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

ESR meter readings on C2 2ND McIntosh tube preamp

24.50.224.123
Posted on August 13, 2023 at 17:59:20
rafaelfernandezpr@gmail.com
Audiophile

Posts: 5
Location: Greater Antilles
Joined: August 13, 2023
 I changed the power supply electrolytics in my 60-year old McIntosh
C2entsents\\\ 2ND preamp with new caps 5 years ago. The unit was practically unused
all these years.Now I get good capacitance readings and my ESR meter also
indicates excellent readings.However,hum sound is present when the unit is
turned on. How reliable ESR readings?

 

Hide full thread outline!
    ...
who changed them? Check ALL soldering connections /nt, posted on August 14, 2023 at 04:20:58
Story
Audiophile

Posts: 11543
Location: NJ
Joined: December 11, 2000



 

RE: ESR meter readings on C2 2ND McIntosh tube preamp, posted on August 14, 2023 at 10:49:46
6bq5
Audiophile

Posts: 4665
Location: SF Bay
Joined: August 16, 2001
 the performance of the capacitor and the presence of hum and not interrelated.

The hum is from an open connection to ground-
Perhaps this occurred when the caps were installed?

Many of the old electrolytic caps used in McIntosh equipment were multi sectioned caps - which are not as readily available today- so how did the new caps replace the old?
Happy Listening

 

RE: ESR meter readings on C2 2ND McIntosh tube preamp, posted on November 1, 2023 at 00:22:42
dericmc@live.com
Audiophile

Posts: 101
Location: Amarillo Texas
Joined: October 21, 2023
 try using bypass caps on the electrolytics Ron Welborne at Welborne labs wrote a lot about this.

 

RE: ESR meter readings on C2 2ND McIntosh tube preamp, posted on November 3, 2023 at 04:55:42
stellavox
Audiophile

Posts: 424
Joined: June 23, 2004
 Only real way is to LOOK at the 60/120hz ripple on the B+ as it passes thru the filtering sections (Series R's Parallel C's) and see how low it gets. Need an oscilloscope - and one that can take 300 volts or more DC without blowing up. Should see much supressed ripple as you work "downstream. Final AC ripple should probably less than a volt. Also try hooking the scope up to the line output terminals and "see" what hum is there.

 

RE: ESR meter readings on C2 2ND McIntosh tube preamp, posted on November 26, 2023 at 12:19:06
rafaelfernandezpr@gmail.com
Audiophile

Posts: 5
Location: Greater Antilles
Joined: August 13, 2023
 Are Variac transformers reliable to increase circuit amperes,assuming
Resistance(Ohm's) is maintained constant, say at 120V?

 

Page processed in 0.022 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]