And just now, I received a shipment notification from Xometry that my chassis panels are on the way 
I had a bit more time to kill while some code was running for a research project, so I went ahead and swapped the electrolytic caps in the Heathkit IP-2717A. Only took about 10 mins, and very easy to do.
Out with the old
In with the new!
Luckily it worked perfect on the first power-up!
I still need to replace some smaller non-polarized capacitors, and the diodes but that will be a project for tomorrow...my code is done running and it is time to go back to work!
Out with the old
In with the new!
Luckily it worked perfect on the first power-up!
I still need to replace some smaller non-polarized capacitors, and the diodes but that will be a project for tomorrow...my code is done running and it is time to go back to work!
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I had a bit more time to kill while some code was running for a research project, so I went ahead and swapped the electrolytic caps in the Heathkit IP-2717A. Only took about 10 mins, and very easy to do.
Out with the old
In with the new!
Luckily it worked perfect on the first power-up!
I still need to replace some smaller non-polarized capacitors, and the diodes but that will be a project for tomorrow...my code is done running and it is time to go back to work!
Awesome work, looking forward to seeing the finished product!
A very very exciting day today!
Earlier today the chassis panels arrived from Xometry. And my goodness, they look FANTASTIC! The powder coat finish is exactly what I wanted, with a rough-ish surface and somewhat raised grain.
I couldn't resist and immediately got to work. Rather than dump all the photos here from today's work, I will upload them to Imgur here: https://imgur.com/a/gc8uOH9
Let's just skip to the best part - the completed chassis with all components installed!
I am over the moon with how it has turned out so far!
Some of the highlights from the build.
The beautiful chassis panel.
Installing the copper mesh (2 layers) on the chassis:
This was done easily with hotglue - just lay down a dab and then press the mesh onto it. The hot glue will permeate the mesh and lock it into place. Very easy to get it nicely tensioned this way.
Capacitor installation using 3D printed mounts:
Hot glue used to lock the capacitor into place once aligned with the grilles. Also added some blobs of hot glue as strain relief for the capacitor terminals as they will make some sharp angles.
These little swiches took about 30 minutes to install, because I had to be very careful not to scratch up the chassis or the small decorative ring around the switch:
And finally, the underside of the chassis with all the nylon standoffs installed for the point-to-point wiring (heavily inspired by Decware building style):
Some other random building details:
I'll be out of town the rest of this week, so unfortunately I won't be able to start the wiring until next week, but I'm so happy with how it is turning out so far.
Earlier today the chassis panels arrived from Xometry. And my goodness, they look FANTASTIC! The powder coat finish is exactly what I wanted, with a rough-ish surface and somewhat raised grain.
I couldn't resist and immediately got to work. Rather than dump all the photos here from today's work, I will upload them to Imgur here: https://imgur.com/a/gc8uOH9
Let's just skip to the best part - the completed chassis with all components installed!
I am over the moon with how it has turned out so far!
Some of the highlights from the build.
The beautiful chassis panel.
Installing the copper mesh (2 layers) on the chassis:
This was done easily with hotglue - just lay down a dab and then press the mesh onto it. The hot glue will permeate the mesh and lock it into place. Very easy to get it nicely tensioned this way.
Capacitor installation using 3D printed mounts:
Hot glue used to lock the capacitor into place once aligned with the grilles. Also added some blobs of hot glue as strain relief for the capacitor terminals as they will make some sharp angles.
These little swiches took about 30 minutes to install, because I had to be very careful not to scratch up the chassis or the small decorative ring around the switch:
And finally, the underside of the chassis with all the nylon standoffs installed for the point-to-point wiring (heavily inspired by Decware building style):
Some other random building details:
- #4-40 bolts and nuts were used to install all the components except for the power transformer
- #10-32 bolts/nuts used to install the power transformer
- Nylon standoffs are 1 inch tall, #4-40 threaded
I'll be out of town the rest of this week, so unfortunately I won't be able to start the wiring until next week, but I'm so happy with how it is turning out so far.
Attachments
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That chassis is sleek! Love the copper mesh grills and overall balance of the top plate.A very very exciting day today!
Earlier today the chassis panels arrived from Xometry. And my goodness, they look FANTASTIC! The powder coat finish is exactly what I wanted, with a rough-ish surface and somewhat raised grain.
I couldn't resist and immediately got to work. Rather than dump all the photos here from today's work, I will upload them to Imgur here: https://imgur.com/a/gc8uOH9
Let's just skip to the best part - the completed chassis with all components installed!
I am over the moon with how it has turned out so far!
Some of the highlights from the build.
The beautiful chassis panel.
Installing the copper mesh (2 layers) on the chassis:
This was done easily with hotglue - just lay down a dab and then press the mesh onto it. The hot glue will permeate the mesh and lock it into place. Very easy to get it nicely tensioned this way.
Capacitor installation using 3D printed mounts:
Hot glue used to lock the capacitor into place once aligned with the grilles. Also added some blobs of hot glue as strain relief for the capacitor terminals as they will make some sharp angles.
These little swiches took about 30 minutes to install, because I had to be very careful not to scratch up the chassis or the small decorative ring around the switch:
And finally, the underside of the chassis with all the nylon standoffs installed for the point-to-point wiring (heavily inspired by Decware building style):
Some other random building details:
- #4-40 bolts and nuts were used to install all the components except for the power transformer
- #10-32 bolts/nuts used to install the power transformer
- Nylon standoffs are 1 inch tall, #4-40 threaded
I'll be out of town the rest of this week, so unfortunately I won't be able to start the wiring until next week, but I'm so happy with how it is turning out so far.
funch
Headphoneus Supremus
Looking spectacular. Very well thought out.
Thank you, Funch! Could not have done it without all your help
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Well I’m glad you asked! Today's update - WOOD!
Over the weekend I went home to see my family and build some bases for my DIY amps. I went to the woodcrafting store and picked out some dimensional lumber in Walnut and Patagonia Rosewood.
With help from one of my siblings, we built some boxes over the weekend. I'm not much of a woodworker (in fact this is my first woodworking project), so figuring out how to use a jointer and planer and making miter cuts was a great experience.
Anyways, here are some pics of the final results! I'm very very happy with how they turned out, especially the Patagonia Rosewood
Only thing left to do is add a coat of paste wax after the Danish Oil cures, and attach some feet. The paste wax should add a little bit more shine, and protection.
Over the weekend I went home to see my family and build some bases for my DIY amps. I went to the woodcrafting store and picked out some dimensional lumber in Walnut and Patagonia Rosewood.
With help from one of my siblings, we built some boxes over the weekend. I'm not much of a woodworker (in fact this is my first woodworking project), so figuring out how to use a jointer and planer and making miter cuts was a great experience.
Anyways, here are some pics of the final results! I'm very very happy with how they turned out, especially the Patagonia Rosewood
Only thing left to do is add a coat of paste wax after the Danish Oil cures, and attach some feet. The paste wax should add a little bit more shine, and protection.
Attachments
That looks amazing. Craftsmanship at ist finest! Congrats on the new Wood-worker skills.
Finished up the power supply wiring today! The power supply is quite beefy, and uses a total of 20 capacitors!
Now to get started on the amplifier circuitry wiring, which I will probably finish over the next week or so. Goal is to have this amp done in time for CanJam NYC so I can bring it!
And a couple of beauty shots of the amplifier sitting on the rosewood base:
Unfortunately there is a very small scratch on the chassis
Next amp I build I am covering the entire chassis face with painters tape....
Now to get started on the amplifier circuitry wiring, which I will probably finish over the next week or so. Goal is to have this amp done in time for CanJam NYC so I can bring it!
And a couple of beauty shots of the amplifier sitting on the rosewood base:
Unfortunately there is a very small scratch on the chassis
Next amp I build I am covering the entire chassis face with painters tape....
Keep them coming!
I finished the amp up a couple weeks ago! It sounds fantastic and I've been loving it so far.
In comparison to the ZMF OTL, I noticed it has more clarity, probably thanks to the Mundorf capacitors on the output. It also has excellent bass/texture, dynamics, detail retrieval, and plenty of power for dynamic driver headphones. Overall, I'm thrilled with it!
The tube roll I have enjoyed the most is 0A3 for all voltage regulators, 5u4G on the rectifier, G73-R on input, and 5687 power tubes.
Here is a pic of the (almost) finalized internals:
And a beauty shot of the amplifier on my desk where it will live:
There is a faint hum, most likely from a ground loop somewhere in the amplifier that I have not quite tracked down yet. I've tried increasing capacitance of the first filter cap in the power supply, but that did not seem to affect the hum, leading me to believe it is a ground loop.
So there are a couple things left to do:
------
Overall, I am extremely happy with how this project turned out, performance and aesthetic-wise. My next projects going forward will probably feature the same design style for its simplicity. Besides, I hate cutting metal so I try to avoid cutting holes in chassis myself as much as possible.
So what is next? I've got a few ideas tumbling around:
Not quite sure I have the time/knowledge quite yet to dive straight into a fully DIY build. I might push that off for now. I think the switch box is the most likely next project. I love my Freya S, but I want something that is truly transparent, so a switch box is the way to go.
In comparison to the ZMF OTL, I noticed it has more clarity, probably thanks to the Mundorf capacitors on the output. It also has excellent bass/texture, dynamics, detail retrieval, and plenty of power for dynamic driver headphones. Overall, I'm thrilled with it!
The tube roll I have enjoyed the most is 0A3 for all voltage regulators, 5u4G on the rectifier, G73-R on input, and 5687 power tubes.
Here is a pic of the (almost) finalized internals:
And a beauty shot of the amplifier on my desk where it will live:
There is a faint hum, most likely from a ground loop somewhere in the amplifier that I have not quite tracked down yet. I've tried increasing capacitance of the first filter cap in the power supply, but that did not seem to affect the hum, leading me to believe it is a ground loop.
So there are a couple things left to do:
- Swap the plate load resistors on the input tube to Allen Bradley carbon comps
- Try and track down the faint ground loop hum that is driving me insane
- Add in a toggle-able negative feedback loop
- Add in the circuitry for hi/lo gain
------
Overall, I am extremely happy with how this project turned out, performance and aesthetic-wise. My next projects going forward will probably feature the same design style for its simplicity. Besides, I hate cutting metal so I try to avoid cutting holes in chassis myself as much as possible.
So what is next? I've got a few ideas tumbling around:
- A input/output switch box to replace my Freya S
- A 300B OTL (since I am thinking about selling my Envy, but I do love the 300B sound)
- A true, fully self-designed amplifier
Not quite sure I have the time/knowledge quite yet to dive straight into a fully DIY build. I might push that off for now. I think the switch box is the most likely next project. I love my Freya S, but I want something that is truly transparent, so a switch box is the way to go.
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Hey, any updates? Curious what kind of progress you had at eliminating the hum
Hey all!
Got a couple updates. I've been working to track down this infuriating hum in the amplifier, and I could use input from the other DIY gurus on here. @g0ldl10n, @funch, @L0rdGwyn, hope ya'll don't mind me pinging you guys.
So from what I can tell, it is a 60hz hum, and I initially suspected a ground loop because the hum intensity is constant regardless of the amplifier volume. I am convinced it is not a 120hz hum from insufficient filtering by the power supply because it does not change intensity with increasing/decreasing the first filter cap in the power supply.
The hum is equal in both channels.
Things I have tried without any improvement in the hum:
Here is a drawing showing the grounding schema:
(The ground loop breaker cap is actually a film cap, I drew it wrong).
I am starting to suspect the power transformer may be at fault. I am using a Hammond 272FX. I am looking at the Lundahl LL1683 as a replacement.
My other ideas for addressing the hum are to add a high/lo gain switch on the headphone output, and to negative feedback on a toggle switch. There is no hum with lower sensitivity cans.
Could use any and all help, at this point I am out of ideas! Pics of the amp internals are attached for reference.
Got a couple updates. I've been working to track down this infuriating hum in the amplifier, and I could use input from the other DIY gurus on here. @g0ldl10n, @funch, @L0rdGwyn, hope ya'll don't mind me pinging you guys.
So from what I can tell, it is a 60hz hum, and I initially suspected a ground loop because the hum intensity is constant regardless of the amplifier volume. I am convinced it is not a 120hz hum from insufficient filtering by the power supply because it does not change intensity with increasing/decreasing the first filter cap in the power supply.
The hum is equal in both channels.
Things I have tried without any improvement in the hum:
- Using a star-of-stars grounding scheme, which carefully separates the signal grounds grounds, power grounds, and cathode grounds, and all meet at the chassis star
- Using a ground loop breaker circuit
- Increasing capacitance of first filter cap in the power supply (it is currently 8uF)
- Grounding the shielding of the Mogwai input signal wires from the RCA sockets only at the RCA socket (which is then tied to the signal ground)
- Plugged the amp into different electrical circuits in my apartment
Here is a drawing showing the grounding schema:
(The ground loop breaker cap is actually a film cap, I drew it wrong).
I am starting to suspect the power transformer may be at fault. I am using a Hammond 272FX. I am looking at the Lundahl LL1683 as a replacement.
My other ideas for addressing the hum are to add a high/lo gain switch on the headphone output, and to negative feedback on a toggle switch. There is no hum with lower sensitivity cans.
Could use any and all help, at this point I am out of ideas! Pics of the amp internals are attached for reference.
Attachments
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