Notice how you have to make a choice on the regulator configuration? You don’t know what you’re doing like me so you’re going with the default in Step 8. If you don’t, note that the 2nd picture for Step 6 assumes that you’re gonna install the LEDs in Step 8, and not do the config in Step 9 and 10. But really for you and me reading this, just ignore all this and make it look like the pictures in Step 6.
Step 11: The 15V 1A Negative linear voltage regulator goes next to D8, and the 15V 1A Positive linear voltage regulator goes next to D7. When you start scratching your head what goes where, here ya go. I don’t know that you need the heat sinks given the links above. the guide says if the regulators have a metal top, you don’t need the heat sink. I put them on anyway. Put thermal compound on the heat sink, put the regulator on the compound, screw the regulator on, attach, and solder to the board. no the heat sink won’t touch the board.
I haven’t had a chance to test the PCB. I have blown 2 diodes. If you do the voltage test and you’re off by about 2x, you have a bad part. Buy some extra diodes maybe.
Notes for dummies: you’ll need 2 small screws that you have lying around to screw the thing onto the heatsink
Remember this config doesnt use any insulators between the device and the heatsink.
Depending on the transformer sec VAC u choose you really should use the heatsinks. If u use the 22VAC one and the regs are 15VDC the voltage difference will be eaten up in “heat” by the regulator and get how…best to use them…its a Class A amp so its going to get warm here.
Also use a small lock washer with the small screw and nut (4-40 I believe)…If you dont the heat sink could loosen up over time and the heatsinking efficiency will diminish.
Another thing when you say your having blown diodes.
A few things come to mind…installing them in backwards, when measuring make sure you do not short out stuff…using a meter leads you can use “clips” to attach to things before turning on power. Also you can put some tape on the metal leads and only have the small metal tip exposed helping to eliminate shorts while measuring stuff.
As you add more stuff it can be a more complex issue to figure out whats not correct etc…and the cost and time of getting new parts etc…it can be very frustrating…
But you have the right attitude!! Have fun and learn!!
I used a slightly different IEC power assembly.
Notice I kept the AC wires as short as possible and away from the circuity.
This is too help keep any AC being induced into amp circuitry.
You might want to shorten your wires up a tad.
Since then I have added a to position gain switch and a blue power LED on the front panel.
I also went back ad shortened the black wires doe the input to the board and vol pot.
Once the amp is working on the bench you can package it up and only need to get inside to change op amps if u desire.
The two electrolytic caps on both sides of the op amp IC socket are right next to the socket, making the removal and insertion of op amps a bit of a chore…
The front panel has 4 screws that u have to take off, remove the volume pot knob and carefully pull forward the front cover to get to the op amp.
One good suggestion is to mount those 2 electrolytic caps at right angles to the socket when soldering in, just bend the legs 90 degress.
Did u get your power supply to work? I noticed your comments at diyaudio.com?
Good luck and take is slow and easy and make sure your parts are in the correct area and installed in the right direction, especially those electrolytics!! If u put them in backwards they will fail rather quickly and cause a mess.
This am I was looking at the Whammy and it has not been powered up in two weeks or so…and I have never tried a high impedance headphone with it…somehow with all my crap this was missed! So Listened with the hd650’s on the HPA1 to get my gold standard baseline and then on to the Whammy…with the 650s.
High Gain is needed to really make the 650s sing…(note High gain in this instance is the stock gain when u build the amp)…
Here is a CD that I used for 3D holographic type testing and listening:
Ben Vaughn…a demo CD for years…and I can happily say the 650’s with the Whammy and the Analog Devices Op Amp are “Spectacular” with this type of music…the mids and treble are very, very well done…
Even the bass is well controlled and balanced…no bleeding upwards.
For such a “shallow” headphone (construction wise. close to your ears…not extended out like with the hedds and empys) the soundstage is very good as well…surprisingly so!
For a low dollar DIY amp the Whammy takes the cake here over many other DIY amps I have built and used!
If you have made it far enough to test the power, the rest will make sense. By that time you will have punched holes into one end of the enclosure and soldered a lot of things. You will need to drill 2 holes into the other end, one fixed because the pot is soldered onto the PCB.
I found I could not adequately test the setup unless I had wired everything and put the chassis together. The chassis itself has to be put together for ground to be silent. As such:
Before testing, make sure all soldered connections are good. Wiggle the capacitors and see if they aren’t attached. Same with most of the components. It is a significant frustrate to have to take things apart after putting the chassis together
if you get crazy buzzing noise, from my experience the ground on the headphone jack isn’t right and the chassis needs to be put together or the headphone jack screwed on tighter or something
the screws for the chassis may initially get stuck. be patient. try again. get a different screw driver. they are tight, thread rolling so the difficulty is “intended.”
I am eventually going to replace the headphone jack. It sucks. Sounds good, but I won’t give impressions until I replace the headphone jack.
Been using the WHAMMY for a while and love the sound, was just interested if those with more experience with retail headphone amps have any comparisons for what this competes with and how much you’d have to spend for a better performing amp
