[indikator]

will OPUS benefit from clock upgrade? any guide how to use external clock?

 

[johnsonad]

My power boards are finally finished and boy were they easy! Russ, you guys put together one hell of a product and I thank you for it! Nebby was over last night and talked me through the basics (and put together one of the boards), once started they only took a few minutes to solder up. I only wish wiring them together was as fast

 

[luvdunhill]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif I have a quick question for a usage of the SPDIF receiver. Theoretical setup would be as follows:

heh, reading back through my post, I confused myself. Let me try again.

I really have only a single question at this point. Currently, I am using a "direct" transport to DAC connection using i2s and the requirements for my DAC are 16-bit I2S, 64 BCK/WS and BCK is 44.1kHz * 64, 2's compliment data, WS 44.1kHz. Can I "substitute" the transport mechanism for the Wolfson 8804, which would configured as: AIF_MS to MASTER, TXSRC to SPDIF, AIFCONF1 to low, AIFCONF0 to low and powered using 10V?

 

[soloz2]

has anyone compared the opus USB module to the Alien DAC?

 

[spendorspain]

Hi all

Although this forum thread is for Opus DAC, I'm going
to put here my questions, as I've read several posts regarding
the Ballsie module.
I’m interested in upgrading my universal
Denon DVD-2930 player. I haven’t yet the Service
manual for this model (do you have any idea about where to
find one?) but it uses the digital to analogue
converter Burr Brown 1791, that outputs a balanced
voltage signal per channel (no need for I/V conversion).
I have the output schematic for the Denon DCD-1500AE
which uses the same DACs and probably has a similar
design. In this case, the vL+, vL-, vR+ and vR- signals
from the BB-1791 are summed
and converted to a single-ended L & R signals using
the two sections of a SA5532 dual op-amp. Next, this
signal is filtered and buffered by a half of another
SA5532 (the other half is used for sending the L&R
signals to the headphones section). Then, the signal
goes to the RCA output sockets through an ELNA RFS
(silmic II) electrolytic output capacitor and a carbon
output resistor. You can see this signal path in the
diagram attached to this post.

My questions are:

1) Can the Ballsie module do the job of all these
rather old op-amps and avoid the use of the stock
output capacitor and resistor? (this with the added
benefit of having its own LCBPS supply and
transformer, therefore avoiding the Denon switching
mode PSU in the critical analogue stage). For each
channel, two of the four sections of the LME4974
quad op-amp (IC1) do the balanced to s.e.
conversion and one section of the dual LM4562 (IC2)
filters and buffers the signal and drives directly the
RCA outs and the interconnect cable attached to it.
Can the Ballsie drive directly the interconnects?
Is the LM4562 output stage up to this task, without
the need of an additional buffer?

2) If this use is possible, how is the Ballsie wired
at its input? For each channel, the BB1791 DAC has a
3-leg out but the Ballsie has a 5-pin input.

3) How does the Ballsie deal with the possible DC offset
from the DAC? Does it rely on a DC-free input signal
(I think the other Twisted Pear DAC modules have their
own output caps)? Can I safely connect the RCA
sockets to the Ballsie output, without any series cap?
Is it needed a DC offset protection circuit (like the diy
AMB Epsilon module)?

I hope you can help me. Thanks in advance

Jose

 

[BrianDonegan]

Quote:

1) Can the Ballsie module do the job of all these rather old op-amps and avoid the use of the stock output capacitor and resistor? (this with the added benefit of having its own LCBPS supply and transformer, therefore avoiding the Denon switching mode PSU in the critical analogue stage). For each channel, two of the four sections of the LME4974 quad op-amp (IC1) do the balanced to s.e. conversion and one section of the dual LM4562 (IC2) filters and buffers the signal and drives directly the RCA outs and the interconnect cable attached to it. Can the Ballsie drive directly the interconnects? Is the LM4562 output stage up to this task, without the need of an additional buffer? 2) If this use is possible, how is the Ballsie wired at its input? For each channel, the BB1791 DAC has a 3-leg out but the Ballsie has a 5-pin input. 3) How does the Ballsie deal with the possible DC offset from the DAC? Does it rely on a DC-free input signal (I think the other Twisted Pear DAC modules have their own output caps)? Can I safely connect the RCA sockets to the Ballsie output, without any series cap? Is it needed a DC offset protection circuit (like the diy AMB Epsilon module)?

1) If tis is fact still the design of the output stage of the newer player, then yes, the Ballsie is quite similar in function and should work fine. It is designed to drive your interconnects directly (it is a buffer).

2) The five inputs are to allow connection of dual-mono Opus modules. The two positive and two negative terminals are joined together after going through isolation resistors. To use a standard three input (+/GND/-), just leave the other two inputs empty.

3) If the input signal has any DC-offset, it will still be present at the balanced outputs, but will be effectively nulled at the single-ended outputs. In your case, you should be fine with no capacitors in the signal path.

 

[sleepy dan]

Quote:

Originally Posted by indikator /img/forum/go_quote.gif will OPUS benefit from clock upgrade? any guide how to use external clock?

It may be worth it- you'll have to try it to find out!

You will need to either replace the 12Mhz clock on the Wolfson receiver board (I remember reading someone did this with good results) or, replace the clock on the Metronome if you are using one.

There are plenty of clocks out there to buy or you could build one yourself. An easy place to start experimenting would be to feed the Crystek clock on the Metronome with it's own low noise regulator. If you notice any improvements then you can think about taking it further.

 

[spendorspain]

Thank you for your answer, Brian. I'm sure that the Ballsie module will sound a lot better than the stock Denon analogue output stage: better op-amps, independent linear power supply, no caps directly in signal path, no muting transistors, better PCB layout... BTW, in the assembled and tested Ballsies Twisted Pear sells, do they leave empty the positions not needed for single ended use (CF3, 4, 7 & 8, RI1, 4, 5 & 7 and RO2, 3, 5 & 6)? Is there any critical part that could be upgraded for maximum performance? Are there any suggestions regarding the Ballsie modules from builders and users?

To be sure before any modification, I hope to have soon the service manual for the DVD-2930. However, the usual service manual suppliers, from which I have bought other Denon manuals for reference, don't have it (although it is a model two years old). Of course, any help to find out this manual will be welcome.

Best regards
Jose

 

[johnsonad]

Well my 8 month project is finally finished and the Opus is up and running. Thanks to Nebby for getting me off of my rear and teaching me how easy it is to solder the boards together. The rear case work was surprisingly difficult at least cutting the holes and found out the hard way that I didn't have the right tools. Someday I will have cleaner cuts on the rear panel but for now it will do. I replaced the stock caps with BGs and they are most definitely bright. Here are a couple of pics.

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[Russ White]

Quote:

Originally Posted by johnsonad /img/forum/go_quote.gif Well my 8 month project is finally finished and the Opus is up and running. Here are a couple of picks.

very nice work! You should be proud.

I hope you enjoy it.

Cheers!
Russ

 

[johnsonad]

Quote:

Originally Posted by Russ White /img/forum/go_quote.gif very nice work! You should be proud. I hope you enjoy it. Cheers! Russ

Thanks Russ, that means a lot coming from you

I used Brian's layout but didn't have enough wire to make my power runs look as good as his. Right now it is filling the room with a little Maria Callas and her beautiful voice.

 

[akione]

Quote:

Originally Posted by johnsonad /img/forum/go_quote.gif Well my 8 month project is finally finished and the Opus is up and running.

Nice Layout. One of the best, I've seen.

 

[indikator]

I wonder, what is that white thing near the transformer?

 

[BrianDonegan]

Quote:

I wonder, what is that white thing near the transformer?

It's a terminal block for joining the Mains to the transformers.

 

[luvdunhill]

Quote:

Originally Posted by johnsonad /img/forum/go_quote.gif Well my 8 month project is finally finished and the Opus is up and running. Thanks to Nebby for getting me off of my rear and teaching me how easy it is to solder the boards together. The rear case work was surprisingly difficult at least cutting the holes and found out the hard way that I didn't have the right tools. Someday I will have cleaner cuts on the rear panel but for now it will do. I replaced the stock caps with BGs and they are most definitely bright. Here are a couple of pics.

why not stack the 2 toroids?