Thanks Vunce, fun is guaranteed😀 But I need a forklift for that piece 😵Great looking beefy inductor Plott!
I’ll be looking forward to your progress updates. Enjoy
I hear Ya!!
2 MOT’s, 600va trafo and a large chassis with 3mm steel base plate for my LuFo. Not quite forklift territory, but maybe a pallet jack to move mine around 😂
2 MOT’s, 600va trafo and a large chassis with 3mm steel base plate for my LuFo. Not quite forklift territory, but maybe a pallet jack to move mine around 😂
As I have been listening to my VFET amp with some of the new FE cards by Mark J., it occurs to me that the Dreadnought and Marauder designs would be worth trying. They both can handle 60V power (single-ended one way or another), and will swing enough output voltage to drive this amp to full power.
They happen to include on-board DC-DC converters, and may be Ok running of the main 28V rail. Otherwise, there are several other DC-DC converter solutions available..
They happen to include on-board DC-DC converters, and may be Ok running of the main 28V rail. Otherwise, there are several other DC-DC converter solutions available..
Hi TA,
Please do take those MJ front end designs for a spin with LuFo. I am sure they would work out fine. We have been having a heck of a time finding DCDC converter chips that are not getting hit with the global parts shortage. 60v single rail should be more than enough.
Please do take those MJ front end designs for a spin with LuFo. I am sure they would work out fine. We have been having a heck of a time finding DCDC converter chips that are not getting hit with the global parts shortage. 60v single rail should be more than enough.
If you are looking for LD1014 (LU1014) parts, I have a bunch available here:
https://www.diyaudio.com/community/threads/ld1014d-lu1014d-matched-by-vgs-and-curve-tracing.381338/
https://www.diyaudio.com/community/threads/ld1014d-lu1014d-matched-by-vgs-and-curve-tracing.381338/
Hi,
I have now started my project, after receiving the PCBs from X.
I have sent my order to Mouser - with the exception of the Nichicon audio electrolytics and the Mundorf silver gold oil capacitors, which are not available 🤔
The hunt for the missing components begins 😀
I have now started my project, after receiving the PCBs from X.
I have sent my order to Mouser - with the exception of the Nichicon audio electrolytics and the Mundorf silver gold oil capacitors, which are not available 🤔
The hunt for the missing components begins 😀
Good you did not buy the Mundorf fairy-**** caps, they are not worth the money. Just use some no-nonsense MKP caps. The standard Mundorfs are fine, and Mouser has many more, whiich will not cost an arm and a leg. Once you have the amps up and running put a temporary jumper across the input DC blocking caps (if your source has no DC). I am pretty sure your ears will not be able to tell the difference without the help of your eyes telling your brain if the jumper is in place or not.
I have no experience with electrolytics in the audio path. I believe I read a post by Nelson Path somewhere, sometime... maybe you can find his comments.
I received my LuFo boards yesterday, and am looking forward to building a new amp with these.
I have been working with output capacitor coupled amps for a few years, beginning with the original ACA and most recently with the DIYA (lottery) VFET amp. I haven't found electrolytics in the audio path to necessarily be an issue. I do take care in selecting which types are used, and frequently use two or more in parallel with each other to achieve a tonal balance.
Starting with the ACA, I found that the Nichicon LKG series sound good. They are designed for audio use. One will notice that the pictures of the LuFo amp show big Nichicon electrolytic caps with gold lettering. These are examples of the LKG series. I recently ordered a few of the Nichicon LKS series for the next couple amps in the queue. These are compact, high quality Type-1 versions of the LKG series.
https://www.mouser.com/ProductDetail/647-LKS1K103MESCThe big electrolytics that are included with the VFET amp kits are these. Papa seems to like them, and I do as well:
https://www.digikey.com/en/products...5438?s=N4IgTCBcDaIIxwBwE4C0YDsBmNA5AIiALoC+QA
Beyond the big electrolytics, there are a few film caps that are used in the new VFET amps and their various front ends cards.
These polypropylene caps are used in several places in the new VFET amp front end cards. They sound quite good in signal coupling applications:
https://www.mouser.com/ProductDetail/80-F461BY225K160LHere are the 0.33 uF capacitors used in both the input and output stages of the latest VFET amps. The VFET output stage boards use one of these in parallel with the big Rubycon electrolytics:
https://www.mouser.com/ProductDetail/505-MKP20.33-100-5
I have been working with output capacitor coupled amps for a few years, beginning with the original ACA and most recently with the DIYA (lottery) VFET amp. I haven't found electrolytics in the audio path to necessarily be an issue. I do take care in selecting which types are used, and frequently use two or more in parallel with each other to achieve a tonal balance.
Starting with the ACA, I found that the Nichicon LKG series sound good. They are designed for audio use. One will notice that the pictures of the LuFo amp show big Nichicon electrolytic caps with gold lettering. These are examples of the LKG series. I recently ordered a few of the Nichicon LKS series for the next couple amps in the queue. These are compact, high quality Type-1 versions of the LKG series.
https://www.mouser.com/ProductDetail/647-LKS1K103MESCThe big electrolytics that are included with the VFET amp kits are these. Papa seems to like them, and I do as well:
https://www.digikey.com/en/products...5438?s=N4IgTCBcDaIIxwBwE4C0YDsBmNA5AIiALoC+QA
Beyond the big electrolytics, there are a few film caps that are used in the new VFET amps and their various front ends cards.
These polypropylene caps are used in several places in the new VFET amp front end cards. They sound quite good in signal coupling applications:
https://www.mouser.com/ProductDetail/80-F461BY225K160LHere are the 0.33 uF capacitors used in both the input and output stages of the latest VFET amps. The VFET output stage boards use one of these in parallel with the big Rubycon electrolytics:
https://www.mouser.com/ProductDetail/505-MKP20.33-100-5
A good speaker crossover MKP cap around 2.2uF bypass on a good electrolytic is all you need. The Nichicon’s with black lettering do sound very good. I have had good luck with Panasonic FR series too. They are not designed for “audio” but have a nice sound.
There are 2 R121 on the board,is it where the unpopulated R121 the 0 ohms "resistor" should be?
Hi X,
is there any specific recommendation for the PSU? I'm planning to build 2 monoblocks, with a 200w donut, a rectifier with 10A (because I have 5 pieces), and big electrolytics, so about 68.000-100.000 uF, per monoblock. Would it be okay? A thermistor, maybe?
is there any specific recommendation for the PSU? I'm planning to build 2 monoblocks, with a 200w donut, a rectifier with 10A (because I have 5 pieces), and big electrolytics, so about 68.000-100.000 uF, per monoblock. Would it be okay? A thermistor, maybe?
On LuFo I would recommend a cap multiplier to reduce ripple. On SuSyLu it’s balanced so good PSRR and only CRCRC needed. I used my own CRC cap Mx board for the LuFo and that worked well. It does impose a 3v drop in the rail voltage so keep that in mind when sizing transformers.
You can try CRCRC with a high ripple current high ESR 105C rated 15,000uF cap on first C. Use 22,000 on the others. So that’s about 59,000uF total per amp. About 0.1ohm 5W resistors. First cap gets hit with a lot of ripple at 3A current so gets hot.
You can try CRCRC with a high ripple current high ESR 105C rated 15,000uF cap on first C. Use 22,000 on the others. So that’s about 59,000uF total per amp. About 0.1ohm 5W resistors. First cap gets hit with a lot of ripple at 3A current so gets hot.