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AmpFest 2010-11 Down Under
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Author:  mwhouston [ 13 Feb 2011, 16:28 ]
Post subject:  AmpFest 2010-11 Down Under

A few years back I rounded up a three local and one inter-state DIYer for an amp and equipment shoot-out at my place in Southern Victoria Australia. The first year we did this was 2009 and the day was labeled "AmpFest Down Under 2009" or AmpFestDownUnder2009.

The 2010 AmpFest got postponed to early 2011 due to the fact the inter-stater, Dan, could not get over 'till then. We held the day at Dave's about 40mins drive from the three local DIYers. And even closer to Dan once he was over in Vic from South Australia.

Dave had just purchased a pair Osborn Monuments which sell locally for $AU26. Dave had also just completed a Pass F5. These we must hear.

Equipment listened to:

Mark: (mine) 3W SET amp. my verson of the boozhoudlabs Le Pacific phono preamp and Pass BoZSE preamp
Paul: Hafler preamp, original but tweaked Le Pacific phono preamp
Dan: Two stage tube preamp (6SN7) and his (from 2009) Hiraga La Class A about 70W
Dave: Pass F5,

My summation of the Day: Once more I felt the Hiraga the best power amp for better textured mids and articulated bass. Dave's F5 had deeper heavier bass but a thin airy (for me) mid range. Dan's tube preamp shows great promise and we are hoping Dan will continue to improve it and bring it to AmpFestDownUnder 2011.

Paul's Le Pacific really shone and out-performed my BHL Le Pacific with a much clearer mid-range. Paul's Hafler did not impress me but Paul says it works better with Quads at home.

My 3W SET did not like the Monuments and though the others liked the sound I felt the amp did not shine with these massive speakers. I doc file will be loaded to this post with images of the day.

Author:  Dan [ 14 Feb 2011, 20:10 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Hello All

Amp fest 2010-11

Venue: Dave Duffen’s House, Melbourne Victoria, Australia.

Dave Next to an Osborne Monument speaker
Dave - Osborne Monument Speaker.jpg

This year we had three amps to listen to and three preamps.
Two of amp designs have reputations that precede them……

Dave Duffen's Nelson Pass F5 build
Dave Duffens - Nelson Pass F5 build.jpg

My Jean Hiraga Le Class A
My Jean Hiraga Le Class A.jpg

Mark Houston Also brought a Tube amp with ground shaking 3 watts of single ended indirectly heated triode fury.

Mark and His 3W Single ended class A tube amp
Mark and His 3W Single ended class A tube amp.jpg

The three preamps were, the modified La pacific in a gold case, modified Hafler DH101 and La Pacific built point to point on copper PCB.

Hafler preamp
Hafler preamp.jpg

Author:  Dan [ 14 Feb 2011, 20:24 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Gold box La Pacific 36V lithium powered “naked”
Gold box La Pacific 36V lithium powered.jpg

La pacific point to point copper 36V lithium powered close-up
La pacific point to point copper 36V lithium powered.jpg

The following components were used:

Speakers: Osborne Monument’s all 160kg (each) of them
Speakers Osborne Monumens.jpg


Turntable 2
Turntable 2.jpg

Author:  Dan [ 14 Feb 2011, 20:33 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Leads… Bi Wired Cat 5 leads, DIY silver highways, fine wires, OFC’s, and Dave’s Special solid coax leads with drain wires.

Power conditioner hiding in the cupboard below the screen. Sound deadening on rear wall open cell diffractive foam (correct me if I am wrong here).

Anyhow on to the music, first off we listened to XXXXXXXX from Dave's collection on CD via a passive attenuator then some classical and also some Herbie !@#$%^& using the Pass F5 which had been thoroughly warmed up, Having built a Pass F5 myself in 2010 using a regulated supply I was familiar with its sound, and true to form in Dave’s high quality build It did not disappoint, with extremely low, clear and defined bass, crystalline and precise top end and reserved yet clear midrange. Nelson Pass truly has designed an excellent amp with this one.

Next we tried the Hiraga in the same system with the same few tracks, the amplifiers certainly sounded different and but not dissimilar, To my ear the Hiraga has ever so slightly more midrange a little less tightly controlled bass although it still extends to the same depth as the F5 however the treble is slightly less bright. I could certainly live with either amplifier. One thing I did notice was the F5 was noticeably quicker to thermal stability in comparison with the Hiraga and the difference between the sound from cold to warm – or warm to hot rather was more pronounced with the Hiraga.

I actually like both amplifiers for different reasons. The F5 portrays a very clear and distinct sound stage as discussed on the night where the Hiraga displays a little more emotion in the music – somehow… If you have the required skills then either amplifier is a worthwhile project to build.

The next amp in the list was Mark Houston’s 6AS7 single ended class A triode amp fed via the La Pacific which boasted approximately three watts of output. With Dave’s fantastic Osborne speakers this amp gave excellent results showing that moderate to high sensitivity speakers do not require a lot of power to sound dynamic. Voices and instruments had an excellent earthiness and a certain realism and of course the classic single ended triode sound that so many are fond of.

After this we auditioned the La pacific in two forms marks veroboard build in a gold box and Paul’s point to point copper PCB construction, both were used with 36V of lithium batteries providing a very clean power source for phono preamplification.

Personally I am not a vinyl enthusiast but done correctly it can sound very good and after some setup tweaks both preamps performed well. The Hafler did not fair so well there was a glitch with the setup somewhere when we tried this.

And I nearly forgot… the other preamp. My 6SN7GTA tube preamp built in a rack chassis. This is an unfinished build in need of some tweaks to the power supply to reduce the turn on thump and output cap charge times there was some promise shown with this design but it is a work in progress.

Please see a few more pictures attached apologies for the clarity they are from a mobile phone with a grubby lens. I did not bring my camera unfortunately.


Tube preamp > Le Classe A
Tube preamp Le Classe A.jpg

Action shot
Action shot.jpg

Listening 2.jpg

Author:  Dan [ 14 Feb 2011, 20:39 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Mongrel dog audio preamp
Mongrel dog audio preamp.jpg

Twin level leather recliner opulence…
Twin level leather recliner opulence.jpg

Mark Houston, the man the myth…. The Man behind Mongrel dog Audio.
Mark Houston, the man the myth.jpg

AR Turntable
AR Turntable.jpg

Fancy Vinyl
Fancy Vinyl.jpg

Author:  Gio [ 16 Feb 2011, 13:19 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Great notes guys. Thanks for sharing. Just another reminder for me that I need to push on with my F5 build.


Author:  dtsup1 [ 17 Feb 2011, 09:51 ]
Post subject:  Re: AmpFest 2010-11 Down Under

WOw nice report.

Aren't the speakers too close to the wall ? Did it have any effect on the sound ?

@Mark - Omg you gained so much weight ?? LOL
Love this quote " Mark Houston, the man the myth…. The Man behind Mongrel dog Audio."

Author:  Gio [ 17 Feb 2011, 13:26 ]
Post subject:  Re: AmpFest 2010-11 Down Under

We will have to put Mark on a strict diet of high efficiency amplifiers - class-D and class-T! :twisted:

Oh I can hear the complaints already!

Author:  mwhouston [ 17 Feb 2011, 15:33 ]
Post subject:  Re: AmpFest 2010-11 Down Under

Dinesh: you knew me when I lost a stack of weight. I have put back on most of it.The room is probably too small for the speakers. Not a lot of room and they can't be moved. Too heavy.

Class Ds are getting better but still not for me.I have a few more tube amps ahead.

The Man the Myth. I can live with that,

Author:  dtsup1 [ 18 Feb 2011, 01:44 ]
Post subject:  Re: AmpFest 2010-11 Down Under

You were trim and fit when I last met you. Try and do more exercise ! hahaha :mrgreen:
mwhouston wrote:
Dave had just purchased a pair Osborn Monuments which sell locally for $AU26.

You surely mean AU 26K ! :D

Was the best combo = Hiraga amp + Boz SE preamp ?

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