New (to me) amp: McCormack DNA-125

txcoastal1

I know it's a bitter issue, and I'm sorry it occurred. We all were rooting for you.

Hopefully the shipping was fair, and you didn't get tatoo'ed like Larry did with W4S.

Chin up sir, maybe a good deal will fall in your lap

Tony M

Amen. I hear ya.

This thread is going to get a little bit more interesting after my revelation and comments are put on here for all to read.

Maybe I won't post what I read.

kharp1

I wouldn't say he was listening in a warehouse...most diagnostic tables aren't in a warehouse type setting. Many amps, probably most, have some level of noise when powered on, to what level you're comfortable is up to you. I think the portrayal of this company is slightly unfair. If a mechanic can't reproduce the problem on your car at a dealership they typically wont work on it, at least as far as warranty work goes. If he put it on the bench and heard nothing, put his ear up next to the top (where the vents are) and heard nothing than what is he supposed to do?

I understand that I assume a shipping expense in these instances, I consider it a cost I have to factor in when making a decision...there is a chance I could be stuck with shipping so I proceed accordingly.

Be happy he was willing to take it back at all, there are many audio places that are allowing returns ONLY if the item arrives defective as the business model has changed in the audio world.

Lesson learned. There are many more amps out there, at least you didn't terribly.

mikeyb128

I borrowed a DAC for an at home demo last year, the Dam thing had a buzzing noise audibly in the back ground on quiet passages, I could hear this from my seat. I have a dedicated circuit, balanced power and a power conditioner. At the audio shop this thing didn’t make a peep! The DAC didn’t like me, or the power at my house. Maybe it’s one of those strange situations. The DAC in question was even sent back to the manufacturer, and no faults could be found with it. Weird...

Clipdat

What is he supposed to do? Well, apologizing for my experience and for the inconvenience would go a long way. I just went back and re-read the 5 emails he sent me and not once did he say "sorry" or offer any kind of apology. Strange behavior coming from the "Technical Manager of Customer Service".

He also could've enlisted the help of some of his colleagues to get a second/third opinion. Perhaps it was a situation of a certain high frequency that was more difficult for his particular ears to hear.

If the amp goes back up for sale on their site, hopefully the next person who buys it doesn't care that it makes a hum when powered on.

Also, the only reason I mentioned warehouse, as it seemed like that was their working area according to a photo on their website:

kharp1 wrote: »

I wouldn't say he was listening in a warehouse...most diagnostic tables aren't in a warehouse type setting. Many amps, probably most, have some level of noise when powered on, to what level you're comfortable is up to you. I think the portrayal of this company is slightly unfair. If a mechanic can't reproduce the problem on your car at a dealership they typically wont work on it, at least as far as warranty work goes. If he put it on the bench and heard nothing, put his ear up next to the top (where the vents are) and heard nothing than what is he supposed to do?

I understand that I assume a shipping expense in these instances, I consider it a cost I have to factor in when making a decision...there is a chance I could be stuck with shipping so I proceed accordingly.

Clipdat

Let's get some other perspectives and opinions. From the February 2018 issue of Stereophile that arrived today.

Review of the PS Audio Stellar M700 monoblock power amplifier by Robert Deutsch.

"Sound Quality

The sound of a power amplifier has many aspects, some of them quite subtle and requiring extended listening to pin down. However, one aspect is immediately obvious: noise. Whenever I connect a new amp to my system and turn it on the first time, it's always with a certain trepidation. Will the system be quiet, or will I hear noise? And if I do hear noise I haven't heard before, it's not necessarily the fault of the new amp, but of an interaction between it's ground-level voltage and that of one or several other components. Tracking down the source of this noise and eliminating it by trying various grounding arrangements can be a frustrating process, and not always a successful one.

With PS Audio's Stellar M700, I knew at first turn-on that there was no problem with noise. With no music playing but the volume set to a normal listening level, I had to go up to one of the speakers to hear even the slightest buzz or hiss."

Tony M

I will def. go up close to my SDA-SRS2's with no source selected and turn the dial up to 9:00 or 10:00. I pray I don't hear any hiss.

If one is supposed to accept hiss in the tweeter like that, why would I want to spend $$$$ on every other piece of gear, wires or TT and cartridges to try and reduce distortion levels all the while my amp produces a hiss on silent passages? It might be audible up close to the speakers only, but, IT would still be there. Isn't the goal of moving UP the chain of highly designed equipment and super speakers, is to reduce noise and bring forth realistic sound stages? I've heard many musical songs that made me think how BEAUTIFUL it sounded in all it's clarity and realism. It took 10K worth of gear and speakers at full retail to get me there though. But I never heard a hum from an amp or hiss during the quite passages.

See what I'm thinking about here. I understand component mismatch instances can occur. I've found that out in the past couple of weeks from experienced members talking about on this thread. 188 posts out of 2.2k looks. what a ride its been.

Sorry Drew.

F1nut

It's perfectly normal to hear a slight hiss with your ear an inch or two from a tweeter. When using tube gear it's a guarantee you will hear it.

daddyjt

F1nut wrote: »

It's perfectly normal to hear a slight hiss with your ear an inch or two from a tweeter. When using tube gear it's a guarantee you will hear it.

I’ll second that.

FWIW, I’m far more interested in how an amp sounds when it’s playing music, than when it’s not. I run a McCormack DNA 225, and yes, I get a tiny amount of hiss from the tweeters with no input signal. I also get a very slight transformer buzz, if I get right up on the amp. Both are completely normal. With music playing at even the slightest level, I can no longer hear either.

With that said, what YOU value in an amp may differ from what I value. Life’s too short to suffer an ampmthat you don’t enjoy.

Good luck with your quest!

tratliff

Tony M wrote: »

I will def. go up close to my SDA-SRS2's with no source selected and turn the dial up to 9:00 or 10:00. I pray I don't hear any hiss.

If one is supposed to accept hiss in the tweeter like that, why would I want to spend $$$$ on every other piece of gear, wires or TT and cartridges to try and reduce distortion levels all the while my amp produces a hiss on silent passages?

Not sure how you will turn the volume to 9 or 10 without a source selected. Help us understand what equipment you will be using.

Also if you have a TT source selected I promise you will have some noise. Depends on pre, phono pre and cartridge. If you don’t Have any I would like to know what equipment you are using because I would start trying to replace mine with the same.

Many general statements are and have been made in this thread that are unsupported.

I just tested my system. I selected CD, without a CD playing. At 50% volume I could hear a very very slight hiss with ear at tweeter. At 75% it increased slightly but my point is that some exists. I then selected my TT input with phono pre powered on. Hiss can be heard at 50% volume. This is related to the low level compatibility of the phono components. Not a surprise.

See my signature for list of components used. These components are considered pretty high end in certain circles.

I’m just not sure you are being realistic!

F1nut

My big rig amp has a THD rating of 0.007% and I can hear a very slight hiss with my ear less than an inch away from the tweeters. Two inches away and I can't hear it.

tonyb

To some, realistic is no noise at all. However you have to be willing to chase it down and correct it.
It may or may not be the piece you think is the cause. Others don't care or are accepting of a certain level of noise. Makes neither position wrong.

tonyb

F1nut wrote: »

My big rig amp has a THD rating of 0.007% and I can hear a very slight hiss with my ear less than an inch away from the tweeters. Two inches away and I can't hear it.

Now that would be my idea of what acceptable noise would be.

Tony M

WOW. That is an IMPRESSIVE list of audio gems and speakers to die for too.
I see from another tubes Will hum or hiss at the speakers. I don't owm tubes and have only heard them 40 years ago.

My quest brought me to own ( thanks to NooshinJohn ) a Carver 600x2 signature Sunfire to power the SRS2's easily. I thought. Well, it did pretty well. I also had a NAD C372 Int. with a NAD tuner and a nice full featured Kenwood CD player.

The Carver had a Carver tuner I think, the Ultech UCD-100 (?) Cd player and my Technics SL-1400 MK2 TT and a Shure Mx-85 (?) cartridge. It sounded nice but when I upped the cartridge to a Denon DL-106 ( from a member here on the forum too ) at a great price, I might add, the sound improved a lot. The cartridge changed the stereo's sound so much, I was TRILLED! It's stayed that way for years. I was coaxed to sell the Carver , so I put the NAD C372 in it's place. I heard very little change to speak of and the volume dials were equal compared to sound output between the 2 amps. I never , never noticed any hum or hiss from either but.... Well the carver blew the right channel rail on quiet afternoon and I had it repaired. It worked fine for years after that I thought. I've had DCM time windows hooked up for a year or more on my third system or second for a while to. I had about 6 systems hooked up once. I've had and still do have a 1200.00 pioneer Blu-ray hooked up to my main HT system out in the cave with a big Yamaha surround receiver with Polk RT3000P fronts, C1000P for the center and FX500 for the surrounds for years now. I have a Big Onkyo Beast powering My Polk LS-90's beside the Rt3000P's because that was a good place to put them in my cave. Now another wall has a nice denon HT receiver with a old JVC Cdplayer that I've liked for 20 years I guess. The speakers have varied and now it's hooked up to Polk RTi100P's I think they are, and a pair of DCM 112 I think.

There's another system with a Yamaha receiver and that Kenwood CD player, no TT even though I want to hook one of many I have up to it. I had it hooked up to my Polk Monitor 10's for the longest time but disconnected the speakers and was in the process of wireing up a pr. of Infinity Qa's and a pr. od Infinity Qb's just to it. I was going to get those Polk Monitor 10's hooked back up ASAP but I had a Black Widow infestation around here 2 years ago I guess and the outdoors around my house took priority over EVERTHING. When I had energy , I would go out and look for webs and kill any widows I saw. I've about eliminated any chance for an outbreak but but with a neighbor next to me, where I supect they came from, I have to keep a lookout every spring, summer and especially fall when they lay their egg sacks.

Now I haven't been as involved with critical listening as I was, say 7 years ago. I was always out there trying to get comfort and relief from my neck issue. I slowly got more and more tired till I didn't even go out there much and I didn't even get on this PC much either.

But I still made it to a yard sale once in a blue moon or to a trift store just to bring me back to wanting to stay alive for my hobby at least. I used to go EVERY weekend looking for Stereo stuff and speakers 15 or more years ago. It slowly got to where I was never going. But that's in the past now. I have components I've bought over the past few years and brought them home, tested them real quick and put them in a rack but never hooked them up to the nice gear and speakers yet. I'll get there.

But this hiss coming from an amps output or due to component grounding differences got my attention. I experienced it once in my life and it was the Pre amp. Switching the Pre killed all hiss. The amp was a Adcom GFA-555 and a Adcom 555 Preamp. Switching to another Adcom Pre eliminated it. Completely. So, I have heard the hiss, but can't say I've heard a amp hum from the case that I know of. I'm never too old to learn!

But I'm a common sense hard head that has to experience something for myself to fully understand. Like speaker wire. Skeptic turned believer that wire can change speaker sound.

I wish we all could've heard Drews' amp humming sound.
That's all.

Clipdat

Last week I reached out to a few amplifier manufacturers and asked them if their units have any turn on transients, and also if they hum or otherwise make any sort of noise while they're powered on. Here are the responses:

Schiit Audio: "The Vidar does use muting relays and should have little to no thump but it’s impossible to guarantee it will be 100% silent on power on. As for the transformer, there will always be some hum, typically beyond 1’ it’s inaudible."

NAD: "The only sound you will hear is a click as the relays engage to power the amp on when you press the power button. There is no hum what-so-ever."

Tony M

Clipdat wrote: »

Last week I reached out to a few amplifier manufacturers and asked them if their units have any turn on transients, and also if they hum or otherwise make any sort of noise while they're powered on. Here are the responses:

Schiit Audio: "The Vidar does use muting relays and should have little to no thump but it’s impossible to guarantee it will be 100% silent on power on. As for the transformer, there will always be some hum, typically beyond 1’ it’s inaudible."

NAD: "The only sound you will hear is a click as the relays engage to power the amp on when you press the power button. There is no hum what-so-ever."

That's what I hope I experience when I go out there tomorrow to ear test my NAD C372 Int. I'll also test a Adcom GFA-555II I have hooked up on my test table for the past couple of months. I have a Adcom 545 Pre hooked up to it. It is not the same as the one that produced the hum a year or 2 ago. That one that made the 555 amp hum is in the back room though.

I'll post my findings, good or ok, it hums and hisses too, results.

I guess I would accept a very slight hum from the unit if it couldn't be heard from a foot away. As long as there wasn't hiss getting to my tweeters.

I was thinking, do old capacitors or old resistors in an amp or set of speaker make the speakers hiss?

I'm worried now, to tell the truth.

Tony M

I forgot to mention the system with a Carver TFM-35 THX amp, A Kenwood C2 Pre. , a sony es773 tuner I think it is. A very, very nice Pioneer CD/DVD player where one flap mechanically comes out and down out of the way and then another flap folds down, and then the tray comes out. The damndest thing I've ever seen on a CD player.

No TT on this one either. I have a few cassette decks and had one hooked up to one of my systems ( with the Infinity speakers ) and played some cassettes while playing chess a year ago and that deck sounded clear and quiet. I was blown away at how great it sounded. JVC I think it is. I have a few cassette decks on a shelf. A couple of Nakamichi's, Double Drawer Denon's, etc. etc.. And the speakers are those NewForm Research 645-RB's I think they are. The components are in and on top of the rack but not wired together. I want to put the Polk Monitor 10's on this system also.

Wires are MonoPrice or Parts Express 14 ga. mostly but the main has those 12 gauge AR's that some of us here bought years and years ago.

Before I had some Monster " Monster " wires for my main systems speaker wires to the SRS2's. They're hanging up in the back room now.

kharp1

Clipdat wrote: »

Last week I reached out to a few amplifier manufacturers and asked them if their units have any turn on transients, and also if they hum or otherwise make any sort of noise while they're powered on. Here are the responses:

Schiit Audio: "The Vidar does use muting relays and should have little to no thump but it’s impossible to guarantee it will be 100% silent on power on. As for the transformer, there will always be some hum, typically beyond 1’ it’s inaudible."

NAD: "The only sound you will hear is a click as the relays engage to power the amp on when you press the power button. There is no hum what-so-ever."

Regardless of what NAD states, if it has a transformer it has the potential to hum. Period. That's just the physics involved. As they age that potential grows. The click they are referring to is a "soft start," which is utilized in better gear to keep the signal path/output from kicking in while the unit is powering up. It's just a delay. SS gear using has a shorter delay, up to 5 seconds or so, tube gear can be a minute, maybe more. This allows time for the tubes to ramp up and the system to verify that they are "OK"

F1nut

I guess I would accept a very slight hum from the unit if it couldn't be heard from a foot away. As long as there wasn't hiss getting to my tweeters.

I'm the other way around. Again, a slight hiss is normal.

StevieB

Sorry to hear about the McCormack. My new to me DNA-1, kicked the Parasound A23's azz all the way from Florida to New Hampshire!

tonyb

StevieB wrote: »

Sorry to hear about the McCormack. My new to me DNA-1, kicked the Parasound A23's azz all the way from Florida to New Hampshire!

LOL, glad to hear this. I don't push them for no reason. On the used markets now, they are a few steps up from the Parasounds and B&k's we all love. All good amps in their own right too.

vmaxer

tonyb wrote: »

StevieB wrote: »

Sorry to hear about the McCormack. My new to me DNA-1, kicked the Parasound A23's azz all the way from Florida to New Hampshire!

LOL, glad to hear this. I don't push them for no reason. On the used markets now, they are a few steps up from the Parasounds and B&k's we all love. All good amps in their own right too.

I have 2 of them although only using the deluxe.

Have an Adcom, B&K reference, and the other McCormack sitting on a rack.

Tony M

tratliff wrote: »

Tony M wrote: »

I will def. go up close to my SDA-SRS2's with no source selected and turn the dial up to 9:00 or 10:00. I pray I don't hear any hiss.

If one is supposed to accept hiss in the tweeter like that, why would I want to spend $$$$ on every other piece of gear, wires or TT and cartridges to try and reduce distortion levels all the while my amp produces a hiss on silent passages?

Not sure how you will turn the volume to 9 or 10 without a source selected. Help us understand what equipment you will be using.

Also if you have a TT source selected I promise you will have some noise. Depends on pre, phono pre and cartridge. If you don’t Have any I would like to know what equipment you are using because I would start trying to replace mine with the same.

Many general statements are and have been made in this thread that are unsupported.

I just tested my system. I selected CD, without a CD playing. At 50% volume I could hear a very very slight hiss with ear at tweeter. At 75% it increased slightly but my point is that some exists. I then selected my TT input with phono pre powered on. Hiss can be heard at 50% volume. This is related to the low level compatibility of the phono components. Not a surprise.

See my signature for list of components used. These components are considered pretty high end in certain circles.

I’m just not sure you are being realistic!

I don't know why but this just popped back into my mind.

You are so right there. I have to select SOMETHING don't I. LOL. I'll select tuner with the tuner being off. I'll try the CD player but it had a cap blow a year or two ago and the HDCD doesn't work right anymore. So I don't know what I'll hear. My TT has a Phono pre I bought from a forum member years ago, hooked up to it and then pluged into an aux. input. I will select the Aux. source indicator too. Going out in a minute.

tonyb

vmaxer wrote: »

tonyb wrote: »

StevieB wrote: »

Sorry to hear about the McCormack. My new to me DNA-1, kicked the Parasound A23's azz all the way from Florida to New Hampshire!

LOL, glad to hear this. I don't push them for no reason. On the used markets now, they are a few steps up from the Parasounds and B&k's we all love. All good amps in their own right too.

I have 2 of them although only using the deluxe.

Have an Adcom, B&K reference, and the other McCormack sitting on a rack.

Sitting on a rack ??
Send the McCormack to me and I'll let it sit on my rack actually doing something.

Tony M

Here is what a minute of testing shows on two systems of mine with amps.

I saw my NAD Int. is a C370. Not a 372.. sorry.

I tested the 555II first. with a Adcom GTP-450 Pre.
The amp runs silent.
The pre has issues of bleed through. When you turn the pre on, the tuner is automatically shown in the window.
I selected the CD source. I turned the Vol. dial to 11:00. I put my ear toward a tweeter. I heard a faint, very faint noise but not hiss. It is even lower than a hiss but then again, my hiss hearing isn't what it used to be either. I got to an inch and it was the radio playing. I couldn't make out any music or words but it was def. the FAINTEST of what a song would sound like if you took it to the weakest level before zero sound. But it was there. Picture the tiniest radio boombox you could imagine. O picture a boombox a mile or more away from you and you know it's playing and you concentrate and can just hear something that sounds like it's coming from it. This is that sound.
I switched to Video 1. Same very faint noise. same vol. vvvv
I switched to Video 2. Same very faint noise. Vol. at 11:00 to 12:00
I switched to Video 3 / Aux. Whoa...NO NOISE. that shocked me. Why not be like the rest? Wierd!

Now to the big rig.

Turned on the NAD. Of course a little soft click at turn on.
NAD pre. comes on automatically. Vol. at zero.
Turned the pre to CD and turned on CD player. Vol. to 11:00.
No hum at all from the amp.
I go to my SRS2's. No noise or his at all.
I switch to Aux. since my TT is on those inputs through a Phono pre-amp.
I see the pre isn't on. I've unplugged it the last Lightning storm and I don't want to move some stuff to plug it in right now.

I will def. test things with emphsis on unit hum and speaker hiss OR radio bleed in the future.

Like I said, I don't want to know there is hiss in my tweeters IF I spent a lot of $$$ on something that permits it to exist. Now I buy everything secondhand and have gotten GREAT deals on things and speakers. I can live with VERY SLIGHT NOISE if I can't hear it from 1" or so from what's making it. I'd try to find out if there is a perticular thing making it and then KNOW exactly which component needs to be replaced if it gets too loud in the future. I have tinitus the past 5 months or so. It sucks. So maybe I wouldn't hear a hiss if there was one at this Frequency in my hearing. BUT the ringing does stop for a second when it wants to and then back to the BS. 24/7.

I'm def. NOT OCD personality. I used to be with dust and dirt in the house but I've mellowed over time due to age and the bad 10 years. I'll still wash my hands after picking up a little dust ball off the wood floor. Dust Mites you know.

That noise, like a very tiny radio playing, was coming from those Cerwin Vega's I refoamed a few months ago. They have horn teeters and are very efficient. It doesn't take much to get them loud. So to have the lowest of noise coming from that tweeter shows the bleed through from the Adcom pre is very, very low. But it IS bleeding the tuners sound to some other sources.

Pretty interesting!

Clipdat

That's interesting that you didn't hear any hiss from the tweeters or transformer hum from the NAD. Sounds like you got a high quality unit there.

Oh also that the 555II had no hum. Go ahead and drop that in the mail to me if you would.

Tony M

Got it from a Pawn Shop YEARS ago and it is like new. I've been using it pretty much since I got the set, I guess I've kept the guts energized and didn't let them get dried out. Man did it sound BEAUTIFUL when I switched to tuner and turned the vol. up a bit. Those SRS2"s are MAGNIFICENT! Thank you POLK AUDIO.

tonyb

Slight hum or hiss is not a trait of what makes a piece quality or not. Some just by design will have a harder/easier time with it's playmates and cabling hooked up to it. Too many variables with hum or hiss to blame one thing.

Tony M

Clipdat wrote: »

That's interesting that you didn't hear any hiss from the tweeters or transformer hum from the NAD. Sounds like you got a high quality unit there.

Oh also that the 555II had no hum. Go ahead and drop that in the mail to me if you would.

I have 3 of them now. I could.

What YOU need is the Nelson Pass designed Adcom GFA-555 original.

StevieB

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