Hi all. I just finished my „experiment“ which was to add a DAC to my already existing whammy.
I share it with the community because it might be if some interest for others.
As DAC, I choose the Khadas Tone 1 because it has the size to mount it on top of the PSU caps. I wanted to keep the chassis as small as possible.
The Tone 1 is an excellent sounding DAC. As opamp I used the Muses 8920, in my opinion one of the best sounding opamps for a really reasonable price.
The Tone1 needs 5 V power supply. Normally it receives its power from the connected USB host. But if you use the spdif input, you would be required to connect a usb power supply. Not the best solution. So I added a mini high quality switched power supply. It is the black cube next to the transformer. I was curious if that would implement distortion. But everything is absolutely clean. No audible noise, hum or so and the measurements with the scope are also very good.
All in all an excellent sounding headamp, preamp and DAC
I share it with the community because it might be if some interest for others.
As DAC, I choose the Khadas Tone 1 because it has the size to mount it on top of the PSU caps. I wanted to keep the chassis as small as possible.
The Tone 1 is an excellent sounding DAC. As opamp I used the Muses 8920, in my opinion one of the best sounding opamps for a really reasonable price.
The Tone1 needs 5 V power supply. Normally it receives its power from the connected USB host. But if you use the spdif input, you would be required to connect a usb power supply. Not the best solution. So I added a mini high quality switched power supply. It is the black cube next to the transformer. I was curious if that would implement distortion. But everything is absolutely clean. No audible noise, hum or so and the measurements with the scope are also very good.
All in all an excellent sounding headamp, preamp and DAC
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Nice work! I'm impressed you fit it all in the standard enclosure.
I'm glad you're happy with the Toneboard, there doesn't seem to be many other compact board only DACs available.
The comments button does not work on the Builders Guide. What is the bast method to provide feedback for clarifying the build guide?
I have a few comments. A small one assembling the heatsinks:
FYI… Bullet point 4 says “think” layer of heatsink compound instead of “thick” think layer of heatsink compound.
I have a few comments. A small one assembling the heatsinks:
FYI… Bullet point 4 says “think” layer of heatsink compound instead of “thick” think layer of heatsink compound.
Nice work.
Nice way of implementing the DAC,
Removing the RCAs makes it much easier to accomodate.
Hey guys I desperately need some help with the C26. I am not experienced in PCB soldering. I think it is very possible that I just damaged the PCB "little gold ring" of C26. Now the solder cannot be melted and stick to the C26 negative hole. I have seen people using a extra line to "bypass ( I guess)" some parts of the PCB. Cam I use similar method to solve my current situation. I really dont wanna start from the beginning to make a new whammy pcb.
Can you share two pictures:
One showing the top of C26 solder pads, and one showing showing the bottom side of those same pads
My diy pcb etching and building the Whammy amp. It started with a preamp board i bought from a local diy group, it use a clone GM regulator with AD797 and with AD586 voltage reference. I only need to build the buffer. The buffer then would be wire with the preamp board, including Input, wire for gain/feedback, voltage supply from the rectifier. The buffer has it own regulater with a pair of LM317/337, a relay protection circuit, Oyaide 102CCS as hookup from preamp to the buffer and used IRF540/9540 for output.
I tested it with AD797 and the result is pretty good.
I still have a bunch of 2SJ407/2SK2381 too but I'm not sure if they could be used for audio, so that's for future upgrade.
I tested it with AD797 and the result is pretty good.
I still have a bunch of 2SJ407/2SK2381 too but I'm not sure if they could be used for audio, so that's for future upgrade.
Attachments
Issues with Dale RN55 resistors supplied with kit
The marked:
All other resistors measured within tolerances.
The marked:
- 47 ohm resistors measured 29 ohms (over 35% variance!)
- 100 ohm resistors measured 64 ohms (45% variance)
All other resistors measured within tolerances.
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Also the schematic states 2SK2013 and 2SJ313, but the kit supplies IRF610 and IRF9610. I assume they are interchangeable?
2SK2013 = IRF610 (N-channel)
2SJ313 = IRF9610 (P-channel)
2SK2013 = IRF610 (N-channel)
2SJ313 = IRF9610 (P-channel)
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Finished my WHAMMY about 1 month ago - very nice headphone amp, and I love the case from the store as well, lets us all finish these amps in a very nice way.
What does it sound like ?
In stock configuration sounds great (op amps and input caps etc) , in my opinion it sounds better than my SPL phonitor , the sennheiser HDVD800 in balanced mode slightly pips it,
I was wondering what others think about changing the op amps and is it really an issue - from my side the biggest difference is the headphones used. This amp really sing with Sennheiser HD800 (using a chord mojo as the input) these sound much better than my Focal Clear's, yet to try my try SE846 IEMs.
What does it sound like ?
In stock configuration sounds great (op amps and input caps etc) , in my opinion it sounds better than my SPL phonitor , the sennheiser HDVD800 in balanced mode slightly pips it,
I was wondering what others think about changing the op amps and is it really an issue - from my side the biggest difference is the headphones used. This amp really sing with Sennheiser HD800 (using a chord mojo as the input) these sound much better than my Focal Clear's, yet to try my try SE846 IEMs.
My experience has been that different opamps do actually impart a slightly different sonic signature. It's more apparent with the WHAMMY than with other gear I've tweaked.
I shorted the input caps and am using a pair of OPA828 (with 0.1uF film decoupling caps across V+/V- & GND), and am using 100uF Panasonic FR instead of 220uF after the SparkOs Voltage Regs. Probably have to be careful with the 828 and oscillation. I've not measured it to verify.
This amp is awesome, and pairs very nicely with my HD800S. I say try a couple different opamps and see what you think.
The low ohm resistors measure low was related to low battery in my multimeter. 😱 Thanks 6L6 for the pointer.
BTW, it sounds marvelous.
Question: How are people wiring the white front panel LED? What resistor is recommended to inline with the LED when hooked to power supply output?
BTW, it sounds marvelous.
Question: How are people wiring the white front panel LED? What resistor is recommended to inline with the LED when hooked to power supply output?
Here is one way:
https://www.diyaudio.com/community/...adphone-amp-guide.317803/page-77#post-5876670
Mark Johnson posted a different way somewhere in this post that takes power before the caps to avoid the low dimming when turning off. I haven't found his post again since the forum updated.
Thanks guys!
The above approach as indicated on post 4412 seems appealing as well, grabbing LED power before the regulators.
I have a question about using the whammy as a preamp. Does the (RCA) output need to be loaded with any resistance to when connected to a power amp? I thought I had seen photos with a resistor in series with the output somewhere in this thread.
@KevinHeem
Posted somewhere in this thread:
https://www.diyaudio.com/community/attachments/hpa-pre-out-jpg.986263/
Posted somewhere in this thread:
https://www.diyaudio.com/community/attachments/hpa-pre-out-jpg.986263/
I ran the Whammy as a preamp for several years without the output resistors. When the case was delivered and a lot of soldering was needed for installation there were resistors added to the output.
Haven't had any issue before or after.
Haven't had any issue before or after.
Thanks Chris,
Honestly, I do as little math as possible unless I’m trying to help the kids with elementary and middle school homework.
Honestly, I do as little math as possible unless I’m trying to help the kids with elementary and middle school homework.
I hear you, Kevin. Thankfully, this forum is full of generous people who share their knowledge! I have been slowly working on my WHAMMY and can't wait to hear it.