The Bug is back

[majex45]

I was somewhat involved with CVD heat spreaders back in the day. I once held a diamond about 3 inches in diameter by about an eigth inch thick. It felt cold as it sucked the heat from my fingers but was slightly grey and not completely transparent. We used them to spread the heat from high power solid state lasers. Ah, happy days.

[maximax]

No forced cooling for me. So are you saying that wavy profile is preferable for completely passive cooling?

Re eu taxes, yes you will probably have to pay import duties ie vat unless there is a deal to that effect, but you won’t have to pay vat at source. The standard vat rate is 23% in Poland.

[Bksabath]

I was somewhat involved with CVD heat spreaders back in the day. I once held a diamond about 3 inches in diameter by about an eigth inch thick. It felt cold as it sucked the heat from my fingers but was slightly grey and not completely transparent. We used them to spread the heat from high power solid state lasers. Ah, happy days.

I am really interested to try them I have been on to Element 6 way before they started making them for the purpose ( not on TO3 size that would be a special order) , they stole my idea
They do make a few different types and performance is fantastic not only in regard to the temperature but also mechanical the Kerafol 82/83 which as far as I know is the best interface only takes 60 Nm of pressure

As I have no alphabet after my name they were not really helpful so I have to vin the lottery so that I can make the machine to make my own

[Bksabath]

No forced cooling for me. So are you saying that wavy profile is preferable for completely passive cooling?

Cool.... seen a few pictures of the sit 3 both whit fans at bottom and fans on top, fan sucking is bad idea IMO as it is going to get hot blowing is much cooler

If you where to use the fans I have a simple circuit to share as the one on Hifidog amps

to exchange heat the surface area of the sink is probably the most important if not a really thick base plate

I am not sure which ( the 83 or the 100 ) is betterer

[Bksabath]

Re eu taxes, yes you will probably have to pay import duties ie vat unless there is a deal to that effect, but you won’t have to pay vat at source. The standard vat rate is 23% in Poland.

+ the charge that the shipping company charge to make the payment not counting the delays while your thing is held at custom (4 weeks ) + (2 weeks ) for the letter whit the 17 digits number to arrive
+ you must be polite at all time because due to the current situation they can send same one over to beat the crap out of you

But not one told you this when you voted at the referendum

[maximax]

We should stay off politics here, but since that door is currently open, may I casually remark that it sounds very much like you voted for the wrong cause in 2016, no excuses. The money behind leave just wanted to get rid of eu style consumer protection, so more £££ for them.

Anyhow, amplifiers... the sit-3x project is not looking good, the guy behind it appears to be shifting towards a non-sit implementation because his two channels measure and sound different and he can’t make sense of it I believe. No criticism, he did rather well so far, and the 2sk182 is maybe not the best known quality. Maybe it’ll be the singing bush amp for me then. But no rush.

[Bksabath]

Not being politic at all They are all the same just by wanting to be voted for place them in the wrong place and wrong job

Well maybe Papa will publish his F7

It all boils down to politics even me telling you build an F5 in the mean time

[maximax]

Pass has already said that he will issue F7 kits one the Sony vfet stuff is out of the way. Output transistors are not publicly available I think but he has a large supply, unlike the vfets.

[Bksabath]

DSCF2669.jpg

Just got the transformers and plan has changed a bit
I got 28 V 800 VA units
Rail voltage is going to be around 39 V
There is going to be a fair bit of work to do


I had a couple of hours to spare

DSCF2670.jpg

so I made 2 RC filters in series 10Kr 300 nF and 10KR 500 nF
and whit bits from the loft and a roll of Duck tape


DSCF2671.jpg


I made myself a sub woofer
Quite pleased whit it so far. is it going to be the next project?

I have read that it is difficult to pair the maggies to a sub woofer

Advice is most welcome in this regards

[Bksabath]

DSCF2672.jpg

I am working on the soft start board

whit 2 800 Va transformers the surge current at power up is far to hi to safely rate the fuses

I am going to use 2 relays for each transformer the first one power the transformer trough a thermistor the second relay to bypass the thermistor

Four delay on timers will take care of the sequence

It has it's own supply from the mains whit a small block transformer