IT was playable but needed touch up. Most stations came in twice on the dial but faily stong but a little noisy.I played it for a week or so and it got worse. The 12AT7 bit the dust. I replaced it and it started working again but with even worse alignment from before. So I said what the heck and replaced all the tubes except those in the demodulator. Now it was really bad and bairly playable but I let it in the system for a week or so to see what would shake out and burn it in before sending to Terry DeWit for a check up.

Off to Terry it went. Great service I had it back in about a week and that was without being payed!! I payed him ASAP. It now tunes like a champ!! and even gets the stations that are in the null or the dipole strong and quitly. It's very quit on strong stations.

Sonicly it was good but maybe a little thin sounding. It imaged nicely maybe a bit forward. So, down to the shop it went. I very carefully replaced C69, 70, 72, 73 with .1uf Angela tin foils and C74, 76 with 1uf Angela tin foils. Sonicly it was a slight, not huge improvement overall. Mids and highs are smoother and the soundstage became a little more detailed but still a little forward. Female anouncers are a little essssy. Overall it was worth it the mod is easy and fairly cheap, about 45.00.

I might change one pair of the tin foils for a nice Seimens mid 50s oiler to see if the tone with warm up some and the esssing with decrease. I might also wire around the mode selector connecting C69 and 70 directly to pin 9 on the 6BL8s and connecting C74 and 76 directly to the output jacks bypassing the volume controls. But I'll let the new caps and tubes burn in another week or two before makeing more changes.

 Cool, been tinkering wtih an MX-110.... - doodlebug 19:22:42 06/26/04 (2)
 Re: Cool, been tinkering wtih an MX-110.... - Scholl 06:17:07 06/27/04 (1)
 Thanks for the heads-up.... - doodlebug 11:55:36 06/28/04 (0)

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 Cool, been tinkering wtih an MX-110.... - doodlebug 19:22:42 06/26/04 (2)
 Re: Cool, been tinkering wtih an MX-110.... - Scholl 06:17:07 06/27/04 (1)
 Thanks for the heads-up.... - doodlebug 11:55:36 06/28/04 (0)

Now, I've been working my way through the demodulator - there's only a handfull of caps there - and the depth and quietness of the local classical station really improved, too.

I'm thinking about working my way through the IF strip, too, for the same reason.

BTW, in 1965, Mac issues some factory updates to the MX-110's tuner section. You might want to check with Roger Russell about any for the MR-65, from whom I received copies of that documentation.

Cheers,

David

It's odd that MAC used disk caps in the signal path.

On the early model MX-110's up to March of 1965, ceramic discs were used in the audio path. After that, polys were used. I have 2 MX-110s, one before and one after that changeover. Still, the later ones also can use swapping with new ones after almost 40 years, as I have discovered.

I also did the few ceramics in the stereo decoder circuits and they've helped so far. The IF section would be next but I'm pretty happy with the tuner's operations now.

Cheers,

David