"WHAMMY" Pass DIY headphone amp guide

[Jaccher]

If it has been disassembled it will have minimal tin residue on the pins.
I will examine it carefully with a magnifying glass and if it is like new I will not assemble it.

 

[NIXIE62]

I looked when I got them, maybe you can see some small marks, because they polish it. The main thing was measuring and listening. I have a small line preamp for those rehearsals and measurements. I can plug single or dual opamps into it, I always check them there first, even the ones I know are original from Mouser, DigiKey, etc.

 

[dotneck335]

"Try OPA1656..."
Love to. WILL IT DRIVE 32Ω HEADPHONES????

 

[howarthcd]

Just building my second one of these amps and found that Rapid Electronics in the UK currently list the motorised ALPS 100K RK27 FOR £10 in their clearance section:

https://www.rapidonline.com/alps-rk27112mc-100k-motorised-dual-gang-rotary-potentiometer-66-0227

Even if the motor isn't used this seems to be a really good price, although I'm not sure whether it would fit in the Hammond case without the motor and maybe the gearbox being removed.

They also list the Hammond case so this could be added to bump up the total to get free postage.

Also I have a couple of spare PCBs (1.6mm thickness so a sligtly loose fit in the Hammond case) which are available if anyone needs one (please DM) - £10 each inc P&P, they were made by JLCPCB. They are the earlier PCB version that don't have pads for the 2K2 input resistors R39 and R40.

 

[ClaudeG]

Quote:
"Try OPA1656..."
Love to. WILL IT DRIVE 32Ω HEADPHONES????

I haven't built the Whammy but my understanding is that its output "drive" is done by a pair of Mosfets, so the op-amp (whatever its type) isn't working hard...

I hope this helps

Claude

 

[Jaccher]

Whammy as a preamplifier?

 

[cubicincher]

Hello Jaccher,

the WHAMMY is also a really good preamp. Done by many members here (me included).
A pair of RCAs in parallel / switchable to your headphone-socket. You can add a pair of resistors to the
hot mid pin of RCA-out. Described in this thread.
Cheers
Dirk

 

[cubicincher]

check post #2380 and #4264...

 

[mawi]

Hey all! If I had the option to choose on a super preamp, would it be the FE2022 or the Whammy? Or what?

 

[ItsAllInMyHead]

^ Iron Pre... but I'm very, very biased.

 

[6L6]

What are your goals? What is your system? What do you want out of a preamp that you don't currently have?

Anything mentioned so far can be very, very good. To fully answer your question we need more information .

 

[mawi]

I want to eliminate the impedance problems with my "light speed" volume controller

• One Musical Paradise DAC
• One home designed DAC Rhodes Rain DA380 based ES9038PRO
• One Light speed volume
• A pair of ACA (Modified)
• One F6 revised (Diamond and will probably be a dual mono with one F6 revised and one F6 original in one cabinet)
• A pair of 6550 singel en with separat power
• A pair of el84 PP as alternative SE
• A pair of Klipch Hersey (Baby Cornwall Mod)
• One Whammy not build
• One FE2022 not build

And tons of other stoff.... 🙃

 

[6L6]

Build Whammy.

 

[mawi]

Great and thanx 6L6! Order things now 🙂

 

[garybx]

I built a WHAMMY last year that is working great. Now I'm building another WHAMMY for a friend. This new kit did not include the brown capacitor between the input shields and chassis ground (I'm not sure of the value since my old build has the cap buried where I can't see the markings). The new kit does include an otherwise unused yellow axial capacitor that I suspect is intended to be equivalent to the old brown cap. The markings are: ic 334K 1914 100V T MWR

Can anyone confirm that the new yellow cap is the one to use where the brown cap was in the old kit? And can anyone help extract the value from the markings on the yellow cap? I have tried searching this thread but I'm not finding any discussion of this cap.

Thanks in advance.

 

[6L6]

Yes.

From the marking you post I'd assume it's an Illinois Capacitor MWR series 0.33uF 100V capacitor.

 

[garybx]

Thanks, 6L6. So do you think that it's the appropriate cap for bridging from signal ground to chassis ground?

 

[NIXIE62]

I put this in place of that one capacitor. R=22ohm 0,6W and without a ground lift switch.

 

[Stoggy]

Hi everyone,

I'm an absolute beginner that is nearly done my first build of any kind and I'm realizing that I'm missing a 2.2k resistor, no doubt I lost it myself. Can I replace it with any 2.2k resistor? Does it need to be 'audio grade', or also Dale to match all the others? If I can use a different brand, should I de-solder the one that's already in so that they match?

Thanks so much, this has been so much fun. I'm also very nervous(excited) to see the end result.

Appreciate getting a peek into your community and your expertise.

 

[DSP_Geek]

That'd be the input resistor R39/R40? The 2.2K value is discretionary, simply a voltage divider with the input gain potentiometer. Just replace both those resistors with bits of wire and you'll be fine.