Hi Wayne, yes, it seems that having C2 an C7 in there is giving me a subtle but noticable improvement. It's surprising to me as the general advice is to leave them out. I wish I had a scope to see what I'm hearing.
(please ignore my totally professional and very accurate panel drilling)
My two wammies, one uses the vishay dale resistors (black chassis), and the other is running military surplus resistors, mostly pre-vishay dale. Both sound excellent and I thank whayne, 6L6, and diyaudio for supporting hobbyists in such a big way.
But here's my questions/issues:
The black chassis originally had LED regulator setup, but I was having issues so I went naked. Now, as my name suggests, I'm not the brightest bulb in the tool shed, and I messed up on the naked regulator by adding a 1kohm resistor and shorting the 330ohm... What this do?
Probably wise to just remove them but I went through a few tribulations on the build (hence all the flux still on the board) so I'm a bit reluctant to change things. Here's the biggest thing though: this particular whammy is super silent when unplugging and plugging in headphones. The vintage resistor/LED regulator build isn't noisy by any means but it definitely has a noticeable pop and scratch to it, where the naked-ish regulators contend with my balanced XLR stuff.
Another weird thing is that I currently have a opa2134 singing away nicely in the naked-ish regulator build, but with he LED regulators the left channel drops in and out and end sup being a fuzzy mess. Not sure if that's because of the regulators or other part choices, these aren't too different in terms of BOMs though.
Thanks everyone for the insights and sorry for the long post.
Hope you all have a good one
I installed the sigma 78 and 79 regulators today, resistor-tuned to 16 volts. This gives 17.3 volts paired with the IR LEDs I installed a week ago.
These tiny chips do run a lot hotter than the 7815 and 7915 to220 packages they replace, but we'll see how they hold up
These tiny chips do run a lot hotter than the 7815 and 7915 to220 packages they replace, but we'll see how they hold up
Attachments
I installed the sigma 78 and 79 regulators today, resistor-tuned to 16 volts. This gives 17.3 volts paired with the IR LEDs I installed a week ago.
These tiny chips do run a lot hotter than the 7815 and 7915 to220 packages they replace, but we'll see how they hold up
Nice: voltages measure -/- 17.25V and +/+ 17.26V respectively. Perfectly matched.
These are Aliexpress copies of the original design. They come with tantalum caps, but I changed them to X7R ceramics as per the original design. I used the formula on the AMB site to calculate the values of R1 and R2 to achieve a target voltage of 16V. All in all it turned out well.
The reduction in noise is probably measurable, but to be honest I cannot hear any difference in audio performance.
Other than that, I do like the fact that both rails are now exactly matched, at a nice voltage for 18v max speed opamps.
Whammy Mouser PCB project parts list
Note: the following project at Mouser was updated today to parts in stock. This is for PCB main board components only, not including the transformer, which is not available at Mouser. The list also does not include the opamp. I recommend the OPA1612A on an SMD to DIP adapter. If SMD adapting is too challenging, The OPA2134PA is pretty good and I think better than the kit RC4580IP (although I'm sure 6L6 would disagree).
Heat sinks are 38mm tall, so this will not fit in a 1U DIYstore chassis. Resistors are RN55D except for the 2 watt and the 499 ohm which is Vishay MBB series. The RN55D 499 ohm is available from Mouser but they are $1.20 each! 220uF caps are 35V except C3 C4 which are 25V to get the diameter down to 8mm to facilitate opamp rolling.
Here's the Mouser project link:
Mouser Electronics
Note: the following project at Mouser was updated today to parts in stock. This is for PCB main board components only, not including the transformer, which is not available at Mouser. The list also does not include the opamp. I recommend the OPA1612A on an SMD to DIP adapter. If SMD adapting is too challenging, The OPA2134PA is pretty good and I think better than the kit RC4580IP (although I'm sure 6L6 would disagree).
Heat sinks are 38mm tall, so this will not fit in a 1U DIYstore chassis. Resistors are RN55D except for the 2 watt and the 499 ohm which is Vishay MBB series. The RN55D 499 ohm is available from Mouser but they are $1.20 each! 220uF caps are 35V except C3 C4 which are 25V to get the diameter down to 8mm to facilitate opamp rolling.
Here's the Mouser project link:
Mouser Electronics
Opamp rolling continues with opa627 and opa828. Opa828 has very low dc offset of 0.2 and 0.3 mv left and right, and has a very low noise floor. However, there seems to be a hardness in the sound that I find unpleasant to listen to. It might me oscillating? Maybe this opamp is just too fast for this circuit.
Opa627 has 5mv dc offset on the right channel and 0.1mv on the.left. I'll check whether this difference is due to some leftover flux. Both opamps have the same codes and are from the same sample order with TI. Noise floor is very low, same as opa828.
Opa627 really sounds very very nice. Dynamic, authoritative, honest, non fatiguing. Not sure if this can be beat. I'll try opa2210 next.
Opa627 has 5mv dc offset on the right channel and 0.1mv on the.left. I'll check whether this difference is due to some leftover flux. Both opamps have the same codes and are from the same sample order with TI. Noise floor is very low, same as opa828.
Opa627 really sounds very very nice. Dynamic, authoritative, honest, non fatiguing. Not sure if this can be beat. I'll try opa2210 next.
We had some good clean fun with single blind opamp rolling in the M2x power amplifier.
Person_A would use sandpaper to remove the part numbers from the top of a pair of opamp packages, and then paint the top surface with a colored enamel paint. Repeat for a total of 6 pairs of opamps: Red, Green, Blue, Yellow, White, Silver.
Then Person_A would mail those opamp pairs to Person_B, a thousand miles away. Person_B installed them in his/her M2x power amp and listened to them for as long as they wished. Eventually Person_B decided which opamps sounded best and published a review / listening evaluation here on diyAudio. Only after publication of all reviews, were the identities (Part_Number vs Color) disclosed.
Any two diyAudio members can do the same. Try it, you might have a lot of fun!
Link to M2x post 4755 is HERE. There are some surprises, at least some results which surprised me. (The 741 did NOT finish dead last, for example). Try it, you might have a lot of fun. Naturally with WHAMMY you are limited to only trying dual opamp chips: no AD825, no LT1122, no OPA604 for you!!
_
Person_A would use sandpaper to remove the part numbers from the top of a pair of opamp packages, and then paint the top surface with a colored enamel paint. Repeat for a total of 6 pairs of opamps: Red, Green, Blue, Yellow, White, Silver.
Then Person_A would mail those opamp pairs to Person_B, a thousand miles away. Person_B installed them in his/her M2x power amp and listened to them for as long as they wished. Eventually Person_B decided which opamps sounded best and published a review / listening evaluation here on diyAudio. Only after publication of all reviews, were the identities (Part_Number vs Color) disclosed.
Any two diyAudio members can do the same. Try it, you might have a lot of fun!
Link to M2x post 4755 is HERE. There are some surprises, at least some results which surprised me. (The 741 did NOT finish dead last, for example). Try it, you might have a lot of fun. Naturally with WHAMMY you are limited to only trying dual opamp chips: no AD825, no LT1122, no OPA604 for you!!
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Using a single to dual op amp adaptor will get around that problem, it worked for me
Update: opa2210 is also very good, but opa1656 is the first one that I think is at least equal to opa627. I really enjoy this one. It might be a bit more "composed" or whatever that may signify, and it's very musical. I will listen to it some more, but this is a very very good opamp. This should be on everyone's shortlist, not even talking about its low cost. DC offset measures 0.1-0.2mV for both channels
Unregulated supply
Good day all.
I have a diy board version by Ergo of the Whammy. I currently use a smallish transformer with dual LM317
regulators to get +-15Vdc which I normally just use for testing. I have wondered if the PSRR of Whammy is good enough so one can use a NON regulated CRCRC supply for rails. I use a L bracket to mount the fets to the heatsink.
Much appreciated.
Good day all.
I have a diy board version by Ergo of the Whammy. I currently use a smallish transformer with dual LM317
regulators to get +-15Vdc which I normally just use for testing. I have wondered if the PSRR of Whammy is good enough so one can use a NON regulated CRCRC supply for rails. I use a L bracket to mount the fets to the heatsink.
Much appreciated.
Attachments
Unregulated supply
Good day all.
I have a diy board version by Ergo of the Whammy. I currently use a smallish transformer with dual LM317
regulators to get +-15Vdc which I normally just use for testing. I have wondered if the PSRR of Whammy is good enough so one can use a NON regulated CRCRC supply for rails. I use a L bracket to mount the fets to the heatsink.
Much appreciated.
Good day all.
I have a diy board version by Ergo of the Whammy. I currently use a smallish transformer with dual LM317
regulators to get +-15Vdc which I normally just use for testing. I have wondered if the PSRR of Whammy is good enough so one can use a NON regulated CRCRC supply for rails. I use a L bracket to mount the fets to the heatsink.
Much appreciated.
