If you look at the spec for the transformer here:
Toroidal Transformer Catalog - Talema Group LLC | DigiKey
You will find that its a M4 bolt that is 6mm in length (max).
I screwed the transformer down before I soldered the pins. This ensures that the transformer lies flat on the board before soldering it in place.
Toroidal Transformer Catalog - Talema Group LLC | DigiKey
You will find that its a M4 bolt that is 6mm in length (max).
I screwed the transformer down before I soldered the pins. This ensures that the transformer lies flat on the board before soldering it in place.
A Jedi:
As a followup, I posted a request in the DIY store forum that in the future, they include the proper transformer mounting machine screw in the Whammy parts kit. It never hurts to assemble something a securely as possible, especially when the project is as worthwhile doing as the Whammy, a headphone amp equal to some commercial units costing 10 times as much.
As a followup, I posted a request in the DIY store forum that in the future, they include the proper transformer mounting machine screw in the Whammy parts kit. It never hurts to assemble something a securely as possible, especially when the project is as worthwhile doing as the Whammy, a headphone amp equal to some commercial units costing 10 times as much.
It's all good, thanks. I have no plans for it to ever leave my desk but it seems like the right way to do things.
Last edited:
Quick question: how do I discern between bipolar and non-bipolar op amps? I've looked at the datasheets for the RC4580 that comes with the kit and a few others that I'm interested in trying and I can't find anything specifying them as bipolar or not. This is in regards to the C26 and C27 optional caps. TIA.
They've been talking about the chassis since November 2018. I'm waiting, too.
Much thanks to Wayne for providing us with the WHAMMY amp design.
I've never been a headphone fan but I recently moved into a home with the worst listening room acoustic space that I've ever had. Lots of hard parallel wall ceiling and floor surfaces that reflect everything and turn it into a mess.
I know I can add acoustic treatments to fix it but that is another big project and I still have several other DIY projects that have been in the works and deserve my attention first. So a diversion to "Wayne's Headphone Amp Must Make Yourself". A perfect name and a quick solution to my listening problems.
The design looked good and it was easy to build and I got it into shape very quickly. I built mine with a power transformer that has dual 22V secondaries.
The only reason that I chose that secondary voltage is so I could drive a MoFo amplifier which needs a big voltage swing from a preamp. So this is a dual use project. I have 80% of what I need to finish the MoFo right now but that one is still low in my list of projects to finish.
I bought the Beyerdynamic DT770 Pro 80 ohm 'phones a couple of years ago as a tool for recording to avoid the headphone leakage into the microphone.
I never put much time on the 'phones so when I powered up the amp with the headphones both of them hadn't been broken in and sound like crap right off the bat. Leaving them on with loud music while I went to work helped to smooth them out. After a week or so of that it started to sound good.
Unpacking and sorting out everything I own after a recent house move was a terrible chore and I have been slow with the process. Since the WHAMMY build I have finally found my Hagerman Audio Frykleaner audio break in generator which really speeds up the break in period and now this will be included in my test bed for breaking in every new op amp.
A few pictures are attached showing that you can easily operate this amplifier on a slab of plywood rather than in a chassis. Notice that I have extended the leads of the two filter capacitors near the opamp and bent them away from the socket. This to allow large op amps such as the Burson series into the socket. If you do this you should sleeve the capacitor leads before soldering.
I hate the idea of a small chassis for this amp. I think that this amp is a perfect platform for opamp rolling so I want to add a daughter board that will allow discrete op amps such as the Jensen 990 and the API 2520 to be used. Separate power regulation for the op amps would be perfect. I own several different flavors of discrete op amps that I use in microphone preamps and I would love to compare them this way.
I've never been a headphone fan but I recently moved into a home with the worst listening room acoustic space that I've ever had. Lots of hard parallel wall ceiling and floor surfaces that reflect everything and turn it into a mess.
I know I can add acoustic treatments to fix it but that is another big project and I still have several other DIY projects that have been in the works and deserve my attention first. So a diversion to "Wayne's Headphone Amp Must Make Yourself". A perfect name and a quick solution to my listening problems.
The design looked good and it was easy to build and I got it into shape very quickly. I built mine with a power transformer that has dual 22V secondaries.
The only reason that I chose that secondary voltage is so I could drive a MoFo amplifier which needs a big voltage swing from a preamp. So this is a dual use project. I have 80% of what I need to finish the MoFo right now but that one is still low in my list of projects to finish.
I bought the Beyerdynamic DT770 Pro 80 ohm 'phones a couple of years ago as a tool for recording to avoid the headphone leakage into the microphone.
I never put much time on the 'phones so when I powered up the amp with the headphones both of them hadn't been broken in and sound like crap right off the bat. Leaving them on with loud music while I went to work helped to smooth them out. After a week or so of that it started to sound good.
Unpacking and sorting out everything I own after a recent house move was a terrible chore and I have been slow with the process. Since the WHAMMY build I have finally found my Hagerman Audio Frykleaner audio break in generator which really speeds up the break in period and now this will be included in my test bed for breaking in every new op amp.
A few pictures are attached showing that you can easily operate this amplifier on a slab of plywood rather than in a chassis. Notice that I have extended the leads of the two filter capacitors near the opamp and bent them away from the socket. This to allow large op amps such as the Burson series into the socket. If you do this you should sleeve the capacitor leads before soldering.
I hate the idea of a small chassis for this amp. I think that this amp is a perfect platform for opamp rolling so I want to add a daughter board that will allow discrete op amps such as the Jensen 990 and the API 2520 to be used. Separate power regulation for the op amps would be perfect. I own several different flavors of discrete op amps that I use in microphone preamps and I would love to compare them this way.
I built my first Whammy in a 2U on tall standoffs. Instead of bolting the kit transfo to the PCB (it's been pointed out that the soldered pins are quite secure) I used the hole in the PCB under the transfo to receive a 5th standoff (obviously without a nut). The weight of the transformer very easily flexed the whole board when only supported on 4 outer corners and a support directly under the main "weight" on the board made the whole shebang super secure and non-flexy.
YouAgain,
I did the very thing you describe a few months ago. I am very happy with it.
My favorite DOA in this circuit is a JFET design inspired by Nelson Pass.
Attachments
Built in fuse
JKSeriously though, it's more than enough. The amount of power this can push is much higher than I expected. I have pushed the transistors into borderline overheating with a 4ohm load, but the power rail was still rock solid.
Last edited:
I also dislike using vias for connecting 2 tracks, signal or power, and end up soldering a lead/wire to confirm the join - a particular objection is using the pins of power caps as vias (sorry, top <-> bottom trace connection) because if ever you replace/change the caps, sometimes the via will also be removed and you can end up having "a learning experience"!
I appreciate your concern but in all my years of crafting commercial and DIY gear I've never had a problem with vias. They are usually unavoidable if you are laying out a complex 2 layer PCB. My habit is to be sure to always specify one of sufficient diameter so as to provide a robust amount of surface area for the plating.
Finished my WHAMMY and all is good. Except - it sounds too smooth. Like there is no attack at the beginning of notes. It's missing some "slam". Not sure how else to describe it. My Bottlehead Crack is so immediate and fast in comparison. I've had it on for over 48 hours now and it doesn't seem to be improving. FYI, this is the stock/default build. Any thoughts? Should I start rolling op amps? If so, which ones would you guys recommend? Thanks!