MDAC First Listen (part 00110111)
- Thread starter BigDog
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timola
pfm Member
That makes good sense....thanks.
Except that oil is traded in dollars, so what Trump does has little effect.
Or the Mexican toilet paper manufacturers for that matter.
Great image particularly since "Suavidad Sin Fronteras" translates to "softness without borders".
After his tete-a-tete with Merkel maybe there will be a EU version?! ;-)
misterdog
Not the canine kind
On the left is a Bruno Putzeys fully balanced Pre - amp using a £9 car stereo pot for volume control by removing it from the signal path.
Allows the Mdac to run at 0db.
2 inputs TT and Mdac.
To the right, almost out of shot is the 5 rail Calex LPSU and LPSU for the Auralic Aries Mini, now that is a bigger case than the Pre and Mdac cases combined.
There are around 4 more caps which are shot.
The signal path passes entirely through all of the pot all of the time.
And it's this that allows it to compensate for the non-linearities of the pot
misterdog
Not the canine kind
https://onedrive.live.com/?authkey=...28!25896&parId=DB1E11B2CF05FB28!24970&o=OneUp
Page 10 - The Volume Controller.
Page 10 - The Volume Controller.
mbaudis
pfm Member
Have a pair of those, too. Work well, but not needed.. Anybody?
This is all very off topic and it's sleep time.
Yes, I know that document well. I have 2 boards waiting to be built
This is basic opamp theory
- the -ve terminal is a virtual earth - the opamp maintains it to be at the same voltage as the +ve terminal, IE 0V
- the input signal generates a current through the input resistor, ie the signal passes through the input resistor
- the opamp has (theoretically) infinite input resistance, so the current through the input resistor has to pass through the feedback resistor, IE the signal passes through the feedback resistor
- it does this because the opamp generates an output voltage which sinks all the current fed by the source into the input resistor
In the BPBP the volume stage is a conventional -ve feedback virtual earth opamp circuit. It is arranged so that a single pot is both the input resistor and the feedback resistor. But nothing else is different, the signal still passes through it.
If it never touches the pot then it also mustn't be touching any of the other input and feedback resistors in the other stages of the circuit
A resistive potential divider always has the signal of interest flowing through it - that's how it gets the potential it's dividing.
Yes, I know that document well. I have 2 boards waiting to be built
This is basic opamp theory
- the -ve terminal is a virtual earth - the opamp maintains it to be at the same voltage as the +ve terminal, IE 0V
- the input signal generates a current through the input resistor, ie the signal passes through the input resistor
- the opamp has (theoretically) infinite input resistance, so the current through the input resistor has to pass through the feedback resistor, IE the signal passes through the feedback resistor
- it does this because the opamp generates an output voltage which sinks all the current fed by the source into the input resistor
In the BPBP the volume stage is a conventional -ve feedback virtual earth opamp circuit. It is arranged so that a single pot is both the input resistor and the feedback resistor. But nothing else is different, the signal still passes through it.
If it never touches the pot then it also mustn't be touching any of the other input and feedback resistors in the other stages of the circuit
A resistive potential divider always has the signal of interest flowing through it - that's how it gets the potential it's dividing.
Dark Energy
pfm Member
Was the "New M-DAC" released at Munich? What's the current situation?
DE
DE
adamdea
You are not a sound quality evaluation device
Best have a stiff drink. Someone will be along to explain the good news in a minute
stephengrenfell
pfm Member
How does the difference in SQ compare with, and without, the fully balanced Pre - amp connected in your system (i.e. using the MDAC volume control or not) ?.
Thanks
Dark Energy
pfm Member
"Best have a stiff drink. Someone will be along to explain the good news in a minute"
Yes I thought that might be the jist of it. While the answer may be buried deep in these very posts somewhere, I really don't have THAT sort of time to spare.
I did actually own an M-DAC, but dumped the sucker when Chinese capacitor reliability raised it's head, and although Audiolab informed me it only affected a limited number of machines, they never specified a serial number spread or time period.
I'll forget all about it now, shame so much potential for great performance, shame about the M-DAC + too!
Yes I thought that might be the jist of it. While the answer may be buried deep in these very posts somewhere, I really don't have THAT sort of time to spare.
I did actually own an M-DAC, but dumped the sucker when Chinese capacitor reliability raised it's head, and although Audiolab informed me it only affected a limited number of machines, they never specified a serial number spread or time period.
I'll forget all about it now, shame so much potential for great performance, shame about the M-DAC + too!
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