbalanced inputs and outputs can then be via cable adaptors?
Do you need the differentiator if your input is exclusively XLR in?
Can't this simply be 2 boards, one for the left and one for the right with a common ground signal, connected to earth via a safety CAP?
Unbalanced inputs and outputs can then be via cable adaptors?
Hi PhopsonNY, Sorry I have not seen your response from september. Yes, indeed it‘s just two whammy. I‘m using 2 OPA627BP each channel and I love the sound really. I would rate in comparison with two other Headphone Amps the balanced Whammy the best sounding - of my collection and meeting my listening signature with the Sennheiser HD800S. I‘m using a balanced Khozmo resistor poti which helps to shift the setup to a very high level.
Currently I‘m buliding a balanced preamp with 6 stereo (3 stereo balanced) preamps ( Wayne Colburn LS BA2018 ) as a front end of my headphone amps - the used Holo Audio DAC does not deliver enough power and the combination sounds phantasic. I‘ve build one balanced BA2018 (2 stereo modules) as a preamp for our son and the unit was so dammed good that I decided to create something which I have never seen as a commercial product. BA2018 plus Wammy in a balanced setup with high quality poti sounds indeed absolute great!
Currently I‘m buliding a balanced preamp with 6 stereo (3 stereo balanced) preamps ( Wayne Colburn LS BA2018 ) as a front end of my headphone amps - the used Holo Audio DAC does not deliver enough power and the combination sounds phantasic. I‘ve build one balanced BA2018 (2 stereo modules) as a preamp for our son and the unit was so dammed good that I decided to create something which I have never seen as a commercial product. BA2018 plus Wammy in a balanced setup with high quality poti sounds indeed absolute great!
That sounds like an amazing project.
Sounds like you are having fun with it like I am.
I would love to see pictures of your build.