JLH 1969 revisited…
June 9, 2014 24 Comments
Finally a bit of progress around here 😀
Even though I have already built a Linsley-Hood JLH1969 clone and another is in the works, I still wanted to make my own layout for this classic amplifier – and here it is!.
The board measures measurements are 2.3″ by 2.25″ (app 57×58 mm.) and as usual the layout is as tight (some would say “cramped” as I could make it. The transistors used are based on Geoff Moss’ recommendations. I actually have some NOS 2N1711, but the BD139-16 actually measures better (higher hfe). The output devices are MJL21196 because I had them available and because the larger TO-264 package is nice.
The board will be powered by a regulated PSU (hopefully ready shortly – the last parts are in the mail) based on a normal 3-pin regulator as shown in the 1996 JLH article (if all these references seem a bit like you have to be “in-the-know” to keep up, I suggest you start reading the pdf-articles here instead 🙂 ).
Now, I haven’t really done much with this beyond testing that it plays music, but when the PSUs are up and running I’ll look into more testing. In terms of value-for-money this isn’t likely to compete with the cheap ebay-kits, but hey – if I wanted to save money I wouldn’t be building amps I would just buy one that worked! 😀
theslowdiyer 
Pingback: JLH 1969 PSU | theslowdiyer
Pingback: Project files: Mini JLH1969 | theslowdiyer
Pingback: More JLHs… | theslowdiyer
Hi,
Keep these JLH projects coming ! I built a 2003 version JLH (bipolar supply) and so far it has to be one of my favorite amp.
Is it possible to purchase some of your JLH 69 revisited PCB, they look great and the small size would be great for my application. Great work.
Thanks,
Eric
Hi Eric,
Thanks for the comment – I completely agree with you on the qualities of the JLH amps, old and new.
I can’t remember if I have any spare boards and if so which board revision they are, but if you send me a note through the “contact me” page I’ll rummage through some boxes in the mean time 🙂
/U.
Awesome, thank you.
Pingback: Audiophile or Idiot? | theslowdiyer
Hi,
Well, I have finish building 1 channel and the amp works great. My heatsink is running too hot (about 0.9 C/W) for my taste even though I’m able to keep my hand for about 10 sec. I normallyrun my heatsink at 45C max. I have adjusted the bias at 0.9A with a 27Vdc supply (SMPS, 120W). The fact that the PCB is very small (about 50mmx50mm) does not cause any heat issue amoung the components, ex. T3 is not hot. My transistors are BC560C (T4), 2SC3902T (T3)and NJW21194 (T1,T2).
Thanks a lot for the PCB
Eric
Thanks great. I hope you get the other channel ready soon so you can have a real listen to it 🙂
Hi
Happy ne3 year 🙂 I reallly like to read your blog and have a question: You don’t have 2 of your JLH boards left? Or if not the pcb layout ? Would be nice for my next JLH project…
Best regards
Christoph
Hi Christoph,
Thanks for you comments. If you send me an email through the “contact me” page I’ll see what I can do to help 🙂
BR,
Hi,
I was curious if you have more jlh boards? I would be willing to purchase some. I have a Chinese jlh version and love it! Wanting to try another one!
Thanks,
Brandon
Hi Brandon, unfortunately I have no more spares left. The Gerbers are still online so you can get some made though.
Hi
I follow your website by liking it. There are very nice posts. I made a mini jlh 1969. He has an excellent voice. I used tip3055. I set the bias current to 1.2a. The sound is perfect. I measure offset around 3.5v when the speaker is not plugged in. But when I connect the speaker, the offset is 0 volts. this 3.5 volt offset voltage is causing problems with speaker protection. Can you help me where am I going wrong?
Not sure, because there is a capacitor on the output of the JLH1969 so unless there is a problem with your output caps you shouldn’t really see any DC offset worth mentioning here. There are a couple of very long threads about the JLH-design on diyaudio, maybe you can check them for answers?
how can i connect your pcb amp to the speaker. I can’t find the output. Thank you
how to connect speaker with your pcb? Thank you
Use the solderpad between the transistors as output and take return from the power supply board.
Do you have an illustration?
Unfortunately not.
Where is the negative part of the output?
Good question 🙂 It’s simply taken directly from the negative/0V output of the PSU.
The sound.au.com site doesn’t exists anymore. Please, update the link to Internet Archive:
Old: http://sound.au.com/tcaas/jlhtrans.htm
New: https://web.archive.org/web/20121226215040/sound.au.com/tcaas/jlhtrans.htm
Hi Dimitry, thanks. The right link should be under Rods new site: https://sound-au.com