Since the AD744 (single opamp/pkg) sounds so good in the Norwood circuit, I recommend trying its brother AD746 (two opamps/pkg). Same SOIC-8 as the OPA1612.
I'm considering building a Whammy or a Neurochrome HP-2 headphone amp. Has anyone here built or heard both who can share insights that compare and contrast these two highly rated amps? I'll be using the amp with a BeyerDynamic DT-990 Pro (250 ohm) headphone.
I think the Neurochrome HP-2 only goes up to 300mw at 250 ohms. That may be enough, though?
300 mW will be sufficient. The DT-990 power handling capacity spec is 100 mW.
Done!
Another Whammy is assembled!
First of all, many thanks to Wayne and 6L6 for this Whammy project. Such a great HPA and support for building it!
But also to the others in this thread (... have read every post ...) for valuable input on assembly and parts decision.
This has been so much fun (especially during the lockdown). I have used the full kit and the Hammond chassis - so not much of a special design. But the result is simply outstanding. The Quad Era-1 (20 ohm) is working extremely well with Whammy, never heard something similar before. Full sound, clear and detailed, feels like directly being drawn into the music and forgetting to have an HP on.
First, I assembled the full kit including volume control. Initially, one channel was a litte lounder as the other, but after re-soldering few parts all was fine. In the final version, the Alps pot, R39/R40 and C1/C5 are omitted (although partly left on the board), and of course a blue power-on LED. Signal is coming from a DAC with volume control, going into the Whammy after the coupling caps. FQP3N30/3P20 are used for Q1-4 and the OPamp is OPA2107AP. This was chosen based on the feedback on OPamp rolling in this thread, and I can confirm its great sound in my setup. DC offset is below 0.2 mV for both channels. Only question is that the OPamp voltage of 1-out is higher (~80 mV) than 2-out (~30 mV). Not sure whether this is something to worry about, while the sound is fully fine.
Again, one more Whammy fan here!
Another Whammy is assembled!
First of all, many thanks to Wayne and 6L6 for this Whammy project. Such a great HPA and support for building it!
But also to the others in this thread (... have read every post ...) for valuable input on assembly and parts decision.
This has been so much fun (especially during the lockdown). I have used the full kit and the Hammond chassis - so not much of a special design. But the result is simply outstanding. The Quad Era-1 (20 ohm) is working extremely well with Whammy, never heard something similar before. Full sound, clear and detailed, feels like directly being drawn into the music and forgetting to have an HP on.
First, I assembled the full kit including volume control. Initially, one channel was a litte lounder as the other, but after re-soldering few parts all was fine. In the final version, the Alps pot, R39/R40 and C1/C5 are omitted (although partly left on the board), and of course a blue power-on LED. Signal is coming from a DAC with volume control, going into the Whammy after the coupling caps. FQP3N30/3P20 are used for Q1-4 and the OPamp is OPA2107AP. This was chosen based on the feedback on OPamp rolling in this thread, and I can confirm its great sound in my setup. DC offset is below 0.2 mV for both channels. Only question is that the OPamp voltage of 1-out is higher (~80 mV) than 2-out (~30 mV). Not sure whether this is something to worry about, while the sound is fully fine.
Again, one more Whammy fan here!
Attachments
Op testing !._
My favourite op after all the test is 2xLT1028 with adapter.
FQP's are for my hearings better than 2013/313. More speed and rocks! Toshibas are smooth and sweet/slow.
My favourite op after all the test is 2xLT1028 with adapter.
FQP's are for my hearings better than 2013/313. More speed and rocks! Toshibas are smooth and sweet/slow.
I'm really surprised by this I tried this OP Amp albeit the dual version LT1128 too but found it a little raspy around the edges like the AD823 but additionally it sounded like the soundstage was being held back almost like it was a little muffled.
If you get chance try the OPA2210, OPA2107 and AD746JNZ.
LT1028: 50MHz Min
LT1128: 13MHz Min
n Slew Rate
LT1028: 11V/µs Min
LT1128: 5V/µs Min
Big difference Lt1028, even from my all time love opa627!
LT1128: 13MHz Min
n Slew Rate
LT1028: 11V/µs Min
LT1128: 5V/µs Min
Big difference Lt1028, even from my all time love opa627!
I must say again! Dead silence again! Perfect. Thanks Wayne for the project! I have never done the same project twice! ONLY WHAMMY!
I've ordered the PCB with the intention of building this up using some leftover components from other projects. Having gone through the original BOM I have quite a bit of useable stuff but had a few questions. I'm aiming to drive Shure 1840 CANS which are 65 ohms.
1. Would this transformer be suitable given the low rating of the 1840s : 15VA Talema PCB-mount encapsulated toroidal transformer, 50VA, 2x115VAC in and 2x15VAC out @ 500mA
2. I have a few dual OP amps AD744Jn, OPA2134 and NE5534. Am I better off picking up a better spec one?
3. Are there any universally recommended changes to the original components? (I don't really want to trawl through 260 pages of the thread!)
4. I have a 50K alps pot. Would this work or do I need to go for the 27K?
Thanks!
1. Would this transformer be suitable given the low rating of the 1840s : 15VA Talema PCB-mount encapsulated toroidal transformer, 50VA, 2x115VAC in and 2x15VAC out @ 500mA
2. I have a few dual OP amps AD744Jn, OPA2134 and NE5534. Am I better off picking up a better spec one?
3. Are there any universally recommended changes to the original components? (I don't really want to trawl through 260 pages of the thread!)
4. I have a 50K alps pot. Would this work or do I need to go for the 27K?
Thanks!
Think you are overthinking this one a bit. I have the 25VA/22v Talema transformer which gives just over 500ma current for the whammy on positive and negative rails. I built mine stock and tried various OP Amps before settling on OPA2107. I tried the Shure SRH1540 headphones with mine and they sounded phenomenal. They are just the closed back version of yours. And I also used the 50K Alps pot. It's perfect!
1) If it fits the PCB, yes. (It may be the next footprint bigger, or perhaps two steps up, 50VA will be large. The normal transformer is very big all things considered, more is not going to gain much if anything.
2) Opamp to taste. Opinions differ wildly, as people all perceive differently. What I hear and like is probably not what you hear and enjoy. What you have should work nicely.
3) Not really. The circuit works beautifully as designed.
4) Totally fine.
2) Opamp to taste. Opinions differ wildly, as people all perceive differently. What I hear and like is probably not what you hear and enjoy. What you have should work nicely.
3) Not really. The circuit works beautifully as designed.
4) Totally fine.
Finished my WHAMMY about 3 weeks ago and have been hammering it since, I invested in a pair of planar headphones and haven't looked back. I don't have a case for it yet as I'm looking for a new DAC project and then will box up the full stack.
Clean, crisp, plenty of power and silent. Took around 3 hours in total to put together and is worth every single penny x3. Love it.
Clean, crisp, plenty of power and silent. Took around 3 hours in total to put together and is worth every single penny x3. Love it.
Hi everyone!
Have been having irregular drops in my left channel for about a week now. The amp itself is well over 200h played with no problems.
DC offset on both channels is 14 mV when working normally, measured the left channel when it droped and it was 8 mV left ch. to ground.
Powersupply seemed fine.
Have tried two opams (OPA2134 and the RC4580)
Any tips? I'm thinking a cold solder would have made its presence earlier.
Have been having irregular drops in my left channel for about a week now. The amp itself is well over 200h played with no problems.
DC offset on both channels is 14 mV when working normally, measured the left channel when it droped and it was 8 mV left ch. to ground.
Powersupply seemed fine.
Have tried two opams (OPA2134 and the RC4580)
Any tips? I'm thinking a cold solder would have made its presence earlier.
I'd check all connections especially the RCA. Once I got good quality sockets from Mouser but it would still drop out occasionally if I wiggle the jack enough.
I've now ordered all the parts on the BOM and awaiting the PCB. I couldn't get an OPA 1612 in an 8 pin DIP format so have picked up a SMD version and an adaptor. Just wondering if it's easy to work out the orientation of the ASM version in the same way that the DIP versions have some kind of demarkation?