I put in quite a few more hours this weekend, with good results !
I got the new bourns trimmers. replaced the one I thought was faulty. The problem of the idle shooting up occasionaly stayed
.
Did some more poking around and looking....and found this :
everytime I touched R456, the relay would click into protection. So I removed the flame-proof sleeves of those resistors (they must act like an insulating sleeve as well, with more heat going into the PCB)
So after that no more going into protection at the touch of the PCB, but my idle is still unstable.
Hmmmm, I just went in and redid most of the solder joints in this area of the PCB, and the problem is GONE
I hope for good. I guess there was a bad solder joint somewhere...
The idle now adjusts well on both channels and is stable. I'm happy with the trimmers installed on the bottom of the boards, for both channels.
So the function board went finally back in. Look how much clearance I have between the shafts and the caps :
And I had to put in a washer between the function board "case" and the chassis rail, to raise that part of the function board by a couple of millimeters.
The main caps are 75mm tall compared to the 70mm originals.
So then onto the lights : bulbs changed for 5mm "straw hat" (= wider angle) warm white leds. dropping resistors changed to equivalent of 1.8 kOhm.
Since originally there are 2 in series, I put in series a pair of parallel 3.6kOhm 1/2 watt resistors. That gives me 20mA (nominal for my leds) and a heat dissipation of 1.44 watts (IIRC) so I should be fine with four 1/2 watt resistors...
The original sockets were used, if the led's leads are not as flexible as the bulb's, they are flexible enough
I took out the blue filter, I like it much more like this.
So, I just had to put it back together and try it out
So what's left ?
- I want to put in modern 5-way speaker binding posts.
- I need to repaint the grills, there was some awful glue left on that came off only with acetone, and part of the paint came off as well
- I might take the meters out again : one had some spots due to a solvent I think, and I polished it more than the other, and the one more polished is a bit more white (more "yellowed" plastic came off I guess), it's harly noticeable but I see it...
With a lot of the vintage gear, I have a problem with smells. This one got cleaned as deeply as possible, and it is much better than at the start, but there is still this smell coming off when warm. Just a "warm electronics" smell, nothing bad, I don't mind, but my wife does not like it. We'll see how it goes, I hope I will be able to have it regularly in rotation
.
Oh, and the sound ? I had it on for quite a few hours, but did not do much "serious" listening.
But I can say it sounds really good. Very balanced, pleasant. Often straight after a recap I find amps and receivers too bright. Not this one. The treble is nice and open, with a good sparkle.
Overall is is quite detailed but not agressive. The bass is just right.
And I like the adjustable tone controls, even if normally I run things all "flat"
The adjustable loudness, I never really appreciated...I find the bass and particularly the treble become much too accentuated as you go further from the flat position. Maybe I just don't need it in my system
, which is a good thing !