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Item: RJM Audio VSPS Moving Magnet DIY Phono Stage
Price: $180 + $25 postage
Item Condition: Working perfectly, some scratches on cases
Reason for selling: Now using MC
Payment Method: Pickup - Cash, Paypal, COD Only
Extra Info: Excellent sounding phono, used for six months, built about two years ago. The cases are thin Aluminium, but have brass or Titanium plates at connector points.
Materials used: RJM VSPS and Dual-Bridge Rectifier kits, Dueland wiring for signal paths, Arizona Blue Cactus 2.2uF 200VDC output capacitors (with bypass caps), Altronics transformer, Furutech Rhodium FI-03 IEC inlet with fuse, 2 x Aluminium cases, Stillpoint ERS tape around power cable (light blue) in phono case, Gold coated pure Copper RCA plugs, 2 cm slate pieces under circuit boards and transformer, brass (front) and Titanium plates (rear). Well over $200 of materials used.
This product has not been manufactured by a qualified individual or company, therefore contains electrical circuits that do not necessarily comply with Australian Standards. I understand that as the seller, I may be liable to repercussions in the event of equipment failure. By advertising and selling this product, as the seller I also agree that I am solely liable, and the publisher of this website takes no responsibility for any injury or death resulting from, whether directly or indirectly, any accident that may happen as a result of the failure of the product being sold. If in doubt, seek the services of a qualified electrician to inspect the product to ensure it is safe for use.
Photos: Advertisements without photos of the actual item will not be approved.
Item: 2 x Toroidal Transformers 160VA 2x20V Audio Grade
Location: Sydney, Lindfield
Item Condition: Made in 2013 but never used, mint
Reason for selling: Abandoned DIY project
Payment Method: Pickup - Cash, Paypal
I have for sale a pair of Toroidal Transformers. They are 160VA, 2 x 20V each. Made by Toroidy, great Polish manufacturer of high quality audio grade transformers.
Selling both matched transformers together, so the price is for the pair. They could be perfect for a dual-mono or two monoblock amplifiers.
I bought the transformers 6 years ago, for my DIY amp that I never finished. I did not even put those transformers in. Stored them packed in the box. So these are pretty much brand new.
I did not have time to finish that project and do not need those two any more, so the sale.
Some of the characteristics of the Audio Grade transformers by Toroidy:
- additional magnetic and electrostatic screening
- epoxy filled centre with M6 clearance hole in a potted centre for mounting
- gum pads to eliminate transmission of vibrations
- impregnated core and the windings
- covered with a black Mylar tape
- production process scrupulously controlled at every step
- quiet performance and the highest electrical parameters
- flex leads
- GOSS band
On top of that, my order had a couple of custom modifications:
- doubled diameter of secondary windings
- primary winded on secondaries
Primary: 0-230V @ 50Hz
Estimated dimensions: 105mm diameter x 50mm high (plus 10-20mm for leadouts)
Mounting: M6 clearance hole in a potted centre
Leadouts: approx. 110mm long flexible (stranded)
Weight: approx. 1.35kg each
I’m happy to post anywhere in Australia. Pickup available from Lindfield (2070).
For our October club meeting we are very pleased to have club member Bill Louey present his own highly modified home system including his DIY loudspeakers. Bill last presented his system to the club back in April 2012 – much of it has now changed and improved.
Details of Bill’s system (details below were written by Bill)…
These are 3 way open baffle loudspeakers using dynamic drivers with active and passive hybrid crossovers. Open baffle loudspeakers have some unique advantages over conventional boxed speakers in that:
· They don’t have an enclosed box so they have no box resonances hence no box colourations,
· Their dipole radiation pattern reduces side reflections hence room interaction and increases the portion of direct sound over reflected sound in the room, and,
· The first sound reflection from the wall comes from behind the speakers in the front instead of from behind the seat for conventional speakers, hence producing a more realistic, life-like sound. Open baffle loudspeakers are substantially harder to design due to sound wave cancellation, reduced efficiency and lobbing effects and usually require active crossover to shape frequency response and need multiple amplifiers to drive. Since open baffle speakers are much harder to sell manufacturers usually don’t make them, except with electrostatic loudspeakers. However, because of the greatest technical challenges and potentially the highest possible sonic result, open baffle speakers with dynamic drivers are the ultimate for loudspeaker DIY builders.
Bill designed the crossover networks and has been tweaking them for 10 years now. He has only lately been very happy with the results and concluded the 10 year loudspeaker DIY project.
CD/SACD/Blu Ray Source
The source is a modified Marantz UD7007 universal player that plays CD, SACD and Blu Ray. Bill has undergone multiple revisions of his own upgrade over the years and has replaced hundreds of parts to change the player to suit his needs. He also changed the player from a Class II player to a Class I player in order to reduce the noise from the switch mode power supply unit.
Preamp / Active Crossover
This is a custom built unit designed by Bill to house the active crossover also to serve as a preamp. All buffer stages use OPA627 driven by an extremely quiet shunt regulator.
Bill originally bought a DIY amplifier kit with conventional 3 stages, class AB, fully complimentary design. He later completely redesigned the printed circuit boards and incorporated a very quiet capacitor multiplier into the amplifier’s first two stages. He also designed his own very quiet and muscular power supply for the amplifier. These are MOSFET amplifiers rated 160W.
The second half of the music sessions will be our popular BYO. Members and guests are welcome to offer music to share with us all. So bring along your favourite music on CD/SACD/Bluray (sorry, no vinyl this month). All we ask is that the music and recordings be interesting. We'll ask you to tell us a little about the artist/recording before it is played. Tracks over 6 minutes will be faded out, to give everyone a fair go.
Whether you are a novice or a seasoned veteran, you will have the opportunity to listen, learn and share your experiences with others. Feel free to come and hear the capabilities of the system, or to just share the experience with like-minded music lovers in a friendly and relaxed atmosphere.
Guests are welcome – we are a very friendly club so you don't need to know anyone to join us for an afternoon of fine music and sound.
Venue: Epping Creative Centre, Dence Park
Address: 26 Stanley Road, Epping
When: Sunday 13th October 2019
Doors open 1pm
Meeting starts at 2pm
Sydney Audio Club
By Primare Knob
For the first time, I have a dedicated room for HT and Gaming and I have finally finished the acoustic treatment of the room. To create this space of 3.4 x 4.9 x 2.5 meter, I had to move the laundry, toilet and bathroom and knock some walls down. Yes…….. the missus really, really loves me.
I had a look at soundproofing the room but decided to not go through with that idea, because the room was rather smallish to begin with and the build a bit complicated, with all the different walls and joist intersecting with each other and with the rest of the house. The room has a double brick outer wall with an air gap in between it, as the front and the right wall. The front wall also has a window in it behind the AT screen. The left wall is a solid double brick internal wall. The ceiling has a couple of 200mm exposed roof joist with some timber on top, 100mm insulation and a flat sheet metal roof. The back wall is newly constructed and is made out of 17mm plywood with 10mm gyprock on top, on both sides, with insulation in between. And the floor is a solid concrete slab.
This room is rather solid and therefor rather challenging regarding bass issues. All treatment is DIY, and the total material cost for acoustic treatment is around $1100 AUD.
The screen wall is a timber frame held up by corner (bass trapping) towers, resting on top of the floor boards, and locked into place by screwing it into the roof joists. It is sitting 550mm from the front wall and is basically functioning as one giant bass absorption trap with 50mm Autex High Density insulation. The wall around the screen has been finished with 6mm MDF sheets with a RPG binary pattern as a finish, and to bring some reflections back into the room. The area behind the AT screen is fully covered in insulation, except for the center speaker. The coverage of unexposed absorption of the front wall is roughly 60%. This improved clarity and sound stage a lot. It also helped with decay rates in the bass frequency. Enough to improve bass clarity, but not enough to even out the decay rate over the full LF frequency range.
The bulk heads around the ceiling have been added on later and consist out of 10mm gyprock with more insulation behind them. The rest of the ceiling has been covered in a binary slat pattern that is hung from the 200mm exposed roof joist, and the space between the roof joist has been filled with more insulation again. The coverage of unexposed absorption on the ceiling is roughly 38% I found that this improved stage depth the most.
The back of the room has been treated with panels made from the same 6mm MDF binary pattern and Autex insulation and have been mounted at various distances from the wall, 50-100-150mm. I had the mount one on a hinge as it was covering the door. I found this to be a big improvement in clarity and precision of tracking in sound effects.
Thanks to clever placement of subwoofers and listen position I have been able to create a LF response for subs and full range front speakers, without any nulls and only need to cut off peaks to receive a flat SPL response. The frequency response of the decay times is less than flat due to the rooms solid build, but doesn’t kick in for the first 20ms, which isn’t too bad.
All in all I am quite happy with the outcome, but isn’t my best work regarding finish, as I have favored speed instead of a quality finish.
Item: Elma Rotary 4 pole 24 way switch 04-4133
Location: Sydney, Lindfield (2070)
Price: $200 (including postage)
Item Condition: Brand new, never used
Reason for selling: Abandoned DIY project
Payment Method: Pickup - Cash, Paypal
I have for sale an Elma Rotary 4 pole 24 way switch (model 04-4133). Perfect for a High-End 2-channel ladder stepped attenuator. It comes with the stop pin.
I bought it a couple of years ago from the hificollective in the UK to build a stepped attenuator for my DIY project. I could not find time to finish the project, so the sale.
"High quality selector switch, non-magnetic bodied switch with 3 micron gold plated contacts over copper alloy. Ceramic wafer. Swiss made. Mounting hole 10.2mm, 6mm diameter shaft, 15mm shaft length body dimensions 76mm L x (32mm dia. x 25mm dia.). Make-before-break type. Superb for ladder stepped attenuators, balanced stereo stepped attenuators and stereo balanced TVC selector. Elma part number 04-4133."
Pickup available from Lindfield (2070) or Sydney CBD, and I'm also happy to post anywhere in Australia.