Gyraf Headphone using HYbrid module...

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trinity
Posts: 3
Joined: Thu Mar 05, 2009 4:36 am

Gyraf Headphone using HYbrid module...

Post by trinity »

Yeah so bassicaly i e-mailed Joe.
Asking for a solution on using the Hybrid as a headphone amp.

Then later found out this Gyraf schematic: http://www.gyraf.dk/gy_pd/hpamp/HP-Amp.pdf
It looks like the hybrid but with some components more in the surrounding circuit...

I'm pretty sure that with some xperimenting and tweaking this will probably work just fine...

The only thing is that 1 channel of headphones will need 2 Hybrid :shock:

chrisp
Posts: 184
Joined: Sun Mar 04, 2007 11:46 am
Location: Sydney, Australia

Re: Gyraf Headphone using HYbrid module...

Post by chrisp »

Trinity wrote:It looks like the hybrid but with some components more in the surrounding circuit...
Similar, yeah - you could use the Gyraf front end (C1, C2, R1, R2 and the volume P1) in front of a Hybrid and that should be fine. Both designs use high output transistors to drive the outputs.
The only thing is that 1 channel of headphones will need 2 Hybrid
Lost me here. By "1 channel of headphones" do you mean a L and R signal? Then yes, you'll need two hybrids to do that, just as the Gyraf schematic shows only 1 channel and you'd need to repeat it for the other. If you mean 2 hybrids each for L and R (ie 4 in total), why do you say that?
Chris P
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I do lots of things. I believe eclectic skills are best.

trinity
Posts: 3
Joined: Thu Mar 05, 2009 4:36 am

Re: Gyraf Headphone using HYbrid module...

Post by trinity »

What i meant is that each pair of headphones will need 2 hybrid for stereo.
altought its not stated on any thread for gyraf headphone amp....

chrisp
Posts: 184
Joined: Sun Mar 04, 2007 11:46 am
Location: Sydney, Australia

Re: Gyraf Headphone using HYbrid module...

Post by chrisp »

The Gyraf schematic to which you link in your first post states that you need to repeat the amplifier circuit for the other channel. So the Gyraf design uses two quasi-hybrids as well.

I suppose the question is why go for the hybrid rather than just build it as per the Gyraf schematic. There main reasons would be -

(1) the JLM Hybrid offers a servo circuit for the opamp and the choice of class A or class A/B operation
(2) buying 2 hybrids gets you parts and circuit board without having to do much running around.

It would be slightly more expensive than building it from scratch yourself (assuming your build all goes well), but much quicker.
Chris P
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.

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Joe Malone
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Re: Gyraf Headphone using HYbrid module...

Post by Joe Malone »

Below is a similair circuit I drew for someone who wanted summing mixer and a headphone amp using BAD PCB's and Hybrids. For just a stereo headphone amp you can use 2 x BA PCB with no input transformers and use 2 capacitors and resistors to make a electronic balanced input headphone amp.

Image
Joe :-)
JLM Audio
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