randytsuch's audio page

Squeezebox 2 rebox part 4

2008-10-02T18:12:00.001-07:00

Part 3
So, I decided to upgrade the +5 DAC power, to use a separate transformer/bridge/caps/regulator.

For this +5 DAC power, again using a Hammond, 12.6 VCT, 12VA transformer, filtered by Felix #1.
This is full wave rectified with two diodes, then to a CRC filter with 3300uf FC caps and a .47 ohm R.

Regulator is a single voltage version of this
http://www.audio-gd.com/enweb/pro/diy/zd.htm
They no longer have the model I bought on their website.
I was buying some discrete buffers from them anyway, they had a 2 for 1 deal going, so I decided to buy one of these regs, it was only $10.

Based on the PCM1748 datasheet, I need 13mA max of +5V, and 10mA max of 3.3V for the DAC.

+5 is now set up for 50 mA, so I need to change some resistors for a lower current, or add a load to it, to draw more power. I added a load
40 mA
V=IR
R = 100 ohms gives a load of 50ma + the 13ma, max load of 63ma
But the transistors were getting kind of warm, so I disconnected the load resistor.
I am going to try a 200 ohm resistor, and see what happens.

I put a little piece of perf board under the regulator, to keep it from shorting anything else.

I used one of the screw holes for the transistor, to help hold it down. That, and the wires are holding it down.

I hooked up ground to a pad for a connector I removed.

Power is hooked up to a via, next to a cap on the +5.

I mounted it like this, to keep the wires as short as possible.

Before I made this change, the sound was detailed, but could be a little fatiguing.

After this change, the detail is still there, but sound is more relaxed, no fatigue anymore. Not sure why, I am happy with it.

Squeezebox 2 rebox part 1

2008-10-01T23:04:00.000-07:00

So here is my SB2 rebox story.

Top still needs painting

In short, it is a SB2, with three Felix’s for power filtering, a bunch of transformers, mostly CRC filtering, a variety of regulators, a built in Burson Buffer, and provisions for adding a Twisted Pear Buffalo DAC later. Clock is a Tent clock XO3.

Here is a pic of the guts, not quite finished, but getting close

Box
Bought a par metal 20-16165A for $64.50 for the chassis plus $15 for internal plate.
This one has “Gold/Clear alodine finish for EMI shield”. Alodine is conductive, so after you screw the thing together, the top makes electrical contact with the bottom, and front and back, as long as you don’t paint over the wrong part. And Aluminum is a good EMI shield.

It is a 16 x 16 x 5 box, so lots of room to put stuff in it, and I plan to use lots of the room

I had some different thoughts about how to handle the display.
I was going to make the entire front out of plastic, and sand everywhere expect a box for the display. I saw a thing where Peter Daniels did something like this, and it looked nice.

In the end, I got lazy. I cut a rectangular hole in the front, a little smaller than the SB2 smoked plastic display front. I then filed the hole a little bigger, until the display would just fit in snuggly, so I could “press fit” the display into the hole. I pressed the display into the front on a flat surface, then epoxyed the display in place, so it won’t come out. I also made a few cutting mistakes, where there were some gaps, and I used epoxy to fill in the gaps.

Not perfect, but it looks OK, as long as you don’t look too close ;).

To mount the actual display, I exposed flat head, number two screws in each corner. The display board has mounting holes in each corner, even though they were not used, but I thank Squeezebox for putting them there. The display is simply mounted with the screws, with a small gap between the display itself, and the smoked plastic.

The first time I tried, I did not use enough epoxy, and some of the screws came off, so this time I used more epoxy

AC Power
When I started this project, over one year ago, I was going to use a Felicia, and a REALLY big transformer. At some point, I decided to take a more “distributed” approach.

I ended up using three Felixes, and a bunch of different, smaller transformers. Pretty much dedicated transformers for different functions.

I did not use the group buy Felix cards, because they took up too much space, so I made a smaller version

Here is the at this time uninstalled IEC jack, with my “fuse” board, and the first felix. The transformer is for powering the burson buffer power supplies

Here it is, after wiring in the switch and IEC, but its harder to see stuff.

The three Felix’s are separated per below:
1. Analog circuits – Burson buffers and analog DAC supplies
2. Digital circuits – Digital DAC supplies
3. Digital circuits - +5 for SB2 and clocks.

These feed the various transformers I have.
Transformers
T1 36VCT, 44VA for Teddy Reg Felix #1 (Analog)
T2 Not installed yet. Felix #1 (Analog)
T3 12.6 VCT 12VA for +5 DAC Felix #1 (Analog)
T4 12.6 VCT 12VA for Display no filtering
T5 Not installed yet 12.6 VCT 12VA for 3.3 V DAC Felix #2 (DAC)
T6 12.6 VCT 12VA for 3.3 V SB2 Felix #2 (DAC)
T7 12.6 VCT 12VA for Clock Felix #3 (SB/clock)
T8 16 VCT 25VA for 5V SB2 Felix #3 (SB/clock)

12.6 VCT 12VA = Hammond 164G12

Picture of power side of box

When the transformers are close to each other, I put them at 90 degree angles to each other, to reduce interaction between them.

Squeezebox 2 rebox part 2

2008-10-01T07:19:00.001-07:00

This picture helped me figure out how to power the SB2

First, I built a power supply for the +5, 2A input in to the SB2, replacing the cheap walwart that come with it.

To start, the AC is filtered by Felix #3. Then, AC goes to a Signal Transformer, 16 VCT, 25 VA transformer, courtesy of my local surplus store.

I started with a Hammond 12.6V CT, 12VA transformer, but it was a little underpowered, at least I thought so. Powering a SB3 with wireless, Hammond would get to about 130f, with a room temp of 75f, so a 55 degree temp rise. Plus, with the reg I was using, the voltage was a little low. I expected it to provide 6.3*1.4 = 8.8 volts. I got closer to 7.5 volts.

With the larger Signal tx, I get around 11.5 VDC out of the bridge.
After the transformer, I have a full wave bridge, using two diodes, with the centertap going to ground. So, one diode goes to the one secondary tap, the other diode goes to a tap on the other secondary, and the two other taps are tied together, and these two taps form the ground.

This feeds a Panny, 3300uf FC cap, then a small inductor, another 3300uf cap, 0 .47ohm resistor, then a Jensen 10,000 uf cap. The Jensen cap is next to the regulator.
In general, I kept the transformers, bridges, and the first and 2nd caps in the noisy part of the box.

Not the final wiring needs to be cleaned up still.

For the regulator, I am using a PowerReg, a higher power version of the TeddyReg, from PFM.

Link here
http://www.pinkfishmedia.net/forum/showthread.php?t=39306&highlight=power+teddy
I used these values for my PowerReg
R1 = 479R
R2 = 90R5
R3 = 50K
R4 = 100 K (added on top of board)
R5 = 50K (marked as R4)
R6 = 110R (marked as R5)
C1 = 0.1uF X7R Ceramic
C2 = 10uF Tantalum
C3 = 10uF Tantalum
C4 = 33uF Tantalum
C5 = 0.2uF X7R Ceramic
C6 = 3.3uf Wima MK4
T1 = SK117 GR
T2 = BC550C
T3 = D45H11
LR1 = LT1038

Heat sink is out of my junk drawer. Overkill, it hardly gets warm at all.

Ground is connected from the SB to the reg by a VERY short wire, it is under the yellow tantalum cap in this picture. I scrapped off some solder mask, in the ground plane, as close to my PowerReg as possible, to make the ground wire short, so the two grounds would be well coupled.

I removed the power connector, and connected +5 to a pad for an inductor right after the power connector. I also removed the inductor. I also added a 220uf silmic, close to where I wired power in. There were a couple holes, near here, a convenient place to install the cap. You can just see the top of the cap at the edge of this pic.

When I first powered up, I thought it was not regulating well, because it varied a lot over different loads. I had three 15 ohm power resistors to test with, and I would add them in parallel, so I could draw up to one amp with a 5 ohm load at 5VDC out of the reg.
Turns out, my input voltage was not as high as I expected, so the input regulator was not regulating, because I was not feeding it enough voltage. I started with a LM317, but changed to the 1038 because the 317 needs over 2 VDC of voltage difference, the 1038 is around 1.3 volts.
2nd problem I had was the PowerReg comes up too slowly, and the SB did not come up when I powered the reg up. Fortunately, Teddy came up a quick start up circuit, because other people had similar problems with the TeddyReg.http://www.pinkfishmedia.net/forum/showthread.php?t=50718It adds a transistor, and a couple resistors. Resistors are same value as R3 and R4 (50K and 100K). Transistor he used was a BC639, a NPN with 1A collector current. I found a MPSA42 in my transistor box, a NPN with 500mA collector current.
Added the resistors and transistor to rear side of board, hooked everything back up, and the SB2 came on when I turned plugged in the power :).
Last problem was with tweaking the output voltage. Seems like the voltage drop from the circuit varies with the regulator output voltage, the voltage drop increases as the regulator output voltage increases.
So, I had it working, but output was around 4.8VDC to the SB. I calculated new values, to get a 5.2 V output, but it was lower, because of the increased drop. It took one more iteration to get my current values, voltage is 5.14, where my target was 5.2VDC.

Squeezebox 2 rebox part 3

2008-09-19T06:27:00.000-07:00

5VDC for the DAC

The 5VDC analog power for the DAC comes from a linear reg, but the linear reg is powered from a switching reg on display card. I decided to supply my own power to it, but for the time being, I am still using the little 5v reg on the SB board.

To do this, I removed R29, shown in this pic. To get to R29, you need to remove the wireless board (if you have one) and the processor card. R29 is under them.

Then, I just connected a wire to the positive lead of the "big ass" cap, which is to the right of R29 in this pic.

For now, I supplied a voltage of around 11.5 volts, unregulated. Its the same power I feed to the PowerReg, which generates the 5VDC input for the main SB board.

It made a small improvement, I was actually expecting more. Things sounded a little cleaner, and I think the highs improved the most.

This turned out to be a temperary solution, I will explain the more permanent change later.

5VDC for the Display board
Since I was not using the +14 from the display board anymore, it was time to feed the Display a different +5. In the stock SB, the display board is powered from the same +5 that powers the main SB board.

This involves isolating the display board from the main +5, and generating a seperate +5 to power it.

You need to remove the processor card to make this cut.

To power the display board, I used a seperate 6.3V, 12VA hammond TX. This TX does not go to a Felix, it is powered directly from the fuse board.

I connected the secondaries of the TX in parallel, so it generates the 6.3VAC at 12VA, and then ran two wires to a bridge. The bridge is next to a cap, as shown here. And both of these were glued to a heatsink, which is in the corner by the display card.

On the other side of the heatsink, I have a generic 7805 regulator, to take generate a regulated 5VDC. It puts out 5.1VDC, which is good enough. After hooking up the regulator, its a good idea to check the regulator output before connecting it to the display :)

All that's left now is to hook up power to the display board, which is easy because there are test points you can just solder wires to.

The ground test point is labeled J3

The +5 test point is labeled J17.
They are right next to each other, on the left side of the display board looking from the back.

This change had a bigger difference then I expected, I thought the background noise dropped, and things got "blacker" after making this change. I think it keeps noise generated from the switching regs on the display from getting into the main SB.

Taylo Monitor review

2006-02-21T11:37:00.000-08:00

My review of Tyler Acoustics Taylo Reference Monitor, it was posted at Harmonic Discord, but that site is no longer working.

I have been thinking about writing a review for a while, and a suggestion from Dan finally got me started. I bought a slightly used pair, direct from the factory, in an Audiogon auction. I also bought the custom speaker stands and some Dhlabs T-14 speaker cable. Ty takes equipment on trade in, so he always seems to have used speakers for sale on his website, and he also puts them up in Audiogon auctions fairly frequently.

When I got my speakers, they looked almost new. There were some very minor blemishes on the bottom, but otherwise they looked pristine. When I talked to Ty about them, he said they were not even really broken in yet. Oh, that is one really good thing about Tyler Acoustics, you can just call them up and talk to Ty, the owner. He has always made time to answer my calls, and is very friendly and helpful on the phone.

The Setup
My current setup is a Sony SCD-C333ES Cdplayer, connected to a AMC CVT 1030 and Monster M500 IC’s to a Quad 306 amp to my Taylo’s. I have them biwired, using DHLabs T-14 for the bottom, and old Randall Research speaker cable for the tops. The Randall stuff is made up of a bunch of small gauge Teflon insulated wires, put together in a big braid.
Room is 12 W by 18 L x 8 H. It is carpeted over a cement foundation. About 12 feet of the right side of the wall, on the speaker side of the room, is not there, as this is where the kitchen/breakfast room connects to this room. The rear wall has a large window, which is covered by a vertical blind. I think the blind helps deflect the rear wall deflections. There is a large entertainment center with a TV and the stereo in the front of the room.
I put the speakers a little over 5 feet from the front wall, to get them in front of the entertainment center. The speakers are a little over 3 feet from the side walls. Currently, I use very little toe in. I used to have about 1 inch of toe in (1 inch difference between distance of right and left sides of speakers to front wall). I tried about ¼ inch toe in, and found I still had good focus, and a better soundstage. I am still going to experiment in this area. As I do not want to be kicked out of the house, I do not have any room treatments.
I have also used a NAD 906, 30 w by 6 HT amp, but I like the quad better. The quad has better focus than the NAD, and also the mids sounded fuller with the quad than the NAD. The NAD does seem a little quieter, with a blacker background than the quad. The NAD also had a better low end than the quad.

The Stands
Let me say a few words about the stands that come with. They are very well made, made of MDF, painted black. They can be filled, but I have not done so yet, as I move them too much. I have to move the speakers on top of the entertainment center, and stands out of the way, when I am not listening to music. I have a two and a four year old, so I can’t leave the speakers out in the middle of the room.
Stands have brass cones on the bottom, which can be height adjusted to level the speakers. Only problem with the cones is it’s hard to get them through the carpet, to directly couple to the cement. Stands came with 4 hard rubber “feet”, which the speakers sit on. I have since changed the feet to four Vibrapod #3’s. I think the pods help the definition of the speakers. They seem to have a cleaner sound with them, but that could be my imagination. I do not have help around to do a double blind test, so I just have to try swapping and listening. The ‘pods also let the speakers play louder without distortion. Before I used pods, I heard the some distortion on an Andrea Boccelli cut at load volumes, it went away when I put pods on. Only issue I have with the stands is they are a little tall, would prefer if they were 2-3 inches shorter.

The Shopping
Before I bought the Taylos, I listened to many speakers: B&W Nautilus 805, Joseph Audio RM7 Sigs, Paradigm active 20’s and Studio 40’s, Sonus Faber Concerto’s, Speakercity DIY MTM 18, Revel M20’s, Anstrom Legato, Dunleavy SC1’s, Dynaudio Contour 1.3’s, Monitor Audio Golds, Proac Tab 2000’s, Reference 3 MM De Capo’s, Soliloquy 5.0, Spendor 3/5, Tannoy S8, and Westlake Audio not sure model number.
As you can see, quite a list. I live in LA, so there are a lot of high end audio stores, who carry a lot of different speakers, so it was not too hard to do, except it took a couple of months to do this. I would carry the same CD’s with me, and a RS SPL meter, to make sure I listened to the speakers at the same levels.
I did no home auditions of any speakers. I was going to, but then when the Taylos’ went on auction, I bought them because I got such a good price. The Nautilus 805’s and the RM7 Sigs were my next choices BTW. 3MM De Capo’s were really nice too, but they do not have a center speaker available for HT.

The Speaker
In case you do not know, thought I would describe the speakers. These are monitor speakers, but pretty heavy, weigh about 40 lbs each, I think. Tylers uses thick MDF to make the cabinets, think it is 1.5 inches thick. He uses the Scanspeak Revelator tweater, and a Seas aluminum mid/woofer with a brass phase plug. Nice, expensive stuff. He also uses Hovland caps, in the signal path, and other quality components in the xover. Internal wiring is DH labs wire, unless you pay for the upgraded Cardas wire.

Store Sound
I went down to San Diego to hear these in a store who had a used pair. I did not buy from the store because the pair they had was zebrawood finish, which was kind of funky and my wife was already not happy about buying speakers. Listened with NAD 2100 amp, Adcom 565 preamp, Adcom CDP. Tried to use equipment on par with what I had. I took notes as I listened to different songs, and the notes say things like great soundstage, good depth in soundstage, transparent, speakers disappear, good focus, good definition and no grain. I remember being impressed with the 3 dimensional aspect of the soundstage, where you get width, depth and height. Most other speakers I heard don’t do the height aspect very well. I was also impressed by the ability of the speakers to disappear, and make it seem like Diana Krall was in the room with me. They did this as well as anything I heard.
The only area where the Taylos were bested was in the mids by the Nautilus 805’s. The 805 have a very rich, full sounding midrange, which I liked. However, since I did not hear this quality in any other speaker I heard, I wondered if the 805’s were colored in this area, so in the end, I am not sure the 805’s were really better in the mids.

Home Sound
When I first got them, I did not like them as much as when I heard them in the store, but I figured that was because of what I was feeding into them, so I started working on the rest of the system. I got rid of the jumpers Tyler uses between the binding posts, and after some listening, settled on my current speaker wiring. A set of Monster cables was also in the mix.
I have added the preamp and cdp since getting the speakers, along with numerous tweaks, such as changing the AC outlet, playing with Vibrapods, changing a couple electrolytic caps in my amp, just started rolling tubes in my preamp (I just got the preamp).

Good points
I love the way they soundstage. With my current setup, the sound gets well outside of the speakers, especially on the open wall side of the room. They do not seem very setup dependent, as I move them a lot, and it does not make a noticeable difference in the sound.
They are mostly non fatiguing. This is a big deal to me, since I seem to be sensitive to this. I am not really sure what causes it, but I can tell when it is happening. I have made changes, like when I first put in the preamp, I started to notice a little fatigue. Rolling tubes has fixed this, since it came with cheap Chinese tubes that are kind of harsh. Mostly, I can listen for long periods of time with no fatigue.
They are very transparent. I used to have a pair of the original quads, and no, they are not as transparent in the mids as those, but I am have not heard anything that is. These are very good though. They also let me hear when I make a tweak for better, or for worse.
One last good think about them. To me, they are detailed without being analytical, that is they let me hear the nuances in the music, but they are still musical. I really did not hear any over analytical speakers in my list, but I heard many that were not as detailed as the Tylers.

Bad points
They do not do the really low notes, but that is to be expected of a 2 way monitor. They really do not have any faults, that I can spot, other that this.

magic box

2005-10-18T15:39:00.000-07:00

From the Oct 2005 PS audio newsletter

The Magic BoxI'll end this cartridge discussion with an interesting story, of many years ago, concerning a certain Magic Box. Back in the early 1970's when Stan and I were running PS Audio and primarily building phono stages, we got a call from a fellow named Owen Bennet who claimed he had a "magic circuit" that could turn a $15 Grado moving magnet cartridge into something that sounded superior to any moving coil. At first we paid little attention to this wild claim as we tired of spending time dealing with over-the-edge customer claims we (supposedly) needed to investigate and then change our products to reflect their discoveries. Discoveries like: our preamp sounded better upside down, it sounded better without an LED and so on.We eventually invited Owen and his partner, Tony Dichiro, to our California facility to demonstrate the Magic Box. Stan and I were both dumbstruck because, low and behold, the damn thing worked. It worked well and it did just as advertised. How the heck...? Well, after a lot of needling (pun intended) we got the boys to explain what they had invented and, to this day, I still think it's one of the coolest ideas I've seen.They explained that one of the problems of a moving magnet cartridge was rising inductance at high frequencies. This simply means that into a fixed load (like the 47K standard load for MM's) the loudness of the cartridge would be reduced as the frequency went higher. 'OK', we said, 'so what? We can compensate for that'. "No, you can't really, because the way it rises is complex, not a straight line or predictable function". Moreover, it was different for every cartridge.So, they opened their little Magic Box (where the magic lived) and inside was a simple op amp (integrated circuit preamplifier) and, lo and behold, another MM cartridge soldered to the PC board! Here was an identical Grado cartridge, sans needle, soldered into the feedback loop of the op amp. Brilliant. Faced with a complex impedance problem, all they did to solve it was reverse the complex response by placing it in the feedback loop of an amplifier. So, whatever the cartridge did wrong, the same cartridge in the feedback loop did exactly the opposite and the result was a flat line response that was simply breathtaking!We passed on the Magic Box as a PS product because it would require every owner of a moving magnet cartridge to buy two: one for the turntable and one for the correction circuit. These wonderful ideas finally found their way into a company and products you may remember, Kinergetics. Ahhh, as Satn was fond of saying, 'the bad old days' .

This page started a thread at diyaudio below:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=66243

My system

2005-10-11T07:50:00.000-07:00

Home - main headphone
Analog Source
Empire 208 turntable with corian plinth
Rega 250 tonearm and Dynavector 10X5 nude cartridge
Hagtech cornet phono stage
See link below for more info on table
http://randytsuch-new-empire-tt.blogspot.com/2005/08/empire-turntable-completed.html
Digital Source
Squeezebox3 with RWA analog mods with DIY power supply to
Audiosector NOS dac
Amp
Charlize digital amp with a SMPS.
Headphones
AKG K-1000's
Speakers
EVS modded pair of VMPS 626

Portable System
Rio Karma
superfi UE-5 Pro canalphones

Office System
Laptop/sound card
Monsoon M500 Speakers with two subwoofers

Some random pics
http://www.audiocircle.com/circles/modules.php?set_albumName=albuv23&op=modload&name=gallery&file=index&include=view_album.php

Pacific Phono stage

2005-09-19T16:20:00.000-07:00

Pacific RIAA Pre - 24V Version==============================

..................o-----------------------------------o------------+24V
.................R2.......................................R6
..................].....................................D---o---C7---o
............D---o---C1--R3--o----o-----o---G .............OUT
o---o---G......................................... S---o........... o
IN....... S---o............... R4........... R5 o o--o--o o--o--o R1 C2 C3 C4 C5 C6 o---o-------o--------o--o--o--o-----o---o-------o--------o--- 0V

R1 = 100k C1 = 0.47 micro
R2 = 2.4k C2 = 15 nano (ideal C2 + C+ +C4 = 99.3 nF)
R3 = 27k C3 = 15 nano well my copy says 100nF
R4 = 3k C4 = 68 nano
R5 = 100k C5 = 22 nano here its 30nF total
R6 = 2.4k C6 = 6.8 nanoC7 = 2.2 micro

Empire plinth

2005-08-28T16:35:00.000-07:00

Building a new plinth out of Corian.

I bought two 1/2 thick pieces from Ebay. Cut them down a little, and then glued them together.

I glued one of the cut pieces to one side, because I need to raise my tonearm for the thick empire platter. Drilled holes for the arm and spindle. I used a wood hole saw to drill the hole for the arm, but I wish I would have done it differently. Hole came out a little large, and I have to put electrical tape around my VTAF to make it snug.

Tooks lots of sanding to get to this point. I sended the edges starting with 60 grit with my orbital sander, to get it even. It was not even after I glued it together. I worked my way down to 2500 grit (from an auto paint supply store), and finished with rubbing compound. Lots of work, but I was happy with the results.

Ready for the tonearm.

Legs are made from 1/2 inch "all thread", bought from home depot.

With the motor attached, it spins ;).

Empire Turntable - Motor

2005-08-13T22:47:00.000-07:00

So, here is the motor and everything else, after I pulled it out of the table. I traced the wires, and drew a simple schematic for it.

I ended up changing the power cord, because it was so old, and had a very cheesy plug on it. I was going to put in a bigger motor run cap in it as well, but then I saw somewhere that the motor is designed for a certain capacitance, which is on the motor. And the motor says 4 uf, which is what Empire used. So, since it works, I just left the old cap in.

Now, I was trying to figure out how to mount the motor. I wanted to not have it part of the plinth, which is different from how it came. It was isolated on three rubber mounts, but it is connected to the top, with the rubber mounts, in the original table.

I had a piece of 1/2' thick cocobola I was going to use for the armboard, but ended up doing something else, so I just mounted the motor to this piece of wood. I drilled out a few holes to screw the motor in, and one big hole for the spindle. I used thread all for the 4 legs.

I ended up removing the top plate from the motor assembly, this is the plate that allows the motor to move, with a spring to adjust the tension. It is meant to maintain the right tension on the belt. I figured I could just move the motor farther away if the belt gets loose.

That's it for now. Here are some pics.
My biggest mistake for this is I was not carefull when I drilled the holes for the legs, and one leg is crooked :(.

Rega RB-250 Tonearm mods

2005-08-13T11:21:00.000-07:00

Rega RB-250 tonearm mods

Structural mod

That is what origin live calls their version of this change, but is really is just changing out the cheap plastic end stub with a metal one, and using a better counterweight.

I picked the Michell counterweight, as reviewed here
http://www.vinylengine.com/michell_tecnoweight.shtml

It was not cheap, but I liked it because it is easier to adjust the counterweight on it. It was a scale built in, versus the others where you just move it back and forth, and need a scale to set it.

Rewiring

I also rewired my arm. I got the arm cheap because it had an intermittent wire, so I just changed it out.
There are many pages out there that talk about rewiring regas, here are some links
http://www.hi-fi.com/diy/rega/
http://melhuish.org/audio/rewire.html
http://csown.dhs.org/hi-fi/rega_mod.html

And, here is what I did. Sorry, did not take pics while I was doing it.
I decided to use the Cardas tonearm wire from Percy for this job. Some people advocate the discovery wire, and solid silver wire, but I was worried about how this wire would effect tracking. Cardas is only 33 ga wire, and it is stranded to make it more flexible.

First, I removed the rubber stop from the bottom of the arm, and cut the wires at the little circuit card that is attached to the rubber. I cut the card off, and just saved the rubber stopper.

I tried to solder my old wire to the new wire, but when I tried to pull the new wire through with this method, it just broke the old wires, and broke the ground wire to boot. The tonearm ground wire went from the little circuit card to a little copper piece that is close to where the end stub screws into the arm. The copper is wedged into the arm to make ground contact there.

I ended up running a piece of 30 gauge solid wire through the arm. It is pretty easy if you remove the end stub, and start from the bottom.

I then soldered the new wires to the 30 gauge wire, and pulled them through. It worked, but it was a little too fat at the solder point, so it pulled out to little rubber gaskets, one a little before the wires enter the bearing area, and one where the wires enter the tonearm tube. The point of these gaskets is to make sure the wires don’t mess up the bearing movement, I think.

I was able to pull the new wires back and forth, to get the rubber gaskets back in place.
I used a piece of solid 30 gauge wire for the ground wire. I soldered it to the same copper piece the old ground went to.

I drilled a small hole in the rubber stop, and pulled the tonearm wires though the stop, as well as the ground wire.

I carefully soldered clips on to the wires at the headshell. I reused the rubber piece that was there, to run the wires through.

I then pulled them back, to leave just enough at that end. Then, I put the rubber stop in at the bottom of the arm, but stuffed a little wire in at the bottom, for a service loop.

For now, I taped the wires to the rubber stop, where they come out of it. This is temporary, and I will glue them in place, as soon as I am sure it is all working ok.

I put on Eichman bullet plugs on the other ends. For a phono plug, the low mass design of the RCA’s makes sense to me.

I did not shield at all, was a little worried, but no noise when I connected.
Also, tracks fine. I was worried about how it would track after I rewired, but played a few albums, and they had no problem at all.