That was some very delightful news that I received in the wee hours of the morning as I was up for a midnight snack. Many thanks to Nelson, the tireless crew at diyAudio, and some dedicated aluminum smiths at Modushop for making this possible. Now my excitement for the opportunity to build a special amp is changing to anticipation of receiving the kit and beginning the build process.
I'm starting this thread for all the lucky builders who wish to share their process, ask questions and suggest new things to try out. I look forward to reading 6L6's illustrated build guide and plan to document my construction of Papa's version of the amp, plus what I expect to be some wonderful alternate boards that have already been suggested by Mark Johnson and a couple others so far. I may have an idea or two of my own to share as well, possibly just so others can avoid the errors of my ways.
UPDATE: 6L6's build guide is now live
I'm starting this thread for all the lucky builders who wish to share their process, ask questions and suggest new things to try out. I look forward to reading 6L6's illustrated build guide and plan to document my construction of Papa's version of the amp, plus what I expect to be some wonderful alternate boards that have already been suggested by Mark Johnson and a couple others so far. I may have an idea or two of my own to share as well, possibly just so others can avoid the errors of my ways.
UPDATE: 6L6's build guide is now live
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Once we have built and appreciated Nelson's latest creation in unadulterated form, I'm sure there will be some who wish to tweak it in ways to make it their own. This is DIY after all...
Here are a couple links that may be useful:
Scourge, Bulwark, Marauder, Dreadnought front end cards for DIY VFET amp
DKRed
Here are a couple links that may be useful:
Scourge, Bulwark, Marauder, Dreadnought front end cards for DIY VFET amp
DKRed
Woohoo, I lucked out and snagged a unit!
Tough decision now to figure out which front end to pair it with... much reading to do.
There are two things I can think of right away that I'll want to do for this build:
1. passive filter board for the Meanwell SMPS. Just a simple CLC to clean up the high frequency switching residual. Unless a suitable PCB already exists, I think I'll whip something up in KiCAD and have it fabbed - willing to order boards for others if they'd like in.
2. I've become rather fond of Neutrik SpeakOn connectors - they're not exactly platinum-plated bling (although still pretty good looking in my book), but most importantly they perform very well electrically, have great insulation / safety shrouding, are ludicrously affordable, and a dream to actually use in practice. Highly underrated speaker connectors, IMHO... solid engineering, no snake oil. I've been using them on all my amp & speaker projects. So, I think I'll be drilling some extra holes on the rear panel to mount a pair in parallel with the traditional binding posts.
Tough decision now to figure out which front end to pair it with... much reading to do.
There are two things I can think of right away that I'll want to do for this build:
1. passive filter board for the Meanwell SMPS. Just a simple CLC to clean up the high frequency switching residual. Unless a suitable PCB already exists, I think I'll whip something up in KiCAD and have it fabbed - willing to order boards for others if they'd like in.
2. I've become rather fond of Neutrik SpeakOn connectors - they're not exactly platinum-plated bling (although still pretty good looking in my book), but most importantly they perform very well electrically, have great insulation / safety shrouding, are ludicrously affordable, and a dream to actually use in practice. Highly underrated speaker connectors, IMHO... solid engineering, no snake oil. I've been using them on all my amp & speaker projects. So, I think I'll be drilling some extra holes on the rear panel to mount a pair in parallel with the traditional binding posts.
I used a Neutrik SpeakOn connector for the SMPS connection when I build ACA.
I have a 24mm bi-metal holesaw bit to drill those holes for the chassis connector.
It could be nice to build it as a "dual mono" construction. A SMPS for each channel and two SMPS filters.....that should be possible?
I have a 24mm bi-metal holesaw bit to drill those holes for the chassis connector.
It could be nice to build it as a "dual mono" construction. A SMPS for each channel and two SMPS filters.....that should be possible?
This is going to be fun. Another thing you will find in the “front ends” link I posted is a more extensive filter for the incoming DC from the SMPS, also designed by Mark Johnson. I will probably try using two of these in my Sony VFET, one for each channel to give a quasi dual-mono configuration for the power supply. The next step would be fully independent power supplies for each channel.
Here is the higher current SMPS filter from Mark Johnson:
DIY Sony VFET pt 1
I forgot where I saw it originally
DIY Sony VFET pt 1
I forgot where I saw it originally
That’s correct. The SMPS filter is designed specifically to remove high frequency switching noise from the DC power. It would be ineffective at removing ripple from a conventional linear PS. Having said that, it wouldn’t hurt to leave it in place either.
I think that a well built PSU with a FW style CRC filter could perform quite well if constructed in a separate chassis. Even better if separate secondary windings, rectifiers and CRC filters are used for each channel. This is based on experience with my modified ACA builds, where I used a larger chassis from a donor Hafler DH-220 amplifier to house a linear PSU. However, a different style DC power inlet connector would probably be necessary to support the dual mono configuration with an external PSU. Since we don’t know which Meanwell SMPS is being used yet, we will need to wait and see when the kits arrive.
I intend to spend a lot of time listening to the amp with its kit SMPS before I start making changes.
Hi everyone,
I am so excited to be a part of this, and it is great to see that we already have a builders thread.
After reading the 2013 article and a few of the newer articles about the Sony VFET by Nelson, I am left with a (perhaps stupid) question.
Is this amplifier a current source amplifier similar to the Firstwatt F1/F2, or a more conventional amp? I am happy either way, as my speakers are single driver, full-range transmission lines. I just want to take this opportunity to learn as much as possible, and the constant current source in the circuit made me wonder.
A huge thanks to Nelson, Jason and the rest of the team for making this happen.
I am so excited to be a part of this, and it is great to see that we already have a builders thread.
After reading the 2013 article and a few of the newer articles about the Sony VFET by Nelson, I am left with a (perhaps stupid) question.
Is this amplifier a current source amplifier similar to the Firstwatt F1/F2, or a more conventional amp? I am happy either way, as my speakers are single driver, full-range transmission lines. I just want to take this opportunity to learn as much as possible, and the constant current source in the circuit made me wonder.
A huge thanks to Nelson, Jason and the rest of the team for making this happen.
Maybe I want to use those (picture) heatsinks for VFet (approx 60W dissipation per channel) and they should be sufficient when installed properly (fins vertically).
But i want to use them with fins horizontally. Does anybody has experience how much efficiency I will loose. I mean, no numbers needed, but maybe experience from a former build or so...
Heatsink is 300mm x 170mm
tnx, stefan
But i want to use them with fins horizontally. Does anybody has experience how much efficiency I will loose. I mean, no numbers needed, but maybe experience from a former build or so...
Heatsink is 300mm x 170mm
tnx, stefan
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