If you drill a 4mm hole in the PCB you can use any potted transformer you like.
30VA 2x15Vac or 2x18Vac,
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Whammy Transformers
So I guess a better question for me is if I use the 70054K PC Mount Transformer 110/230V-18/36V 110V-36V 110V-18V 230V-18V 230V-36V and change the bias resistors to 15 ohms what are the pros and cons?
So I guess a better question for me is if I use the 70054K PC Mount Transformer 110/230V-18/36V 110V-36V 110V-18V 230V-18V 230V-36V and change the bias resistors to 15 ohms what are the pros and cons?
But why is it recommended to change the bias resistors to 15R, thus reducing bias, when using the surplus 70054K transformer? Is it because the power output is only 15VA? If using an 18V transformer rated at 25VA, are the 10R resistors preferred?
Thank you for your input! I'm sorry that I've taken so long to acknowledge your post, but I just now came across it.
The bias point isn’t that critical for almost all headphones and levels. It was mostly done to show that with the opto bias that is how it could be adjusted.
Have you reached out to their customer support? If so, I'm curious what they may say here since I just placed an order. 🙂
Btw, as I'm typing this, I'm listening to my Verités on naked regulators without C8/C10 installed. This little amp is very impressive.
No use 10R, I tried all sorts of bias values and around 60-70ma is perfect for everything. You can use 10VA transformer and be fine, check the secondary current specs on the transformers'.
A 15VA 15V transformer will have secondary current of around 500mA, the whammy with 10R bias resistors will pull 60mA per rail. The entire amp will pull less than 150mA.
You'll be fine 😉
Use 18V transformer if you want 18V at the output of the regs, use 15V transformer of you want 15 -16V. Don't over spec the voltage if you can design your supply.
15V AC = 15 x 1.41 = 21.15V DC after the rectifier, the diodes steal a volt, the regs need half a volt or so and convert the remaining 4 volts into heat. If you get it right you won't need big expensive heatsinks on the regs 🙂
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Yes, I sent them an email earlier. I'll post their response here once they reply. I can also send you a PM to make sure you don't miss my post.
I would use 18V transformer even for naked regulator. Then you have the needed voltage if you want to convert it to LED reference later.
my first whammy
It has been some time sines I have ordered the PCB, dec2019. But I have begone with the build of my whammy. The reading of the complete thread took some day's and is fun to read, but building is more fun.
I have chosen for the led configuration.
The bulk of the component are from Mouser, the rest are from DigiKey.
The transformer I bought is the Talema 22V, after reading about a lot of problems with high voltage and temperature I was doubting this choice.
First measurement's on my board 16.65V and -16.75V HAPPY day's 😀
The regulators I used are from ON Semiconductor
It has been some time sines I have ordered the PCB, dec2019. But I have begone with the build of my whammy. The reading of the complete thread took some day's and is fun to read, but building is more fun.
I have chosen for the led configuration.
The bulk of the component are from Mouser, the rest are from DigiKey.
The transformer I bought is the Talema 22V, after reading about a lot of problems with high voltage and temperature I was doubting this choice.
First measurement's on my board 16.65V and -16.75V HAPPY day's 😀
The regulators I used are from ON Semiconductor
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First thing I noticed, it has been a while, that I need a magnifier these day's.
Last time was with melf resistors, SMD and it was obvious but now I cant do without.
I stuffed the compleet pcb and it looks all-right by me.
I did buy several OpAmps; RC4580IP, AD823ANZ
For now I will start with the RC4580IP.
For now I stop, tomorrow I'll do some controles.
And hopefully some music.
Last time was with melf resistors, SMD and it was obvious but now I cant do without.
I stuffed the compleet pcb and it looks all-right by me.
I did buy several OpAmps; RC4580IP, AD823ANZ
For now I will start with the RC4580IP.
For now I stop, tomorrow I'll do some controles.
And hopefully some music.
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a helping hand for a beginner
😀Hello everyone. I admire all these whammys so I too would like to contribute to this big family. Only certain questions bother me.
i want to use it as headphone amplifier and preamplifier with class T power amplifier
Hifimediy T4 2x180W Class-T Tripath TK2050 Amplifier, Jantzen caps which already has a lot of horses under the hood the why of all these questions about power supply. My current installation consists of raspi + digione -} dac khadas -} buffer fx audio tube 01 -} t4 class T power amplifier and I have too much gain, the volume on the first notch is very difficult to adjust. I have already changed the potentiometer and rca attenuators with little results. So for my whammy I would like to change that and have more progressivity.
I would like to have the widest possible opamp compatibility with the power supply I would choose as I am a total beginner in DIY electronics and I don't really feel able to adjust it to suit it.
So if I have followed correctly (for now I am on page 323 of the wire and I intend to read it all the way) a 2 x 18v transformer would be best?
then with 15 v regulators and leds?
I apologize for these questions which may seem ridiculous but with the power supply for only one voltage there are a few possible variations and I don't really know which one to choose.
In addition, I received my pcb a short time ago and I can't wait to order the parts.
Thanks
😀Hello everyone. I admire all these whammys so I too would like to contribute to this big family. Only certain questions bother me.
i want to use it as headphone amplifier and preamplifier with class T power amplifier
Hifimediy T4 2x180W Class-T Tripath TK2050 Amplifier, Jantzen caps which already has a lot of horses under the hood the why of all these questions about power supply. My current installation consists of raspi + digione -} dac khadas -} buffer fx audio tube 01 -} t4 class T power amplifier and I have too much gain, the volume on the first notch is very difficult to adjust. I have already changed the potentiometer and rca attenuators with little results. So for my whammy I would like to change that and have more progressivity.
I would like to have the widest possible opamp compatibility with the power supply I would choose as I am a total beginner in DIY electronics and I don't really feel able to adjust it to suit it.
So if I have followed correctly (for now I am on page 323 of the wire and I intend to read it all the way) a 2 x 18v transformer would be best?
then with 15 v regulators and leds?
I apologize for these questions which may seem ridiculous but with the power supply for only one voltage there are a few possible variations and I don't really know which one to choose.
In addition, I received my pcb a short time ago and I can't wait to order the parts.
Thanks
so I did my first listening session. And it was a pleasant surprise.
All the connections were professorial, no hum what so ever.
Just music.
I was surprised because it is not in an housing, just on an aluminium plate.
The music is from low to high nicely balanced.
Next on the list is the building of the housing.
All the connections were professorial, no hum what so ever.
Just music.
I was surprised because it is not in an housing, just on an aluminium plate.
The music is from low to high nicely balanced.
Next on the list is the building of the housing.
Good job gervenja, enjoy your Whammy! Do post pictures of it when you've finished its enclosure! Will you build it from scratch?
It's good I found my answer thanks to post 3230 of 6L6 so it will be a 2x18 v transformer with bare 7815/7915 regulators
logarithmic potentiometer
I would like to find a good quality resistance potentiometer but I am not sure which one to choose.
What are your favorites?
I would like to find a good quality resistance potentiometer but I am not sure which one to choose.
What are your favorites?
Thx Swifty
I am making the housing from scratch. Aluminium with wooden sides. it's probably going to be walnut. And of course I will keep you informed. Starting with these pictures.
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I'm building a second whammy, and my favorite 3300uf caps are out of stock 🙁
Would using 4700uf caps have any downsides?
Would using 4700uf caps have any downsides?
