My new headphone amp

[Algar_emi]

Hi. Here on of my newest project. It is a fully dual mono all discrete FET headphone amplifier in Class-A. Real Class-A at 100ma per supply, and channel. With supplies of +/-24V it is 9.6W in Class-A (200ma * 48V = 9.6W). It is cooking

It sounds superb, perfectly silent with dual fully discrete low noise regulators with CRC pre-filters. The case was made by Front Panel Express, side wood panels in exotic Padouk wood with oil finish.

The circuit is DC coupled, we no coupling capacitor in the signal path. A servo takes care of the small circuit thermal drift.

Here the prototype pictures

 

[Algar_emi]

And the completed amp. It is using great parts everywhere Furutech AC power inlet, Non-magnetic line noise filter (aka Ayre es filter), Low noise vibration decoupled dual toroid transformers, Philips/Vishay huge pre-filter caps, Wima, Nichicon KG/Muse, CDE and Vishay caps, Caddock MK132 and Vishay CMF55 film resistors, Noble volume pot, Canare power & Mogami audio cables, 6N single crystal copper hookup wires, Cardas and Amphenol connectors and the classic blue led power on indicator.

Even the bottom is nice, with vibration decoupling feet, laser trim ventilation holes and concealed power-on switch.

 

[Algar_emi]

The power section is all assembled point-to-point. I did my own PCB. Ventilation holes can be seen on the back. You cannot see it but there is bitumen vibration absorbing pad under the top cover. Front and Back views. It is real statement amp, top of its class. Difficult to do better I guest...

 

[jacques antoine]

Any schematics?

 

[Nico Ras]

Why do you run a headphone amplifier from +/-24V rails? I would think it is wasted energy dissipating 9.6 watt if 200 mW/ch would certainly damage most headphones/ears.

 

[Algar_emi]

Sorry no schematic. This is a design is copyright and I cannot disclose any details. This circuit can also be used as a preamp, single-ended or balanced. Indeed the supply can be lowered to +/-18V, but the regulator will then dissipate more heat. Input of the regulators are +/-31V. I may try that to lower the amp dissipation. It is a balance between amps and regs.

 

[gk7]

Sorry no schematic. This is a design is copyright and I cannot disclose any details. ...

Why post it on a _diy_ site then ?

 

[jacques antoine]

Why post it on a _diy_ site then ?

Admiration only

 

[Avro Arrow]

Why post it on a _diy_ site then ?

Free Advertising?

 

[aparatusonitus]

Judging by a small visible part of PSU schematic, it's one of Erno Borbely design: all-fet Super-shunt regulator as well as all-fet Preamp.

 

[Algar_emi]

Yes indeed, to show the completed project. You can find the design on the net if you look closely.

 

[Nico Ras]

I have never heard of a product being designed to mach available transformers and regulators. Commercially it is already a failure.

 

[Algar_emi]

It is not a commercial product. I built it using mostly parts that I had in stock hence the compromise. No need to argue over the design. It plays wonderfully and it fits my needs.

 

[Nico Ras]

I built one of the greatest headphone amps ever four years ago and it is a match made in heaven for only the best headphones available. Here is a photograph of it open but unfortunately no schematic since it is also copyright.

 

[jacques antoine]

Here is a photograph of it open but unfortunately no schematic since it is also copyright.

Is the photograph copyrighted as well ?
One is never too careful

Jacques

 

[Nico Ras]

I think copying it should be fine

 

[Algar_emi]

Very nice case, like the Lyra Connoisseur preamp. I like it