I used 1.0uf janzen caps in one of my 140's and left the original gray blocks in the other. I think you will like them.
Great, I can hardly wait to get it finished...
I used 1.0uf janzen caps in one of my 140's and left the original gray blocks in the other. I think you will like them.
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What are you using for some of those axials, I loove the atoms by Sprague (newark for once carries something useful) or TVX nichicons in the more robust values.
The LM334Z mod can be used to incorporate a true constant current source (CCS) for just about any differential input amplifier that just uses a resistor to feed the differential pair. I would expect the effect to be subtle under most listening situations; the originator of this modification, Dan Mattis of DRM Audio Kits, reported: "a noticeable improvement in the stability of the stereo image and depth". When I did this mod on the Kenwood M1 (http://www.audiokarma.org/forums/showpost.php?p=8034327&postcount=4), it was at the same time as all of the other improvements, so I wasn't able to evaluate the LM334Z modification separately. Theoretically, in instances of high power demand on the output stage, the CCS is likely to be beneficial by isolating the input stage from power fluctuations and hence preventing induced distortion.There is a differential pair on each channel that used a resistor as a current source (R305, 306). Based on a thread by Leestereo, I wanted to replace these resistors with a true current source, the LM334Z IC. With guidance from Ben, I calculated the setting resistor as follows: 20.6V drop across R305 (22k ohm) is .936 mA. Using the formula in the LM334 datasheet, the value for the Setting Resistor is 67.7mV/.936mA = 72ohm. The setting resistor goes between the center leg of the TO-92 package and the V- leg (need to refer to datasheet - it's on the right facing the flat side). This IC/resistor then fits where the R305, 306 were, with the V+ leg to the higher voltage side (in this case, the emitters of the diff pair). Once I got over the worry about screwing things up, this is an easy mod and I'll probably use it in other locations that have a differential pair. There are also other likely places for a true current source. Maybe Ben will chime in with reference to the work he did relative to this modification. It should bring some stability. I've been informed that it will allow me to determine how much change the conductor has in his pocket during quiet passages
A truly excellent restoration and upgrade, Bill.
How does it compare sonically to your MAC gear?
Excellent wright up and restore. I do not even own Marantz equipment but, had to read it all. Thanks !
Thank you.Inspiring work... kudos!