diyAudio Forums - Discrete Super Symmetric(I think) Opamp for I/V Etc... Quote: Originally Posted by Russ White I see someone else on another forum had the same concern about a voltage source in series with a resistor for a current source. In reality most current sources are much...

Quote: Originally Posted by tomb Yep. Suffice to say that it may be the highest quality tube available at these voltages - period. EDIT: If I'm not mistaken, Runeight's EHHA uses the 6GM8. According to dBel, it may be the highest quality hybrid available. The Sigma is a definite...

http://www.opencores.org/browse.cgi/by_category

I can make if it's after July 19th. I'll bring one of these (pics). You haven't heard one before.

Quote: Originally Posted by tomb Nah - I'll stand by my "quite ridiculous" assertion. The small film coupling caps are not enough to block all of the DC from the tube, period. Sigh...the attitude is uncalled for, especially when you are incorrect in fundamental understanding and...

Quote: Originally Posted by tomb Yes, you are correct, but it's the differential output ground technology - not the virtual ground channel itself. Virtual grounds such as those in the CMoy are OK to tie together with signal input ground. I had forgotten this distinction, so thank you...

Quote: Originally Posted by dakotart1984 Snoopy: Mouser part# 568-NAUSB-B Neutrik quality there, and they also have it in silver And what BOM did you go by On order. I used this one (see attached). There are a few items not listed because I already had them (usb jacks &...

I finally got around to populating two of my boards from the 2nd group buy today after free time suddently manifest. Both work great, though one malfunctioned due to some solder bridges on the 2702 and a mistake soldering the oscilator connections. I'd like to case them up with some...

It's roughly the intrinsic output impedance (~170 Ohms seems reasonable for this opamp) divided by the loop gain. This results in approximately 170/200,000=850 uOhm at low frequency for a unity gain follower version of this opamp.

HeadFi conventional wisdom isn't always right. In this case, IMO, the presumption that Grado is much better Sennheiser for rock/metal is greatly exagerated. Because I followed the flock, I went through the following progression MS1 to 325i to 325i w/ cpads to HD600. (I still have all of...

Quote: Originally Posted by El Condor Hello, I stayed up late last night trying to understand sampling vs bandwidth and I think I got it down. I understand why sampling needs to be double the bandwidth (Nyquist-Shannon sampling theorem). From what I understand, it would be very...

Quote: Originally Posted by t52 here's my approch to i/v conversion: some explanation: the i/v conversion resistors r1 and r2 and c1 form a first order lowpass tuned ad 80khz (hope the values are correct, did some quick calc only), followed by another two lowpasses (r4/c3 nd...

The 19th means I'm out since I'll be out of town until the 20th. Have fun

It's nice to see someone who wants to tackle an ambitious project. PLLs can attenuate jitter on the incoming clock. They typically have a lowpass loop characteristic that filters the incoming jitter. However, lowering the 3dB frequency of the PLL's loop filter to reduce the incoming jitter...

I should be able to make it.

Quote: Originally Posted by tangent Really? Here in the US, the cheapest option for a linear-regulated wall wart style power supply is the Elpac WM080, at $30. The full TREAD kit is $17, and you can find a basic unregulated wall wart to go with it for $5-6. If you put the TREAD in the...

http://www.national.com/an/AN/AN-779.pdf http://www.circuitsage.com/filter.html These should get you started.

Quote: Originally Posted by 00940 Snoopy : don't we have a lpf anyway with C37, C40, C51, C53 ? Considering how high the first alias will appear, isn't sufficient actually ? I agree it would be best to move the pads, to avoid assymetric interaction with the output lpf. Yes...

Nice work. Some comments: spdif receiver Is it too late to reconsider the SPDIF receiver chip choice? A PIC controller seems like an unnecessary complication. Hardware programming is preferable. Right? (I must have been asleep when the change was made. ) Differential outputs It's...

The input impedance is being misinterpretted here. With closed loop operation, you cannot simply take the input impedance. In fact, the impedance seen looking into the opamp small, roughly (Z_f+Z_o)/A_o, where Z_f and Z_o are the feedback and OpAmp output impedances. A_o is the loop gain. The...

This is being made into a bigger issue than it really is. Match them as well as you can and be done with it. I built two dynalos with transistors from different gain classes. My matching betwen npn (~250) and pnp(~170) wasn't even close to what you've measured. Both have low offset (~6mV with...

It's nice to know that progress is being made. At a cursory glance, it looks ok. I am not a fan of the power supply arrangement and the virtual ground in particular. It just seems like more trouble than it's worth for a project like this. This linear regulated +12@0.3A,-12@0.3A,+5@0.86A DC...

I'll state what should be obvious. ESD is not discussed on the forums here because it is essentially a nonissue. The major semiconductor companies have seen to that, with rigorous ESD qualification, typically 2kV minimum, before a product launches. ESD protection simply entails nominally...

Quote: Originally Posted by NeilPeart You guys are forgetting that the op-amps in the M-cubed won't have the same impact as op-amps in fully op-amp-based design (such as a PPA or PIMETA). The op-amps in the M-cubed simply handle voltage gains while the MOSFETs handle the current gain...

I can do layout but there are some caveats. First, like 00940, I only have the free version of Eagle. Moreover, I'm not familiar with Eagle and I presume that it is just as difficult to pick up as other PCB suites. I'm willing to give it a shot though. As a side note, I do have a full version of...