I've just built me an headphone-amp, it's an OPA2134 from Burr-Brown(Free samples). The powersupply is 2 6volt in serie(+-12volt).
The sound is great, atleast in my AKG headphones.
I post some pictures and schematic later(tomorrow) if anyone are intressed.
Question: Is it hard to build some kind of bassBoost to the amp ?
Anyone have a schema?
The sound is great, atleast in my AKG headphones.
I post some pictures and schematic later(tomorrow) if anyone are intressed.
Question: Is it hard to build some kind of bassBoost to the amp ?
Anyone have a schema?
Also, if you have a CMoy design (most common 1st headphone amp) you can tweak the bass by playing with the signal coupling cap values.
Mine headphone amp is under the thread "my new baby" on this forum. The circuit is at:
http://www.tangentsoft.net/audio/cmoy-tutorial/
His (Tangent's) advice on signal-coupling cap tweaking for bass enhancement is at:
http://www.tangentsoft.net/audio/cmoy-tutorial/tweaks.html#caps
GnD
Mine headphone amp is under the thread "my new baby" on this forum. The circuit is at:
http://www.tangentsoft.net/audio/cmoy-tutorial/
His (Tangent's) advice on signal-coupling cap tweaking for bass enhancement is at:
http://www.tangentsoft.net/audio/cmoy-tutorial/tweaks.html#caps
GnD
caps
Thanks for
I'm sorry for the confusing picture/text.
The input-caps are not electrolyt, I do have 0,1µF ceramic there instead of 4,7µF
But i do ghange it soon
A friend give me the advice to change the ceramic to MKT-caps instead because he think the ceramic could act like a highpass-filter, is he right about that ??
Thanks for
I'm sorry for the confusing picture/text.
The input-caps are not electrolyt, I do have 0,1µF ceramic there instead of 4,7µF
But i do ghange it soon
A friend give me the advice to change the ceramic to MKT-caps instead because he think the ceramic could act like a highpass-filter, is he right about that ??
If you admit that you use ceramic caps as input caps you will get the big wolves after you.
It's not very common to use ceramics because of the poor properties in audio performance. I don't say that the amp will sound like a disaster but almost anything else is better. Start with polyester or polypropulene.
The input filter IS a highpass filter!
f = 1/(2*pi*R*C)
It never hurts to combine this filter with a lowpass filter. I would suggest 50-150 kHz as cut frequeny.
1 k + 1 n to 3.3 nF this is good to reject RF disturbance.
It's not very common to use ceramics because of the poor properties in audio performance. I don't say that the amp will sound like a disaster but almost anything else is better. Start with polyester or polypropulene.
The input filter IS a highpass filter!
f = 1/(2*pi*R*C)
It never hurts to combine this filter with a lowpass filter. I would suggest 50-150 kHz as cut frequeny.
1 k + 1 n to 3.3 nF this is good to reject RF disturbance.
I made a "textbook" opa 627 , buf 634 headamp yesterday the sound of which was not bad at all but nothing special.This was powered by a regulated bench power supply.
I was wondering why we need the buf634 or indeed any buffer as most people are using (peranders ?) here and elsewhere .
I drove my Senn 600 directly from the 627 output which provided more than enough volume plus it was much more transparent than with the BUF.
I have also driven the headphones directly with just a DRV134 balanced line driver and this set-up seemed to me the best.It is also the simplest since you only need a couple of decoupling caps - no resistors needed.I used balanced drive and in this mode you get about 6db gain which might not be huge but is more than enough if you are driving it from a standard cd line out.
So for me it seems that keeping it simple sounds the best - no need for extra output buffers/stages when your cans only need less than 10ma.
I was wondering why we need the buf634 or indeed any buffer as most people are using (peranders ?) here and elsewhere .
I drove my Senn 600 directly from the 627 output which provided more than enough volume plus it was much more transparent than with the BUF.
I have also driven the headphones directly with just a DRV134 balanced line driver and this set-up seemed to me the best.It is also the simplest since you only need a couple of decoupling caps - no resistors needed.I used balanced drive and in this mode you get about 6db gain which might not be huge but is more than enough if you are driving it from a standard cd line out.
So for me it seems that keeping it simple sounds the best - no need for extra output buffers/stages when your cans only need less than 10ma.
The "normal" opamps in typical DIP-packages are not intended for low impedance loads. Datasheets of such give performance and output voltage/current into 1kOhm for example.
Some opamps deliver +-50mA and more and might suffice at normal listening levels.
You probably even get away with 32ohm cans with high sensitivity.
Most 300ohm cans like Sennheiser should be OK but still distortion and performance should be much better with a buffer.
Some opamps deliver +-50mA and more and might suffice at normal listening levels.
You probably even get away with 32ohm cans with high sensitivity.
Most 300ohm cans like Sennheiser should be OK but still distortion and performance should be much better with a buffer.
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