Yes, R39 & R40. Wow good to know, I will just use the spare 1k resistors then. Thank you so much!
I finished this up a year ago but put off and forgot about posting a conclusion:
Only mod is an added standoff under the PT, 30ys from now I'l open it up with no worries the board sagged 🙂 I kept the input caps as I have decent headphones, Beyer 880s 600R and AKG 501s, I would be upset to lose. Putting giant boutique caps here is IMO wrong and silly and ugly, tiny signal with no current has to go through a giant roll of mylar or foil, makes no sense. I used Polyphenylene Sulfide (PPS) caps 2.2uf/63v which are reputed to work well for audio (says so in the spec sheet!) nice and small as they should be, used them for C13/23 too just 'cause I don't like Wima's shade of red, didn't sweat the e-caps just used long life high quality caps and used not super low ESR caps around the regulators just in case.
My sophomore opamp rolling two cents, Wayne designed this to be an easy kit for amateurs to build, maximized the power supply and used a clever setup to get around power transistor matching and biasing, the preamp is just an opamp, there's nothing else to play with, you can roll opamps all day long, it's interesting to try but the maximizing is already built in, opamps will make lateral changes but won't take it to a higher level, some of the high speed ones could make it worse without you even noticing, it'll just sound different.
The boss says he likes the cheap LM833, he's right, I tried a few listed below, the LM833 adds energy and vim, brings the music to life and with good forward motion, instrument tonality has body and sounds correct, fender bass has the proper grunt and drive. Maybe it's a second order harmonics effect like tubes do but I don't really care the amp is plenty clear, none of the other, admittedly few, opamps I tried had any of that vim, just wider soundstage or airy quality that might indicate a bit more transparency, something very secondary for me compared to bringing the music to life and involvement. Rolling opamps is fun but if you are indifferent just use the recommended LM833 and save time and money, go ahead and solder it in if you're not a tweaker.
Maybe not the ultimate in transparency or clinical headphone amp but the Whammy is a super nice musical, rich sounding amp that with the LM855 has magical synergy with old AKG K501s. I never really found anything that thickens up their thinness and sweetens them up till the Whammy.
Thanks boss, mod, and all the posters for the help.
Tried OPA2107AP, OPA2134PA, NJM4556AD, LM833N or maybe P. The amp's fine as it is, glad I refrained from rare opamps and Bursons and Sparkos, IMO money better spent on another pair of phones 🙂
Only mod is an added standoff under the PT, 30ys from now I'l open it up with no worries the board sagged 🙂 I kept the input caps as I have decent headphones, Beyer 880s 600R and AKG 501s, I would be upset to lose. Putting giant boutique caps here is IMO wrong and silly and ugly, tiny signal with no current has to go through a giant roll of mylar or foil, makes no sense. I used Polyphenylene Sulfide (PPS) caps 2.2uf/63v which are reputed to work well for audio (says so in the spec sheet!) nice and small as they should be, used them for C13/23 too just 'cause I don't like Wima's shade of red, didn't sweat the e-caps just used long life high quality caps and used not super low ESR caps around the regulators just in case.
My sophomore opamp rolling two cents, Wayne designed this to be an easy kit for amateurs to build, maximized the power supply and used a clever setup to get around power transistor matching and biasing, the preamp is just an opamp, there's nothing else to play with, you can roll opamps all day long, it's interesting to try but the maximizing is already built in, opamps will make lateral changes but won't take it to a higher level, some of the high speed ones could make it worse without you even noticing, it'll just sound different.
The boss says he likes the cheap LM833, he's right, I tried a few listed below, the LM833 adds energy and vim, brings the music to life and with good forward motion, instrument tonality has body and sounds correct, fender bass has the proper grunt and drive. Maybe it's a second order harmonics effect like tubes do but I don't really care the amp is plenty clear, none of the other, admittedly few, opamps I tried had any of that vim, just wider soundstage or airy quality that might indicate a bit more transparency, something very secondary for me compared to bringing the music to life and involvement. Rolling opamps is fun but if you are indifferent just use the recommended LM833 and save time and money, go ahead and solder it in if you're not a tweaker.
Maybe not the ultimate in transparency or clinical headphone amp but the Whammy is a super nice musical, rich sounding amp that with the LM855 has magical synergy with old AKG K501s. I never really found anything that thickens up their thinness and sweetens them up till the Whammy.
Thanks boss, mod, and all the posters for the help.
Tried OPA2107AP, OPA2134PA, NJM4556AD, LM833N or maybe P. The amp's fine as it is, glad I refrained from rare opamps and Bursons and Sparkos, IMO money better spent on another pair of phones 🙂
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Hello
Can you only buy the "Whammy" board here in the shop or is there a way to buy both the "Whammy" and the "Muse Volume" boards from someone else?
Thanks for the help.
Can you only buy the "Whammy" board here in the shop or is there a way to buy both the "Whammy" and the "Muse Volume" boards from someone else?
Thanks for the help.
https://diyaudiostore.com/pages/project-whammy
Muses volume is something you’ll need to implement yourself.
Muses volume is something you’ll need to implement yourself.
Everything I’ve purchased from the diy store has been with credit card. I think you will find the option once you go to checkout.
I'm an old man approaching 70 and I've gotten by without a credit card my whole life. Fortunately, Whammy isn't the only headphone amplifier on the market that you can build yourself just for fun.
^ Are you saying you do or do not have a credit card???
No, a credit card is not required to purchase a WHAMMY kit / PCB from the diyAudiostore.com. If you have any problems, e-mail the helpdesk. They can walk you through various options.
Yes, you absolutely can use a credit card to purchase a WHAMMY kit / PCB from the diyAudiostore.com.
No, a credit card is not required to purchase a WHAMMY kit / PCB from the diyAudiostore.com. If you have any problems, e-mail the helpdesk. They can walk you through various options.
Hi all, first post here. I'm relatively experienced building valve amplifiers but the "whammy" was my first serious solid state project. I sourced the parts myself. My "whammy" was completed yesterday and it sounds great with the LM833 recommended here, and no compensation caps.
I initially had a problem with hiss, present even with the OP amp removed, and volume at zero. It transpired, after a lot of swearing!, that the texas instruments lm7915 regulator (Mouser) didn't like the 220uf capacitor (c28) in the psu. I replaced it with a 4.7uf which is closer to the datasheet value and it's completely silent now. I'm surprised this never came up before and I'm not sure I can explain why this happened. In any case, hoping this may help someone in future.
Sharing some pictures of the completed build. The case is from Aliexpress (it required some drilling). The square wave is at 20kHz and shows no oscillation (the slight notch is from the square wave generator, not the amp). I'm verry happy with the outcome.
Currently enjoying it with my sennheiser hd560s headphones. Many thanks to the designer and to 6L6 for the great guide.
Gabriel
I initially had a problem with hiss, present even with the OP amp removed, and volume at zero. It transpired, after a lot of swearing!, that the texas instruments lm7915 regulator (Mouser) didn't like the 220uf capacitor (c28) in the psu. I replaced it with a 4.7uf which is closer to the datasheet value and it's completely silent now. I'm surprised this never came up before and I'm not sure I can explain why this happened. In any case, hoping this may help someone in future.
Sharing some pictures of the completed build. The case is from Aliexpress (it required some drilling). The square wave is at 20kHz and shows no oscillation (the slight notch is from the square wave generator, not the amp). I'm verry happy with the outcome.
Currently enjoying it with my sennheiser hd560s headphones. Many thanks to the designer and to 6L6 for the great guide.
Gabriel
That is really interesting in that you actually observed an issue (its one of those things that affects other people kind of problem 😀) but its not all that surprising in the scheme of things and comes down to the regulators output impedance interacting with the cap's e.s.r. and self inductance. A different brand of regulator could well see the problem vanish as could a different brand of cap but that is not the answer to the problem.
Large caps are often a bad idea on the end of an active regulator and can do more harm than good.
Nice build by the way 👍
https://www.diyaudio.com/community/...dphone-amp-guide.317803/page-254#post-7567614
... the whole post is very beneficial, and the paragraph that specifically talks about what you experienced, and the remedy, is here:
"The Vcc/Vee decoupling electrolytes do not have to be 220uF... even 22uF will be more than enough (and much preferable, actually, if a uniform very low voltage rail impedance is desirable at the broad frequency spectrum range). Actually, a 10uF is all that is needed.... but I'd definitely try 4.7uF as well."
Thanks for pointing me to that post, very interesting and I think you got the value spot on. I didn't have 10uf capacitors in the junk box but I tried 22uf and my impression was that 4.7uf was the quietest, but this could have been my imagination. A different brand of 220uf made no difference. I didn't try a different regulator.
The texas instruments 7815 regulator, incidentally, had no issue with the 220uf capacitor, although i did replace the latter too. If building another I'd probably just go for 4.7-10uf from the start, as you've advised.
The texas instruments 7815 regulator, incidentally, had no issue with the 220uf capacitor, although i did replace the latter too. If building another I'd probably just go for 4.7-10uf from the start, as you've advised.
I opted for 100uF Low-ESR Panasonic for decoupling caps as per the recommendation from Sparkos Labs — I went with Sparkos discrete regs and my WHAMMY is a contender for “most quiet headphone amp” I’ve heard.
Cree SiC Schottky rectifiers are completely overkill, but maybe they help contribute too — if not just placebo 🤓
Cree SiC Schottky rectifiers are completely overkill, but maybe they help contribute too — if not just placebo 🤓
Sorry for warming up this issue, but... I'm using a white diffuse LED ( spec. 2.9V/20mA) @5v rail - and it is very bright, altough I'm now using a 6.2kohms resistor which means 0.3 mA... how far can one go with the resistor?