You dont need a toggle switch. Just a switched headphone Jack. When you plug your headphones in the preamp output will be muted. Unplug the headphones and the preamp can be used. This is how I wired mine.
Thanks for the link to the part.I would like to get one of those eventually.
But for now I just have to use what i have. Just looking see if what I showed will work?
But for now I just have to use what i have. Just looking see if what I showed will work?
I finished this PCB and added some pictures on the empty space, it looks quite good.
PS: i crossed my NAME by white pen for Privacy.
There are two posts, which post should i join for my DIY ?
No. You don't have enough terminals on the switch to get both L and R switched, and the way you have it drawn L is always "on" to the 1/4" and the RCA.
You either need a DPDT switch or a switching headphone jack.
Ashleytt, I bought this row of 30 breakaway pins from Mouser
TS-132-G-AA Samtec | Mouser
They fit beautifully into the SOIC-to-DIP8 adapter PCB sold by Sparkfun (link). After soldering the IC chip to the adapter board, then soldering the pins to the board (broken off as two rows of 4 pins/row, naturally), the entire assembly fit perfectly into a DIP socket. I prefer the sockets with "milled" pins as shown on the attached image below.
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TS-132-G-AA Samtec | Mouser
They fit beautifully into the SOIC-to-DIP8 adapter PCB sold by Sparkfun (link). After soldering the IC chip to the adapter board, then soldering the pins to the board (broken off as two rows of 4 pins/row, naturally), the entire assembly fit perfectly into a DIP socket. I prefer the sockets with "milled" pins as shown on the attached image below.
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Attachments
Thanks so much Mark! I searched aliexpress and ebay for these pins and got nothing! I'll give these a try and report back! Cheers!
i ordered some components for modification.
6 different Opamp which included AD823
2 type of output transistor. 2013+313 was matched
RIFA PHE450 MKP 224 0.22UF 630V VS WIMA 0.22uF 300v
WIMA 1UF/100V MKS4 VS ERO MKT 250V 105 1UF
i dont know the 0.22uf and 1uf which type is better.
Here is a big question, i ordered 3 types of 220uf, but nichicon and SIC SAFCO are too big for installation, only Panasonic FC 220uf is suitable for this board.
Nichicon BP 220uf/50V got the ESR is 0.1324r @120Hz
SIC SAFCO 220uf/100V got the ESR is 0.148r @120Hz, bur the true value is 280uF, is it OK for use ?
May i know where should i install nichicon BP or SIC SAFCO is better as i can't install all of this on the board.
6 different Opamp which included AD823
2 type of output transistor. 2013+313 was matched
RIFA PHE450 MKP 224 0.22UF 630V VS WIMA 0.22uF 300v
WIMA 1UF/100V MKS4 VS ERO MKT 250V 105 1UF
i dont know the 0.22uf and 1uf which type is better.
Here is a big question, i ordered 3 types of 220uf, but nichicon and SIC SAFCO are too big for installation, only Panasonic FC 220uf is suitable for this board.
Nichicon BP 220uf/50V got the ESR is 0.1324r @120Hz
SIC SAFCO 220uf/100V got the ESR is 0.148r @120Hz, bur the true value is 280uF, is it OK for use ?
May i know where should i install nichicon BP or SIC SAFCO is better as i can't install all of this on the board.
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I don’t think there’s a much better electrolytic made than the FC. All the factory Pass Labs products are filled with them.
+ 1
The Panasonic FC are my standard go-to electrolytic capacitors for a few years now. Have always been very happy with their performance.
Best regards, Claas
The Panasonic FC are my standard go-to electrolytic capacitors for a few years now. Have always been very happy with their performance.
Best regards, Claas
Thx 6L6 and chede solved my question. I will use FC in my board.
The 3300uf/50V i will use NipponChem KY series. I tested this cap then got the size is 3200uf and ESR is 0.0424R, the result is good.
hello,
when you measure the distortion of a headphone amp, what are you using as a load and under which voltage?
when you measure the distortion of a headphone amp, what are you using as a load and under which voltage?
Hi there. I'd like to know how to calculate the power outputs (mW) of Whammy to the phones I'm using: 14ohms, 46ohms, 250ohms and 300ohms. I'm using the default 17v rails and 60mA bias. TIA!
Power = Voltage * Current
Current = Voltage / Resistance
Therefore
Power(in watts) = Voltage^2 / Resistance
The typical max volume level is 2v, and going off that:
2v^2 / 14ohms = 286mW
2v^2 / 46 = 143mW
2v^2 / 250 = 16mW
2v^2 / 300 = 14mW
That would be peak, not RMS. Divide by the square root of 2 to get an approximation of the RMS, if that is what you want.
From what I understand, the 17v rail is mostly for the op amp, to allow it to swing further, to keep the output from dropping lower than the input without clipping.
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I tested it into 32 Ohms and it is about 400 mW at low distortion. This will hurt your ears! It is capable of more than a watt into lower impedance loads.
fwiw I spent an enjoyable couple of hours with the Whammy driving my 12" 100db 8 Ohm open baffle drivers and while they do benefit from a bit more oomph it was still very much an enjoyable listen with a clean & detailed presentation. The Whammy didn't seem to be stressed the heat sinks were no warmer than normal and the transformer (22v) stayed cool to the touch during that time.
Normally I use a 2W Set amp.
Normally I use a 2W Set amp.