randytsuch's audio page

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.

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.

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.

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.

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

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 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