New Phono/Pre III build

[david beard]

Hi Tom,

I'm willing to bet that as soon as you try the PhonoIII / Pre III pairing you'll take a break from construction to do some listening!

I'm an incurable tweaker but they were enough to have me put down my soldering iron for the best part of a month and just listen to music, to be honest I'm only back on the "tweaking / projects" trail now because I got an opportunity to pick up some Hypex Class D amp modules at a bargain price and just couldn't resist an experiment!

(Class D powers driven by PHONOIII / PRE III - can't wait to try it!)


Cheers
Dave

[mikew27]

Dave,

That is what I am hoping to do at some point when I am confident of my soldering skills (more practice needed) & SWMBO releases the finances to buy the stuff! LOL!

Which power version of Hypex modules will you be using? I am reckoning I'd need (at the very least) the 400 to satisfy my current-hungry B&Ws.
Will you be using Hypex's own power supply, transformers & regulators?

I would be very interested in hearing your setup when you finish fettling it.

Michael

[david beard]

Hi Michael,

A couple of quick points,

1) I'm using the UcD400HG with HxR regulators along with Hypex own MonoHG Psu, 500VA transformers and soft starts so truly an all Hypex set up.

2) You're welcome to come for a listen once my monoblocs are built BUT
(a) it may be a while as I have to sort out chassis for them and for me that's the difficult bit and (b) I'm in Abu Dhabi so getting here may cost you a few bob!

3) The Hypex modules all use a combination of FASTON and screw terminals so there's actually very little need for soldering skills.

I'll post a build blog and comments here once I actually start putting them together,

now back to the thread topic - Enjoy your PhonoIII / PREIII

Cheers
Dave

[mikew27]

Dave,

It was the soldering involved in the Pre3/Phono3/PSU3 i was worried about

You are right that Abu Dhabi might be a bit far to go for an audition.

I thought that these looked rather nice enclosures: -
http://www.hexateq-av.com/standard_enclosures.html

and even she might not mind them too much. LOL

Michael

[david beard]

Hi Michael,

Yes the Hexateq enclosures do look nice but there are a couple of problems with using them for my planned monoblocs (1) I don't think the 500VA transformers will fit the mono enclosure and (2) have a look at the pricing once you add the various options for connectors power sockets etc!

They really do look lovely, I've seen the stereo version "in the flesh" but they are just a bit too pricey for me at least until I'm really certain that the Hypex amps are "keepers"

Right now I'm seriously considering a couple of these:-

http://www.autocostruire.com/catalog...roducts_id=326

They are a lot less costly and whilst nowhere near as wonderful looking as the Hexateqs I think they look good enough for SWMBO to permit access to our home.

Cheers
Dave

[tomtidswell]

Two comments:

Michael - I am not an experienced solderer (bit of hobby electronics as a teenager, then had to do some 10 years ago in research), however the World Designs Pre3/Phono3 build has been an absolute joy:
1. The instructions are brilliant (occasional slight errors - i.e. measurement of cables, but as too long, easy to put right).
2. The design of the kits (everything packaged in individual plastic bags in a reel, with components labelled - no errors found at all, so well done WD)
3. The circuit design and layout of cables, components, PCBs, switches and transformers just smacks of great design and forethought.

I have spent about 1-2 hours a day for the last 2-3 weeks, and estimate that each part of the build takes a week.

I would recommend some good tools (the expensive soldering iron from WD is well worth it), and a bench vice is an absolute must.

Other than that I think anyone, with a bit of soldering/electronic experience at a mild hobby level, should be able to do it.

AS this is a long post, I will go to the next.

Tom

[tomtidswell]

Hi Dave (and anyone else watching the build with baited breath).

I'm near completion of the Phono 3 and deciding which way round to wire the transformers (I will now have to purchase a low output MC to test it). Does a 0.5mV output constitute low or high output, as far as the transformers are concerned?

The kind people at WD sent me a replacement capacitor to replace the polystyrene one I burnt, and I also got some Soniqs caps to replace the orange drops in the output stage (I thought I may as well, along with more cable and connectors). They arrived next day (so thanks Andy).

The anticipation of wiring it into my system is almost palpable (at home here at least, maybe not on the forum) - I have my Jazz collection (with some other genres) lined up next to the Michell Gyro.

Hopefully I will show some piccies when finished.

Tom

[david beard]

Hi Tom,

The question of high / low mc output is one I debated long and hard (at least in my mind) I use a 470uV Ortofon Rondo Blue and a 500uV Kontrapunkt b so very similar to your 0.5mV. I wired the transformers for x10 i.e. low gain and have been very happy with the result.

I couldnn't say x20 would be "wrong" as it's a bit of a "suck it and see" issue but I'd be inclined to go with x10 and only if you have issues with sigmificantly lower volume from phono than any other source consider re-wiring for x20. Personally I think it would only be necessary with very low o/p cartridges like the Denon 304.

That's my 2P worth!

Cheers
Dave

[tomtidswell]

Thanks Dave,

I am considering a Kontrapunckht (?sp) model which seem to be favourites with HFWorld, although a similar output Van den Hul MC 10 (2nd hand, re-tipped) may be within reach, if still available.

I will wire the transformers to x10 tonight in anticipation. The only thing I will have to redo is the loading resistors which are currently a bit high at 82k (the only ones spare in the Phono3 set, but thought I would wire them in now as access is a tad fiddly). I'll only be able to try out the high output MM input as my Dynavector MC has a 2-2.5mV output. Still wondering how much improvement I will hear, given that I still have an old transistor front-end in the Quad 405, but should be a difference between the solid state MM input in my Quad 44.

Best wishes

Tom

[GolfBalls]

Tom,

Sorry to ask what may be a silly question, but as a complete newcomer, can you please tell me to what purpose you put a bench vice when building these kits.

Thanks

John