Lynx 3

[Jan Dupont]

Hi dexter;

Glad you could read the files.....

I run my amps at +/-60VDC, but less can do it e.g. +/-35 to 45VDC. Warning! The drivers Q110 and 111 runs very hot, so you may want to change R118/119 to >30R !! And if you are going to use a low rail Voltage, you may need to decrease R122/123 from 2K7 to 1K8.

You can supply the input/VAS stage with the same Voltage as the output stage or a low current well regulated Voltage that are +/-5VDC higher, so you can drive the output stage from rail to rail.
A supply to input/VAS stage of 3-500mA should do it.

I don't have plans for making a single side layout, because it is impossible to keep the symmetri in the layout with only one layer.

If you need it, I have a few of the PCB's for sale. Contact me by email.

 

[Jan Dupont]

It seems like some here are interested in the price for the LYNX v3.0 PCBs.....

I only have very few left my self (4 pcs.), and the price per PCB for those is $25.00 + postage (as this was a very small test production).

If some one is interested in starting and handle a groupbuy, I am able to get these boards at a good price (FR-4 with gold plating).

Let me know

 

[Carl_Huff]

Jan,

Your project looks interesting. Do you have a BOM by chance??

Best Regards,
Carl Huff

 

[Jan Dupont]

Yes I got a BOM, but sadly not on this computer......

Most values are on the schematic.
Standard resistors are 0.6W with 10mm/0.39" lead

I will post the BOM tomorow

 

[dodi_firman]

Hi Mr. Jan..

Thanks 4 u tip...its works...the hum are reduce significant..javascript:smilie('')

I plant to use u amp for P.A.., during I bulid the amp I never found the good characteristic as yours...thats are very near the ampl as bulid form the wellkonown manufactured...

I Hope your'nt borring on me..I'll wait your tip 4 my next isues..as I mention in my post earlier...

with regards..
Dodi

 

[Jan Dupont]

dodi;

It depends on your supply rails and speaker load.
Your supply is +/-65VDC which in theory should give you 450W peak output.

Here is a little help for the calculations:
http://www.audio-circuit.dk/Formular/ohmslaw.jpg

You may want to take the SOA into conciderations:
http://sound.westhost.com/patd.htm

Do you use the output protection circuit in the LYNX v3 ?

Let me know

 

[Jan Dupont]

Here is the SOA curve for your 5200/1943.

As you see, max Current output @ 30 Volt is just 5A, and 4A @ 40 Volt. What is the load of your speakers ?

 

[dodi_firman]

Dear Sir,

Yes I use speaker protection for LYNX 3...

I plant to use in 15" 700 W 8 Ohm speaker...
On your experince if I expand The layout PCB to 8 Transistor Output...could that configuration give the 800W with 8 ohm...?..or more..?

Sorry I'm begginers in modified the amp...usualy I just copy the layout & bulid without modifying anything...

But when I see your LYNX. I see a different. The layout...Its small and simple...thats interest me..so I think could that small give the Maximum...?

BTW in my country its hard to find the OPA 627..I use LF351 for the OpAmp..as the same with your transistor on the layout....

Thanks 4 your support...
With regard...
Dodi

 

[Jan Dupont]

Sorry but your rail voltage at +/-65VDC and a 8 Ohm speaker can only give you max 250 Watts =app. 7.5A per rail or <2A per output device.

Adding more output devices normally doesn't give you more output power. If you go for 800 Watts you need much higher rail voltages and get a 4 Ohm speaker

 

[dodi_firman]

Dear.. Mr. Jan.

8 Tr output..I mean 8 pairs transistor so...total 16 Tr..

Thanks..
dodi...('')

 

[Jan Dupont]

Hi dodi

What ever you use 4 pairs (8 devices) or 8 pairs (16 devices) doesn't give you more output power.........

The total Current will still be App. 60VDC (65V - 3 time BE Voltage + other losses) / 8 Ohm = 7.5A

Putting more output devices in (from 4 pair to 8 pair) will only result in, that each device shall handle less than 1A (which is good and makes sure that you keep the devices within the SOA curve), however it demands more Base Current from the drivers....

 

[Jan Dupont]

Problem solved
Don't bother about the image below

 

[Jan Dupont]

List of material or BOM

 

[Carl_Huff]

Thanks for the BOM

I am guessing that L101 is probably 10 turns of #14 copper wire formed around a 13mm wooden dowel??

Best Regards,
Carl Huff

 

[tinitus]

Jan, you scare me when you write(BOM) that fake transistors blew up your amp...hopefully not the MJL21193/94well, mine are measured and paired so hopefully not a problem

 

[Jan Dupont]

Carl;
You are right about L101

tinitus;
No only the MJE15032/33
It took me over a week to discover that these where fakes.....
Fitted it with original OnSemi's and haven't had a problem since
By the way: BOM = Bill Of Material

 

[tinitus]

Good to hear that

Well, when I get the time and money to build this amp, by then it may be v3.1, hopefully not v3.2

 

[Jan Dupont]

There may come a v3.1 sometime, but I doubt that a v3.2 ever will see the light, as I have lots of other projects going on

 

[Carl_Huff]

Jan,

What would be new in a vrsn 3.1? You look to have a robust design in the current iteration.

Best Regards,
Carl Huff

 

[Jan Dupont]

Carl, I wrote;

There may come a v3.1 sometime

Not that there ever be one
Frankly I don't think there will be any further mods to this, as it plays as intended, and because I have several other projects in progress