SystemD LiteAmp

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C

ChocoHolic

Member
Joined 2003
ChocoHolic said:
Or if you don't want to claculate, simply use the search function in this thread in order to get my power statements.
Click to expand...

Copied from one of my earlier posts (in bridged mode you will get the double power into double load resistance):

2x40V_IRFI4212:
This Version has been shown in very detail over the previous part of the thread.
Possible operating range: 2x25V...2x42V
Max. power at stabilized 2x42V: 400W / 2R
Power with realistically sagging supplies, idling at 2x40V:
250W/2R, 130W/4R, 70W/8R

2x80V_IRFI4020:
Slightly less audiophile than the 2x40V-version, but still better than average.
Possible operating range: 2x50V...2x84V
Max. power at stabilized 2x84V: 400W / 8R
Power with realistically sagging supplies, idling at 2x80V:
250W/8R (not suited for 4R and 2R !)

2x65V_IRFI4020:
Possible operating range: 2x40V...2x68V
Max. power at stabilized 2x68V: 500W / 4R
Power with realistically sagging supplies, idling at 2x65V:
300W/4R, 160W/8R (not suited for 2R !)
 
Reactance

Reactance

Member
Joined 2005
ChocoHolic said:
Ok. Time is mature for this step.
In this and the next post I will disclose all the open source data.
Please be aware of the following hints:
1. The design uses voltages which can cause harm or even kill humans.
Only step into this project when you have a proper knowledge about working on electronic circuits with dangerous voltages.
2. Do not misuse the amp in any manner which could harm humans.
3. There is no evidence whether the LiteAmp violates patents/IP or not. In case of commercial use please clarify this topic first.

Attached to this posting you will find the schematics, BOMs and simulations.
In the next posting (Open Source Part2) you will get the layout data and gerber files.
Click to expand...

Hey Marcus, thank you for this appreciate your work!.. your warning should be taken very seriously, at those power levels I don't think its meant for a domestic flat.
:D
 
H

Hadighorbani

Member
Joined 2010
protection

ChocoHolic said:
The layout has been done with KiCad, which is a crossplatform layout software for any of the most common operating systems and available for free.
KiCad EDA

Attached you will find the KiCad files for the LiteAmp, so you can work with my files and modify, improve or worsen them according your taste.
Besides this I am also attaching the GerberFiles of the previous group buy.
Click to expand...

Hi
please give me more information about protection on this amp.
thank you
 
C

ChocoHolic

Member
Joined 2003
Hi Hadighorbani,

the amp has about 4sec. turn on delay and does not show any plop during turning on.
Also during turning off it does not plop and also there are no sirene sounds,
no matter how slow your supply is fading off.
Over current protection is solved by the internal protections of the IRS2092.

However the design does not have a specific speaker protection for DC.
Furtheron in case you wish a thermal shut down, you will have to place your own temperature switch on the heat sink.
 
H

Hadighorbani

Member
Joined 2010
ChocoHolic said:
Hi Hadighorbani,

the amp has about 4sec. turn on delay and does not show any plop during turning on.
Also during turning off it does not plop and also there are no sirene sounds,
no matter how slow your supply is fading off.
Over current protection is solved by the internal protections of the IRS2092.

However the design does not have a specific speaker protection for DC.
Furtheron in case you wish a thermal shut down, you will have to place your own temperature switch on the heat sink.
Click to expand...

thank you
IRS2092 have an shutdown pin. this is very good.
i work with altium designer.
do you have PCB files?
not gerber
if you have good schematic for dc and thermal protection please share with me for modify your amp.
thank you
 
F

fushfush

Member
Joined 2015
Hey guys :)

I have read the whole systemD liteamp, it's a freaking awesome board.

I know its an old thread, and i'm waaay to late to get into the group-buys...
But are there any plans to open another group-buy ? :)

I got some 4 ohms speakers, which setup is the most audiophile? The liteamp 2x40V version not bridged ? :) with the gain board or not ?
And is the gain board needed if another preamp is used, fx the pre from a NAD C326BEE or another DIY preamp with sufficient gain.

My biggest request: does any of you have a enough parts for a stereo setup for the 2x40V version laying around ? :D Or name someone who might have some 'left-overs' ?
And in parts i mean those things ChocoHolic shipped with the PCB
 
C

ChocoHolic

Member
Joined 2003
;) You have detected the right point for a low risk modification in order to change the gain. The input network with its key components R10, R12, C4 are the key components for this.
Pin IN- of IRS2092 is forming almost a virtual GND, which makes handling easy - at least within a reasonable range of adjustment.
Bandwidth follows this equation: fc=(R10+R12)/(2*Pi*C4*R10*R12)
Keep fc between 40kHz and 80kHz.

Further rules...

..if you want reduce the gain:
Keep R12 & C4 unchanged. Simply increase R10.

...if you want to increase the gain:
Reduce R10 & R12, but keep ratio of R10 & R12 within R10/R12=0.5...2.
Keep R10+R12 in sum high enough that your signal source can still drive it properly and in any case I recommend to keep the sum higher than 550 Ohms.
Increase C4 in order to keep fc beween 40kHz...80kHz.
Please note: This method of increasing the gain will let you suffer from the poor input noise characteristic of the IRS2092. The resulting noise level will remain better than average commercial IRS2092 designs, but will gradually grow to similar levels like good commercial designs with IRS2092. For this reason I prefer to use the gain board, or any other reasonable gain stage for lifting line level signals to an level of approx. 5Vrms.
 
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F

fushfush

Member
Joined 2015
Hi again guys.

I got some boards from ASTX, hurray.

Now i got some questions, please consider i'm a noob but not stupid .. There must be some difference i hope :D

1. Is it correct that R17 is a ghost/ non-existing resistor?

2. R16 and R18 is for grounding the mounting-holes and by that the case, correct ? Should those be soldered or not ?

3. The 12x2pin array, that is just for debugging correct ?

4. The input connectors, can someone explain them to me ? (see the picture)
The arrows does not make sense to me.. is it unbalanced or balanced input?

5. The inductor.. First, i might be stupid; but which holes should i use (I have circled my guess) ?

Second question about the inductor, i can't find the T106-2 ring on digikey, but i can get these at my school. Can i use those instead? If yes, how many turns with which wire should i use ? Link to digikey please..

6. Would it be an improvement to change the C20/C22 (PSU caps, as i can understand) to something larger, and by larger i mean with higher capacity?

7. If someone would validate it's the correct diodes i have picked, thanks!
The parts that is missing i already have :)

8. How do i setup it up with BTL? A rough schematic would be nice.. i cant really understand it.

Thanks, i know it's a lot.. :D:D

BR
Per.
 

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F

fushfush

Member
Joined 2015
astx said:
Wow - fast delivered ...

T106-2 for example you can buy at Reichelt:

T 106-2: Amidon-Ringkern bei reichelt elektronik

BR, Toni
Click to expand...

Its not because of the Danish postal service..

Yeah, i must go to a third dealer to get those... But that dealer also has the wima caps.. Thanks!

This one has winding already, but OD is around 1.3 inches and dcr is higher than shielded inductors

http://www.mouser.dk/ProductDetail/Coilcraft/ED0006-AL

I found 1D23A considerably hotter than VER2923 at 400khz fsw (more than 10 deg C on idle) maybe why it's cheap.
Click to expand...
Yeah, but for some reason Markus picked a 5% tolerance, and yours is like 20%.. If it works, dont fix it :D
 
F

fushfush

Member
Joined 2015
jlester87 said:
You can unwind some turns to get +/- 3% 15uH (i was referring to 40V BOM) if you have an inductance meter. If you can wind better and tighter than coilcraft then no problem :D
Click to expand...

I'm going with the third-part dealer that astx sugggested, the IRFI's are also cheaper where, and i can get my wima caps also.

And mouser is quit expensive in freight, as i remember.

Ill got a buddy with an LCR-meter, so i'm going to wind it my self.. :D
 
F

fushfush

Member
Joined 2015
jlester87 said:
Yup true especially in customs charge. When I order from mouser, the package are shipped from USA, then I have to pay 2x taxes because the parts are categorized as electronic. Advantage is that it's very fast, around 3 to 5 days.
Click to expand...

Yeah, Its not a question about time :D I'm a student so rather slow and cheap.

I still need an explanation of the 2x12 and 1x6 connectors.. :confused::confused:

R16 and R18 should those be soldered ?
 
astx

astx

Member
Joined 2011
Paid Member
fushfush said:
Yeah, Its not a question about time :D I'm a student so rather slow and cheap.

I still need an explanation of the 2x12 and 1x6 connectors.. :confused::confused:

R16 and R18 should those be soldered ?
Click to expand...

R16 and R18 need not to be soldered, when you otherwise have a connection to chassis ground either directly, via PSU or by ground breaker.

1x6: balanced inputs and clock sync port.
2x12: connector for the gain board.

BR, Toni
 
F

fushfush

Member
Joined 2015
astx said:
R16 and R18 need not to be soldered, when you otherwise have a connection to chassis ground either directly, via PSU or by ground breaker.

1x6: balanced inputs and clock sync port.
2x12: connector for the gain board.

BR, Toni
Click to expand...

Thanks again again Toni.
I'll drive it from another pre, so i should be covered with only using the 1x6 connector.. Until i get the gain-board working.

Cant get those BC546C/BC556C, but i can get the B or A model, isn't the a-model the highest spec ?
 
F

fushfush

Member
Joined 2015
fushfush said:
Thanks again again Toni.
I'll drive it from another pre, so i should be covered with only using the 1x6 connector.. Until i get the gain-board working.

Cant get those BC546C/BC556C, but i can get the B or A model, isn't the a-model the highest spec ?
Click to expand...

BC556CTA Is obsolete and is the only thing i need so i can place the order, and start soldering :confused: I don't want to buy it on ebay from some unreliable dealer.

Any replacements? I can only get the BC556A or B.. And i can understand the C is the one with the highest gain.. So what do i do??
 
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