"WHAMMY" Pass DIY headphone amp guide

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Joined 2018
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+1 to keeping the Pi outside of the chassis. I understand the allure to having "one box", but there's several benefits to having separates.

A) better noise isolation from interference
B) easier upgradability (if you'd ever like to upgrade the Pi or DAC), with more options for upgrades
C) less mess within the chassis for potential, future tinkering with the circuit

Plus, hiding a RPi and running RCAs to the back is quite easy. I guess the biggest downside to separates here is portability, but it's not like the Whammy is a really portable unit to begin with ;)

But, hey, this is the joy of DIY. Modify to your heart's content. And, this awesome forum contains many who are happy to lend a hand. :)
 
I've searched through the thread and can't find this, so....

I'm planning to use an Antek AN-0218 (18V, 25VA) toroid in my fourth (!) Whammy. I just want to check on how to wire it. If I'm looking at the data sheet right for the Amgis, I want one red and one black on each side (for the primaries), and similarly for the secondaries. Should they be the same on each side (e.g., red on the left) or does it matter?
 
Octocoupler

Hi everyone !

I would need some information.
They no longer have 4n35 but on the other hand they have 4n37. I have looked at the datasheet and they seem totally similar to me, but since I am ignorant on the subject :RÉ I prefer to seek the informed opinion of certain scholars. : scratch2:
So my question is, can I take this one for my whammy or not? I still have a doubt, why Vishay would have made 3 completely similar references?

Thank you to those who will help me.
 
I've searched through the thread and can't find this, so....

I'm planning to use an Antek AN-0218 (18V, 25VA) toroid in my fourth (!) Whammy. I just want to check on how to wire it. If I'm looking at the data sheet right for the Amgis, I want one red and one black on each side (for the primaries), and similarly for the secondaries. Should they be the same on each side (e.g., red on the left) or does it matter?

One sec winding for each side is correct.
 
Hi everyone !

I would need some information.
They no longer have 4n35 but on the other hand they have 4n37. I have looked at the datasheet and they seem totally similar to me, but since I am ignorant on the subject :RÉ I prefer to seek the informed opinion of certain scholars. : scratch2:
So my question is, can I take this one for my whammy or not? I still have a doubt, why Vishay would have made 3 completely similar references?

Thank you to those who will help me.
Digikey appears to have about 5000 in stock:
Blocked

Mark Johnson always points people to Octopart to do stock searches:
4N35 | Octopart

Maybe some are available where you are?

Hope this helps, no idea about the 4n37.
 
Digikey appears to have about 5000 in stock:
Blocked

Mark Johnson always points people to Octopart to do stock searches:
4N35 | Octopart

Maybe some are available where you are?

Hope this helps, no idea about the 4n37.

Gracias Rafapolit,

I will buy the 4n35 elsewhere then and thanks also for octopart, I did not know, it will be very useful for me because I still have other components to buy.
I also take this opportunity to congratulate you on your availability, in any case on this thread, you are always quick to respond and to help others.
I went through the whole thread so I can vouch for that, of course you are not the only one.
 
WHAMMY BOM
(1) U3 7815 7815 positive regulator 863-MC7815CTG Digikey - NJM7815FA-ND


(1) U2 7915 7915 negative regulator 863-MC7915CTG Digikey - NJM7915FA-ND

Thanks, my only reservation is these are 1A and the originals in the BOM are 1.5A.

Well, this is indeed a very interesting observation. The BOM in the first page has a PN from Mouser (first) and a PN from Digikey (second). The Mouser parts are EXACTLY the ones I pointed out, which are, indeed 1A. The Digikey part numbers do point to a 1.5A regulator. :confused:

So, at this point, I defer to someone with more knowledge than me regarding the actual current that these regulators see.

There is a small discrepancy in the BOM, it would be nice to know if this is an important factor. @6L6? You are the man here. :eek:

Best,
Rafa.
 
WHAMMY finally finished

I've finally put the finishing touches on on my Whammy. Thanks to everyone on here that has offered advice.

Currently running a Burson V6 Classic which I think I prefer to the Vivid. Very tempted to try the OPA627s that everyone raves about.

A full build log can be found on my website and there are also some videos and photos of the build process on my instagram account.