I am approaching the end of the project. This 1060 phono preamp sounded phenomenal even with the old caps.

I started to replace the resistors and electrolytic, the plan is to replace it all and the tantalum too. As on the other boards the original films and polystyrene capacitors will stay.

As I learned here, the original green Nissei films are good sounding and the polystyrene capacitors last forever, have low distortion and tight tolerances.

The transistors 2SC458 will be replaced with KSC1846 type. I have to do this later, I need a transistor tester to be able to match transistors gain for left and right channel before I get to it, there are no diodes on this version.

I have to say that this board was somewhat tricky, it different from service manual and required extra attention...

Before photo:
0FDCC425-296A-4D92-B65A-909EBB4CF936.jpeg

Progress:
8B68B20C-E440-47D8-8AB6-24B389514E9A.jpeg D5E6ED49-C174-42AE-AF27-D869E60D98CE.jpeg
 
I have added UF4004 flyback diodes on this 1060, I was not sure if I got it oriented correctly.... cathode on (+) and the anode towards (-), right?

376F9296-3948-4BA2-91BD-2C6A713ED573.jpeg 42EE98BA-D0D4-424A-A25C-3B641BAD5EE1.jpeg
 
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Looks like you got it right but can't see all the pin numbers. Just verify the following.
J710 [cathode] to J714 [anode]. J718 [cathode] to J724 [anode]. J709 [cathode] to J713 [anode]. J711 [cathode] to J723 [anode].

Transistor identifaction diagram.jpg
 
Looks like you got it right but can't see all the pin numbers. Just verify the following.
J710 [cathode] to J714 [anode]. J718 [cathode] to J724 [anode]. J709 [cathode] to J713 [anode]. J711 [cathode] to J723 [anode].

View attachment 1143534

Thank you! got it right.

Also replaced the 450k ohm idle current pot with the 450ohm, it’s much easier to set now. All settings remain stable:

Idle: 7.5mvdc
DC balance: 29vdc 31.25ma (J715 and J716 to ground)
I think I can hear diferences between bias settings from 7.5mvdc and 10mvdc. I had the impression that mid and upper frequencies have a loudness effect and bass seems to decrease when this voltage is set higher. Not sure if this makes sense.

Lastly, when rotating up the volume pot from zero, left channel kicks in first, at really low volumes (7 and 8 o’clock) left channel look a tinny bit louder.

Not significant, but the image is slightly shifted left and I have to rotate the balance a tad past noon to align it. The channels even out when the volume knob passes 9’clock position.
 
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Thanks sx-70, this Model 1060 plays several hours daily since rebuilt. It is difficult to turn it off. I understood the importance of “burning in time”, there were noticeable changes throughout the process. It superseded all my expectations, sounds much better than the original without losing its identity.

There is a sense of joy and accomplishment when I listen to music through it. I don’t know what else to say without using the usual cheese adjectives :) I never heard the original unit when new, but I like to believe that it may be sounding close to what they sounded when new.

I have been considering increasing the scope and maybe replace RCA jacks, speaker terminal, and the skinny old power cord.?! And again, thank you to all the mentors on this forum for their invaluable source of knowledge and kindness!
:beerchug:
 
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