Headphone amp

[colin.hepburn]

Hi iansr

The Wad h/phone amp has had some good revues in the past for all versions thou haven’t heard it I almost bot one but that was before WAD was taken over by peters with WD but that’s another storey I went for the mapletree audio design the Ear+ HD High Definition Headphone Amplifier (kit and assembled very good amp but I have upgraded it somewhat or theirs his New Ear+ HD Super http://hollowstate.netfirms.com/#headphone%20amps I have the schematic for both the amps if you want to have a look at them just PM you Email and ill send them to you

[petercom]

Please, everyone, bear in mind that the current WDHD3S is a major upgrade of the HD83 and so the comments you are making are not necessarily relevant compared to what we are offering today.

WDHD3S has a completely revised PCB layout, roomier chassis, switched headphone impedance, improved power transformer, superior cabling and so on.

As for valves these are, of course, a matter of personal taste!

[NickW]

All,

I would add my support to Peter's comments. I built the WAD Headphone II some time ago and used it very regularly for quite some period, and then some months back upgraded to the new WD HD83S (I run the old original WAD amp in my office at work now).

I was quite surprised at the difference, finding the new model a bit "scary" at first until I heard through the differences and came to appreciate the upgraded presentation. How much of that is due to each or all of the upgrades Peter listed I don't know. All I can say is that I do prefer the newer model. I should note that I did upgrade the coupling caps to the Soniqs (which I didn't have in the WAD HDII), but the valves were identical, being the Mullards that I moved over from the WDII to the HD83S. I would add that the HD83S PCB design is considerably better than the original with mush better grounding layout - and I suspect this must have some influence (?).

Just my opinion of course......

Nick

[fatgaz]

Originally Posted by John T

For many years I've used Ben Duncan's Phones 1. It was originally featured in a Hi-Fi News article. I built it mainly for three reasons - 1) It was designed by Ben Duncan, - 2) It was available in kit form and - 3) It is battery powered (2x 12v accumulators) so is completely silent. I use it with Sennheiser HD650 'phones and Cardas leads.

I have listened to the WAD HD83 and in my opinion, it doesn't compare with the Phones 1.

John,

I've just bought a pair of sennheiser HD600 and I'm considering a dedicated headphone amp.

however, rather that a WAD amp, i'm more interested in the Ben Duncan amp.

What is your opinion of the PHONES-01 as a kit ?

Is it a straightforward build ? It doesn't look like it would need much 'setting-up' ? Is it reliable ?

Also, do you only run it from SLA batteries ? I know BD wouldn't approve, but I'm considering building a mains PSU for the phones-01 as I'm considering using it in work. I'd probably have the PSU in a separate box so I could easily swap to using SLAs If I wanted.

Last night I did try to directly run the HD600 from my musical fidelity A3cr pre-amp, it worked supprisingly well due to the over-engineered output stage. (I did beef up the output coupling caps however to avoid bass roll off) As far as I am aware, the output stage for their X-cans is substantially the same as for this pre-amp, using a version of thier 'discrete op-amp' circuit.

Gareth.

[John T]

Hi Gareth,

Obviously I'm just a little biassed as far as performance is concerned however, to answer your queries...

What is your opinion of the PHONES-01 as a kit ?
Is it a straightforward build ? It doesn't look like it would need much 'setting-up' ? Is it reliable ?

The amp is well designed and easy to build (providing you can solder a PCB!) THe PCB is v good quality on fibre glass. The case is 1/8" ali and all components are top quality (no need to upgrade in the future!) all wiring is teflon coated stranded silver. Mine was supplied with a Sferice pot (in my opinion, much better than the Alps). Apart from fitting the correct output resistors to match the impedance of your 'phones (600ohms) there is no setting up. As far as reliability is concerned, I've had mine for 10 years + (I built it when it was first introduced) and and I've had no trouble whatsoever.

Also, do you only run it from SLA batteries ? I know BD wouldn't approve, but I'm considering building a mains PSU for the phones-01 as I'm considering using it in work. I'd probably have the PSU in a separate box so I could easily swap to using SLAs If I wanted.

The amp is powered by two sealed lead/acid batteries (similar to the type used in burglar alarm backups) which are contained in the main case. There is no power supply - an assembled custom designed trickle charger is supplied with the kit and its output is permanently plugged into the amp. When the amp is switched "off" the the charger is connected to the batteries - keeping then topped up when the amp is not in use. On switching the amp "on" the charger is completely disconnected from the amp which is now powered by the batteries. There is sufficient charge in the batteries to power the amp for approx 12 hours.

So, you don't need a mains PSU - the unit is self-contained. All you need is a source and a pair of 'phones.

I see you live in "old South Wales" (?) if that's anywhere near Cardiff, you are welcome to pop over and have a listen - send me a PM if you're interested.

John.