Hi,

I have the original version of the Buffalo/IVY with LCBP+DPS. I've put everything in a case but as of now there's no connection between the Buffalo and case ground. Case ground is connected to safety earth. I see there are about 5 places I can connect to chassis ground - LCBPS ground, either the VA or VD ground from the LCDPS, and the analog output grounds from the Buffalo's Iout or the IVY analog output. It made the most sense logically to send the LCBPS ground to chassis, is this OK?

I cased it up to prevent clicks and pops due to loss of sync when switches were flicked on and off in the house. The case has helped, but only slightly. I assume it's because it is still 'floating' to the DAC. There is a filter on the mains input, and the S/pdif input is routed from the RCA input to the Buffalo board directly using one Twisted Pair of CAT5 wire.

Thanks for the help :)

Yup, the output RCAs are floating (as is the input RCA). I checked and they are routed to the same ground point somewhere, and connecting them to case ground didn't help one bit.

The other thing is that I have no receiver, just the single RCA input going direct to the SPDIF input of the DAC board. I had this issue from day 1, and moving halfway across the country didn't solve it. Russ was pretty sure it was a shielding issue so I managed to get a case for it, but the problem still persists.

I initially had about 4 inches between the the DAC and the IVY, but now the DAC is on top of the IVY with about an inch of wire connecting the two.

There is no transformer on the SPDIF input, but the output of my soundcard has a transformer for SPDIF output.

What makes it even more frustrating is that very occasionally, there'll be days when the signal will lock hard and stay like that - no dropouts at all, then the next day it's gone again.

Edited by user Wednesday, September 22, 2010 12:22:09 PM(UTC)  | Reason: Not specified

Hi :)

I have three sources, both the pro audio interfaces (M-Audio Delta 66 and e-Mu 1212m) with transformer output have dropouts when appliances switch on and off. The third is a cheap motherboard, there is no loss of sync with light switches, but it gradually loses sync and simply stops working.

I might mention I do have pops in all my DIY amplifiers when lightswitches are flicked, but it's always solved when I connect safety ground to chassis and connect the analog ground with a low-value resistor or directly. The Buffalo is the only piece of equipment that it does not work on...

Try measuring the AC voltage into the LCDPS VD section. Does it sag also ?

Is your tranny up to the job ?

Don't adjust the voltage under load, the LCDPS can deliver the juice needed, if the tranny can deliver.

Edited by user Thursday, September 30, 2010 11:22:18 AM(UTC)  | Reason: Not specified

LCDPS has two 10 ohm resistors, IIRC. I assumed a 9VAC, 18VA transformer would be fine but obviously mine is pretty close to the limit (haven't measured at the AC terminals on the LCDPS though). I'm using a transformer with two 9VAC windings, each rated at 1A, guess it's not really enough. I'll try upgrading to a bigger transformer to be safe.

What really worried me was that from 6V open circuit to 9V open circuit (where it is now) the output voltage didn't change at all under load, remaining at ~4.5V.

Try shorting the resistors.

Hello there,
I have the same problem. Flicking on/off a light switch somewhere in my appartment
will cause dropouts in my Buffalo/Ivy/Placid combo. Sometimes, two dropouts/mutes will occur within one and a half seconds when flicking a light switch.
One can hear, that the dropouts are soft-muted, so I guess it is not the relais of the Ivy.
The custom-wound transformers driving the combo are up to the specs.

Current and voltages are as proposed, the Buffalo runs with 350mA/5,35V, the Ivy is 15V, but the current I do not remember right now , I guess 190mA each rail.

Some weeks ago, I thought it was my setup during testing which causes the dropouts, without casing and isolation of the spdif input.
But now, with the project almost finished (pictures will be shown in the project gallery),
the SPDIF input being isolated with a transformer and capacitors, the setup is still prone to other equipment or lights being switched on or off.

I have not yet tried connecting the Placids grounds to the the chassis ground, but as sangram notes, this will not help.
Maybe the Placids need more capacitance?
All the best, Nak

Hello Sangram,
I guess, nothing will help. I use Pulse6512 isolation Transformers (designed for SPDIF)+ 10nF capacitors,
they do not help. I have not tested optical input yet.
But this is ridicilous!
I have been using many DACs (Theta, Parasound, Rockna, Digidesign) in my appartment for many years without any problems!
And muting small glitches of whatever reason is a BENEFIT? (As being stated in the other thread)
The "cold" wire of the AC powerline and ground in my house are connected, maybe this is the reason why.

Russ and Brian, will a 74HC04 buffer help? Can the Signal reach TTL-Level of 5 Volt because of the buffer or has the buffered output to be brought back to 0.5 Volt?
I did not check optical input yet, should be the same as a buffered input.
All the best,
Nak

No Idea, how commercial resellers implemented the DAC.
But I tested the optical input today, using TORX173.
Because the casing of the optical receiver is too deep, (and i can not drill squares)
I had to cut the TORX173casing open and glued the optical receiver module behind a cinch socked.
I did proper shielding and decoupling according to the TORX173 datasheet.
Also the receiver runs from a different power source.
Right now, the optical connection is very poor.
I still have to modify a cinch jack with an optical cable to get a good connection.
In the moment, the blank fibre sticks in the cinch socket.
I hear a crackling like in good old record days, but the electrical koax digital inputs are perfect.

So I guess the 9018 input does not mute much earlier than other DACS, because I am still able to hear errors.
The problem must be power related.
The only other gear that gets "triggered" by a light switch is my Sony ZA-5ES DAT.

Edit:
I finished the SPDIF inputs now (6 in total using relais, one of the inputs optical), using a PE65612 1:1 transfomer after the relais board.
Interesting, decoupling the inputs with 10nF capacitors or terminating them (like being proposed in many applications onformations) makes the signal look worse.
So I guess, all decoupling and terminating is done on the Buffalo 2 board? No buffer needed?
Any information on that

I endened up with the PE65612 only in the signal path and a resistor from signal to ground in the torx173, to reduce output from TTL-Level to SPDIF-Level.
The optical signal looks as clean as the coax inputs now.
Playing around with resistor values on the TRX173 showed, that the buffalo would accept SPDIF voltages much below 0.5V.

Also interesting:
The Buffalo 2 will mute an error on a CD on the optical input, but play flawlessy from coax???
Both signals are identical, same source!
Assuming, the optical signal is still degraded (I cannot see any differences on my scope), I do not understand this.
Does this mean, that in some players SPDIf is taken before error correction and interpolation?
But anyway:
The lightswitch problem still exists...

Edited by user Monday, October 4, 2010 12:09:50 AM(UTC)  | Reason: Not specified

Big news:
I finished building the Buffalo, IVY, Placid combo into my CD-Player.
There is no galvanic connection between the Buffalo and the CD-Players circuitry.
There is also no galvanic connection between the Buffalo, IVY, Placid combo and the CD-
Players case. Player and Buffalo communicate via SPDIF, isolated by Pulse PE65612 transfrmers
But:
Even though the player had never a connection between chassis and the mains power ground. I implemented one
because of safety reasons.
Now, because of a center-tapped transformer feeding the player, there is a connection between the mains power grond
and the CD-Players digital circuitry ground.
And the problem vanished!
No muting when triggering a light switch.
As i wrote, I added 5 extra digital inputs via relais so the player can be also used as a DA-Converter for other equipment. Player and Buffalo, IVY, Placid combo have also their own power switches and can be run independetly.

BUT:
The mute problem remained with a DVD-Player which chassis is not grounded.
Maybe this is the reason.
I am not much into electronics and as I wrote, there is no galvanic connection between the equipment via SPDIF
in my stereo setup. But in the analog signal path via the amplifier. The amp´s chassis is also not grounded-yet.
So I guess without a grounded chassis, small bursts from switching lights seem to affect the electronics.
Maybe they emit into the electronics instead of being shortcut to earth.
Hope this helps,
Nak

Edited by user Tuesday, October 5, 2010 1:48:32 AM(UTC)  | Reason: Not specified