Official LYNX Power Amp builder’s thread

[OzMike]

G'day

I don't think it's very good using a simple current limiter. A dual slope VI protector is no more complex really and provides more in the forward sense and much less in the reverse sense so difficult loads don't cause damage.

the chip is quite heavily loaded which would worsen its distortion.
I wouldn't use LF356 or LF357 with this - they are awful sounding even lightly loaded.

mike

 

[tinitus]

I dont know what you mean, but I suppose that as I use a seperate low current(0.5A) supply fore input/driver stage there will no problem with current limiter under heavy load 😀

 

[Jan Dupont]

Some component data updated in the Quick Assembly Guide

 

[crt]

sorry for my stupid questions

yes,If we bent all the pins then was obtained by 14mm.

But if we were bent the pin from his starting point, the pins was still being easy to be broken.

can i use 2x47uf polar in series to replace the original 22uf non polared?

for 13K resistor, can I series 12K with 1K?
very hard to find 13K resistor in my town

I will continue to used lf356 and 1n4148 to replace BAV21


Thank's

 

[Rembulan]

Hello,

CRT .......
Use LF356 its has a good sound believe me.
better to place the driver in main heatsink .............Its hottttt or you in trouble dealing with a big driver heatsink.

Jan,
The difference between Lynx 2.2 and lynx 3 are in some resistor value, added C in feedback, and diode paralel with base and colector in first Transistor stages, do you mind to explain why ?
1. you use this diode ? ( honest I cant Find any difference with my scope and ears)
2. what the benefit for C in feedback loop?
Thanks

 

[Jan Dupont]

crt;
Yes you can use 2x47uF in series (will not fit the pcb, but it will work)
If you replace the 13K (R105&106) with a 12K, you may want to reduce the 1K (R107/108) to app. 850R

Rembulan;
The main diff between v2.2 and v3.0 is that now the output devices are on the pcb + some miner tweaks.
The diodes d107/108 acts as soft clipping when VAS stage reaches it's max output.
C109 in the feedback is just an option for providing some extra feedback at higher frequencies.

 

[gary s]

Hi Jan.

Thanks for keeping us updated as you add information to the Lynx assembly guide.

You are really doing a professional job on this. Much appreciated.

Regards

Gary..

 

[Rembulan]

CRT

Eh CRT di surabaya dimana bisa beli OPA627 75rb asli ngak.

Jan, I remember 30 years ago when I started make tubes amp every day I try a new tubes I got from flea market now I hunt to every local shop look for a single opamp and try it in my Lynx. Tomorrow I want to try something different perhaps change the driver from BJT to MOSFET. Thanks to made a new addiction to me

 

[crt]

halo rembulan

Saya juga belum nemu toko yang jualan opa627. kelihatannya sih yg ada cuma di jakarta. Saya tetap pake LF356 koq, murmer!😀

Many thanks for you
Jan Dupont!😀

 

[Ragnwald]

Hi

What type of isolation is recommended between the transistors and heatsink ? Kapton or Aluminiumoxid ? And are they used together with some glue ?

My first try with transistors.

Using Jans picture.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1291284&action=thumb&stamp=1188574234

 

[Ragnwald]

Here´s a bigger one.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1291284&stamp=1188574234

 

[Jan Dupont]

Hi Ragnwald,

I have just used ordinary silicone pads and heat conducting paste (even though the manufacturer states that paste is not necessary....)

 

[Ragnwald]

Thank´s Jan

I ask because some of these can only be orderd in 100 pack.

regards

 

[Jan Dupont]

Ragnwald;
See elfa.se and search for 75-646-51 and 75-646-44

 

[Ragnwald]

Thank´s Jan

Kapton 0,05mm, 1,00 degrees C/W
Silicon 0,75 - " -
Silicon adhesive 0,30mm, 0,40 - " -
Aluminiumoxid 3,00mm, 0,30 - " -

These differences is nothing to bother ?

I belive you have proven the silicon to work with this amp.

ELFA 75-646-77 ? The adhesive one.

regards

 

[peranders]

I used at work SILPAD silcone rubber and they worked fine. I was used for a 475 A PS. Jan did you notice any effect with grease together with the rubber? I used nothing inbetween.

 

[Jan Dupont]

peranders;
Frankly I have never made a temperature measurment with and without grease....

 

[Agus Widarto]

Re: CRT

Eh CRT di surabaya dimana bisa beli OPA627 75rb asli ga

Permisii Pa Rembulan, Pa Crt.. buat cari High End Spare part dari resistor 0,5 w dari harga Rp: 500 ampe yang berharga Rp: 50.000 pcs, dari ic ampe tabung, black gate capacitor dll ada di www.langsungjadi.com malah di surabaya ada tokonya kok? call Pa, Alex kualitas Barang tergantung isi dompet kita trus Pa Crt kit2 yang mereka jual juga ga kalah loh ama produk luar...
OK selamat berburu Spare Part ya...


😀

 

[Jan Dupont]

I don't know if it's a case for a moderator to comment on these personal comments between crt and Agus Widarto, however if we all should find this thread helpfull, then please write in english......

 

[Agus Widarto]

I don't know if it's a case for a moderator to comment on these personal comments between crt and Agus Widarto, however if we all should find this thread helpfull, then please write in english......

Oh My God,,, Sorry Mr Jan, don,t miss understand i'am just to tell to my friend crt and rembulan, were thy can to find spare part for build LYNX Power amplifier ( OPA, NP capacitor etc ) I cant write werry well in english so i write in Indonesia language Sorry Mr Jan?🙁

Thank and GBU!
regards