Power Amp advice

Usually when an amp hums, it is because it forgot the words, lol. Anything change recently in your set up that can cause the hum ? Have you added any light dimmers, etc. Try a cheater plug, or try plugging the 2200 into a different electrical outlet. See if a different combination ( try a different set of tubes in Aric ) eliminates the hum. Do you have a source with its own volume control to bypass the Aric? If you have done all this and know it is the amp, read through these pages, as you will get several different opinions from several different people. Parasound A21, Odyssey Stratos, a Bryston, and the list will go on and on and on. But with time, they will all be here shortly, as you have requested. Enjoy ! MrD.

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.

Personally I went from a beastly class D to a Pass XA60.8 for my 3.7i's.  The sound is sweet as long as I dont play LOUD.  My room is over 500 square feet.  Quality over quantity every time.
I found this at the review below, maybe you can save the Parasound.
http://www.audioreview.com/product/amplification/amplifiers/parasound/hca-2200ii.html
[May 17, 2007]greasemonkeyAudioPhile
STRENGTH:

The amp delivers a powerful and clear sound. It is only seconded only by my favorite amp the BA-5000 from Sansui. Great design carried out with quality components.

WEAKNESS:

The initial hum caused by a floating ground condition.

I picked up a HCA-2200 II from ebay a few years ago. I also had the same problem with a 60 cycle hum which came out of one channel only. I decided to explore the problem internally after trying the ungrounded plug adaptor trick which only minimized the hum slightly. What I found was that almost every screw either internally but especially externally in the case was loose. They were loose enough that you could turn them by hand. So, I checked each fastener and tightened down every loose one. That one thing eliminated the hum completely. I could only guess that the problem was from a floating ground condition. I can only surmise that the fasteners were not torqued down to a reasonable amount during assembly at the factory and over the years they continued to back out by themselves due to vibration.

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).

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

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.

Hi Mark, I have a pair of 1.7i Magneplanar speaker and love them, especially with my new Mye Stands. I started out with a pair of Schiit Vidars running as monoblocks. Those are a good recommendation within your budget. Overall, when I had them, they were fine expect for the time of when one of them went into thermal protection when I was playing Jeff Beck loud. But I think if you watch the volume and they are in a well ventilated area, they should work for you. I have since I graded to a pair of Bryston 4B3 amps run in Bridge Mode as monoblocks. No issues and sound great. You could also likely by one 4B3 and run it in stereo mode. For cost considerations you can see if Bryston has a model that is lower in cost than the 4B3 that you can run in stereo or bridge/ mono mode. The Bryston amps may be out of your price range but they run well and with no issues. If the budget needs to be maintained, look for Schiit Vidars which sometimes you can find on B-Stock. Here or usaudiomart or on eBay for a good bit less than retail. Good luck!

I ran through a number of amps for my 3.6 Maggies and discovered McIntosh MC501 mono blocks.   

You will probably not need that much power, but a smaller McIntosh might fit your needs, even if you have to atretch the budget a bit.

Maggies and Mac are magic to my ears.  Others may differ.

I have had three sets of Maggie's. 2 1.7s and one 1.7i .started with a onkyo 805 reciever which was a high currant amp at 185 w @ 4 ohms. Oh. Than some sales man sold me a McIntosh mc 50 and that was an improvement but still no omg. Thank another salesperson said it will sing with a McIntosh mc 275 tube amp great imaging a smooth sounding but still something missing. Than I bought a parasound A21+. WOW!!! Paired with a Parasound p5 it was off to the races . Only 5 years to get there but worth it.  P.S. I just changed the stock tweeter jumper to a solid copper wire and removed the fuse and inserted a brass tube in place. Nice improvement.  Goodluck 

If you can buy a Pass Labs X250.5 for $2.200 US you better jump on that and run.

Peachtree Nova 300 is super clean 300wpc 4>16ohm, built in state of the art DAC and USB in. It will drive any speaker with authority and a glorious sound stage.

I ran Tympanis with Bryston, and they sounded good. Especially for the price.

Mark, known that Magnepan  have a frequenc.of 40 hz-24 KHz and 86 db. ( This is quite low) . You love Magnepan or you don’t. Putting tube pré-amp is good. As poweramp use one with a high impedance:: i suggest Hegel H90, Moon, Pass,Alchemy DPA-1 { very good match).Try all these on a Magnepan before you buy. Please, don’t use extra subwoofers.
I sincerely hope you find the best match!

Emotiva XPA-DR2 looks good.

Maggies require a lot of grunt! The Digital Amplifier Company (DAC) has very powerful amps that sound fantastic! Very close to the best SET tube amps with power! Contact Tommy att DAC and see what he has to offer. He might have a demo or trade in amp he could offer at a discount. BTW he uses Maggies as well as other speakers to test his amps.
Hope you find what your looking for.

https://www.cherryamp.com/

The 7B ST monos will be a great match for the 1.7i, especially with a tube pre in front. But given their age, I think a Pass 250.5 at the same price would be a better value.

I have Maggie’s 1.7i. With a tube preamp and a high current solid state amplifier. Both are audio research. The combo of the 3 quite astounding. There are plenty of Audio Research deals under $2000 in the used market to complement  the Maggie’s. As for your hum if it is coming through your speakers it is likely a leaking filter cap in the power supply.

happy listening 

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.

Mark,
We have similar systems, the same speakers, and pre-amp, let me strongly suggest.
D-Sonic.
Simply amazing combo.
The longer I live with it, the more it opens.
Give the owner a call.
David

Here's a rare and beastly McCormack DNA 2 LAE a bit over your price target but may still be worth a look...

https://www.usaudiomart.com/details/649428780-lae-mccormack-dna-2-amplifier/

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.

@markainsworth
If its not there a week from now then it would appear that you solved it and its not likely to return. If the amp is doing the job for you will you still replace it?

A pair of PS Audio M700s should make you smile for a very long time

Mark, this is one piece of audio equipment that is relatively safe to buy used. You have a tube preamp which will give you that tube sound regardless of the amp you use. In your case you want a SS amp with as much power as you can get like a newer Parasound unit or Bryston. An AB amp with a high damping factor and direct coupled. Class A amps are a little more dangerous to buy used because of the heat. Just like a light bulb if you turn them on and off enough they eventually blow their output section. I had a Krell KMA 100 do that to me after 20 years of service and a Pass amp do it to a friend. 

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.

Another Parasound?
Sanders Magtech?

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 😎

Maggies are tricky with tubes. IMO one of the better amps you can run on them are Pass Labs. But we have a number of customers running Maggies (we're in their back yard after all so we have the same dealer in town). Its easy to hear what tubes bring to the table on Maggies but you have to be careful about the power issue. 1.7s aren't crazy in that regard though.

If your amp has a toroidal transformer that may be creating the hum. You could try checking the fastener(s) on the transformer.

I installed DC blockers in my earlier Innersound amps so that the transformer would quiet down. These can be made with a bridge rectifier and a couple of electrolytic capacitors. The newer Sanders amps use a fully potted toroid and have virtually no electro-mechanical hum.

By the way the Sanders Magtech should be more than up to the task of driving Maggies or just about any speaker. I have two with LMS (speaker management system) driving my Sanders electrostats. Best sound I've had in my 40+ years at this "hobby".

Good luck.

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.

Last year I wandered in to a nice little store in Deerfield Beach, FL. The owner was playing a pair of 1,7i's with a Prima Luna 35 or 40 wpc tube integrated. I was shocked at how good they sounded!!! I told him that I thought Maggies required high power SS amplification. I believe his response had something to do with the high current capability of the Prima Luna amp.

Just a note on "hum" or other speaker noise... I was getting a crackling paper sound from one channel, replaced tubes in my preamp and it went away.  At least for about six months, then the noise slowly returned.  So, this time, I disconnected all the speaker connections to use a pair of small speakers until I could get the issue figured out.  I was asked to record the sound so the folks at VTL could help me diagnose the issue, but upon reconnecting, at which time I also sprayed the connections with Sprayon S02001 Electrical Cleaner and Lubrications Spray (Sherwin-Williams), the issue was resolved.  I now use this spray on every electrical connection when putting things together.

Doesn't the Parasound have toroidal power transformers?  If that is the case, these tend to hum if there is DC offset coming from your power circuit.  You should looking into getting a DC blocker for your AC line.  These are not that expensive.

Two things to help you get the best out of your maggies (from a long time maggie owner).  You need high current, and you need an amp that is stable to 2 ohms.  (Maggies will drift into the 2 ohms area at times.)
I own a set of all in Odyssey monos with the new cap array from Symphonic Line and paired it up with a Don Sachs custom pre.  I am currently listening to the best set up I've ever had with my 3.7i's..... and I'm not a young man.

Hi.. I’ve been running my Maggie 1.7 with a Prima Luna Dialogue Premium. Drives them no problem. I know. I didn’t believe the big audio store down in MPLS when they told me the PL would. So I went with the 100wpc Rogue Cronus Magnum.  Long story short- I eventually sold the Cronus and upgraded to the Prima Luna after listening to the synergy. The PL not only drives the Maggie’s better.. but significant upgrade in sound as well IMHO.

I have to say that one of the BEST upgrades you can do for your 1.7i Maggies is to get the MyeStands. Incredible. The sound is tight and focused. The bass is great deep and clear. No need for a subwoofer with MyeStands. My next upgrade is the Mike Powell instant upgrade. Only $79. For the money, this is hopefully going to be hard to beat. I am waiting to receive it. 

I have had a Maggie speaker since the 1980s, started with the MGIII, then 3.7 and finally the 20.7s.  The 3.7s and 20.7s with Mye stands.
For the MGIIIs the best amp I had for them was a Bryston 4BST, on the 3.7s and 20.7s I tried a MC452 which was the worst of all amps, no guts, then tried a Sanders Magtech which was better but not as good as as Bryston 14B3.  There is a reason why Magnepan & Bryston are demoed together, they just match really well.  I would bet that Pass amps would also match up will but they are class A.
Only amp I would consider above Bryston would be Burmester but there is a huge price jump there.

markainsworth OP

Noticed no one yet has put up the impedance V -phase angle graph, on these Maggie’s.
It shows that they are a relatively benign 4-6ohm load for any amp from the bass up to around 4khz, then things change for the worse, with the combined EPDR load of the impedance and -phase angle.
From 4khz to 20khz they become a bit of a pig to drive, from 6khz to 10khz they have an EPDR load as seen by the amp of 2ohm or even less!!!.
Pick your amp carefully, so it’s stable into this load and can deliver current. Or you could get quite a softening (recessed) effect in the upper mids and highs.
https://www.stereo.net.au/forums/uploads/monthly_06_2016/post-118179-0-66659900-1466167994.gif


Cheers George

In case you haven't  come to a decision - I am driving my Maggie 1.7s with a Rogue Cronus, Mag II integrated tube amp, with a decent phono stage and am very pleased. I have auditioned my Maggies with other more expensive tube and SS amps that didn't do as well. The Rogue, Cronus Mag. II can sometimes be found used for under $2K on AGone or Audiomart and for the money and even much more, in terms of over all good sound and performance is pretty hard to beat, to be paired with the Maggie 1.7s......Jim

I have been living with my Maggie 1.7i’s for 4 years - pushing them with my Krell S550i with great results. Just added the $800 Maggie Baes Panel -DMW in parallel - per Maggie’s recommendation - all my Krell does now is overheat!! Added the Son of Ampzilla 220 watts per ch. into 8 ohms - for $2,800. OMG - my base is the best I have ever heard. The DMWs couple with the 1.7s and my bass is very strong, My high end has opened up and vocals are amazing. Everything is new!! The Krell pushes the base panel - the Son of Ampzilla pushes the Maggie s. I have a sound system beyond my dreams. The more power the better for Maggie’s. No need to go up to the 3.7s !!! I hope this helps. Current for Maggie’s is everything.