Vintage Asylum

Classic gear from yesteryear; vintage audio standing the test of time.

Return to Vintage Asylum

Message Sort: Post Order or Asylum Reverse Threaded

Tweak, but not really?

47.147.50.202
Posted on October 14, 2016 at 21:06:00
dirtyvinyl
 My Mac MR71 tuner sounds great stock. It's plugged into a Power Plant which seems to enhance its performance. All other equipment use decent power cords. Wondering if any owners have used higher quality cable/plug with good results?

Seems like a very straight forward mod,but is it worth the effort?

 

Hide full thread outline!
    ...
What antenna are you driving the tuner with? , posted on October 15, 2016 at 02:02:40
Timbo in Oz
Audiophile

Posts: 23221
Location: Canberra - in the ACT - SE Australia
Joined: January 30, 2002
 how much did it cost?

and, how much did the power plant cost?


Warmest

Tim Bailey

Skeptical Measurer & Audio Scrounger


 

RE: What antenna are you driving the tuner with? , posted on October 15, 2016 at 08:36:20
dirtyvinyl
 Just using an inexpensive omnidirectional. Reception is very good. I thought the dipole I had tacked to a window frame was good, but when I did this, WOW!The entire system is plugged into an older PS Audio PP Premier acquired for cheap($600)which improves everything.

Curious if it's even worth the time replacing the cord with nicer stuff since performance seems to improve in all my equipment. I don't want to ruin resale value of the Mac, just possibly improve its captive lampcord cable.

 

Caps?, posted on October 15, 2016 at 10:29:02
M3 lover
Audiophile

Posts: 6601
Location: SW Mich
Joined: May 29, 2005
Contributor
  Since: July 4, 2007
 Have the electrolytics been replaced? That unit must be old enough now that should be done.

"The secret of life is honesty and fair dealing, if you can fake that you've got it made." Groucho

 

RE: Caps?, posted on October 15, 2016 at 10:59:57
dirtyvinyl
 Yeah, the unit had a thorough check up with appropriate parts replaced and is in top condition.The output jacks were also updated.

It's a daily driver purchased a few months ago.

The audio geek in me leaves me wondering about the Modaferri mod(pricey$$) along with this power cord inquiry.

Otherwise, I'm quite pleased with it.



 

RE: Tweak, but not really?, posted on October 19, 2016 at 15:35:57
Lee of Omaha
Dealer

Posts: 1800
Location: Omaha NE
Joined: September 8, 2006
 We had an MR71 come through for a check up about 5 years ago. It had had the heck used out of it, and needed about half the tubes replaced. The owner didn't want to put any money in it she didn't have to (but wanted retail plus for it).

It is a fantastic sounding tuner.

I would like to hear the difference upgrading power supply and changing audio-path capacitors would make.

 

RE: Tweak, but not really?, posted on October 19, 2016 at 17:29:56
dirtyvinyl
 "I would like to hear the difference upgrading power supply and changing audio-path capacitors would make"
As the list indicates, the caps are part of the Modaferri mod:

Install Hysteresis Modification
Modify IF amplifier output stage to reduce IF noise radiation at 9th and 10th harmonics of IF (96.3 MHz and 107.0 MHz)
Replace all audio coupling and bypass capacitors in the feedback circuits with High Quality Metalized polypropylene capacitors
Install bypass caps in the power supply (Tube Units)
Modify the Stereo Decoder to improve Stereo Separation
Modify the Stereo Decoder for higher Slew rate and Stereo Separation
Optimize pilot carrier limiter circuit
Change muting and 19 KHz circuits for more reliable muting and stability of the stereo decoder (Tube Units)
Re-route IF cable from IF chassis to detector to eliminate tailbiting at 96.3 and 107.0
Modify Narrow Filter to accept over modulating stations.
Front end modified for higher RF selectivity
Adjust IF gain
Perform complete RF, IF and MPX alignment
Convert to 220 Volt operation - if required
Change de-emphasis to European Standard - if required
Listening check
Install Cardas output connectors
Unit will now exceed original factory specifications
Run performance graphs
Clean chassis, controls, panel and knobs
Unit signed and dated (inside) by Richard Modafferi
Selectivity modification

The price of the mod ($1k) is more than the cost of purchasing a nice unit.

Upgrading from a budget SS tuner, it's easy to hear the quality of the Mac. I now have NEAR CD/record sonics that is convincing. I probably could step it up with a proper roof antennae and NOS tubes. Other than the audio tubes(2) It's my understanding fussing with the others would affect the performance since it was tuned/retubed recently. It locks on any station and quiet. Guess I will just leave it alone and enjoy.

 

Page processed in 0.022 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]