audiobastard - Introduction

This Blog is dedicated to DIY audio enthusiasts and audiophiles who enjoy two channel audio and more so high-end stereo. Not only will this Blog focus on equipment including, amplifiers, speakers and cables but the music. Because this is why we strive to build, buy, borrow or beg for quality equipment-to better listen to and enjoy to the fullest, music. Music of quality and distiction, however you see that whatever you believe it to be.

This whole site and all on it is from my point-of-view. It is about equipment I have built and bought. About theories, beliefs and understanding I have about music, the reproduction and recording thereof. Myths, here-say and rumors will be mentioned in some Blog entries with the intention of sparking ideas in others to pursue a never ending quest for beautiful equipment playing beautiful music. Enjoy the ride.

This site is not intended as a sales site but more about getting my progress and ideas out on the Internet in a convenient and easy to manage Blog form. Items will be marked for sale and come as is. Please contact me if you wish to purchase. I invite you to view and read about some of the projects that have rocked my music world and have given me immeasurable pleasure.

Now your listen!

Woodford Reserve - Kentucky Bourborn Timber Knobs

The Woodfords Reserve is a really excellent drop and with a nice bottle to match. But if you think the whiskey's good the knobs are even better. By removing the corks and gluing in a suitable "plain" knob you have a, very unique, dark timber knob. Here I have shown two types with a Al and black finished on the mounting knob.

Use eucalyptus oil to remove the final bits of glue from the seal across the top of the knob. Then rub the oil into the timber. Be careful not to get it in where you will glue in the mounting knob. The dark American Oak (I think ) will really shine.

KT120 Be Bamp - when good gets better

The KT88 Be Bamp is an excellent sounding amp and if taken no further would satisfy most audiophiles. But the Be Bamp with KT120 valves, replacing the KT88s, just takes excellence to a new level.

In previous iterations of the Be Bamp improvements were made to bass response and over all musical weight. Now with the replacement of the KT88s with the over-size KT120s so much more of the music is presented to the listener. Mid range and bass have lifted and the treble has received extra air.

Now bass is extended and controlled, mids are crisper, brighter and better defined and treble just a hint airier. Power has increased in the amp and though efficient speakers and still required to obtain voluminous listening levels, greater musical weight is heard right across the audio spectrum.

Oatley Electronics Jan6418 tube phono preamp

This JAN6418 valve based phono preamp is soon to be released by Oatley Electronics. It is a two stage preamp with FETs buffering each stage.

The cast Al enclosure has been finished in epoxy enamel hammered copper paint. The sound is excellent and noise is very low apart from a faint hiss. Music from your fav. TT will flow extremely well and I found it only took a few hours of play for the preamp to "come to the party" and sound relaxed.

In this build I have used the kits standard components but better parts would make an all-over better preamp.

retro-thermionic Merlot with JJ KT88 Blue Glass

My son had ordered a valve amp. He wanted nothing on the top plate but valves and transformer. So a front plate holding the volume control and rear plate holding the speaker and input connections was constructed.

The amp is a two stage KT88 based single end UL amp (SE UL). The driver valve is the 6N1P. It is a common Russian valve quite capable of driving the KT88s. In this shot you can see JJ Blue Glass KT88s. I have tried EL34. 6L6, 6V6 and 5881 valves in this map with no bias change. In the EL34 range I have used Black Sables and Siemens (NOS) tubes. But I think over all the KT88 is the best. When this amp went to my son Sovtek KT88s were reinstalled. He was more concerned with the look than the sound.

This amp requires speakers with an efficiency of at least 90db to provide high volumes of music. SE UL amps provide exceptional sound staging, pin-point stereo imaging and a very natural sound. Though they only produce 6Wpc, through efficient speakers, good listening levels can be obtained.

Lookout for the Merlot Black top to be posted on this blog.

Portable Triode Headphone amp

You take a look at all those schmucks on the train listening to their audio-dead iPods and their super compress modern day pop/rap/crap/techo "musicless" MP3 files and cheap super "shitty" ear buds and think why? When they could be really listening to well recorded, non-compress, lossless music files on a pair of Phiaton MS400 close back carbon fibre and leather headphones and a Cowon S9 (for example) player and a portable Triode headphone amp.

Though there is an on/off switch no battery drain occures until there are plugs in all sockets and it is switched on. Pull out a either plug the power is cut. Battery life is about 100 hours.

The two experiences are worlds apart. THANK GOD!! What this weighty but musically beautiful instrument does is buffer/amplify between player and HPs. It uses tiny sub-mini pentodes valves (tubes) in triode config. It also has a HP driver chip (PT2803) which buffers the whole connection back to the player and DRIVES the HPs.

Ruining on a a couple of lithium 9V batteries it is truly portable and divine sounding. And they provide 6db of gain. But much better than that. Tell me how many of your audio savvy friends have one. Good reason to get one "rule"quick.

KT88 SE UL tube power amp

This my second SE UL two stage power amp. This time the top plate was brushed Al and Sovtek KT88s were installed right from the start. The base is Mirbeu and the front-end valve is a 6N1P. Edcor XSE OPTs and a 10H Hammond choke with X2 caps make this a very pleasant amp to listen to. Mids are exceptionally clear and highs extended (46khz @ -3db point). In this build all connections are on the back and just the attenuator on the front.

Twinings Tea Box preamp with remote valve PS

This was the first of the remote, valve rectified Twinings Tea Box preamps I made. I have just recently completed another, commissioned by a supporter of DIY gear in Denver. In this build I used the original Jupiter, beeswax and paper capacitors. Sadly these caps are no longer made and a more modern beeswax cap has replaced them. In this build, as in the latest, silver wire and silver solder is used throughout the audio path.

The cct. is the original Silcon Chip two stage valve preamp employing 12AX7s. I replaced the Sovteks with Golden Dragons. The rec. tube is a very old 5Y3 which visually appeared in good condition. A 10H Hammond choke and Hammond power tranny supply plenty of power to the amp. Alps blue velvet attenuator and quality passive components lift the basic build to a higher level of performance. A 4oz solid brass knob gives this retro-thermionic two part preamp an old world "dad's gramophone" look.

The preamp was sold within a few weeks of completion to a couple who grew up with "dad's gramophone" which resembled a science experiment but conveyed the passion of the music. Not much has changed where passionate reproduction is concerned. And it may still look a little like a science experiment.

Woody Pro - under the bonnet

Not hard to see Woody Pro. is constructed of base components. Base components form modules which are then interconnected to form the whole buffer/driver. The output caps made from 20 X 10uf polypropylene caps (20 in all) can be easily seen with the aluminium and tar rapped PS to the left. A two stage filter is used comprising of 2 X 10,000uf Nichicon electrolytic caps per channel (total 40,000uf) which are snubbed. The single 2N3055 per channel bolted to the timber is on the far left. All of this in a 1U 19"case. The case is fully earthed and fused and the ferrite chokes use used to filter RFI\EMI.

All internal wiring is via pure silver wire and all internal power connections are via medium gauge OFC speaker wire. A 4oz solid brass knob tops off the attenuator\volume control. Woody Pro. is sleek and very quiet partly due to UF4003 Ultra-fact diodes (which are all individually snubbed) and encapsulated twin toroids. Wood Pro. is dual mono construction. The frequency response is below 10Hz to over 135Khz. Harmonic distortion is extremely low.

Woody Pro.

I had built two head phone drivers (HPs) for my low impedance Grado and Audio-technica head phones. I also discovered they were very good line buffer\drivers due to their low output impedance and high input impedance. They are named Woody and Woody Pro. due to the fact the the single transistor per channel is bolted hard to a block of Asian timber.

In Woody Pro. dual encapsulated mini-toroid transformers drive ultra-fast diodes and 40,000uf of filtering plus resistive ripple reduction to produce two very clean supplies. Twenty 10uf polypropylene capacitors are paralleled to produce 2 X 100uf output caps. There are two selectable inputs. The first input and output have both RCA and 6.5mm phone jacks connected.

Each channel has one 2N3055 in an emitter follower configuration. The sound is immediate, clean, with good bass extension bass and fast. Because Woody Pro. is an emitter follower 10% of the input signal is lost. This has never been a problem with most sources deliver around 2V.

Cased Aussieamps nxV200 amp

Only missing the front panel and lid this Aussieamps nxV200 VFet stereo amplifier is complete. The four 10,000uf 100V caps can be seen "stuck" to the sides of the case. The led is ready for mounting on the front panel. In this image the amp is under test and a faint blue glow can be seen at the rear of the case. Surface mounted blue and yellow leds light-up when the amp is on. The heat sink and caps just fit in the case. The HS also acts as a magnetic shield between the amp modules and the big toriodal tranni. The rectifier module is on the left and is constructed from individual high current, high surge fast switch diodes. 0.01uf caps snub each diode. The power caps are snubbed with 0.1uf caps.

The internal signal and speaker wiring is intentionally kept very short because unshielded OFC speaker wire was used throughout for hook-up wire. The input gold plated RCA and gold plated speaker binding posts are mounted on the rear so amp modules and terminals are close to each other. The amp is dead quiet.

The sound is pristine and crystal clear. The modules are rated over 200W and after winding the volume up on my small bookshelf speakers I believe the specs. They can drive hard with no harsh overtones or strain. I made a pair of these stereo amps for bi-amping a 2-way speaker system.

Aussieamps nxV200 V-Fet 200W amp

These compact and powerful Aussieamps amp modules were bought by a DIYer to construct two stereo amps for bi-amping his large 2-way speakers. He approached me to design the power supplies, assemble and provide enclosures.

I modulised the construction by: mounting the amp modules on the heat sink, constructing the rectifier ccts. on a tag strip, assembling the speaker binding posts, AC captured cord, fuse, on/off switch and input jacks on back plate of the amp and mounting the transformer and large electrolytics caps (20,000uf per rail).

It took two days just to do the marking and drilling of the case and HS. And four days to assemble the first amp. The second amp only two days. Oxygen free copper wire was used for the hook-up and signal wires. Brass cones were mounted for the feet and the case is heavy gauge steel. See the image above.

Kit form Phono Preamp to top commercial product.

After revamping my TT and deciding I was going back into vinyl I required a phono preamp. I bought the Pro-ject SE (SS version). Coupled this with my new Grado wood bodied Sonata cartridge, I thought the sound was great. My TT is a Rega Planar3 with an RB300 arm. I changed many preamps and power amps over time but until the day I saw a kit form, OP amp based, phono preamp in the local electronics store I never changed that which was closest to the source.

The kit was $AU35. You required an AC supply and case but everything else was supplied (See image of the build below). With some variation to the kit I completed the project and now was interested to see (and hear) how it sounded. Immediately, from the first track of the first LP I was very impressed. The preamp was dead quiet, no hum hiss, just nothing. Music just flowed from the whole system. The sound appeared creamy and smooth and oozed from the speakers. When switching back to my Pro-ject I felt the sound was course and rough. The music sounded like it was being forced out, not rolling or flowing out. I cannot find one thing the Pro-ject does better than this inexpensive kit. The gain control is a bonus but without changing brd. level components various input capacitance and loads cannot be changed easily. The phono preamp is excellent.

Kit form Phono preamp

The construction for the preamp was reasonably easy once I found the right enclosure. Up to that point I tried a number of different boxes. What I was trying to do was find an enclosure which worked with all of the external connections for the kit mounted on the cct. brd. Once I removed them to mount them off-board things got better. The hard ABS plastic case fitted the cct. brd. easily and once lined with a Al and tar foil provided a good enclosure for the project (also see image above). The gain pot is mounted to the cct. brd. so mounting the brd. is critical to ensure the pot can extend out of the box. Insulated gold plated RCAs were used but probably not required in a plastic case. Non-insulated would have been OK.

Cct. brd. populating is easy from the kit except when fitting components for the various compensations. Though there is information for five different compensations there is only enough parts for one. The RIAA is the logical choice. Also if you install for other compensations you have to be able to access the cct. brd. to link them in.

An AC supply is used to bring energy to the device. +/- 12V regs. are mounted on the brd. and of course a diode assembly. A good size copper shield is mounted between sensitive ccts. and the power section. Some capacitors can be upgraded but others, due to their size cannot be. Often I used silver wire for signal line hook-up but in this case stuck with shielded wire. The preamp is exceptionally quiet and has a very smooth sound.

Fostex full range speakers

These compact 15L ported single driver boxes contain the Fostex FE167E 6" twin cone driver. Built to compliment a couple of 6T9 valve amps. No Xover is required and though the valve amps only provide 4.5W of power @ 94db efficient good listening levels can be obtained. For build notes see article below.

If you are not use to a single driver speaker system at first the sound appears quite different. The drivers do take some time to break in and the surrounds are extremely stiff when new. The frequency range is quoted 20hz to 20khz. Bass is good but is very dependent on the amp driving them. Voices 'tend to be a little forward but not unpleasantly so. Treble extension is good but you need to have the boxes pointed toward your listening position. Detail and sound stage is excellent when driven by my 6T9 valve amp. Sound stage especially can be broad and reasonably defined with an unusual ability to project instruments well beyond the distance the boxes are apart. When friends compare the Fostex with my standard two-way boxes they are generally very divided in opinions. For such a simple design they do sound very good. And no Xover distortion-bonus!

Fostex FE167E full range driver in ported enclosures

Hard to believe that after forty-something years of listening to hi-fi I finds myself back enjoying single driver twin cone full range speakers. Back then I bought a pair of 8" twin cone Kaltros to go with my very first Rotel based hi-fi system. Of course the 6" twin cone Fostex FE167E driver is far superior to the Kaltros but he Kaltros took an absolute pounding at the hands of Jimi Hendrix, Stones, Cream and a bunch of others. Not once did they whimper.

With the Fostex drivers comes two sets of box designs. A more complex one in which the top part of an integrated stand is part of the port loading and a simpler design 15L enclosure with a 50mm X 50mm reflex port. I built the simpler one. I really only built the speakers at alll because I needed an efficient speaker system to go with the two 6T9 valve amps I had just finished. At 94db efficient the 4.5W 6T9 amps drive these compact boxes with ease and at good volume levels.

The boxes were glued, nailed and clamped during drying. The internal back of the box is lined with dampening vinyl and all interior walls have a layer of Dacron. Grills were cut from the same thick 18mm particle board with black speaker cloth stretched over them. The grills are retained to the boxes with heavy duty Velcro. There is no Xover and OFC medium gauge speaker wire was used for hookup. For listening notes see article above.

Valve preamp in a Tea Box

I have built a number of audio devices in wood boxes. The timber box above is a Twinnings presentation Tea Box. This two stage valve preamp with remote PS performs beautifully partly due to the fact it is chock full of Cardas Golden Ratio caps and pure silver wire (see article below for more info.). In fact it performed so well, that on hearing it, a friend bought it on the spot. I had only had it a week. A switch mode 260V has PS has its own die-cast Al case. The lid was polished then clear coated. The base is black epoxy paint-quite attractive when paired with the Tea Box amp.

Though standard 12AX7(s) were used the preamp produced a very clean and natural tone across all music types. Classical music had a particularly enchanting and romantic feel from this preamp. When matched with a SS power amp, the full warmth and charm of valve pre-amplification could be enjoyed for many hours with boredom or fatigue. Distortion is usually an issues with valve gear but the levels for this preamp remain under 0.2%. It has a frequency extension to 180KHz! Great looking and great sounding.

Tea Box valve preamp with Cardas caps

My fascination for timber and electronics has lead to me assembling a valve preamp in a timber presentation Twinnings Tea Box. I like the idea of timbre helping to control cct. resonance and adding it's own signature to the over all sound. I also wanted to continue trying various coupling and input caps and for this build selected the excellent Cardas Golden Ratio caps.I did find their multi strands of fine leads difficult to work with if they were too long. But I was very pleased with the final sound. The box is lined with a tar and heavy Al foil layer for additional resonance control and RFI shielding. Computer stand-offs with rubber grommets fitted to them, support the brds. to further reduce cct. resonance.

You can see the cct. brds. above and rear terminal panel ready for installing in the drilled tea box. The timber is easy to work with in this box because it is a reconstituted wood and resin compound. So when drilling huge holes it does not splinter as other woods I have used. The valves are standard 12AX7(s) and other caps used are polypropylene types. All silver wire was used throughout, silver solder, Apls blue velvet attenuator and 4oz solid brass knob. The PS is remote in a metal enclosure. The amp is a two stage affair and over all gain is about 6db. Glorious sound.

SS preamp with Jupiter beeswax and paper caps

This is the third of these OP amp (OPA2134) based preamps I have built. One was sold to an audiophile in Denver. In this build I wanted to use the Jupiter beeswax, paper and foil caps. They are 1uf in capacity and very large in size and supposedly hand made caps. With four of these large caps (see image below) in the die cast case there is not a lot of room for much else. A lot of attention was payed to cct. resonance control (see below), quality components, component layout efficiency, flexibility of input device selection and overall looks.

A 4oz solid brass knob looks well against the thick epoxy red paint. The Alps blue velvet attenuator provides a smooth and very linear feel to level control and helps keep the overall noise level down. The sound of the preamp is extremely detailed with mids and highs given full range and very extended. Mids carry multiple textures with voice sounding very earthy, even gritty and raw from male performers. The bass is deep, textured and rich. The sound stage comes through wide and detailed. Instrument placement is point sharp with each instrument or group of instruments having their own space and time. The background is deep and black. This is the best sounding preamp I have ever built and I intended to build more equipment employing the Jupiter caps.

Beeswax and paper caps SS preamp

Most DIYers build audio gear because they have a need for a device or they just like to build equipment. I built this OP amp (OPA2134) based preamp because I liked the idea of using beeswax and paper caps. These are 1uf Jupiter caps and according to the advertising, are hand made. They ARE covered in beeswax that is for sure. I timber sub-floor was placed on computer stand-offs which themselves have rubber grommets around them. The rubber grommets and timber base are used to help control cct. resonance. The cct. boards, tiny in size, are also mounted on stand-offs and fitted with grommets. Only component leads are used to connect the individual components together on the brd. There are only three short straps on the cct. brd. and these are three earth straps made from silver wire. The Jupiters also have silver leads. Alps blue velvet attenuator and 4oz solid brass knob was used as much for decoration and smooth operation as for quiet running of the preamp.

20V DC is supplied to the preamp via a computer plug pack and a resistive voltage divider network provides +/- 10V to the brds. Each brd. has an individual power network with 2X 220uf low ESR caps. Power filtering and snubbing is provided also within the case. The preamp is two stage with gain and buffer and I used the Burr-Brown high performance chips on milled sockets. All solid pure silver wire is used for internal hook-up and WBT silver solder used also. A switch at the back allows selection between two input sources. The case is 2mm die-cast aluminum with two coats of epoxy enamel paint.

Cool looking SE 6T9 UL amp

The 6T9 tube has both a triode and a pentode in the one small compact glass envelope. The amp uses Spare Time Gizmo cct. brds. and is in SE UL mode. This is the second of the two amps I built. The first was on a Teflon $7 baking pan chassis. Edcor XSE15-8-5K OPTs are under the lid and help produce a frequency response from 20hz to 20khz (-3db points).

The sound stage produced is extremely wide and deep and when coupled with a pair of Fostex single driver 94db efficient speakers produces the most sumptuous music. Especially classical and voice. The paint used is Epoxy enamel and though the two coats take eight days to dry the finish is very tough.

The amp has no audible hum at 12" from the speakers and produces very sweet mids with excellent detail. At no time does the amp not sound musical and I would recommend the build to anyone wanting a very inexpensive and exceptional sounding amplifier.

SE 6T9 UL amp curcuit board

This Spare Time Gizmo cct. brd. only cost $AU16 and is double sided, screen printed and solder masked. I used it in both 6T9 amps. The components are quality without getting into exotica were available form my local electronics hobby shop. The coupling and input caps I increased to .22uf metallised polypropylene types and the final PS cap I doubled in capacity. Snubbing was added to the diodes and the PS caps. Edcor SE OPTs (XSE15-8-5K) were used and the UL tap wired to pin 10 of the valve sockets. The screen grid resistor left out. The power tranny is Hammond and I went slightly over-size. This is an excellent sounding amp and I would recommend it to any builder of audio gear wanting to try valve amp construction.

SE 6T9 UL amp on a teflon baking pan

This delightful little amp is incredibly musical though it only produces 4.5W of power. When coupled with some very efficient speakers (e.g. Fostex FE167E 6.5" drivers) more than sufficient audio levels are easily obtained. The sound stage is huge and particularly wide. This was the first of these amps I built. The second is also posted on this blog and was purchased by an iPod only user.

Portable high quality mini-recording setup

The setup seen above provides a portable recording facility with direct to digital facilities. The preamp (red lid) is the ESP two transistor low noise preamp and is simple to make and really is very low noise. No hiss or other audio artifacts can be heard at all in even quiet recordings. Mine was built over-size to allow a 12V battery pack to be included under the bonnet. Gain is limited though.

Low noise mic preamp

After purchasing a couple of Berhinger studio mics and valve preamps and doing some recordings of live choirs etc. I decided I wanted something more portable. I bought a Sony ECM-MS957 but required a portable preamp. This is the ESP low noise two transistor preamp. Though it is quite large it has a 12V battery supply and uses large 10uf polypropylene caps throughout. All silver wire and quality components were used. Two attenuators allow separate channel level control. I use a Cowon Audio6 mp3 player with a line input connection for recording direct to digital at 128kps. The whole mini-recording desk runs on batteries and even after four hours of recording barely effected battery level.

Step-Up Transformer Project

I had upgraded my cartridge on my Rega Planar3 by replace my cheap shure with a Grado wood body Platinum Reference. But even through a Project SE phono amp and a valve preamp the signal level was low. The Grado cartridge is a MM variety and I knew K & K Audio had a MC tranni kit. On an enquiry to them they provided me with a MM tranni kit. The Lundahl LL1550 amorphous trannies and cct. brds were configured for my cartridge and fitted in the wood box the cartridge came in.

Silver wire and WBT silver solder was used throughout. Sticky bitumen coated thick aluminium strip was used to shield the wood case and vinyl speaker dampening glued to the inner lid. The trannies were Velcroed to the inner lid and low profile felt feet added to the bottom. The sound is just as pure and now just a little louder. The trannies also provides some dampening back to the cartridge and the cartridge accurately loaded.

Headphone amp cct. brd

The large input caps block the other components from view but you can see how small this whole amp is. Smaller input caps could have been used but I wanted to use locally available metal film polypropylene caps. The original cct. uses .22uf but on a friend's suggestion I use .47uf. Even the power caps (330uf low ESR) fit on the brd. It could not be more compact if you tried.

Computer style adhesive stand-offs with rubber grommets provide easy and removable mounting. The inside of the box is lined with sticky bitumen coated aluminium thick foil. The amp is dead quiet when listening so all the trouble I went to to shield the cct. from RFI etc. was successful. A very satisfying and easy project. And no big PSs or high voltage to scare off the novice. In timber or tin this project was very successful.

The Wooden Cased headphone amp

Inspired by the the headphone amp on diyaudioprojects and after purchasing a wood body Grado phono cartridge, I decided to make my headphone amp in an old Essential oils cedar box. Grado also make a wooden cased headphone amp but a friend said he tested the CMoy styled amp against the wooden boxed Grado and believed his to be better sounding. The owner of the Grado headphone amp agreed!

I never intended this headphone amp to be portable. Though the amp weighs very little it is bulky. All connections are at the back. An aluminum strip at the back of the amp holds all the connectors and the on/off switch. Large holes had to be drilled to take the body of the connectors and drilling the soft cedar was difficult without causing damage. Movable compartments inside the box allowed my to have separate battery and amp cct. brd. areas with two spots for spare 9V batteries. Aluminum and bitumen adhesive (flashing) strips line the whole inside of the box and speaker dampening vinyl also lines the lid.

Cotton coated pure silver (.4mm) wire is used in the signal path. Over size power caps (330uf low ESR) and polypropylene input caps (.47uf) were mounted on the tiny cct. brd. with all the other components. I wanted the passive parts as close as possible to the OP amp chip the OPA2134PA. The chip was socketed with a gold pin socket. The cct. brd. was mounted on plastic stand-offs encircled with rubber grommets (resonance reducing). Two 9V batteries and a voltage divider network provide the +/- 9 volts for the chip.

The test set-up was a portable CD player with a line-out, new Grado SR80 phones and my home made Cotton ConneX cables. Bass was a bit muddied and there was a nasaliness in female vocals. A NAD C542 replaced the portable player and things got a whole lot better! I'm usually a speaker freak when it comes to listening to music. But two hours latter I was still glued to the lounge in a world of my own listening "up-close-and-personal" to both live and studio recordings. How would I describe the amp - "GREAT"!

Synergy Chip Amp

The Synergy Amp is by far the best sounding amp I have ever built. Taking the concept of using inexpensive baking dishes for chassis one step further I grabbed the heaviest cast aluminum (3mm thick) Teflon coated baking pan I could find and torqued it down to a super thick timber chopping board. Using the principals of a mass-loaded amp the active amplifying components almost become a minor consideration. Now chassis and active components move-as-one, pure Synergy. The amplifying "bits" are a minimalist chip amp (LM3875) bolted to the underneath of the chassis under the heat sink.

This 26lb retro looking monster is dead, dead quiet with no signal. When played it delivers big time. Punchy, clear and a massive sound stage. The sound does not appear to emulate from the speakers but leaps from the wall behind and to the sides on the speakers.

The big caps are 10,000uf 100V electrolytics, the plastic rapper is pealed off and a red coat is sprayed on. These are by-passed by 10uf polypropylene and .1uf green caps. The 10uf caps for better mid-range transparency. 160VA toroidal tranny powers up the 50W RMS pc amp and a well snubbed rec. bridge provides clean power. The massive heat sink on top helps with cooling but also adds some extra weight directly above the chips. Pure silver wire is used for the sig. path and OFC use for the power wiring. Extra heavy copper wire connects the speaker binding posts to the amp output pins.

There is NO cct. brds,. at all in this amp. It is all point-to-point wiring. The passive compenent s are woven into the chip. The chassis is torqued down to the chopping board by two ¼” bolts, spring washers and wing nut. An RFI filter cleans up the 240V power and aluminum and pitchmen flashing covers the internals surface of the board to provide additional shielding and more resonance deadening. The amp plays extremely well and was in-expensive to build. It has now replaced my monoblocks as my main amp. Check-out the full write-up on diyaudioprojects.

Under the chassis of the Synergy amp.

The Synergy breaks all the rules by making the chassis far more important than the active components. As you can see no cct. brds, all point-to-point wiring, minimalist chip amp construction now turns the sound focus to the chassis. This concept was born in the original Gaincard amp. Low component count, a big quiet PS, short feed-back path solid chassis and quality parts. Where my Gainclone varies strongly is in large line capacitors. Usually Gainclones have small 1500uf line caps. This amp features 10,000uf caps! Another stunning quality of this amp is the stereo imaging. Is extended and multi-layered. A very revealing amplifier.

DIY afternoon with the MAC

From my first meeting with the Melbourne Audio Club I got into one of the break-out group meetings. This one was held at a member's house and it was to show off his new Millennia amp. This is a solid state discrete component power amp capable of 120W. All equipment here is DIY except for the unusual speakers which have also been modified. A BBQ and some drinks stated the afternoon but soon the gear was warmed up and the music started. All music is played from hard drive and controlled from within iTunes and operated from the owners comfy chair. There is way too much very specialised gear here to go into but basically from media center to valve preamp and then the millennia power amp. The sound was excellent and all who attend commented on the beautiful balance of components. The builder hadb an exceptional eye for detail. The Millennia was a work or art both aesthetically and auditory.

Jean Hiraga-symmetry and Croatian Circuit boards.

Jean Hiraga designed and built an number of symmetric amplifiers which were renowned for purity of sound and natural tone. I love the design philosophy of an amplifier which not only says it is symmetrical but looks symmetrical in circuit and build. These circuit boards I ordered from Croatia and are extremely well made, you guessed it, symmetrical in appearance as well as layout. Jean did state that the boards should not be solder masked and these are. I can only imagine the difference in tone and performance. The mask remains.

What you see in this image is the assembled circuit boards and their related heat sinks (HS). The HS(s) will form a part of the case by employing some heavy aluminium panels, self tapping screws and isolation feet (you must check back to see this). This ensures vibration and resonance issues are controlled. The power supply will be assembled around 60,000uf of filtering, ultra fast diodes, PS snubbing and EMI and RFI reduced, high current deliverable power. The quietness and beauty of this 8 watt audio amplifier lays not in multi-stage, multi-feedback enhanced "more stages are best" design but in its simplicity, ability to deliver and balance of design. Not to mention NO signal caps AT ALL! Not even line caps on the circuit board. Want to find inner musical peace:- Jean Hiraga

Finally this amp is complete and sounding excellent see the new images above. See the retro-thermionic blog for more details.

Columbia and Spice Engines

We have seen audio amplifiers move from valves to transistors. Of course the next step on is to place many transistors on a single substrate. Yes the integrated amplifier or monolith is born. Not integrated in the normal way we think of amplifiers with preamp, attenuators, selection switches, tone controls and power amps all combined under the one lid. But integrated depletion layers and resistors on a tiny slab of silicon. Less than 1" square and weighing but a few grams some of these chips can put out 100s of watts. My axe of choice when it comes to chip amps is the LM3875. My nanoo and mono blocks use the same chip and the amp modules shown here are what I base all my chip construction on. See the next Blog for more detail about these powerfull little amps or visit diyaudioprojects.

Spice Engines (LM3875 with 2000uf of low ESR line cap) are used in my mono blocks. In the nanoo the same chip was used with 5,600uf caps which form a Columbia Engine (bigger caps-the one pictured uses 10,000uf line caps). I have currently built Spice Engines with 1000uf low ESR line caps for a special project yet to be completed. Why the small and large caps? Simple, the smaller the cap the better the mid range especially with low ESR caps. You may lose heavy bass or extreme dynamics at high volumes with this design though. So I build different engines for different amp uses and styles. If you constantly played loud hard rock with difficult speaker loads-the Columbia Engines would be for you. Quiet jazz or simple jazz or classical trios or a lot of acoustic content with vocals-Spice Engines.

I always use the same chip amp PS. This has not varied to date. Usually UF diodes are employed but the one pictured used a diode bridge. As you can see from the photo the amp modules are very easy to construct and build into a full system. See the next Blog for more information. As noted below I will build these amp modules for $90 each.

Columbia Engines - Chip amp modules-LM3875.

What no printed cct. brd? With such a small component count (only three resistors) and the opportunity to do a little point-to-point wiring, why go any other way. These Columbia Engines (LM3875 chip amp modules with large line caps) lend themselves perfectly to this type of "get-your-hands-dirty" construction. With the ability to deliver an easy 56W RMS pc @ as low as .06% THD, these small, powerful and excellent sounding chip amps can be the centre of any high-end amplifier construction. The Gaincard from 47 Labs is based on a similar chip.

This is a view from the bottom and from here you can see the line cap (10,000uf) snubbers (.1uf polies). Also obvious is direct wiring to the the amp module with no clamp-down or plug connectors. Every connection is direct soldered. All wiring is heavy duty. Earth is a perfect "star" configuration. I use the component leads as part of the cct. Less than 1" of additional heavy duty copper connecting wire is used on the cct. brds. and this is an all one piece wire which is also the Ve- PS wire and part of the fuse assembly. The rest of the "hook-up" wire is the component leads themselves. No hook-up wire, no printed cct.

Resistors share the same mounting hole as the chip leads and are rapped around the chip leads, with one other connection if required and silver soldered all together. No tracks, no additional hook-up wire no added signal path length. The feed-back resistor is also mounted in the chip lead holes resulting in a feed back path the total length of the .5 W metal film resistors itself. And with the whole chip less than an 1" long, and this is the amplifier complete, you can only guess how fast these chips are. With excellent PSRRR and SPiKe these chip are very tough and dead quiet. Don't want to build your own - I can supply for $90 each (minimum of two) including in-line fuse housings and fuses. Why not build your own. Here's how: diyaudioprojects

MAC - Melbourne Audio Club - second oldest in the WORLD!

I had been looking for the MAC for some time but for whatever reason could not find it via the Internet. My Canadian friend Gio (see his diyaudioprojects site) lead me to a local site which sells cotton insulation. From a link on that site I found the MAC site. And believe it or not they were meeting that night. You can "try before you buy" so I went along. They had two very nice pairs of Canton, German made, speakers powered by Hugh Dean's Aksa Lifeforce 100 W transistor amp and a pair of 50 W valve mono blocks (under the table). The CD player was a Marantz SACD unit and all preamped through Hugh's GK1 valve preamps (valves ECC189).

The Group meets on the third Wednesday of each month and they have also break-out groups of:- Pop, Opera, Classical, DIY etc. Plus restaurant nights. And they have been doing this for 33 years to-date. I'm off to their Hi-Fi feast night where (amongst others) Halcro will be displaying their incredible goods. I also snuck into a DIY group to be convened in early June at a members house.

Good carefully chosen music was played across combinations of amps and speakers. For my money the best sound was from the Karat (silver outside speakers) and Hugh's Lifeforce tranny amp. The speakers are voiced very accurately and for me probably a little forward. The other speakers, Ergo (brown ones), were too boomy on bassy tracks with the bass also a little muddy. The Ergo(s) didn't really shine until classical was passed through them. Great night.

From No-Fi to Hi-Fi

So how good can 12 litre $AU60 speakers sound. If you say "like rubbish", you would be close. When I first listened to these Dick Smith Electronics (DSE) small bookshelf speakers I new I was in for a challenge to get them to sound even half reasonable. I was also certain they were really only being let down by one component. The tweeter was an insult to the words "design and manufacture". The tweeter had to go first and foremost. The Xover wasn't much better.

Now for the good points. They look good though in simple black. Not like $10K speakers but appeared well made from a low density particle board. The woofer/mids are small but the bass is well extended (comparatively) and as long as they are not driven hard, appear well balanced though a little inefficient. They come with GOLD speaker binding posts and have a bass port.

Firstly I replaced the tweeter with a $AU19 mylar, ferro-cooled, shielded variety, with phase plug. Instant improvement. The Xover (what there was of it) was replaced with a high wattage 12db roll-off, air cored chokes with upgraded metal film polypropylene speaker caps. The terminal plate was upgraded but the original gold binding posts were recycled. Heavy copper speaker wire was used for internal hook-ups and lots off additional dacron was used to line and dampen the boxes.

Hi-Fi came to No-Fi speakers. In my system the tweeters were to dominating over balancing the small woofer. A -6db reduction in the tweeter volume with non-inductive 5W resistors (maintaining 8 ohms impedance) was implemented. Now you're listen! The bass port had a restrictive grate. This was cut-away and the opening smoothed out with a file.

I absolutely love these speakers. These are the only speakers I use in my current system. Yes, the bass is not ball shaking deep. They are small woofers, it ain't "gunna" happen. BUT the bass that is there is weighty, precise, clean, controlled, tonal, room filling and thoroughly enjoyable. I do have them out from the wall a good way and they sit atop heavy duty stands. BUT the sound stage from such a small box is razor sharp. Each instrument is clinically defined, sits in it's own space and time. The two boxes are 2.5m apart and if you walk toward the center of the speakers the sound stage leaps out and grabs you. It is not imaginary. I have tested this with a number of armature listeners and I always get a startled reaction.

So you CAN morph cheap speakers into good speakers. The thin timber walls do flap a bit. They ARE light weight. The bass could be more extended. Yes, I know all their short comings but $60k speakers have short comings too. What really appeals to me about these diminutive bookshelves is their accuracy, sheer speed, chiseled sound stage, clear crisp mids, beautiful highs and cute looks. For a total cost of $AU200 these babies speak with a razor tongue. If I purchased them from a store for $600 I would deem then good value. But the real value for me comes with the knowledge that I made them what they are. Should you feel the urge to own these precise little speakers, I can produce a pair for you for $400.