Carver MX-130 "The Receiver" Issues

[btmacdou]

I have a Carver MX-130 Receiver. It works well and I've done updates but it has two issues.
(Note: I am surprised that there is not more discussion about Carver and this receiver on AK?).

What I've done:

• Replaced all main power supply caps with new larger capacity electrolytics
• Replaced the tuner trimmer capacitor to restore tuner function (common issue)
• Installed a new precision voltage regulator board from "Circuits and Concepts" (eBay)
• Replaced the burnt up power resistors on the noise reduction board

Issues left to resolve:

• The tuner works, but in auto tune mode, it "locks" .1 mhz higher than the center frequency of the station. For example, if the station is 92.3, the tuner will lock at 92.4 mhz. It seems to sound OK and it switches into stereo in auto mode. I can flip to manual tuning mode and adjust the station to it's exact frequency. What could be causing this? I have tried adjusting the new trimmer capacitor but can't get the tuner to lock at the exact frequency of any station.
• The power meters are in sync when in low power mode but when I release the button to allow the VU LED's to operate in full power mode, the left channel is lower VU by 2-3 led positions. Any ideas?Carver

Top View showing the replaced parts... new PS caps, new noise regulation board resistors and a custom voltage regulator from Circuits and Concepts (eBay company):
Close up of the precision voltage regulator board. Well designed. Remove a few resistors, diodes and caps, and it just uses the same holes!


This is the tuner trimmer cap that I had to replace to get the tuner to work. Also sourced from Circuits and Concepts:

 

[Grenadeslio]

Nice looking piece.

 

[btmacdou]

Update: Now the tuner locks .2mhz high. Not sure what changed. But adjusting the trimmer cap makes no difference. One oddity, the tuning voltage measures a constant 7.8 volts across the entire tuning range. The service manual says it should vary from 2.85v at 87.5mhz to 21.0v at 108.0mhz. How can this be?

PS: I'm surprised at the lack of replies to this post! I thought this was a poplular receiver in its day. There must be a lot of them out there?

 

[Pat Finnigan]

Btmacdou, what value resistors did you use? I've received differing responses (68 ohm or 680 ohms?), and the manual is little help since R-values cross-reference to Carver part # NLA. My 130 has the toasty resistors on the power amp board as well as the noise reg board.