Power Amp advice

Thanks, MrD.  There has been no change that I can think of, but I will move the beast around to see if changing outlets / circuit makes a difference.
My tendency is to just leave it on and one morning I woke to it singing. (sans words)

I have been on Hifi Shark looking at a couple of units:  A pair of Bryston 7B ST monoblocks and a Pass Labs 250.5 Both around $2,200 U.S.

Thanks anzaanimalclinic. The folks at audioreview all said the amp hummed when they received it. Mine was absolutely silent for a year (I bought it used on e-bay for $400). I will give the cheater plug treatment a try even though that seems wrong to me. Maybe that emulates ’floating’ the signal ground.

BTW I have had the top off so all of the exterior screws are tight.

Blissful silence

It has been a long time since I have lived in a house that had any two pronged receptacles, so cheater plugs are in short supply.  Not so unused IEC power cords.  So I cut off the ground prong on one of them.  No luck  Still, it was worth a shot.
Reading some more of the reviews, one of the reviewers indicated that a tech at Parasound suggested tightening the screws on the transistors.  Though none of them seemed loose, I made sure they were torqued down pretty solid.
Problem solved.  Thanks again anzaanimalclinic.  (and to Joe at audioreview).

Well as long as I had everything disconnected I turned the unit over and tightened all the screws on the bottom. This would include the screws that secure the transistors to the chassis. Some were very tight. All were tighter than finger tight. a couple I could not tighten. I suspect the issue with the ones I couldn’t tighten is that the glue that makes the nuts on the other side ’fixed’ has at some point during the last 25 years or so become ineffective.

Silence again (for now). 15 minutes in and still silent.I will post again if it resumes its wordless song.

I am still interested in what amp people think might be an appropriate upgrade for my Magnepan 1.7i’s and 6SN7 tube pre-amp considering a (roughly) $2,000 budget.

LOL  After a few minutes the hum is back.  Not as loud as before, but still annoying.

Thanks everyone, for all of the great advice. I look forward to more!!

I had not considered DAC, McIntosh or any of the brands mentioned by Lukaske (except Pass). I will definitely look into those.

I very much appreciate gratefuleric’s suggestion, even though I am not a fan of D class amps like the Nova. I am familiar with Peachtree’s excellent reputation, but I have a bias toward amps that look and feel substantial. (You know I’m a MAN because I can lift my amp!!)

Lukaske: Don’t worry I have never been tempted to use a sub-woofer with my Maggies. When I first got my Maggies they felt a little shallow on the low end. I knew it was the fault of my previous wimpy amplifier, (an old Yamaha AV receiver) because they did not seem shallow in the showroom where they were driven by hefty (and expensive) AR and PS Audio amplifiers.

With respect to the 7B’s and Pass 250.5, I am in agreement with kalali and adg101 on the value front. Plus, the Pass Labs amp is much prettier (I’m not too macho to appreciate pretty)

audiomaze:  I have not played with the tweeter jumper.  Maybe I will try that.  I am shy to disable the fuse, though.  I like my old Parasound, so an A21+ sounds like something I should look into.
Speaking of the tweeter jumper:  If my HCA2200 doesn't bite the dust, I may experiment with using it and the new amp to bi-amp the Maggies.

Schmitty: FYI the hum was not coming through my speakers. It appears to be solved, at least for now, by tightening all the screws I could access without dismantling the innards. I suspect a sympathetic resonance of some stripe. I also suspect it will return.

lndryguru: Thanks I will check that out.


Soix: Since my Parasound is working well, I am in less of a hurry. However I am still looking to upgrade and have read good things about McCormack gear especially the DNA 2. I will consider.


atmasphere: Thanks for the encouragement. 3 days and still silent. Yes I am still contemplating an upgrade. Before putting the HCA on the market, though, I think I will have it recapped, as a visual inspection shows signs of a need.
I presume, given your screen name, you will reccomend an Atmasphere amp 😎


tweak1: No doubt. PS Audio A/AB gear is likely to be out of my price range, I fear.

mijostyn: My sentiments, exactly.

Kcleveland: Thanks. I am sure the Sanders are fabulous. New they are well out of reach for me. I have not seen any on the used market.
BTW. The hum appears to be fixed. It was mechanical rather than electrical. (something was vibrating). Tightening all the screws on the bottom fixed it. Note I did not tighten the torroidals. They are secured with a pretty hefty bolt.