"WHAMMY" Pass DIY headphone amp guide

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#2,981
Jim,

Thanks I understand in the naked reg config the diodes are not installed.

My question was more if u choose reg setup #2 LED refrence.

Then wanted to try the +15v via shorting the R9/10/13/14 could u do this without removing the leds already installed in setup #2?

Any issue with this? Or would you need to remove them?

Alex
 
#2,982
From what i read, maximum voltage for AD797 is 36V or +/-18V. And current draw av around 8mA. R35/R36 is 47ohm.
With the diode option there is about +/-16.8V
47x0.008=0.376 or 0.4V ish. And there is 2 of them. So 16.8-0.8=16. So the voltage the AD797 will see is +/-16Vdc. That should be fine 🙂
 
#2,983
Thanks 6L6 I'll be sure to get one with the dingle / adapter.

Does anyone have any spare 71-RN55D3300FTR? Also are there any alternatives? It's all sold out online. Hoping to get 4, the other 2 for spares. Let me know!
 
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#2,984
AudioSan said:
From what i read, maximum voltage for AD797 is 36V or +/-18V. And current draw av around 8mA. R35/R36 is 47ohm.
With the diode option there is about +/-16.8V
47x0.008=0.376 or 0.4V ish. And there is 2 of them. So 16.8-0.8=16. So the voltage the AD797 will see is +/-16Vdc. That should be fine 🙂
Click to expand...

Thanks for the info AudioSan. I'm curious to know how it matches against the OPA627. I've always preferred Texas Instrument opa's over other brands. We'll see and I'll fill you guys in on my impressions
 
#2,986
JimmyC23 said:
Thanks 6L6 I'll be sure to get one with the dingle / adapter.

Does anyone have any spare 71-RN55D3300FTR? Also are there any alternatives? It's all sold out online. Hoping to get 4, the other 2 for spares. Let me know!
Click to expand...

Lots of alternatives. Since you put in a Mouser part number, I'd recommend typing that back into Mouser. When the part comes up, the page has a number of tick boxes in the description. I'd suggest (if you want) clicking the Vishay, RN series, and 330 ohm boxes. Then click the "Show Similar" button. You'll see some options. Since that part is 1/8W - pick your favorite option that is 1/8W or more.

The "Show Similar" and the sorting functions in Mouser and other on-line shops are great for finding alternative parts.

As an example, this may be a nice one.

https://www.mouser.com/ProductDetail/Vishay-Dale/RN60D3300FB14?qs=F%2B4GoDNhlYSOSNOO13HqMw==
 
#2,990
Let me try to ask this again in a different way.

Built the Whammy with 22 v sec xfmr using:
Step 8 Regulator configuration option 1 - "LED reference"

D5/D6 populated. R9/19/13/14 unpopulated.
C8/10 Populated.

All is well.

Then wanting to try the 15 volts out, can i just short R9/13 WITHOUT removing the D5/6 diodes to get the 15 v?/

OR

Do I need to remove them?

Thanks Alex
 
#2,992
Thanks!!!

This is what I thought, but wanted confirmation from others.

So this leads to my thinking that I could use the 22 v sec xfmr and wire for the LED reference and then install a switch that would short out R9/13 and have an easy way to go from one to the other, if desired?

Thanks again !!
Alex
 
#2,997
Wayne shows the measurements in the video posted. If it's configured as described in the video, it's ~400mW @ clipping per Wayne. The "base setup" still has a few options you can choose. The store kit may not use exactly the same parts from Wayne's 2017 presentation, but that's a good ballpark, and you know you can vary from there.
 
#3,000
I can't think of very many diodes which DON'T need to be installed in the proper orientation. They are one-way devices after all; install them backwards and you certainly don't get the behavior that the circuit designer expected. Now they conduct the wrong way!
 
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