Quote from: mfsoa on February 17, 2011, 05:10:24 PMI know Bill goes hiding in the corner with his teddy bear we we say it, but if you haven't heard the EE DAC with different op-amps, you haven't heard what it is capable of.Not even close.Those beautiful DIP-8 sockets just sitting there, waiting to be stuffed with cute little spider-lookin' chips...Haven't listened to the tube stage for a while now -Mike Doug Schroeder from Dagogo is doing a mega roll of what he calls the super op-amps that are now available. Keep your eyes open for that article. He currently has a couple suggestions already in his article but he says those that he already has written about pale in comparison to the new super op's he is currently auditioning.Keep your eyes open for that article to be released shortly.
I know Bill goes hiding in the corner with his teddy bear we we say it, but if you haven't heard the EE DAC with different op-amps, you haven't heard what it is capable of.Not even close.Those beautiful DIP-8 sockets just sitting there, waiting to be stuffed with cute little spider-lookin' chips...Haven't listened to the tube stage for a while now -Mike Doug Schroeder from Dagogo is doing a mega roll of what he calls the super op-amps that are now available. Keep your eyes open for that article. He currently has a couple suggestions already in his article but he says those that he already has written about pale in comparison to the new super op's he is currently auditioning.Keep your eyes open for that article to be released shortly.
......this type of parts swap voids the factory warranty but it sounds pretty straight forward to me and i firmly believe that nothing ventured is nothing gained. this is supposed to be a killer mod for very little outlay
......but i do want to get my hands on the custom op amps ASAP before they are sold out or the price goes up.
The AC thread mentions that the stock opamp is Texas Instruments 5532, it is a good candidate for upgrading. The original Signetics 5532 was a great audio opamp, still available on Ebay now and then or from parts brokers. I don't know what the Clarity opamp is, but I would not be surprised if it is LM833, since they mentioned that it is from National, and that is an excellent sounding chip designed specifically for audio.As I understand the Minimax design, there is a I/V converter immediately out of the DAC chip, which provides an extremely low impedance load to the chip, allowing it to run in current mode, which increases S/N significantly. Then the output of the I/V opamp goes to the output opamp for current buffering, then to output (or to the tube, if selected.) The buffalo designs are like this also. So the output opamp is always in the signal, as is the I/V converter. There is a picture of the Minimax innards posted in an AC post about opamps. Iirc, there are 2 opamps near the DAC chip (I/V converters for balanced output,) but I don't remember whether there are two output opamps, or just one to sum the balanced signals to unbalanced. I guess it would be better to run two in mono even if half was unused. Then the tube runs single ended class A. So I think there are 4 opamps, but not sure. It is very cool that the opamps are in sockets. EE knows how to fan the flames of nervosa!
Very interesting William! Thanks for the clarification. The 5534s make sense being monos. Is the 5534 direct coupled to the tube, or is there a electro cap there also? I think the Auricaps are DC filters for the tube outputs, right?
