The power regulators get hot upto
58’ C here in Delhi ...unless with proper ventilation...I may have to drill lotta holes just above them in the chassis
I experienced the same thing kpsthakur. I'm about to switch to 2x18v transformer to reduce the voltage difference. Should help a lot with the heat. I'm sure I'll find another project to use the 2x22v on.
read the datasheets, got it
Sorry couldn't help asking, did you use any compensation caps?...
I experienced the same thing kpsthakur. I'm about to switch to 2x18v transformer to reduce the voltage difference. Should help a lot with the heat. I'm sure I'll find another project to use the 2x22v on.
What if I replace the linear regulators with 7818/7918 pair and use OPA2134 opamp rated till +- 25V...the one in my cMoy sounds amazing
Another one in the wild. Bias set to 112mA. 2SK2013/2SJ313 output devices. LM4562. Sounds awesome, thanks Wayne!
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OPA2134 scores way above AD823....far more vocals and mids...although a bit low on Bass compared to 823.
Dead silent...by far the best headphone amp I have heard...also planning to use it as a pre
I am going to set this up in a cookie box, which is a perfect size match....
For the power supply IC’s modded the heatsink, looks awefull, but the average temp after 3 hrs of play is around 48 C, output Transistors don’t go above 43 C in my setup
Dead silent...by far the best headphone amp I have heard...also planning to use it as a pre
I am going to set this up in a cookie box, which is a perfect size match....
For the power supply IC’s modded the heatsink, looks awefull, but the average temp after 3 hrs of play is around 48 C, output Transistors don’t go above 43 C in my setup
Hello guys,
I am following the thread for a while but didn’t noticed anyone asking the following question.
I use a sony vfet part 2 frontend(balanced) as a preamp that I like very much.
I would like to direct couple the output stage of WHAMMY to the output of the preamp without including the buffer in the global feedback loop of the preamp. Soundwise is it better to include the buffer in the global feedback loop?
I will use coupling caps after the buffer if needed.
The entire setup won’t be used to drive headphones and only in front of my aleph j monoblocks.
For setting the dc offset after the buffer I was thinking to add a pot like in the m2 amp
Any ideas if something like this could work?
I am following the thread for a while but didn’t noticed anyone asking the following question.
I use a sony vfet part 2 frontend(balanced) as a preamp that I like very much.
I would like to direct couple the output stage of WHAMMY to the output of the preamp without including the buffer in the global feedback loop of the preamp. Soundwise is it better to include the buffer in the global feedback loop?
I will use coupling caps after the buffer if needed.
The entire setup won’t be used to drive headphones and only in front of my aleph j monoblocks.
For setting the dc offset after the buffer I was thinking to add a pot like in the m2 amp
Any ideas if something like this could work?
I have done my WHAMMY with LM833 opamp, FQP FETs, 60ma bias, 20KA pots.
The sound quality is awesome. Thanks Wayne.
The sound quality is awesome. Thanks Wayne.
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I may have messed something up, while changing the voltage regulators... the 7918 side gives -19.3V and the LED is lit, the +ve side has got some issues...the output is -7.65V post regulation...this is not right...I have changed the regulators twice (7818's), but the issue remains the same...it could be the diodes or if I have fried the LED or something else...not made any other changes to the circuit...any suggestions
YesNice routing on the wires and the chassis. White board solder mask?
I ordered 10 boards for around USD$100 here in Taiwan.
Your amp looks delicious.
Last edited:
Resolved
Busted LED...replaced (getting soldering off took almost 2 hours), all is good now....board back in the box now & singing.
Thanks Wayne, great solid amp...no reduction in performance between moving from low ohm to very high ohm headphones...in fact it becomes way better...the extra volts on the PSU provides enough room I presume.
Although I am using shielded cables and twisted to ensure no crosstalk or interference, I feel a very very faint hiss when nothing's playing. Also a power up/power down thump has arrived...none of this bothers me much but would definitely like to troubleshoot. I am grounding the input jacks via 0.01uF cap
- Voltage on pin three is a big clue. Something in the circuit is putting a - voltage on the output of the regulator.
Busted LED...replaced (getting soldering off took almost 2 hours), all is good now....board back in the box now & singing.
Thanks Wayne, great solid amp...no reduction in performance between moving from low ohm to very high ohm headphones...in fact it becomes way better...the extra volts on the PSU provides enough room I presume.
Although I am using shielded cables and twisted to ensure no crosstalk or interference, I feel a very very faint hiss when nothing's playing. Also a power up/power down thump has arrived...none of this bothers me much but would definitely like to troubleshoot. I am grounding the input jacks via 0.01uF cap
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