Gordon's System

[Halfway Tree]

I promised I'd get a few pictures posted, so here they are: Michell Hydraulic Reference - no longer hydraulic this has an Origin Live dc motor, acrylic platter mat and RB250 w/Michell Technoweight.
http://i1213.photobucket.com/albums/cc480/musicmusic2/2011_0929michell.jpg
The Curcio Dynaco ST70 was my first foray into DIY, built from an article in Glass Audio magazine almost 20 years ago. It's been a constant in my system ever since. Incedibly reliable (probably shouldn't have said that! :rolleyes:) Black Gate power supply caps, Russian milspec 6922 driver stage, triple regulation = a very modern sounding power amp. The Beard is a monster dual mono amp weighing about 40 kilos and operates in Class A up to about 20 watts.
http://i1213.photobucket.com/albums/cc480/musicmusic2/2011_0930beardst70.jpg
Sitting on the floor on a spiked platform is theCurcio Dynaco ST 70, and behind it the Beard. A 4 channel valve/fet hybrid preamp uses Curcio Dynaco PAS boards fed by two offboard independent regulated power supplies (the oak fronted box). The preamp is remote controlled, can be switched to passive mode (yes, it's in a Dynaco FM 3 case). Above that on the left is the Origin Live motor controller and a Graeme Slee Era V phono stage. Next, a Squeezebox 3 and some Behringer DSP gear - an SRC 24/96, a DEC 24/96 (both these run digital only avoiding their so-so analogue inputs), and a DCX 24/96. The DCX is modded with a high quality cap passive output stage. On top of the rack is a Michell Hydraulic Reference, a Pioneer PD9700, a HP netbook and a 500GB Freecom Harddrive.
http://i1213.photobucket.com/albums/cc480/musicmusic2/2011_0930hifi.jpg
My Shed - The Magneplanar 2.5r's had cracked frames when I got them so I had a local hardwood joiner build new oak frames. They are fed by the Curcio ST70 (for the ribbons, which go down to 1Khz) with the Beard driving the planar panels. Room EQ Wizard measures a low frequency roll off of -3db at 37hz - exactly what Magneplanar claimed for this speaker.The system provides a big, dynamic, open sound that's easy to listen to - it just makes good music really.:)
http://i1213.photobucket.com/albums/cc480/musicmusic2/2011_0930musicroom.jpg

[keiths]

Lovely system Gordon and great pictures.

[Reid Malenfant]

I see a few bits of Behringer kit, i recognise the DCX2496 at the top ;) The others i don't but what the heck...

Nice to see another member thinking out of the box so to speak :eyebrows:

Cheers for posting the pics ;)

[Halfway Tree]

Thanks guys,

Mark - the other bits of Behringer gear are a sample rate converter which primarily is there to reduce jitter (allegedly):) and is fed by the Squezebox's digital output. This then feeds the DEC digital eq unit which if used carefully can help with room bass modes or other problems. This then feeds the DCX - so until the output from the DCX eveything is kept in the digital domain.
cheers
Gordon

[jason]

Very nice system Gordon, I love the speakers too they look great.....

Jason

[John]

Lovelly looking system Gordon

[macvisual]

WoW, lovely system there, superb audio bits & pieces! That dual mono Beard amp looks like a big older style chunky 'Classe Audio' power amp.

I had a pair of 0.6 Magneplannars many years ago, liked them ok.

[Ali Tait]

Nice looking system Gordon. I use a 24/96 to drive OB's actively. Do you have any info on the mods you did to it? Mine is standard at the moment.

[AndrewR]

Now that is a really interesting system, particularly with your own build and re-build.

Andrew

[Halfway Tree]

Nice looking system Gordon. I use a 24/96 to drive OB's actively. Do you have any info on the mods you did to it? Mine is standard at the moment.

Thanks Ali,
Once bitten by the OB bug, whether using cone drivers or flat panels it's hard to go back to boxes. I've had Magneplanars for 30 years now and while not perfect by any means they do many things very well. Using the DCX I was able to integrate the mylar panel and ribbon much better and make for a very coherent speaker.

Regarding the DCX I've done the simplest of the mods which is to bypass the active output stage with high quality capacitors. This takes the signal directly from the DAC outputs, using a high quality cap to block the DC, a single resistor to set the correct loading and another small cap to roll off the h/f noise from the DAC and that's about it.

This French site is excellent for taking you through the process.
http://www.dcx2496.fr/en/tweakanalog1.php
Lots of other mods on the site also, but not all pages translated into English yet.

The passive output mod IMO, not only makes a big difference in clarity and detail but also solves the problem that many people encounter with the DCX - namely the very high output level - after all it is designed for a pro environment.

It's certainly a mod worth doing, whether using caps, a transformer or one of the replacement active output stages available for the DCX.
Gordon

[Reid Malenfant]

The passive output mod IMO, not only makes a big difference in clarity and detail but also solves the problem that many people encounter with the DCX - namely the very high output level - after all it is designed for a pro environment.
Hi Gordon, i find this rather strange as i'm using a pair of them :scratch:

The one problem as far as i can see it is the low input from our hifi kit, what i mean is that even at ridiculous volume levels i'm only seeing an input of -30Db..

With a signal that low the ADC is using a lot less than it's 24 bits so there is a consequent loss of potential quality. Ah, i must remember you are using other Behringer kit to, so this may not be a problem in your setup if you have adjusted gains to compensate :)

Me, i'll be changing resistors to increase input gain & output attenuation at some stage to make more use of the full 24 bits ;)

[Halfway Tree]

You are absolutely right Mark - the DCX is expecting a high level signal (about 8V?), so when it gets a 2v signal it's all a bit low. On the digital front it also expects AES/EBU so spdif is wrong impedance wise (although I never had a problem with this).

The SRC is much more flexible than the DCX in that it can accept optical and electrical spdif as well AES/EBU. The SRC outputs an AES/EBU signal so the DCX is much happier with that. I think the SRC analogue input is also a bit better than the DCX, at least when it comes to level matching. Still has to go through some cheap opamps though.

I find the SB3 digital output level at full output is a perfect match for the SRC so I get to use (I think!) all 24 bits.
Gordon

[Reid Malenfant]

Mine are being fed analogue, so only when i'm listening at rather loud levels do i see -30Db (as i'm seeing now :)). I have no complaints as it's frankly stunning, but i know it could be better if i upped the input level. Unfortunately i can't do that via my pre amp so i'll have to change a few resistors, which isn't a problem.

The results should be pretty interesting as well as linearity will improve quite a bit while the noise floor will remain the same :eyebrows:

I just don't want to be without my system for any real length of time so i'm loathe to strip it :rolleyes:

[Ali Tait]

Thanks Ali,
Once bitten by the OB bug, whether using cone drivers or flat panels it's hard to go back to boxes. I've had Magneplanars for 30 years now and while not perfect by any means they do many things very well. Using the DCX I was able to integrate the mylar panel and ribbon much better and make for a very coherent speaker.

Regarding the DCX I've done the simplest of the mods which is to bypass the active output stage with high quality capacitors. This takes the signal directly from the DAC outputs, using a high quality cap to block the DC, a single resistor to set the correct loading and another small cap to roll off the h/f noise from the DAC and that's about it.

This French site is excellent for taking you through the process.
http://www.dcx2496.fr/en/tweakanalog1.php
Lots of other mods on the site also, but not all pages translated into English yet.

The passive output mod IMO, not only makes a big difference in clarity and detail but also solves the problem that many people encounter with the DCX - namely the very high output level - after all it is designed for a pro environment.

It's certainly a mod worth doing, whether using caps, a transformer or one of the replacement active output stages available for the DCX.
Gordon
Hi Gordon,

Thanks for the links, I will have a look. I agree entirely about the OB thing, I also have a pair of ER Audio statics, for which a friend is building me a pair of GM70 direct coupled monoblocks, which I'm much looking forward to!

Like Mark, I'm only using my DCX in analogue, but I get plenty drive from my WAD Pre 2, so I will have a go with the passive mods just out of curiousity, though I agree with his comments that it's a great sounding bit of kit. Can't help myself though, I'm just an inverterate fiddler!

[Halfway Tree]

This valve tester I built last winter has almost become an integral part of my system. The circuit came from a member of the Vintage Radio forum. It's a true transconductance tester and uses the valve settings from an Avo CT160 manual. Great for matching valves. The curved side pieces are a bit of a homage to the Avo MkIV - a beautiful piece of kit - but good working ones are way out of my price range!:)
Gordon
http://i1213.photobucket.com/albums/cc480/musicmusic2/SussexVT1ecc83.jpg

[Ali Tait]

Very nice Gordon.

[Spectral Morn]

Very nice.


Regards D S D L

[Halfway Tree]

Thought I'd update you on my system since it's been over a year.

I've put together a digital pre/crossover/eq using a couple of circuit boards from miniDSP to replace the various Behringer digital boxes I had. The miniDSP kit is very versatile and excellent value for money. I'll get around to putting some markings on the case one day, but the left knob selects between the four digital inputs (there's also a pair of analogue inputs) and the right knob is the gain.

Digital outputs go to a Benchmark DAC1 (low frequencies) and an Audiolab M-dac (high frequencies). These in turn drive a Jungson JA99C and my Beard P100 biamping my Magneplanar 2.5Rs.

Sound-wise there's been a considerable gain in bass power and dynamics as well as detail, yet I can listen for hours without any sign of fatigue.

http://i1213.photobucket.com/albums/cc480/musicmusic2/gordonhifidec2012dspdacstunercd.jpg

[Rare Bird]

http://i1213.photobucket.com/albums/cc480/musicmusic2/2011_0929michell.jpg


Seems i missed this originally! nice one.. :)

[jandl100]

-----

Digital outputs go to a Benchmark DAC1 (low frequencies) and an Audiolab M-dac (high frequencies). -----

Ah. Curious!

Have you tried the other way round, with the MDAC on the lows and the Benchmark on the highs? - for my tastes, that would better play to their strengths and errr -- weaknesses! ;)

[Halfway Tree]

You could well be right. That might work better in some systems and I did try it out.

For me there are several reasons I have them the way I do. In my system the Benchmark sounds the punchier of the two dacs. The MDAC's filters are really useful at the top end, minimum phase suiting me best, but I do use a couple of others occasionally.

These are the main reasons, but there is another reason. The MDAC's volume control is digital (the benchmark's is analogue) and the Beard power amp is relatively insensitive compared to the Jungson, so I can have the MDAC's volume control at a point where I'm using all 24 bits that the miniDSP puts out, typically at about -13db.

The miniDSP also has a digital volume control so with full output from my SB Touch or CD player it also operates in the 24 bit zone. I don't want to be throwing bits away in either the preamp or dac.

Here's the power amps and speakers.

http://i1213.photobucket.com/albums/cc480/musicmusic2/gordonhifidec09201201.jpg

[Barry]

Wow! :eek: Are those Apogee Ribbon speakers? Nice - very nice!

[Halfway Tree]

Thank you - they're 30 year old Magneplanar 2.5Rs with custom oak frames. The 2 series hasn't been made since the 80's. The ribbon in these crosses over to the mylar bass/mid panel at 820hz which is quite low. Given a good recording vocals can sound very realistic. But the speakers are not limited to one style of music - as you may have realised from the framed records I have a passion for 70s reggae. And big latin bands like Fania All Stars can sound - well, big and brassy!

I should clarify that the sofa is not my listening position - I needed somewhere to store it and it seems to make a decent absorber/diffuser!

[Barry]

Ah! I didn't recognise them as Maggies. I love 'planar' speakers. :)

[Halfway Tree]

They do have special qualities and Maggies are one of the cheapest ways to experience the planar sound. They are also incredibly robust - I also have a pair of MG1s which I bought in 1980 for $695 when I was living in the US - they're still going strong.

[Halfway Tree]

Have recently completed the bass section of Siegfried Linkwitz's LX521 dipole speaker. Currently using them to add a bit more welly to the bottom end of my Maggies. Driven by a QSC RMX1250 they have seamlessly blended in with the Maggies. I'm using a miniSHARC for the crossover and EQ and three Curryman I2S dacs. Listening to all my reggae all over again!:D

[Halfway Tree]

Finally got around to taking some photos of my Linkwitz LX521's which I've been running for about 3 months now. First time I've not been using Magneplanar speakers for more than 20 years and first time without valves somewhere in the system for about the same length of time.

http://i1213.photobucket.com/albums/cc480/musicmusic2/LX521-600_zps4apxrxik.jpg (http://s1213.photobucket.com/user/musicmusic2/media/LX521-600_zps4apxrxik.jpg.html)

The upper baffle sits on a bridge which prevents vibration from the woofer and can be toe'd in as required.

http://i1213.photobucket.com/albums/cc480/musicmusic2/LX521Upperbaffle-600_zpsfnazqksa.jpg (http://s1213.photobucket.com/user/musicmusic2/media/LX521Upperbaffle-600_zpsfnazqksa.jpg.html)

The upper baffle is CNC'd from 5 pieces of oak.

http://i1213.photobucket.com/albums/cc480/musicmusic2/LX521woofer-600_zpsmknolxg3.jpg (http://s1213.photobucket.com/user/musicmusic2/media/LX521woofer-600_zpsmknolxg3.jpg.html)

The woofer section is 18mm birch ply with a V-frame mounting for the drivers.

They have that same large soundstage as the Maggies, but with more focused images, better detail, dynamics and bass power. I'm thoroughly enjoying them - going through my music collection all over again! :D

Gordon

[Ali Tait]

Very Nice!

[struth]

Very Nice!

+1

[Anthony K]

Sorry , may I just ask , on the wall you have Garveys Ghost (Spear) Catch a Fire - Seriously valuble if orig 1st press zippo (Wailers) and what is the 3rd? as I cant make out due to reflection (looks like Natural four)

[Halfway Tree]

Thanks guys, it's been a rewarding project.

Anthony - you are spot on - Garvey's Ghost was the first dub album i ever bought (I don't think I had a clue what a dub album was at the time). The zippo lighter Catch a Fire is a promo copy as it has a small hole punched in one corner. The third album is Jimi Hendrix -Are You Experienced -a US pressing. But my prize Wailers album is a BBC recording of the Wailers live in 1973 at the Paris Theatre.

Gordon

[Marco]

Congrats, Gordon. That’s a superb system (and lovely room) you’ve got there. Perhaps I missed it, but are your new speakers the result of a DIY project or are they commercial designs?

Some more info on them, including any relevant links to their design, would be useful :)

Marco.

[Halfway Tree]

Thanks Marco - The room is some converted stables at the back of my house - every man has to have a shed! :)

The speakers are a Siegfried Linkwitz design. They are active, utilizing 6 channels of amplification (lower and upper mid drivers use a simple 6db/oct passive x-over). The upper drivers are a relatively easy load, but the bass units do drop to 2ohms at about 100hz, so need an amp that can deliver some current. If I was to single out one thing that the speakers do exceptionally well its their disappearing act and the creation of what SL calls "the auditory scene."

Plans can be purchased from SL for about $100 or so. All the info regarding where to buy the drivers in the UK (and a kit in Germany) is available from his website, so I won't go into more detail here - http://www.linkwitzlab.com/. The site is well worth a read for anyone interested in loudspeaker design and especially so if dipole theory is of any interest.

Gordon

[RichB]

Thanks Marco - The room is some converted stables at the back of my house - every man has to have a shed! :)

The speakers are a Siegfried Linkwitz design. They are active, utilizing 6 channels of amplification (lower and upper mid drivers use a simple 6db/oct passive x-over). The upper drivers are a relatively easy load, but the bass units do drop to 2ohms at about 100hz, so need an amp that can deliver some current. If I was to single out one thing that the speakers do exceptionally well its their disappearing act and the creation of what SL calls "the auditory scene."

Plans can be purchased from SL for about $100 or so. All the info regarding where to buy the drivers in the UK (and a kit in Germany) is available from his website, so I won't go into more detail here - http://www.linkwitzlab.com/. The site is well worth a read for anyone interested in loudspeaker design and especially so if dipole theory is of any interest.

Gordon

Hi Gordon,

I think you mentioned these as a work in progress when we last met. Easier to get my head around them now after seeing pics.

Room and system looks great, bet it sounds nice too.

R

[Marco]

Thanks Marco - The room is some converted stables at the back of my house - every man has to have a shed! :)

The speakers are a Siegfried Linkwitz design. They are active, utilizing 6 channels of amplification (lower and upper mid drivers use a simple 6db/oct passive x-over). The upper drivers are a relatively easy load, but the bass units do drop to 2ohms at about 100hz, so need an amp that can deliver some current. If I was to single out one thing that the speakers do exceptionally well its their disappearing act and the creation of what SL calls "the auditory scene."

Plans can be purchased from SL for about $100 or so. All the info regarding where to buy the drivers in the UK (and a kit in Germany) is available from his website, so I won't go into more detail here - http://www.linkwitzlab.com/. The site is well worth a read for anyone interested in loudspeaker design and especially so if dipole theory is of any interest.

Gordon

Very, very interesting indeed, Gordon. I applaud your lateral thinking, and it's always nice to see kit that's different from the norm. Having had a quick read through the site, I like Mr Linkwitz's approach and design principles, with speakers. Would be good to come and have a listen sometime, if you're up for that? :)

Marco.

[Halfway Tree]

Glad you found it interesting, Marco.

You are welcome to come and have a listen - I'm sure we can work something out especially now I'm semi-retired and can pretty much set my own work hours.

Need to go out with family right now, but we can discuss in more detail later.

cheers

Gordon

[Marco]

Sure, no worries. If you PM me with some dates in April, we should be able to sort something out :)

Btw, have you been to any of the NEBO bake-offs? They're bang in your neck of the woods!

Marco.

[Halfway Tree]

Hi Marco,

to answer your second question first - yes, I've been to several NEBOs - in fact at the last one we had a long chat about your Celestion 66s when you took them to Scalford several years ago. I almost went out and bought some right afterwards - they really shone that day.

Talking about Scalford - are you going on Sunday? - if so we can chat about suitable dates then - I'll be going along with Ken (Qwin).

Gordon

[Marco]

Hi Gordon,

Sorry, I can't remember the convo we had at Nebo, but then I was talking to lots of people about various things.... Can you think of a way of jogging my memory? :)

Anyway, yup, I'll be at Scalford on Sunday, so we can have a chat then. I'll keep an eye out for Ken, as I know what he looks like! :cool:

Marco.