Hi guys this is Steve Mantz from Zed. To answer your questions with regards to noise here is my opinion.
The noise we hear in the speaker connected to a 30 wattamplifier with say a rated input sensitivity of 1 volt is better than that whe connected to a 300w amplifier with an input sensitivity of 1 volt. Why? Because the 30w amplifier has gain structure of only 10.95x and the 300w has 34.64x. So any noise generated by the electronics is "multiplied" by a larger number in the 300w, thus we hear more white noise in the speaker.
Now take the 30w and modify its feedback network to give it the same 34.64x gain structure (ie it would now need only 0.316v for rated output) as the 300 watter and guess what, the noise you hear in speaker would be EXACTLY the same as the 300w version.
So now to the test on LEVIATHAN. To compare the S/N ratio of one amplifier to the other means one thing and one thing only. The GAIN STRUCTURE of the two amplifiers under test MUST be set to the same value. The output power of the two amplifiers is not important. The only way you can do this is to have a sine wave generator and an accurate meter to measure the output on the speaker terminals. So the test results on LEVIATHAN do NOT specify where the level controls were set and I assure all of you that if you set the level controls full (0.25v sensitivity) and listen you will hear more background "hiss = white noise as compared to turning the level control back to just the 2 o'clock position on the scale.
I listen to each and every amplifier we produce, both with music and listening for noise. I know that with the level controls turned back a bit there is absolutely no noise.
Please also remember that when doing this test at full sensitivity, you must put shorting rca plugs into the inputs otherwise they act as antennas and pick up any noise which may be floating around (and I assure you there is).
So when you read these S/N figures they do not mean that much to most as they are quoted in dB and there are so many methods of measuring noise.
The S/N at 1 watt is a lower number number than that with respect to rated power, in this case 150w.
When I measure the noise with the level controls set to 1v (about 2 o'clock on the scale) it is almost 100dB below rated output.
So as I have always stated, it is best to run as high a signal level to the amplifier and use as little amplification (or gain structure) in the amplifier as possible.
Please feel free to email or call me if you would like to know anything or have further questions about this noise issue.
Hi guys this is Steve Mantz from Zed. To answer your questions with regards to noise here is my opinion.
The noise we hear in the speaker connected to a 30 wattamplifier with say a rated input sensitivity of 1 volt is better than that whe connected to a 300w amplifier with an input sensitivity of 1 volt. Why? Because the 30w amplifier has gain structure of only 10.95x and the 300w has 34.64x. So any noise generated by the electronics is "multiplied" by a larger number in the 300w, thus we hear more white noise in the speaker.
Now take the 30w and modify its feedback network to give it the same 34.64x gain structure (ie it would now need only 0.316v for rated output) as the 300 watter and guess what, the noise you hear in speaker would be EXACTLY the same as the 300w version.
So now to the test on LEVIATHAN. To compare the S/N ratio of one amplifier to the other means one thing and one thing only. The GAIN STRUCTURE of the two amplifiers under test MUST be set to the same value. The output power of the two amplifiers is not important. The only way you can do this is to have a sine wave generator and an accurate meter to measure the output on the speaker terminals. So the test results on LEVIATHAN do NOT specify where the level controls were set and I assure all of you that if you set the level controls full (0.25v sensitivity) and listen you will hear more background "hiss = white noise as compared to turning the level control back to just the 2 o'clock position on the scale.
I listen to each and every amplifier we produce, both with music and listening for noise. I know that with the level controls turned back a bit there is absolutely no noise.
Please also remember that when doing this test at full sensitivity, you must put shorting rca plugs into the inputs otherwise they act as antennas and pick up any noise which may be floating around (and I assure you there is).
So when you read these S/N figures they do not mean that much to most as they are quoted in dB and there are so many methods of measuring noise.
The S/N at 1 watt is a lower number number than that with respect to rated power, in this case 150w.
When I measure the noise with the level controls set to 1v (about 2 o'clock on the scale) it is almost 100dB below rated output.
So as I have always stated, it is best to run as high a signal level to the amplifier and use as little amplification (or gain structure) in the amplifier as possible.
Please feel free to email or call me if you would like to know anything or have further questions about this noise issue.
Thanks for the great info.
Next time you check back, would you care to address the questions about output power and distortion vs. input voltage (that is DC voltage in) on these?
Just for the record since there has been some debate here....I know I'm buying another leviathan either way. Every Zed amp I've ever owned has been money well spent and I've lost very little to nothing on re-sale.
I am totally lovin my new system, now that it is all dialed in (via AC 3050 RTA)
so I am looking to buy another one for my other ride. So what is the deal on this again?
Next time you check back, would you care to address the questions about output power and distortion vs. input voltage (that is DC voltage in) on these?
Just for the record since there has been some debate here....I know I'm buying another leviathan either way. Every Zed amp I've ever owned has been money well spent and I've lost very little to nothing on re-sale.
Not sure I understand the question correctly. I presume that you refer to "input voltage" as the battery supply? If so this works in basically 3 ways
Unregulated power supplies vary directly proportionally to the battery supply, quasi regulated have a knee point below which regulation ceases and fully or well regulated hold the supplies constant no matter what the battery voltage is and to some dgree how much current the amplifier delivers to the load.
I beg all readers, STOP BEING HOOKED ON MEANINGLESS SPECIFICATIONS LIKE THD. THD is measured under static conditions ie a sine wave with an analyser and the last time I "looked" nobody was driving around listening to sine waves!
My opinion is that a THD number of 0.5%, yes you read this correctly is just fine. It is the character of the distortion which matters. Even order THD is pleasant to the ear = tube gear, odd order harmonics are irritating = all solid state amplifiers bar none. The good news is that we are able to minimize these odd order harmonics so that solid state gear sounds very good.
To a large degree all amplifiers driven from a switchmode supply ie all car amplifiers, will exhibit higher MEASURED distortion at lower powers due entirely to noise form the switching supply. Lucky for us our hearing is limited to sub 20KHz and these pesky supplies are normally running at 50KHz and above so if you have your pet bat with you in the car, he may not like these ultrasonic noises.
Sorry HISPLS I obviously missed your post. Thank you for your kind words
Steve
You're quite welcome, and yes, to your previous post, we were discussing input DC voltage and that did clear up the questions that were brought up around page 21.
I have been really enjoying my new Leviathan. It is so clean and really loud, when I hit it. I am absolutely amazed at how much better the low-end
and midbass sounds, which I attribute to the combination of having a 24dB bandpass on the midbass, and the same on the LP, since it has subsonic
(24 db HP) filter, which I have not had before - BIG difference in how dynamic the subs are.
On the onther hand, I have been debating over when to buy my second Zed amp, for my other car, but I just realized (after re-reading the PAS review),
that the price is going up in Jan, so that will save OVER $150 buying the amp now, instead of waiting till next month (not sure if anyone had realized this).
That's enough savings to pay for the digital camera she is getting from Santa...
I have been really enjoying my new Leviathan. It is so clean and really loud, when I hit it. I am absolutely amazed at how much better the low-end
and midbass sounds, which I attribute to the combination of having a 24dB bandpass on the midbass, and the same on the LP, since it has subsonic
(24 db HP) filter, which I have not had before - BIG difference in how dynamic the subs are.
On the onther hand, I have been debating over when to buy my second Zed amp, for my other car, but I just realized (after re-reading the PAS review),
that the price is going up in Jan, so that will save OVER $150 buying the amp now, instead of waiting till next month (not sure if anyone had realized this).
That's enough savings to pay for the digital camera she is getting from Santa...
Happy Holiday's to everyone!
Rick
Don't forget the 2nd Group Buy that is currently going on.[HINT HINT]
I have not jumped on the bandwagon and purchased Zed amplifiers, but would like to comment about my phone call with Steve Mantz earlier today. I called to see if Zed would be willing to repair one of my old school amps. The receptionist put me on the phone with the man himself. All I have to say is the Steve is one of the nicest and honest person I have the pleasure dealing with in the industry. Excellent customer service! Steve WILL have my business when I get the itch to change my system. Bravo!
I have not jumped on the bandwagon and purchased Zed amplifiers, but would like to comment about my phone call with Steve Mantz earlier today. I called to see if Zed would be willing to repair one of my old school amps. The receptionist put me on the phone with the man himself. All I have to say is the Steve is one of the nicest and honest person I have the pleasure dealing with in the industry. Excellent customer service! Steve WILL have my business when I get the itch to change my system. Bravo!
Thip
If it was a lady it was probably his wife. She's a sweetheart to deal with too.
Don't be in too much of a hurry on repairs...it's a small operation, and as anyone can attest he's all to willing to drop what he's doing and chat with anyone who calls.... but it'll be done right and you'll get that level of service.
Loving my Leviathan still and will get a cronos just to have one.
If it was a lady it was probably his wife. She's a sweetheart to deal with too.
Don't be in too much of a hurry on repairs...it's a small operation, and as anyone can attest he's all to willing to drop what he's doing and chat with anyone who calls.... but it'll be done right and you'll get that level of service.
Loving my Leviathan still and will get a cronos just to have one.
Sorry to if it is not related to the thread but can Mantz repair/upgrade any brand? Even those not created by him? (eg.Audison, DLS and the likes...)
Kelvin
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
I got the vibe from talking to him that he doesn't like some brands, and I wouldn't be surprised if he wouldn't work on ones he didn't like.
Also from my experience with other shops in the past, availability of parts can sometimes be an issue.
He looks at things from an engineering perspective. Meaning if an amplifier is laid out in a manner that is very difficult to work on, he usually is not fond of it.
I ordered my second Leviathan today on the buy for the other car. I am still wowed by what the Leviathan did to the sound of my M3's system.
Holy Cow! It sounds like there are a pair of 12's back there (even though it is only a pair of 8's). I think part of this
has to do with keeping the amp at 4 ohms mono. So many systems I hear that sound bad, typically have a Class D amp
running at 1 ohm or lower (ugh!). Bad idea IMHO...
I ordered my second Leviathan today on the buy for the other car. I am still wowed by what the Leviathan did to the sound of my M3's system.
Holy Cow! It sounds like there are a pair of 12's back there (even though it is only a pair of 8's). I think part of this
has to do with keeping the amp at 4 ohms mono. So many systems I hear that sound bad, typically have a Class D amp
running at 1 ohm or lower (ugh!). Bad idea IMHO...
Well I've been emailing Stephen to repair on one of my amplifiers that is not ZED made and he is going to repair it at a reasonable price. I cant wait for him to repair it and maybe even upgrade it.
He is very nice, and he does help understand car audio a little better. Thanks to Mr. Mantz.
I'm kinda new to this forum but was part of the Elite car audio forum awhile back before it went belly up.
Just wanted to give a big thumbs up to Stephen for coming here in person and answering questions . He has always been a top notch guy. I have run many different zed amps over the years and they have never failed to impress.
I feel kinda special since I was the winner of the amp naming contest he ran and I named the Kronos lol
Jerry
Re: ZED Audio amplifier Group Buy
Re: ZED Audio amplifier Group Buy
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