Lottery DIY Sony VFET pt 2 (N-Channel) - assembly by Mighty ZM

[rolandong]

Thinking to use this to mitigate thermal issues for long-term listening pleasure with this jewel.

 

[Zen Mod]

use just one - lower L , mosfet pins are not long enough for doubled thickness

elongating is more important than increased area, per se

so you'll be good

 

[Zen Mod]

of course , M4 screws of proper quality, split washers

proper quality means either quality mark on them (5.6 enough, 8.8 more than enough) , or buy Stainless Steel ones

everything to avoid mass produced cheese hardness

for that length, 4 groups of 2 screws

easiest to shoot between fins, so you can drill through hole and tap more safely

or use Allen head screws from out (maybe some shaving is needed to squeeze them between fins), nuts inside

put some thermal goop between L bar and heatsink

 

[rolandong]

Thanks ZM for advise.
Screws nowadays mostly bad quality specially if you tighten them will easily tear.
Shows many times metals nowadays have been recycled.
I'm also looking at 4 group of 2 stainless screws in between fins.
Like most of your build, I also like to DIY my chassis where possible.

 

[myleftear]

Same here!
(And Mark gave us further reason not to let it rest on the shelve 🙂)

 

[tunasto]

This little jewel come to me.
First BIG Thank You, to all responsible people for this amp, Nelson Pass, DiyAudio crew and Zen Mod.

Without Zen Mod's help this amp would stay in pieces for a long time as my life is in the fifth gear at the moment.

About sound....This amp is sooo pleasure to listen to, so relaxing with all necessary details.

--- Proud owner 🙂

P.S.
Delayed on/off circuit works perfectly.

 

[Zen Mod]

 

[samoloko]

Still on back side of amp

Mean Well switcher PSU is of good quality, but I don't like flimsiness of DC connector, neither male nor female one

Good ole 5-pin XLR is certainly better; I would like Calt Stecker being on cable, Heiss Stecker being on amp, but didn't had Heiss one ....... anyway , I did stay with original topology - Heiss Stecker on cable

superblingy drill and edge reamer, no need to be overly precise, XLR is covering all

I didn't even hop to my vertical drill, done it with hand-accu one

useful tip for soldering pin-equipped connectors - always mary male one with female one - no bending of pins in plastic, due to heat

Would you please point out name of both power Input plugs - chassis and cable

 

[Zen Mod]

regular 5-pin XLR pair, this one made by Neutrik, I believe

though, even better to use Powercon or Speakon pair

also, there is avalanche of so called Aviation connectors

plenty of choices ..... indulge yourself with choice, if you need to order them

I had these in drawer, lazy to wait to get even more appropriate ones

 

[Rewind]

Isn’t XLR for line level signals only?

 

[Rewind]

Delayed on/off circuit works perfectly.

Which delayed circuit did you use?

 

[Zen Mod]

Isn’t XLR for line level signals only?

if pins and their contact is sufficient for duty I gave them, why should I care for original designation?

Which delayed circuit did you use?

try reading thread from first post ......... I did invest some elbow time to present everything

 

[Benjisan]

Still in mechanical realm, sort of

Again post-Pa dealing gone wrong - Pa did arrange 2 pole switch, while hole on back side is for one pole, one pole in kit;

Hi Zen,

What's the advantage of modifying your chassis for using a two-pole on/off switch as opposed to a single-pole switch the chassis was designed for?

 

[Zen Mod]

re-read first post - delay circuit (AntiBigBadaBoom) - as Papa designed it (or as my derivative) is impossible with single pole switch

having small hole and single section switch is result of miscommunication in project Team ..... but we can't blame them, everyone involved is doing it Pro Bono

 

[naz]

Wouldn't this switch work without modification to the chassis?

PN = GRS-4021-0001​

 

[Zen Mod]

it seems existing hole dimensions, so yes

though, if you like flimsy components

for my OCD, it's trigger

 

[ranshdow]

solving thermal issues; see pics, pretty much self-explanatory

whoever did arrange with Modushop guys assembly with M3 screws is not having enough mileage with all things mechanical/thermal; not blaming a guy at all, I know that this wasn't operation made by professionals and outcome is still extraordinary

that's exact reason why I'm posting this, to help Greedy Boyz in proper finishing and to feed my own OCD

fact is -these 4pcs of M3 screws needed to be M4 and additional 2pcs of M4 are necessary

only that way , with lapped T Bar, there is enough squeezing force at disposal to get rid of air gap between T Bar and heatsink

ZM, did you use any loctite or thread fastening compound on the threaded studs, where they enter the heat sink, or on the bolts used to fasten the heat spreader to the heat sink? Any reason not to?

 

[Zen Mod]

feel free to use it, even if there is no reason to use it at all, considering that I insist on using split washer (or any other variation of same) wherever thermal cycling is in case

 

[ranshdow]

feel free to use it, even if there is no reason to use it at all, considering that I insist on using split washer (or any other variation of same) wherever thermal cycling is in case

The primary purpose here is to help anchor the studs in the heat sink. I'm a little concerned that the M4 threads I tapped are too loose to hold a stud properly, hence I want to try a thread locking compound to hold the studs in place. I still plan to use a star or split washer setup to compress the T-bracket to the sink.

 

[Zen Mod]

if tapping is so fluffy, locking compound is not going to help, maybe just hardest - gluing iteration of Loctite

if in doubt, repeat tapping

if nothing else, more holes are allowing more air