JLH Headphone Amp

oz7aff · 2012-12-05 12:29 pm

What about zeners, are they also more noisy than 4148 ?

And when 4148 are connected in serie is the noise then added ?

bkercso · 2012-12-05 8:55 pm

This topic is about diode noise. Please see #107 for latest measurements.

In series case the noise doesn't add, only increase a little bit.

oz7aff · 2012-12-05 9:48 pm

Thank's for the info, but actualy it look's like using a single red LED with a current of 20 mA will give a lower noise than 3 4148 in series.

randomlf · 2012-12-06 8:11 pm

How does this thing compare SQ wise to the popular O2?

bkercso · 2012-12-06 9:47 pm

Probably yes. But never know what type of red LED can you buy.
BUT: LEDs and diodes in transparent capsule are sensitive to light. Did you know BAV99? This is 2 4148 is series in a non transparent capsule.

oz7aff · 2012-12-06 10:11 pm

I can buy the led I want as long I know who the manufactur is, so that's no problem, and light is also no problem, putting these diodes inside something that keep the light out is no problem. And I do not know BAV99 until now, and I see that it is a SMD type in a black house with 3 legs, could be a good component to try for the issue we are talking about.

oz7aff · 2012-12-06 10:12 pm

randomlf said:
How does this thing compare SQ wise to the popular O2?

I simply do not understand the question.

randomlf · 2012-12-07 12:29 am

oz7aff said:
I simply do not understand the question.

I mean how is the sound quality on this amp? Isn't this in approx. same price class as the Objective2 headphone amp? So if I built one, which one should I choose?

jcx · 2012-12-07 1:00 am

headphones vary wildly in Z, senstivity - you should always specify headphone model when asking if an amp is suitable

bkercso · 2012-12-07 1:14 am

I would choose this all poor discete JLH. The sound of this amp is smooth, slow a little bit, relaxed but precise enough. Don't coloring hard. I didn't hear the O2 but I heard the JRC4558: musical, precise, faster than JLH. But IC-like, discrete is better for me, sound of the JLH is more clear. I think if you choose faster transistors instead of TIP41 the amp will faster sounding (maybe MJE243 will be good but the pinout is reversed, see the datasheet!).

oz7aff · 2012-12-07 9:37 am

Ok, I dont't know the Objective2 headphone amp, but I still misses to see IC based phone amps that can drive my phones. If it is solid state we are talking, my favorite is this one http://www.sandcastle.dk/artikler/HP%20Amp.pdf

randomlf · 2012-12-07 10:56 am

bkercso said:
I would choose this all poor discete JLH. The sound of this amp is smooth, slow a little bit, relaxed but precise enough. Don't coloring hard. I didn't hear the O2 but I heard the JRC4558: musical, precise, faster than JLH. But IC-like, discrete is better for me, sound of the JLH is more clear. I think if you choose faster transistors instead of TIP41 the amp will faster sounding (maybe MJE243 will be good but the pinout is reversed, see the datasheet!).

So you mean this amp has "tube like" smooth sound, while the other sounds colder but, more detailed?

My headphones are AKG K240M 600ohm, 88db/mW sensitivity. I would like the amp to work with all my future headphones as well, such as low-Z iems.

I think I will build the O2 for now, and maybe JLH later to compare. Thanks

oz7aff · 2012-12-07 3:13 pm

I will try to go the other way. I think I will try building the JLH HP Amp with some old 2N3054 I have in stock.

bkercso · 2012-12-07 6:50 pm

My favorite is CKKIII (with BJT input), but "HP Amp.pdf" linked above is almost same sounding, very good too (I built all the 3)!
JLH is cleaner than tube amps I heard before.

oz7aff · 2012-12-07 8:26 pm

That CKKIII amp look's very interesting, and the PCB is low priced so I might have a go at it just to try that out to. Is there anywhere one can see the schematic ?
My tube hp amp is sounding very clean and have a nice sound to it, one has a tendency to play very loud with that amp. http://www.sandcastle.dk/artikler/TUBEHPAMP.pdf

bkercso · 2012-12-07 9:37 pm

You can find a 'Schematic' menu point at the left side on The Cavalli-Kan Kumisa III Stereo Headphone Amplifier

oz7aff · 2012-12-07 9:47 pm

bkercso said:
You can find a 'Schematic' menu point at the left side on The Cavalli-Kan Kumisa III Stereo Headphone Amplifier

I had found them, but thank's for the info anyway.

blackdod · 2012-12-08 11:02 am

I changed the pot. volume of my JHL for an ALPS (50K). I prefer this pot. at to original "Step-to-step".

oz7aff · 2012-12-08 3:18 pm

I can understand that, I also prefere the no-click version, but at the time it was the only one in my stock

oz7aff · 2012-12-08 10:47 pm

I have build for the fun of it a small portable class D amplifier witk built in accumulator and charger http://www.sandcastle.dk/artikler/ClassD01.JPG http://www.sandcastle.dk/artikler/ClassD02.JPG

Now I am thinking of doing something similar with a headphone amplifier, could be a very nice portable unit together with at good portable player.

Does anybody have tried this before, and can supply with some hints ?

JLH Headphone Amp

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