Many moons since I've posted here

So, I have peeped my head in because as I recall there were a number of people here that liked B&K smps...

I posted this on another forum,

Hey guys, I’m in the process of changing up my system...Want to be able to run a wider range of speakers plus it’s time for a change ...

so Restored Marantz 1152 DC (70ish watts 8 ohms) ——-and everything else on its way out

I picked up a really nice B&K Reference 4420 amp. Opened it up, all looks nice and clean, original...no signs of corrosion or heat related issues....

So I hooked my 1152 up as a preamp using “pre out” and a little set of infinity bookshelf speakers

when I turn on the 4420 I get a low ”bump” sound....I have cover off and don’t see anything going on that would look like it’s an issue.....but, there is a low level hum (ear to speaker, both sides) that is not affected by volume and goes off when 1152 (acting as pre) is turned off....

what do you think....?
Marantz 1152 DC- Denon DP 1200, Soundsmith Carmen MKII- ADS L980 - Blue Jeans IC's

Comments

  • audioluvr
    audioluvr Posts: 5,420
    Well the thump is normal and the hum sounds like a preamp issue but could be cables too. Try using some Deoxit on/ in your contact points
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  • Nightfall
    Nightfall Posts: 10,042
    I also have the same amp, it's dead quiet. I haven't heard the thump when turning it on but I turn the amp on before my preamp.

    Could the hum be a grounding issue?
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  • BKphoto
    BKphoto Posts: 409


    I would like it recapped eventually, but in the meantime I think having a tech kick the tires a bit would be a good idea..

    I'll take some picks tomorrow

    Marantz 1152 DC- Denon DP 1200, Soundsmith Carmen MKII- ADS L980 - Blue Jeans IC's
  • BKphoto
    BKphoto Posts: 409
    A couple pics of the beast...
    Marantz 1152 DC- Denon DP 1200, Soundsmith Carmen MKII- ADS L980 - Blue Jeans IC's
  • nooshinjohn
    nooshinjohn Posts: 25,034
    edited October 2019
    Impedance mis-match or a gain issue.
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