L'Amp: A simple SIT Amp

[vdi_nenna]

I'm sure it's very fine.

 

[Dzius]

Are there any other suggestions for operating point for 8ohm load other than below?

Juanitox wrote:
"1.6amp 19V with inductor
or at 14V 2.4amp with res load"

Michael Rothacher wrote:
"19-20V across the SIT @ 1.55-1.6A " - IXTH6N50D2 Constant Current Source

 

[juanitox]

i have made some test with a 10ohm reosthat bypassed with a 47000uf
and looking at the loadline it's difficult to find a bad operating points .. or the best one if you don't have a distorsion analyzer .. at this time i run mine at 16V 2.13A with a 1.8R source resistance and 47000uf bypass.

 

[bluewater]

Is there a simple diy preamplifier that could drive the L'Amp?

 

[vdi_nenna]

BOZ-J drives my SIT-CCS L'amp. Mike Rothacher is coming out with a companion preamp for the L'amp, but that preamp might be a few months out.
See his site for more info.

 

[bluewater]

I'll look into that. Thank you

 

[OlavHaal]

Pre-amp for LÀmp...

Hi Bluewater!

I run mine LÀmp with the Passive B1 - and now that my Alp12P is finished - the soundpressure and revelation from the sources is magnificent. Really enough for my 35sq-meter room.

Best

Olav

 

[bluewater]

Hi Olav,
I do have the B1 but I unfortunately only a 2v source. I do plan on bi-amping my BassZillas with two paralleled B1's. With little gain from L'Amp I think it would be good to give the source output a boost.

Eric

 

[OlavHaal]

Hi Eric

Earlier I used my B1 with the LÀmp - and the Alp10.2(which is about 89 db). The source was then the DirectDac(SC4398) which gives about 1,75 volt output!
on some recordings it could be somewhat low output - but mostly very good. Today I have the Alp12P - and I have installed Sowthers on the balanced output on the Dac(so it should give approximately 2,5 Volt output). The same configuration on the LÀmp and....
So today it very good and strong output!

Best

Olav

 

[bluewater]

Hi Olav,
I'll definitely give it a try with the B1 alone. I've just about collected all the parts for my L'Amp. I'm going almost exactly by Michaels Inductor version. I'm only waiting for Antek to make the AS-4428 available. They said some time in mid April.
Eric

 

[Garuda77]

Hi,

Does anyone know what the input impedence of L'amp is? or if it can be varied? I would like to use Lightspeed attenuator in respect of which it is sugested amp has 80kohm or higher impedence.

Thanks Terry

 

[Zen Mod]

put Jfet buffer in between

L' is having input imp. well bellow R1 ( 47K) and it's too much varying for Lightspeed

 

[juanitox]

i use ldr ( Warpspeed) as passive preamp before the SIT with 27K input and it sounds fine..
but for me the magic comes with a tube stage /LDR combo driving the Sit

 

[DIYspaceW]

Guys, If we would need to design a plate choke specialy made
for 2SK82 what would be the guide lines?
We need usually for 100ohm plate resistance 1H inductance,
so we only need 0.1H here or am I missing something?
The hammond filter choke 193V has 0,3H but is not designed for plate reactor.
Any thoughts?

 

[Zen Mod]

even if for toob , it can be useful :

http://vt52.com/diy/tips/platechoke.xls

VT52.com

 

[woody]

A quick look at an air core inductor calculator shows ~ 7lbs of #16 magnet wire will
let you have over 100mh of inductance with a resistance of about 3.84 ohms. If you play with the dimensions you can use even less wire but as i said that was just a quick look.

 

[DIYspaceW]

Ok...

 

[juanitox]

is going parafeed output with the SITAMP will work ? let say we use 130mh
hammond choke what kind of transformer could do the job as parafeed load ?

 

[DIYspaceW]

I am working on a SIT parafeed...It sounds nice, I mean the words...SIT PARAFEED
You wont find a 20-30ohm primary and 10-15W output transformer to use as a parafeed.

I will use higher voltages to be able to use a 50ohm output transformer.
This is an expensive project so far, but will see how it performs. Its an experiment...

 

[flg]

I am working on a SIT parafeed...It sounds nice, I mean the words...SIT PARAFEED
You wont find a 20-30ohm primary and 10-15W output transformer to use as a parafeed.

I will use higher voltages to be able to use a 50ohm output transformer.
This is an expensive project so far, but will see how it performs. Its an experiment...

Have you talked with these guy's???
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