JLH 10 Watt class A amplifier

[prasi]

Ha ha, i believe that Prasi can do it in minutes

Are we talking about this?
The sch is based on 'theslowdiyer' website
JLH 1969 revisited… | theslowdiyer


Regards
Prasi

 

[thimios]

Realy fast!
Now we have 3 versions by Prasi.
Thanks Prasi!
I will have a surprice for you soon.

 

[huggygood]

this one is very good too
GZLOZONE Assembeld PNP A1216 JLH1969 Single ended Classe A Amplificateur de Puissance Conseil dans Amplificateur de Electronique sur AliExpress.com | Alibaba Group

 

[prasi]

Realy fast!
Now we have 3 versions by Prasi.
Thanks Prasi!
I will have a surprice for you soon.

I love surprises!
I will post pdf and gerbers after refinement of this 1969 version
regards
Prasi

 

[Wierd]

hey prasi

Nice layout for the classic jlh.

 

[prasi]

Are we talking about this?
The sch is based on 'theslowdiyer' website
JLH 1969 revisited… | theslowdiyer


Regards
Prasi

gerbers and pdfs

 

[nigel pearson]

QuantAsylum QA400

Anyone got a better idea for my new THD analyser? I have asked my son to look at Raspberry-pie and DAC. Any thoughts? I need to go to at least -100dB. 24 bit should do that. On that point I had a very cheap Philips DVD with 24 Bit DAC that claimed - 65dB THD !!!!Sounded OK.

In the ideal world it is stand alone to work on any computer. I have XP, 7 and Linux. I have 10 also that I don't use much.

 

[e_fortier]

Realy fast!
Now we have 3 versions by Prasi.
Thanks Prasi!
I will have a surprice for you soon.

In the 3 versions is there 1 for 1969 dual rails supply ?

If yes, please show me the post.

Beautiful layout Prasi. Thanks!

My JLH 69 amp works with pcb from the ´slowdiyer’ and it sounds very good.

 

[prasi]

None Eric,
2 are 2003 versions(high power 2 pair and one is single pair ) and the 1 above is 1969 single supply.

 

[mjona]

From a short listening test, no measurements yet, leave this bastard C8(parallel to 2k7 feedback resistor) EMPTY!

I have seen this popular error so often that I can see the lesson in this will be ignored.

Anyway C8 provides a direct access to the inverting input of the amplifier at high frequencies which has implications for out-of-phase feedback signals generated by a speaker load.

Those who remain unconvinced should take note of what Linsley-Hood said in his original 1969 article. To quote from the section entitled "Stability, power output, and load impedance" - "Silicon planar n-p-n transistors have, in general excellent high frequency characteristics, and these contribute to the very good stability of the amplifier.The author has not yet found any combination of L and C which makes the system unstable, although the system will readily become oscillatory with and inductive load if R3 is shunted by a small condenser to cause roll-off at high frequencies".

R3 is the 2.7k feedback resistor.

 

[thimios]

JLH 2003 HIGH POWER

None Eric,
2 are 2003 versions(high power 2 pair and one is single pair ) and the 1 above is 1969 single supply.

Now the surprise.
Another Prasi's pcb tested!

 

[prasi]

Hi

I’ve built the 69 version and really enjoy it.

I’ve also build the Penultimate (dual polarity w ccs for front end and bias current)

For my taste I prefer the 69 version and recently discovered that a dual supply rails version has been implemented successfully.

Does anybody have some PCBs for the dual rail supply 69 version ? Schematic attached.

I just bought some Xtrm that would be perfect for 2 mono amp.

Note to self; finish MoFo first.

Thanks
Eric

Here is single sided version, I will share with you double sided version.

 

[prasi]

Now the surprise.
Another Prasi's pcb tested!

Aha!, so you are using MJL21194? Thats great news.
How does it sound?

Regards
Prasi

 

[thimios]

Aha!, so you are using MJL21194? Thats great news.
How does it sound?

Regards
Prasi

No,i'm using TTC5200.
I haven't any listening test yet.

 

[e_fortier]

Here is single sided version, I will share with you double sided version.

Prasi you are simply the best !!

Beautiful small and compact design.

T2 is hard to get, could you please replace w BD139-16 ?

Thanks again.
Eric

 

[prasi]

No,i'm using TTC5200.
I haven't any listening test yet.

ok, for the TO-126 heatsink you are using, please ensure that its not touching jumpers or resistor leads. Thanks for posting here.


Regarding JLH1969 dual rail as per post #5259, there is an error which I missed out, R2 should be 2k or 1k2 as per the schematic shared e_fortier.

regards
Prasi

 

[thimios]

ok, for the TO-126 heatsink you are using, please ensure that its not touching jumpers or resistor leads. Thanks for posting here.


Regarding JLH1969 dual rail as per post #5259, there is an error which I missed out, R2 should be 2k or 1k2 as per the schematic shared e_fortier.

regards
Prasi

A closer view to ensure you.

 

[prasi]

Prasi you are simply the best !!

Beautiful small and compact design.

T2 is hard to get, could you please replace w BD139-16 ?

Thanks again.
Eric

thanks... but why replace when you can use either?
Attached is the final one incorporating your valuable suggestions.

regards
Prasi

 

[thimios]

Jlh high power ver.

Here is the second chanel.
Unfortunately i ended up from TTC5200, only two pieces installed.
Easy to assembly in one afternoon.
Thanks Prasi.

 

[thimios]

Jlh high power ver.

Now i have two channel and listen to them in stereo.
The first chanel using 2pairs TTC5200, and the second using one pair.
The board with one pair installed is the best sounding.
Clearly better mid and high.
Because of this the first board disassembled and one pair pulled.
Here using an existing power supply from the SX-Bonsai amplifier. +/-18v. 1.5A bias.