JLH Headphone Amp

[Jean]

I've already ordered the board, and have most of the parts on hand but I may just order another one that's pre-populated as well to compare?

Are all of these eBay sellers in China selling the exact same board/kit, in terms of the board layout/traces?

[ashok]

Yes it is a good idea getting a populated board also. You will have one control board ( populated one ) and the other with variable parts. That way you know which way the mods are going. Don't keep soldering parts on the test board . Use very small extender wires to the parts being changed/compared. That way the board's tracks will not get damaged by repeated soldering. Better done on the solder side of the board.

I find some other boards like DAC's being sold by several vendors. Looks like they source it from the same person as the tracks/board look identical. This JLH board might also be similar. Board prices might vary depending on parts type and possibly shipping methods and charges.

[ashok]

Anyone know of Chinese brand polypropylene caps that sound good for audio use ? Small like the WIMA MKS2 types .

[Jean]

Originally Posted by ashok

Yes it is a good idea getting a populated board also. You will have one control board ( populated one ) and the other with variable parts. That way you know which way the mods are going. Don't keep soldering parts on the test board . Use very small extender wires to the parts being changed/compared. That way the board's tracks will not get damaged by repeated soldering. Better done on the solder side of the board.

I find some other boards like DAC's being sold by several vendors. Looks like they source it from the same person as the tracks/board look identical. This JLH board might also be similar. Board prices might vary depending on parts type and possibly shipping methods and charges.

Yeah, or just shoot for the high quality components right off the bat right ?

Board shipped, but won't be here for another week or two. I need to now find a good case that looks good, and of the right size.

Do you have any recommendations on a diy dac by any chance?

Thanks!

[hotiron]

DAC 2496 (AK4393) DAC KIT With CS8416+AK4393+5532

PCB+SMD IC NEW Hi end DAC 24 BIT 192K HZ AK4396 sc | eBay

[Jean]

Awesome, thanks!

[bkercso]

Hi All,

Until now I was read only mode here and now sorry for the OFF, but I would reflect to oz7affs #216.
I built the complementer symmetric amp linked this post and I have to say that this is most superior than the JLH! Fast, precize and natural sound. Not as smooth as JLH, more fast, but easy to listen. I more like this with MJE243/253 BJTs at the end, these give more natural sound; original BD139/140 have too much highs for me. The sound is very similar too CKKIII (with BJT input and MJEs), but a little bit more "negative feedback sound", more disciplined, but same clear.
Here is a photo. Its inside not beauty, this is a fast built prototype. I not used caps in the signal path.

oz7aff, thanks for share this amp! Has it name?

ON: And here is my JLH. It's not from cheap eBay parts, I bought everything in local stores in Hungary. (KITs BJTs have less beta than specified... Other parts was messy look too.). It has less than ideal bass for me, slow, relaxed sound; but more clear than IC devices. I used BC547C/557C and TIP41C.

Regards,
bkercso

[oz7aff]

Originally Posted by bkercso

oz7aff, thanks for share this amp! Has it name?

I think it is very fine that you have tried to build a copy.
It looks fine and I notice that you find it good as I did also.
It has no name, the original project was made by a Danish HiFi magazine back in 1980 and they only called it a High Speed Headphoneamp.

It was build with 2N5210 and 2N5087 as small signal transistors and as power transistors they used MPSU05 and MPSU55. These transistors has become obsolete in this part of the world and that is why I tried to build it with comonlly aviable european transistors.

I can mail you a copy of the original article, but it i writen in Danish.

[EUVL]

I would appreciate a copy of the article if I may.
Please kindly send me a email via the forum.


Many thanks in advance,
Patrick

[oz7aff]

Originally Posted by EUVL

I would appreciate a copy of the article if I may.

Please download it here:

http://www.sandcastle.dk/artikler/HSHPAMP.pdf

You should be able to translate it via Google translate.