AudioCircle
Other Stuff => Archived Manufacturer Circles => Paul Hynes, Paul Hynes Design => Topic started by: steve2701 on 18 Dec 2010, 03:48 pm
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Hello to all.
I contacted Paul some time ago and requested some details on modules for a DIY dac build - the 'Twisted Pear Buffalo II'.
I also said that I would be happy to post the build process on here and keep a type of 'blog account' of how it all goes.
This is a long term build - it is simply to expensive for me to buy everything at once and put it together, but I am very much looking forward to it.
I am looking to do this to the best of my ability (somewhat limited electronics wise) and get the best I can out of the components without going totally overboard on modding the individual boards supplied from anyone. I know there will be some - but it will be limited.
This will end up as either a two or possibly three box design.
Crazy possibly, but the intention is to build it dual mono - fully balanced, with totally seperate power supplies for both analogue and digital (= lots of transformers) and probably keep the dac and output stages in their own seperate 'quiet room' which will also probably be shielded.
I have today been one of the lucky folk to be online and get a couple of the dac boards from TP - so they should ship at the end of January. Until then I can take serious notes of everything else I will be needing - casework, transformers, power supplies output stages, connectors and cables etc - along with the fine detail of front panels, rear panel inputs and outputs - all a bit daunting really.
I know I am going to need help - so please feel free to offer advice if you see me heading for major foopar.
I am looking to input data from my iMac via USB (hopefully on the upcoming asynch usb input also from TP) & have the dac output in balanced AES/EBU for input into my Simaudio Moon system. It might also be fun to have inputs available from a couple of sources like a CD player and DVD that have digital outs - but that decision can wait for a week or so - as complex switching could end up confusing.
OK - thats enough for a first post here, and I'm looking at this being a fairly long haul.
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I had an interesting chat with Paul today, and some good suggestions were made as to how I might proceed, and where I would like to end up.
Followed that with another interesting conversation with a transformer manufacturer who may be able to make what I am looking for, and also hopefully help with the actual requirements I may need, like will single output transformers give a performance boost to above those having dual etc. This could lead to a lot of transformers being needed, but if it's worth the effort - I will be visiting it for certain.
This is going to keep me occupied for ages - that's a certainty.
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I finally got round to ordering another couple of bits today. Two 'Legato' full kits and two additional boards.
My intention is to build the two 'kits' totally stock, and the two boards will be populated with what I want them to be - ie, somewhat 'uprated' components.
The kits will allow two things - 1) a working dac fairly quickly & 2) a reasonable comparator when the other boards are finally completed.
Two more things got ordered as I didn't want to lose them - LME49720 'metal can' op-amps that will replace (the same but non can) LM4562.
Feels like something is happening at last, not certain when the Legatos will get here but the Dac is due to be shipped at the end of the month (Jan).
The shopping list for the bare boards is already looking rather expensive, z foils, tants, Mundorf silver/gold in oil, os cons, tx2575 etc, but it is an interesting list - I just hope that it returns a rather nice sounding signal.
The designs for the PSU's are coming together, along with the thoughts of Paul on just how these are to be implemented / wired so that every single ground plane is kept seperate and silent.
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Where do you hope/think "boutique" components will be of most benefit on the Legato's?
Thanks,
Nic
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Hello Nic,
A very good question and one that has had me reading literally thousands of replies on hundreds of threads about this stage.
My single aim is to get a signal that is as un-polluted as possible , ie, I want no colourations whatsoever if I can possibly get that far.
From that standpoint virtually every component has some importance to it - so getting them all as close to possible to not altering the signal is the aim.
If there is a component that is better than another at this and it happens to be cheaper - fantastic - it will be used. Unfortunately this rarely seems to be the case.
For those that know the circuit my current (and may well yet change) if incomplete list changes the op amp to the metal can version, its associated 100nf caps to mundorf ag/au in oil, the 4 15nf output caps to mundorf ag/au oil probably 5nf or lower, the 1w resistors to be z foils / tx2575.
I am still studying if other caps need changing - those chosen already will need some imagination in their fixing to the board due to physical size. The actual power supplies via Paul may well impact on some of the values already chosen - - I dont know yet. As I said at the start - this is a long term progect so I have s fair amount of learning to do yet for certain.
I am also certain of another thing - the actual supply of power to these modules is going to be very special indeed - but more on that later. That will probably have a far greater effect than a great many of these component swaps, but will hopefully make them even more necessary.
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At last,
Something arrives and I can at least start to do something physical.
Two complete Legato kits, and two spare boards for messing with. I'll post some pics later of what the full kit is.
Parcel force charged £13.50 to take the £8.50 Vat off me for the UK government... (Clearance fee they call it)
Well packaged and looks totally professional I must admit.
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Hello Steve,
Here is the drawing you requested during our telephone discussions.
http://i700.photobucket.com/albums/ww7/paulhynes/PR3PPRAP.jpg
For those who are not up to speed with the ideal power supply arrangement I have included a brief explanation below.
There is a tendency nowadays to power all sub circuit sections of a piece of audio equipment from the same master power supply to save production costs. This automatically produces voltage errors in the ground system because all the ground return currents for all the sub circuits return to the same ground on the master power supply, often mixed along the way by using common ground tracks or planes, which exasperates the interaction between the sub sections using the ground system as a ground reference. This is problematic when using series regulation for the various sub circuit sections, with varying load current draw, as it causes signal related AC and DC voltage shifts in the power supply grounds. Voltage shifts also happen when shunt regulation is used to regulate the sub sections as the constant load current these regulators present to the power supply introduce a DC error that is relative to the actual DC resistance of the ground return. Any sub circuit section that requires a tight voltage reference will have this DC error added to its voltage reference.
The PR3PPRAP (PR3 pre and post regulator application) shows the ideal connection system for one sub circuit section load. Using two regulators in series (Pre and Post regulation) provides a double layer of mains power supply line interference rejection making the equipment less prone to performance variation when the mains power is dirty during high grid usage.
One PR3PPRAP is used for each sub section of the equipment circuitry. Circuit sections requiring a negative voltage rail would use NR3PPRAP constructed using negative voltage regulators. The 0V connection from the post regulator to the load should be connected to the ground terminal of any local load decoupling used in the subsection to be powered. The post regulator +VE connection should go to the positive terminal of the local decoupling. This keeps the ground return currents of each section out of the main earth reference system on the board allowing a very clean earth reference for the whole system. This makes a big difference to the resolution of dynamic scale and micro detail presentation. Timbre and tempo are improved and there is a reduction in confusion in the soundstage particularly when the music gets busy. Music just sounds more like real people playing music.
Setting up the power supply properly where the equipment to be powered has many subsections can be rather expensive and time consuming. Few will venture along this path. Steve is one of the few.
Regards
Paul
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Thanks for that Paul, I'll be printing that off on Monday and studying it.
I am so looking forward to travelling this path - the final destination is very tempting.
A couple of pics just for starters of the kit & how it arrives (Legato) and my first basic layout board. The idea for me is to build the two full kits as completely stock, then start the two bare PCB's as the best I possibly can with no holds barred components where I can.
As outlined by Paul above this is probably going to be a fairly monumental build for me, especially as I have not done anything like this for a while.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4372.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4375.jpg)
I promise the pics will get better, my garage was freezing and I need to get some brighter lights so I can get the lens to work properly.
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Well it's been 35 yrs since I wielded a soldering iron to do work like this - so this board is going to teach me a fair bit. Some close up photos show that a little more solder was needed in some cases - but that can soon be put right. A bit of flux cleaning may be in order as well I guess. Close inspection showed no dry joints or crossed traces - so I'm happy for now.
A couple of hours this afternoon saw all of the resistors in place and a couple of caps.
Tomorrow , if I can grab an hour or so will see me attempting the first multipin opamp ever, they look a bit close together do those legs. I need the eyes I had thirty years ago..
This shows where this board will sit, the next will be to the right. Hopefully the clear l/h side and front will be enough for a couple of psu's.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4381.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4386.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4382.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4391.jpg)
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Thank you for including us in your project Steve. I look forward to your sharing of your time and experience. Much appreciated!
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Those op-amp legs are just a bit small, but a small bit in the iron and my strongest glasses - all went to plan, I think.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4404.jpg)
Time allowed me to not only complete the first board but alos the second as well. Mind you, a bit of practice soon gets speed up.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4393.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4395.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4397.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4403.jpg)
Next is to put a couple of connectors on a back panel for signals in & out.
Then comes the interesting bit - power for the things.
I intend to get power to these and the dacs with modules that can then be used with the final build.
Hopefully it becomes a bit more interesting from here on.
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I managed to spend a couple of hours over the weekend knocking up a basic back panel for input / output. A pair each of RCA's & XLR's for output (I usually run fully balanced) and a 75 ohm BNC for spdif input duty.
Even trying very hard I managed to reverse one set of xlr wires, but spotted that when staring at them through the camera lens...
I have the basic list of PSU's to get this running, and the dac boards are due for despatch now.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4406.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4411.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4410.jpg)
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Hi Steve,
I'm working on a very similar project - also long term. If you don't mind I could post my progress in this thread and we could share experiences. For tasters I have attached a photo of one channel of the dual mono build. The other channel is on the listening and measuring test-bench.
Cheers,
Nic
(http://www.audiocircle.com/image.php?id=42768)
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Hello Nic,
I have no worries about you posting on this thread, as you say, it could be very useful.
My dac boards finally arrived late last week (no duty this time - go figure!!) I'll post a couple of pics up shortly of those in their 'bare' format.
What supplies are you using from Paul - the ones listed above? I see your way of getting them onto the board - I like that.
I'm just saving my pennies for the initail build - and getting very itchy fingers in the process.
Are you going to just supply the dac with SPDIF or are you considering USB as well?
I'm guessing that your not using Legato boards? They appear to have changed resistors & resistor makes not so long ago - this is something I intend to seriously look at in the final build.
I also need to be thinking about the actual voltage of the balanced output - my pre 'expects' to see 4v, not the 2v that these put out as std. I don't think this will make a jot of difference when all is said and done, as it just means less attenuation, but it is all interesting to me.
Intersting looking picture there - I just hope I can get to the same level soon.
Cheers,
Steve.
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Hi Steve,
For the Buffalo I'm using:1x S17LN-1v2 (DAC), 2x Z17LN-3v5 (AVCC, I think set for 20 mA) and 2x Z1703v3 (DAC and XO, set for 120 mA). All these are powered by a single PR3G2-5v5. I think some use Z1A-5v5 for this job but with my (limited) understanding I fail to see any good reason to power a constant load (like shunt regs) with another shunt reg. I might also try a 1v2 shunt reg in place of the current S17LN-1v2, maybe a Trident from twisted pear.
For the I/V-conversion I'm testing/comparing IVY III and Legato 2. At the moment I actually prefer the IVY III but this is maybe because I have been listening to this for much longer and have gotten used to it. Anyway, both are powered in the same way with 3 set of S17/37LN15 (2 sets when not using the onboard Bal/SE stage which is mostly the case for me). I'm using balanced loads; UcD based DIY power amp or head-phones (when family imposes it). My loads do not tolerate DC-offset well and as a fully DC-coupled discrete amplification chain is my main design goal I have added two twisted pear Ventus modules that perform the Bal/SE conversion and allow me to adjust down DC-offset when I bypass the output caps on Legato. I'm not using a pre-amp and do attenuation in the digital domain (virtually a free lunch with a 32-bit dac). For the Ventus stages I'm also using sets of S17/37LN15 for power. All 4-5 sets of S17/37LN15 are powered by a set of P/NR2G3-20. I might try a shunt reg for this purpose but the current draw is significant and I already will have quite a bit of heat generated in the yet-to-be-build cabinet. If Paul H would have a Z1A-20 with on-board rectification and where I could easily tune the shunted current down to a reasonable level I might very well try it. I like the idea mating shunt and series regulators in dual regulation circuits as it simply makes sense to me. The DAC will have a single high-quality custom made transformer (for both channels) with a single primary and 4x 20V + 2x 9V secondaries. This may be a weak point but I doubt it with two levels of regulation at all points. I would like to try Z17/3715 shunts in place of the current S17/37LN-15 series regulators but I believe there may be prohibitive heat dissipation issues. I have measure the current draw on all rails and if interested I could list the.
My IVY III and Legato 2 are only moderately tweaked as the components provided by twisted pear are already of very good quality. Also, improving power supplies in my experience alway improve more that resistor swapping and should therefore be done first. I can post some details/photos if you are interested. The gain can be adjusted on both Legato and Ventus. With the standard configuration I will have 2.4V (with Legato) and 4V with IVY III - I believe.
I'm using the Buffalo with S/PDIF (mostly a SB Touch, 24/96 capable) or I2S sources. Of the latter I like very much the 32/192 capable UC192 USB2->I2S "transport" from Kingrex, but will also soon test a jkeny modded HiFace.
My final goal is actually a three cabinet solution; a "pre-DAC" (i.e. a digital input selector and DAC controller), the DAC and the power amp. The umbilical cord between the pre-DAC and the DAC will be a "HDMI" interface with differential transmission and galvanic isolation of I2S, DSD or S/PDIF. This interface also carry I2C so the Buffalo can be controlled (attenuation etc.) from the pre-DAC.
Cheers,
Nic
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Hi Nic
I wouldn't necessarily assume that the shunt regs will give the better result in a particular application- try them and see! For example Leo told me a while back that he thought he preferred S17LN regs for AVCC duties over Z17. This was only a preliminary observation, and he may have changed his mind. But if so, it might be because the S17LN regs are even lower noise that the shunts- Paul H could confirm?
Have you listened to your dual mono setup next to the usual single Buffalo approach? Is all that extra complexity really leading to a better sound? I commend you for trying it out- but a lot of us would find an honest assessment of its worth very helpful!
Re the transformer. Are you at least using a separate tap- L and R- for each individually regulated stage? I ask, as using the dual mono configuration gives you the opportunity to keep ALL audio grounds separate from power grounds- which- as I'm sure he will confirm- Paul H has found to be extremely beneficial to sound quality in other circuits
I’ve made a number of modifications to my Legato, which- I think- are highly beneficial to sound quality. I have a second board which I’m going to modify back to exactly the original configuration. Then, when I’m feeling strong (!) I’ll reinstall it and try and give an honest assessment of the differences. It’s important, if sometimes painful to do this, IMO. What seemed a series of incremental improvements at the time sometimes add up to very little!
Best wishes
Paul (N!)
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As promised some pics of what you actually get with the Buffalo II dac.
They arrive very well packaged in a folding strong cardboard box – wrapped in anti static bags.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4417.jpg)
The main dac board, AVCC module and mounting hardware.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4420.jpg)
The AVCC module.
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4438.jpg)
Main DAC board
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4422.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4432.jpg)
The object of most of the forthcoming hard work:-
(http://i12.photobucket.com/albums/a221/sph2701/Buffalo%2032%20DAC%20project/IMG_4436.jpg)
That dac chip is just on 9.5mm square - I would hate to try re soldering that thing.
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Hi Steve
I wrecked my first Buffalo (32S, predecessor of the BII), and did unsolder the DAC chip and fit a replacement- successfully! Bloody tricky though. No specialist gear- just a fine tipped soldering iron, fine solder, and a jeweller's eye glass fixed to some reading glasses by a rubber band!
Best wishes
Paul
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Hi Nic, Hi Paul,
A few answers to some questions.
The S17LN reg noise is around 4 times lower than the shunt reg. The error amp device has a wideband noise spec of 0.5 nanovolts root Hz with a noise corner of 1 Hz. The voltage reference is a low noise type and it is well filtered to reduce its noise contribution.
Keeping the ground return currents for each individual stage out of the signal ground reference/ground plane is beneficial even with shunt regulators. This is because all regulated power supplies have bandwidth limits (even mine although somewhat higher than usual). Electronically derived constant current sources that drive typical shunt regulators may have relatively high impedance at low frequencies but there will be a point where, if feedback is used, the feedback drops, reducing the current source impedance, or semiconductor junction capacitance can also reduce the impedance. This allows higher frequency interference to break through to the shunt regulator circuitry and the constant current draw is no longer constant with this additional interference current flow circulating around the system.
The amplifiers typically used for the shunt element of the regulators have high gain at low frequencies but this gain will start to drop once the high frequency compensation kicks in. This drop can begin at surprisingly low frequencies. I see many regulators run out of loop gain at around 1 to 10 MHz. This means they have stopped regulating at this point and might as well not be there. As there is no effective regulation above these frequencies, high-speed signals propagating through the system cause all sorts of transient current disturbances that pass through the local decoupling capacitors and into the ground return system causing intermodulation problems.
So you might have assumed that your shunt regulator will draw a constant current from the supply but this is not true at high frequencies. It stands to reason that any attempt to provide regulation at these frequencies will require extraordinary operating bandwidth, not to mention speed, to have any benefit especially when the digital circuits like the ESS Sabre chips are clocking at 80 to 100 MHz.
The last thing you want is all this interference running amok in the signal ground reference/plane. If you use a common supply for all the regulated signal processing stages, the interference currents have no choice but to mingle, causing inter-modulation between all the stages. Providing a separate galvanicaly isolated supply for each signal stage patched into the circuit right on top of the load point provides a tight return loop for each section’s circulating supply currents that does not include the signal ground reference/plane in it’s path. Inter-modulation between stages is reduced significantly with less disruption of voltage references and reduced power supply induced jitter. The results are easy to hear.
Regards
Paul
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Hi Paul,
To be specific, If I'm having 2-5 sets of bipolar power supplies composed of S17/37LN-15 regulators connected to a circuit with a common ground do you recommend a single ground connection (to the pre-regulator) or 2-5 ground connections back to the pre-reg (effectively generating 2-5 ground loops!)? Advice very welcome.
Cheers,
Nic
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Hi Nic,
The only ground reference the regulators should see is at the load. The local regulator 0v terminal will be connected to the load 0v, which will be at close to ground potential, as it will be connected to the local ground plane. The pre regulator will be left completely floating with respect to ground and it’s 0v terminal will be connected to the local regulator 0v terminal as this is it’s ideal reference point to provide tight regulation for the local regulator. See Post 6 for a link to a drawing showing how the regulators are connected to each other. If you wire each power supply to each individual stage in this way there will be no ground loops via the power supplies.
A clean ground plane cannot be achieved with one common pre-regulated power supply supplying all the local regulators on the buffalo board. If you connect the 0v terminal of one pre-regulated supply to the Buffalo board 0v next to the VD terminal all the return currents from all the board regulators have to pass through the ground plane causing noise pollution at high frequencies as outlined in my previous post. Connecting a wire from the 0v terminal of one pre regulated power supply individually to each 0v terminal on the five board regulators, provides 5 parallel paths for the PSU ground returns creating multiple ground loops that still pass return currents through the Buffalo board ground plane as this is common to all the board regulator 0v terminals.
Regards
Paul
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Hi Paul,
Thank you for the concise answer. So in my understanding the perfect situation requires equal numbers of pre- and local regulators (and transformers I guess...). I think this might bust my budget and chassis space with PR3G2 as pre-regs...
I have never seen anybody using more than one pre-regulator for the Buffalo II DAC, maybe because there is so convenient onboard access to VD. Room for significant improvement - only one way to find out!
Cheers,
Nic
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Hi Nic,
Actually this applies to all multistage signal processing systems. Unfortunately it is too expensive to implement in the consumer equipment market and rarely taken to it’s full extent in the high end audio market. I have been using this method of power supply structure on my own system since 1984 and on my custom high-end projects since the 1991. In fact the first time I used it commercially was when one of my consultancy clients, Russ Andrews, asked me to apply it to a custom built system for a customer of his. The resulting system using the loudspeakers Russ had designed was demonstrated at the Penta Hotel HiFi show at Heathrow airport in 1991. It caused quite a lot of show talk at the time and was the main topic of conversation in the bar. Paul Messenger made some very nice comments about the system on page 176 of HiFi Choice December 1991. Unfortunately I cannot reproduce the page, as this is his copyright.
At the time I didn’t use pre-regulators, but all signal processing stages in the entire system had their own regulated galvanically isolated power supply. There were 6 off 1KVA transformers for the power amplifier output stages (six power amps in tri-amp mode) and another 16 off 500VA transformers for the signal processing stages. Even the Sota turntable was powered with my regulated power supply design. No headroom issues with this system.
Regards
Paul
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''only one way to find out!
Cheers,
Nic''
Yup, thats exactly what I thought, picked up the phone and the result is this thread. As Paul N states - it is going to take some experimentation with dual mono and single, and also some playing around with boxes, but the whole thing will end up being fun in the end.
It may seem insane to some that a tiny chip could require the amount of psu's and faffing around to get an end result, but when the law on diminishing returns sets in (in pretty much anything audio) things start to get real fun as far as I'm concerned. Has anyone been down this road yet? I honestly don't know, but the journey sure looks fun.
Paul (N) if I screw up a dac chip then I know who to sing out to!! I would need a scanning electron microscope to see the thing, along with a load of beta blockers to keep my hands that steady.
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<SNIP>
At the time I didn’t use pre-regulators, but all signal processing stages in the entire system had their own regulated galvanically isolated power supply.
<SNIP>
Regards
Paul
Paul, this is a very interesting direction of inquiry. It falls in the realm of 'of course I knew that', but adds evidence of HOW important optimizing this part of a system really is.
What level of 'galvanic isolation' is required for this to work well. Separate transformers per section or would multiple secondaries suffice in many situations? Also, I assume this also strongly implies a need for full dual-mono construction!
Greg in Mississippi
P.S. Steve, sorry to hijack your thread a bit, but I suspect the answers will be relevent to those following your build, if not to your build directly.
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Hi Greg,
It’s vital to organise the power supply properly if you want truly outstanding performance instead of just acceptable performance from high performance signal processing circuits.
A separate transformer for each supply is the best optimisation as there is less cross coupling of circulating currents between the transformer windings.
Dual mono construction will reduce channel cross-talk via all points of common connection, however if there is any significant difference in the ground reference impedance in any of the stages between the left and right channels this can upset the soundstage image stability. Identical construction throughout the channel signal path will minimise this problem.
Regards
Paul
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Greetings all, another to the fold...
I have a Buff2, and recently placed an order with Paul after reading several positive reviews of his stuff. Had a nice telephone conversation with him last night also - a nice friendly chap to boot :)
FWIW, in my system it's a single Buff2, digital volume control with the Volumite with a modded Lite Audio MV02 for remote control, running P.Hynes regs (soon!), with single ended output (using 1 phase of Buff2 output, other 1Mohm to ground) into a John Broskie Aikido Cathode Follower and that into an LC Audio Millenium XP power amplifier (120W/8R). Nice simple and elegant solution with the convenience of remote control.
I would be happy to support a guide on how to install Hynes regs in the Buff2 in collaboration with others, including this ground plane tweaking. I know Paul will provide me with a basic sketch which will help.
Now these independant supplies could be quite small, right? Most of the currents we are talking about here are in the order of 100mA or less aren't they? So I'm hoping we can identify suitable nice readily available small encapsulated transformers and then make up some soft recovery/shottke diode bridges (or use the Hexfred bridges from Parts Connexion) to suit. Keeping it small helps with packaging and cost to some degree. Recommendations welcome. Cheers
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OK well I now have my 5 regs plus 1 pre reg from Paul. All are nicely built and labelled so am proceeding to upgrade one by one, with the Vd and AVCC ones first which are the easiest to arrange with board mods. I will most likely go down the individual pre reg route with multiple PSUs later, as long as it will fit in my 2U box.
Prior to receiving the regs, I was using a soft recovery bridge followed by a 15kuf Jensen 4 pole into a CRC network to get my Vd. So it was unregulated. Replacing this with the Hynes pre reg (keeping the rectifiers and 15kuf Jensen) was a nice improvement. Mainly improvements in inner detail, layering of the presentation, stage depth, more analogue sounding and better rhythm and pace.
Replacing the AVCC regs (noting pinout, the TPA board has four pins, of which only 3 are used - the pin nearest the digital header is left unconnected) was more of the same and another step in the right direction. More inner detail, lovely listening to EST's From Gargarin's Point of View and the ride cymbal rivets trailing off gradually. Voice is extremely engaging (on other tracks) and piano on the aforementioned track natural, which is no mean feat.
I was expecting the pre reg to have the rectification on board, and I believe Paul makes them this way but what I had is a reg only??? Package wise the all in one would be preferable. I also talked to Paul about requirements of the transformers - he originally recommended 30VA per reg!!! I will probably settle for around 10VA given this is about 100x more than required it should work OK.
Next step is to remove those under board inductors on the TPA Buff 2 and wire in these other 3 regs. Will do them one at a time. I'm also keen to try the synchronous clock from the Hiface mod which allegedly can sound better.
I have some more detailed listening notes at home - if anyone is interested PM me. Cheers, Kendrick
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SNIP
The PR3PPRAP (PR3 pre and post regulator application) shows the ideal connection system for one sub circuit section load. Using two regulators in series (Pre and Post regulation) provides a double layer of mains power supply line interference rejection making the equipment less prone to performance variation when the mains power is dirty during high grid usage.
One PR3PPRAP is used for each sub section of the equipment circuitry. Circuit sections requiring a negative voltage rail would use NR3PPRAP constructed using negative voltage regulators. The 0V connection from the post regulator to the load should be connected to the ground terminal of any local load decoupling used in the subsection to be powered. The post regulator +VE connection should go to the positive terminal of the local decoupling. This keeps the ground return currents of each section out of the main earth reference system on the board allowing a very clean earth reference for the whole system. This makes a big difference to the resolution of dynamic scale and micro detail presentation. Timbre and tempo are improved and there is a reduction in confusion in the soundstage particularly when the music gets busy. Music just sounds more like real people playing music.
Setting up the power supply properly where the equipment to be powered has many subsections can be rather expensive and time consuming. Few will venture along this path. Steve is one of the few.
Regards
Paul
Hi Paul
If doing it this preferred way in the context of the Buff 2, the 0V ground plane is still connected on the board to all these separate supplies - won't this still have ground plane issues? I have your pre and post regs ready to install.
Also is there any issue if I mounted the post reg on the output terminals of the pre reg and ran slightly longer wires -say 10-15cm long to the Buff?
Cheers Kendrick
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Hi Kendrick,
The power supply return currents no longer cross the ground plane.
You really need the post regs on the Buffalo board for best regulation.
Regards
Paul
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Hope it's OK to jump in on this thread. I'm planning to work towards the best implementation I can manage for a BII, with seperate pre- and post-regs for each supply being the end goal. As an intermediate stage I'm going for the standard set of 5 PH post regs, and two pre-regs - one Z1P5V5 and one PR3P5V5. Plan is to use the Z1P to supply VDD, VDD_XO and DVCC and the PR3 for the 2 AVCC supplies. I don't have any particularly sound theoretical basis for this choice, but my thinking is that perhaps the higher bandwidth of the Z1P is best deployed at the digital end, and that it wouldn't hurt to have a shunt pre-reg supplying the one series post reg in the set (VDD_XO). Any thoughts or experiences from those already on this path would be welcome. And note to Paul - I guess you'll be on top of the best current setting for the Z1P in this application. Will I need to change things if/when I add further pre-regs?
All the best
Gordon
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Hello to anyone still out there and reading this.
It has been a very long while since I started this thread, and indeed the DAC project.
Let me be polite and say 'life' decided that the project was going to take a major hiatus along with a good many other things.
Anyways, enough of all that.
I'm back here, the project is again up and running and I'm anxious to pick up from where I left off.
While I've been away Paul has made a few changes to his design for the parts I need for this, so I will list what I am now about to order.
For the two Buffalo dacs:-
2 off S1701v2ADJ @ £36
6 off Z7803v3ADJ @ £36
2 off Z7803v3ADJ HP@ £36
10 off PR3iDC-05v4ADJ @ £80
10 off PR3iAC-12ADJ @ £100
For the two Legato boards
2 off PR3iAC-15ADJ @ £100
2 off NR3iAC-15 @ADJ £100
Paul has made a revision to my requirements for transformers, so now I am looking at 'Centre Tapped' variety,
10 @ 12-0-12 & 4 @ 15-0-15.
To allow for an ocean of headroom I have decided to run with 100Va for each one at present. These are awaiting a quote from Canterbury Windings in their Audio Grade design setup, ie, very low noise with low stray fields etc.
I have some ideas as to how this is going to go together now in my head, but getting from there to actually working is something slightly different.
One things for certain - it's one hell of a big PSU for a dac & output stage.
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So everything is now on order - the wait begins for parts to arrive :D
I know Paul is exceptionally busy at present so his stuff will start arriving with me late January.
transformers due just after the Christmas break.
I've been re-reading hundreds, if not thousands of posts on various threads on forums across the web about Buffalo and Legatto, but unfortunately in the past few months everything seems to have moved to markIII versions.
Fine and well, but all my existing stuff is MkII!
In the meantime I am making ways on connecting all the transformers correctly and making certain a clean as possible Earth is available to the entire system.
Anyone else still building these or are they all done now?
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I have all of the Buffalo III/Legato parts needed which I ordered back in July/August. I also have Paul's regs and am waiting on the SR3-12 which should be here anytime. I probably will begin my build after the holidays.
Regards,
Randy
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Hi Steve
Good to hear you're back to the project! Mine is currently up and running as described in post 30 above. Less ambitious than yours in that I only got one BII in the last stampede so I'm going for best possible stereo implementation for now. Sounds fantastic! Surprise was the difference it made putting everything in a well shielded box. Knocks spots off any other DAC I've tried in my system (Linkwitz Orion). Currently fiddling about with peripheral stuff - remote control of volume, on/off switch, delayed trigger for power amps etc. via a Dantimax remote board. When funds allow I'll add more of Paul's pre-regs so that each part of the BII is supplied seperately. Still waiting for the TP USB board, and using a HiFace in the meantime which works fine. Left room in the box to go dual mono eventually if I can source another BII or decide to move to BIII's, and for SPDIF switching and even possibly an ADC board.
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Still biting my fingernails in anticipation here, but keeping myself busy reading up on what I would still love to put into the chain and just how to go about it.
Wondering which (if any) resistors to swap out for Z foils, caps etc, then there is the case work (indeed, just how many cases!)
I'm making inroads into the basic power supply housing and siting (outside of the main room) and that is going to be very well shielded along with each transformer being mounted on it's own anti vibration mounting (no surprises there then :-) )
I'm also being ultra careful ref keeping the raw mains shielded all the way to and from the transformers (I'll put up more on that one later).
I have ordered a set of Supertex FETS to swap out the existing ones (these are what are now used in the Buff III) just need to remember to solder them in bacwards as pins are reversed.
I'm also ordering a box load of cannon XLR's tomorrow, ready for the connections.
In between all that I've been making a few more bass traps for the room - I had one of the 'Floyd immersion box sets' & decided that I couldn't be bothered in keeping the collectors stuff collectable for someone else to enjoy when I snuff it so the scarf is now a 5' long first reflection point trap (well, thereabouts) and the rest of the pics will be on the front wall as traps as well.
It keeps me busy and away from decorating the stairs at home!
I'm also hoping the TP USB board becomes available sometime soon, and that they are producing a lot as waiting for other stuff has been - ahem - amusing..
They have had Buff III boards available for quiet a few days currently though.
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It's still going ahead - honest!
Transformers arrive on Monday, so I've been making a large 'one in fourteen out' box to allow for the feeds to the individual transformers fed from a 5Kv isolation transformer upstream.
Switching on the 14 x 100Va toroids all at once may be a slight challenge for the MCB - even a c curve, so I have been looking at vaious soft start modules, thermistors etc. All very interesting - and highly variable in price. I did find a very nice way of doing it from Germany, but the 14 modules would end up costing 50% more than the transformers - elegant, & they eliminate inrush totally, but a non starter at that price.
I'm still pondering that one for now.
I have a bunch of Stainless set screws / nyloc nuts and washers on order to clamp everything together, an order in with Farnell for some smaller bits, and a transformer cupboard that is in need of slight localised strengthening.
Plenty to go at for now.
I'll put some pictures up next week when I'm happy with how it looks.
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A few pictures of the progress this week.
Made a 1 in - 14 out (2x7 a side) connector box for the transformers and fitted it into the transformer box on the outside wall of my office. It already houses a 2Kv balanced for the Cd player and a 3Kv balanced for the Pre. As I said before the incoming will be fed from a 5Kv isolating transformer.
I have left a plate in the box ready to mount two soft start modules. This will allow for the seven a side configuration and also allow for all the transformers to be powered at once.
Mounted some of the transformers onto their boards and set the wiring up to them.
Nearly ready to go into their permanent new homes.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5640.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5642.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5650.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5647.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5649.jpg)
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Fantastic, Steve. Are the blue/brown wires shielding screens in the transformers? And how did you drill the marble (pseudo-marble?)?
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Absolutely top notch!
I think the green/yellow wire is the screen connection and the blue and brown 240VAC.
They look like audiophile Canterbury windings TX's.
Can't wait to see more pictures of this build.....
Cheers,
Nic
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Hi Serengeti,
Here in the UK the standard is Brown = Live, Blue = Neutral, Green/Yellow = Earth-safety ground.
I do have electrostaic screens installed in these transformers - they are (obviously) connected to the earth.
Red = +ve secondaries and yellow = 0v.
The material is a phenolic laminate I use at work. Very dense, exceedingly hard and a pain to work with :-) It helps that I have a full workshop and a (very) powerful pillar drill.
Paul suggested Stainless Steel fitting hardware to help avoid any nasties in the way of magnetics, so bolts, nuts and washers are all S/S grade A2.
Complete overkill, but just enough in this case :lol:
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If we define overkill as doing something that has no effect, I don't view your work as overkill. My projects are all about as complex as yours, which I've learned is required to get those extra few percents of subtlety. But as in quantum physics, subtlety is power. Great work.
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Steve, are you using balanced-AC to the Hynes supplies?
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Hi Serengeti,
Kind of - sort of yes is the answer!
Technically it is difficult to use balanced power here in the uk as we have a fixed 240v - 0v and earth system. We *cannot' have 120 / 120 & earth as only the *live* section is fused in the Uk, not the neutral.
So what the guy did that made these particular TXs was rather clever - centre tap to earth for the first one, the second one then re combines the phases. That is as much as I know! So yes - the power has been *cleaned* by balancing - then made legal again by the second. All I know is that 120K of TX's is a lot to play with.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5653-2.jpg)
These two should be in place finally tomorrow, if I can get access to the underspace for them. Trying to move two together while wired is ' amusing' shall we say.
All good fun though and starting to progress nicely now.
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A further update on whats happened recently.
As per last post, the two x 5Kv isolator / balancing tx's have been finally placed and wired.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5695.jpg)
A few other goodies finally landed - cable to wire the tx's together, glands for between boxes, mcbs to fuse each supply..
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5689.jpg)
Made the outlet board for inside the office
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5684-2.jpg)
but this leaves me with a fair bit of soldering :icon_lol:
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5688.jpg)
The soft start modules turned up ready for installation into the main distribution box
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5681.jpg)
After speaking with Paul I decided to make it easier for myself and fuse each and every transformer (and therefore its following circuit) with a 2A MCB right in the distribution board. Using the DIN rail system makes this very easy. Just swapped out the links and installed (well at least some, as 14 ordered and 12 arrived :duh: ) the mcbs.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5696.jpg)
Hopefully over the next few days the transformers will have their permanent homes (just finishing that off) and I will have drilled a lot of holes through my office wall.
I did finally finish mounting each tx onto it's own plinth
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5672.jpg)
& as the eagle eyed NicMac noticed they are indeed Canterbury Windings work
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5663.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5676.jpg)
next up is summing the outputs and putting the lot in their homes :-)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5661.jpg)
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Very impressive, Steve!
Have you, uhh, thought of adding, say, a Felix CLC filter before or after the power transformers? That would diminish the amount of noise reflecting back onto the mains. This is something I'm doing here.
Then, eventually, you can say to your sweet, "Honey, we need a new house."
When I owned a house, I fed balanced power to a pack of old Elgar reconditioners---a conditioner-gaggle---I painstakingly upgraded (all resistors and capacitors, and some wiring) and ran in series, one series leg per component. It was horrendously complicated, but it worked. Cough.
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Hello Serengeti,
I had not thought about putting anything else in the power lines yet - possibly later if I really need to go there.
I took the setup of the mains supply to my office to the Nth degree, so I'm hoping that I don't need to do much else.
Out in our yard (some 15m from the main entrance) is our own sub station which converts 11Kv @5000A to our 415V 100A 3Phase supply.
I allowed two phases to be used for machines, offices and heat / light. The third phase is kept 100% separate and just for the HiFi :-)
This feeds two separate Consumer units. One unit now supplies the power amp and now this dac via separate radial circuits.
The other Consumer Unit supplies the Cd and Pre.
So that is sort of 'overkill' yet again.
As for moving - I know what you mean - my knees and legs get weary with age of stairs at home - so maybe moving will be sometime.
As for moving this office - no chance! After the work that went into making it, I will never get to re-create anything like this again unfortunately, at least until I win the lottery.
Making this room was another journey:-
http://forums.musicplayer.com/ubbthreads.php/topics/1984380/Wall_boundary_trapping#Post1984380 (http://forums.musicplayer.com/ubbthreads.php/topics/1984380/Wall_boundary_trapping#Post1984380)
If you have some spare time you may like to visit that diary.
It has a lot of happy and weird memories for me - and did I learn a lot!
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A few more pics of some rather slow progress over the last few days.
The last two MCBs turned up, so I could continue with the wiring in of the transformers. It all became a 'bit busy' in the distribution box.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5704.jpg)
Only to discover that 50m of CY cable is nowhere near enough :roll:
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5707.jpg)
This rats nest will become tidier I promise.
(EDIT) All of the 'earth' (ground for those in the US) on the right hand side are for the electrostatic shields in the transformers.
The lone earth on the left hand side bottom of case is the safety earth direct from the fuseboard. This is the one that will continue into the dac boxes as a safety earth. A fair amount of experimentation will no doubt follow with getting the rest of the signal ground correct.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5716.jpg)
And finally some transformers get to live in their new homes.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5717.jpg)
I also had delivery of a bunch of stuff to mount Pauls supplies when they arrive shortly - all in s/s A2, so no nasties with electromagnetics. Also a super long drill bit to allow me to drill 17 holes through my lovely sealed office :cry:
Not something I take lightly as it is 100% sealed, I have no 'flanking' noise at all. 100+ industrial size tubes of acrylic sealer / intumecsant made for a big bill. Making a lot of holes was never part of the plan.
All done and ready to move forward again when more cable arrives.
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Great progress, Steve. :thumb:
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In the title of the great Floyd track - One of these days.
Checked where my tickets were for the Festival of Speed? Payment had not been sorted correctly and therefore no tickets sent.. Sorted. Where are my Aussie Floyd tickets? Its nearly showtime.. Printed today sir, will be with you Monday... Sorted. Yipee, another 50m of CY gets delivered instead of me going to collect it. Aghhh it won't go through the holes?? Last cable is 9.47mm dia. This is 11.52. Try and get that through all those 10mm holes I drilled in the office wall :duh: :evil: :roll: :scratch: It's a different manufacturers product, but what was in stock. same spec - different outer layer (much more pliable).
Only have my battery drills at work so can't get anything bigger than 10mm into the chuck.
Going to have to drill through from both sides of the wall with a standard length 13mm drill when I get my leccy drill back up on Monday as I am not buying yet another drill bit just for one job :(
This may just be going to be one of those very frustrating days.
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So after a bit of stomping around things decided to improve.
Went home for an hour and got us a nice lunch on the way.
Found an ancient drill that looked like it may just do the job.
Post contained confirmation of another Floyd concert with a good friend on March 2nd :D, Steve Hacket tickets on the 25th of this month, and Tord Thorgesten the day before my first Floyd gig.
Music is on the up at least.
The drill fitted and looks slightly bizarre.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5764.jpg)
but it works :)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5762.jpg)
So made a quick jig for all the upcoming soldering.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5772.jpg)
and then a knock at the door announced the arrival of my next project - yet more supplies from PH :lol: :lol:
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5769.jpg)
Fortunately my good friend then arrived and it was time for 4 hours straight in the music room - which is what it's all about ultimately!
Left for home in a much happier frame of mind 8)
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So I finally got the outside transformer box all sorted and fitted, as you will see below - a little bit of green lighting, a raise in temp then an increase in humidity to 92% & the Borg would feel right at home in there..
Firstly I completed the fused power out box so that every transformer was wired in to its correct fuse and left or right supply. Fiddly job as first the outer sheath needed removing with a stanley knife, then the shield cutting back and neatly covering with heat shrink to make sure of no shorting issues. The the two inner black (numbered) cores need to be coded blue for neutral and brown for live. (on this juncture 1 = live 2 =neutral) It got very busy indeed in that box. Then I decided when it was all finished that I had better put in a couple of spares, good job as they have already been spoken for in the shape of a 'mux' board from TP and probably a USB power supply.
(http://i12.photobucket.com/albums/a221/sph2701/DAC1.jpg)
Lower 2 left hand shelves house 5 transformers a piece for the dac boards. The upper shelf was a real fun one to get hands into with screwdrivers..
The fun thing I had to remember here was that pin2 equals LIVE every time in an XLR so for the sake of sanity I coded wire two brown = live.
All of this wire stripping, cutting and shrinking while ten feet up a ladder was, ahem, frustrating :o and only resulted in two sliced thumbs (who mentioned H&S) and sore soles of feet.
(http://i12.photobucket.com/albums/a221/sph2701/DAC2.jpg)
Upper shelf contains four transformers for the output stages, wiring got to be very 'imaginative' here.
(http://i12.photobucket.com/albums/a221/sph2701/DAC3.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/DAC_.jpg)
Finally a view of the whole lot before it gets a neat surround fitted and doors put into place.
As can be just about seen, I have incorporated as much 2mm aluminium sheet between shelves and transformers as I possibly can (at least two in each case) to help as much as possibly with EM & RFI. There is a fair amount of laminate in there as well, along with ceramic bearings :lol:
(http://i12.photobucket.com/albums/a221/sph2701/DAC4.jpg)
All completed just in time for the imminent arrival of Pauls regs and getting started on the really interesting stuff :-)
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That's looking very fine, Steve. Soon it all will be together. 8)
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Bit of head scratching going on today as to work out the very best layout for this little lot in a box - do I make the box as well due to size - we will see.
loads of wire on order now as well to put this lot together with. Keeping it all neat and not a rats nest of wire is going to be a test for certain :icon_lol:
(http://i12.photobucket.com/albums/a221/sph2701/DACPS.jpg)
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I'm confused. What are you building though? :scratch:
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Stephen is optimising his power supply to power the Buffalo DAC. The Buffalo on-board regulators are being given their own independent power supplies, to remove any power rail and power ground return current inter-modulation between the individual digital and analogue stages within the DAC architecture that would occur when feeding all the regulators from VD.
This is the optimum power distribution method for all precision electronic systems.
As well as using individual power supplies, Stephen is also attending to mains issues with balanced transformer feeds to all the mains transformers etc.
This is not overkill, it is just doing the job properly and he will reap the rewards accordingly, with a higher level of resolution than would be obtained with a common power supply for all the DAC stage regulators.
Regards
Paul
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Yeah, it's fantastic. Electronics done properly.
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Wishin you the best Steve. That is one big project. Can't wait to hear what you have to say when it is done. :thumb:
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Back after a much needed short break 8)
Just before I left I knocked up some copper angle to see if the idea I had would work :-
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5825.jpg)
Looked ok so got some brass angle in. Didn't fancy the idea much of using a hacksaw through 16 times, so decided to buy a new toy - (it does have a future use :icon_lol: )
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5810.jpg)
The results were OK - so have ordered in some more fittings to set them out like this.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5821.jpg)
I then need to see if it will all fit nicely onto the base of a 18" x 14" box, of if I have to go the alternative and split it into two boxes.
Bit of re-wiring to do in the transformer box - didn't fancy standing up the ladder any longer so decided to bring my building scaffolding back into use and made a propper platform to work from for a couple of days..
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This is the coolest Buffalo PS EVER!!!
Nice job.
-Jim
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It's the most impressive looking but I still don't understand how all of that wire will be a good thing for a very low voltage supply.
What am I missing? :scratch:
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It's the most impressive looking but I still don't understand how all of that wire will be a good thing for a very low voltage supply.
What am I missing? :scratch:
All of 'that wire' that can be seen at present is basically very clean but also very raw AC, the 'magic' has yet to happen, at least it shouldn't have :icon_lol:
This is all just getting the raw juice ready for final distillation for want of a better metaphor.
Things will probably become more apparent when you see what happens after the wallplate back in the office.
From that wallplate each feed will go via (very) shielded cable into a box full of these Paul Hynes PSU's.
They 'do their stuff', and convert the AC to DC, smooth it, de ripple it and that sort of really clever stuff about which I know not a lot hence I let Paul do the (40+ years worth) of thinking & sorting out :P
From the 12v DC side it gets fed directly to 5.4v dc regs.
The output boards are fed 15v dc.
All of this rectification / regulation is a bit 'noisy' & better off in this instance being done completely seperately from the highly sensitive DAC boards.
So now this very finely distilled DC takes its final journey via Chord Co (UK) very highly shielded, point to point wired cables to the DAC box.
Each dac board can accept 5 individual power supplies instead of just one.
Not only are we feeding each seperateely from it's very own regulated supply - each is kept totally seperate in the earth / -ve so that NO interaction - IM can take place their either.
Having two dac boards running in dual mono config means I need 10 individual PSU's for them.
The other 4 15v psu's are used to power the two output boards which are mounted directly to the dacs.
It is a very interesting and somewhat time consuming project, but my personal preference is to do something once, and do it to the best that I can. The thought of taking this lot appart to add a 'better' sounding cap / resistor / etc etc somewhere later kinda chills me to the bone!
Thanks for the kind words - while I guess it does 'look' impressive - that is more function than design for a change 8)
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Another quick update.
Had time to cut to size all of the brass angle. 10 for the 12v supplies and 4 for the 15v.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5830.jpg)
Made a template to make sure they are all the same spacing from a piece of (very) old angle steel knocking about the warehouse.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5836.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5845.jpg)
The template seems to work ok, so proceeded to mark out, drill and linnish up a couple of pieces of brass angle.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5851.jpg)
Brass looks great when freshly linnished - doesn't take long to mark with greasy fingermarks and tarnish..
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5843.jpg)
I finally had a delivery of some more s/s fittings so that I could start and put some together to check all ok.
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5846.jpg)
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5849.jpg)
I'm happy with the results there so I'm a busy boy for a couple of days.
Just before closing for the day I finished off the scaffolding platform ready for the re-fit of the transformers :lol:
(http://i12.photobucket.com/albums/a221/sph2701/IMG_5855.jpg)
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this is awesome. tagging along to see the progress and impression :)
erwin
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Yes, awesome, Steve.
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Well after yet another forced hiatus, this time not of my making :duh: - finally the cases for getting the PH supplies boxed and wired up arrived today.
Yet to even be un-packed, they *should* be well worth the wait.
More updates and pics follow shortly, honest :lol: