L'Amp: A simple SIT Amp

Anyone wondering.......

Thanks Michael, Generg, Juanitox, Nicoch58 AND Nelson for inspiration!:):):)

Tomorrow going to my offshore-schedule! BUT today there for the first time was (and is) sound through this little beast; and what a sound. So fullbody and rich in tonal spectrum. Did not expect that it would be so much better than my ClassDaudio amplifier - but it really shines and fills the room. I have to turn my B1 up to about 40 % to keep the same level as on the ClassD(but that was expected).

I have a couple of unfinished issues still(the big hole you see, as this was originally boxes intended for 3liter wine, that I rebuilt to fit.)

But for now - perfect. May try some other solutions later, but with 12,5 ohm filmresistor and 400 watt on them - and 400 watt/2x35 volt ACtrafo on each monoblock, there is nothing missing. :D:D:D
For the moment......

Best to all and thanks to all!!!

Olav
 

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Olav, thanks for sharing your pictures and description of its sound. We need more of that around here! You guys are too humble! :)

Looks very nice. Has plenty of air flow, but deosn't take away from the look. It adds to it! You also have a nice spot ready for a meter!
Do the heat sinks get hot?

Thanks,

Vince
 
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Still missing some parts to start building my SIT, I was thinking to try the following output changes. Can we avoid the mid and Super tweet caps if I change the signal polarity trough my pre and connect SIT (-) to (+) of my passive crossover caps (SIT for mid and Stweet only, F5 for the woofer)?
Thanks
 

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Just a short...

Hi Vdi_Nenna!

Yeah - get somewhat hot after 1 hour of playing Bruce Sprinsteens - The goast of tom joad. The harmonica is such that you can feel it is in the room - never heard anything so close to live-music from a amplifier before.

I have some special heat-sink(for the SIT and some of the other resistors inside. The heat on top hasn`t gotten over 28 deg Celcius - on top of the enclosure. But I must try to measure inside when I return home 1 of june.
And maybe move the SIT to a heat-sink on the back. That will give me better space inside. It got really STUFFED inside. Had a plan about keeping it tidy - but you loose when have a fixed box and have to build according to those confined area.

So maybe I will change some later......

Have only 2 hours w/music - and toworrow my copter leaves at 1400 hour - sorry am I...

Best to all - and grateful for all your suggestions!

Olav
 
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Still missing some parts to start building my SIT, I was thinking to try the following output changes. Can we avoid the mid and Super tweet caps if I change the signal polarity trough my pre and connect SIT (-) to (+) of my passive crossover caps (SIT for mid and Stweet only, F5 for the woofer)?
Thanks

there is no need for changing polarity , except on speaker cables - and only in case of chasing perfect polarity

schm is good - each driver having dedicated cap
 
Many Thanks Nicoch58

Olav , nice work ! :cheers:


At last- All is well - amp playing Ryan Adams-Ashes and Fire - and it is everyway as good as you all said - if my ClassD sounded good - this amp is revealing the music in a total honest way!

But i used Obligatos 10uf as input capacitors and some really good resistors. The only thing I could have used instead of Caddock FilmCaps was Vishay FilmCaps. But I don`t think that will matter much.

So now I have my B1 with two transistors in ClassA - and my L`Res with ONE transistor to give such honest sound. Less is More
:cool:

Hope to get a couple more hours playingtime before my copter leaves(will need 3 hours bus also)

Best to all

Olav
 
some wrong info...

Hi again all!

I said in my last post - The only thing I could have used instead of Caddock FilmCaps was Vishay FilmCaps. But I don`t think that will matter much. - But the words that was intended was Caddock FilmResistors and Vishay FilmResistors.
But I guess everyone knew what I was talking about!:eek:

Sorry for my mis-spelling.

Have a nice building-experience eveyone.

Olav
 
Would using the large cap, and not an inductor after it, indicate you intend to use the natural roll-off of the woofer?

For the woofer I am gonna use my F5 and SIT for mid - S.tweet!
I gonna also try to drive the woofer with Sit and as I said I use a passive crossover after the SIT caps, my crossover use caps for the mid and tweet so there I can avoid the Sit's caps by connecting the (-)SIT to (+) crossover, the woofer still use the inductor after the Sit cap.

Thanks Zen
 
Hi Michael and tnx...

Yes - at last SOUND - and tonally rich and involving. But I`m out at sea without music for 2 week now - time to plan the last few fixès on my mono`s.

And maybe think about a chocke(but there is not much space available inside for the moment. Have to do something if and when......

For the moment - your ideas have blossomed in many different directions Michael - and in such nice ways!!


Best to all - from the NorthSea.

Olav