Which amp or amps are darTZeel owners using with their NHB-18NS preamp
- Thread starter rugyboogie
- Start date
Well, pretty major shake up in my system here...
My pair of Amati Futuras came with a defective woofer in one speaker, so I got that replaced. Then the replacement also had a defective driver (mid-woofer) that was generating horrible midband distortions.
So I got tired of waiting and got a Dynaudio C4 instead!
The DarTZeel stereo amp was doing great, until it started to blow fuses by itself. Current here is nominally 110V, but reaches 130V easily, and apparently the amp. is not prepared for that, and will fry the fuses if it gets anything above 130V. So I'm going to convert it to 220V, where the current is a little bit better here (doesn't go over 220V much), and see if that helps. In the meantime, I have an old Mark Levinson 432, and it's kicking a lot of ass
Very good machine, for its age/price, currently the 3rd best amp. I've heard here, after the DarTZeels, of course
alexandre
My pair of Amati Futuras came with a defective woofer in one speaker, so I got that replaced. Then the replacement also had a defective driver (mid-woofer) that was generating horrible midband distortions.
So I got tired of waiting and got a Dynaudio C4 instead!
The DarTZeel stereo amp was doing great, until it started to blow fuses by itself. Current here is nominally 110V, but reaches 130V easily, and apparently the amp. is not prepared for that, and will fry the fuses if it gets anything above 130V. So I'm going to convert it to 220V, where the current is a little bit better here (doesn't go over 220V much), and see if that helps. In the meantime, I have an old Mark Levinson 432, and it's kicking a lot of ass
Very good machine, for its age/price, currently the 3rd best amp. I've heard here, after the DarTZeels, of course alexandre
Well, pretty major shake up in my system here...
My pair of Amati Futuras came with a defective woofer in one speaker, so I got that replaced. Then the replacement also had a defective driver (mid-woofer) that was generating horrible midband distortions.
So I got tired of waiting and got a Dynaudio C4 instead!
The DarTZeel stereo amp was doing great, until it started to blow fuses by itself. Current here is nominally 110V, but reaches 130V easily, and apparently the amp. is not prepared for that, and will fry the fuses if it gets anything above 130V. So I'm going to convert it to 220V, where the current is a little bit better here (doesn't go over 220V much), and see if that helps. In the meantime, I have an old Mark Levinson 432, and it's kicking a lot of ass
alexandre
I didn't hear the 432 but it's predecessor, if you like the "Levinson" sound, drove and sounded quite nice on my Martin Logans. If nothing else, you can listen to the Mark Levinson amps forever without fatigue!
Are you sure that it is the mains that triggers the fuse? I had the same problem with some big JMLabs - they had a combination of value and phase impedance at low frequencies that fried fuse after fuse when listening loud ... I have learned that later amplifiers had a less sensitive protection system.
BTW, our Dartzeel dealer sells a lot of PurePower units to Dartzeel units.
Not entirely sure yet. As I said, I'll do the conversion to 220V, and test if that helps...
What makes me think it's the mains is that most of the time, the fuses blow while the amp is idle, without playing anything.
I'll investigate these PurePower units too... I heard they're better than PS Audios...
What makes me think it's the mains is that most of the time, the fuses blow while the amp is idle, without playing anything.
I'll investigate these PurePower units too... I heard they're better than PS Audios...
Wow...and i thought i had problems with my Gryphon. Sorry to hear, Alexandre. Good luck with that. Not good to hear that, under new ownership, the Futura you got was not only faulty...but its replacement drivers were also faulty...hmmmmm...where there is smoke, is there fire?
I have also heard good things about PurePower...
I have also heard good things about PurePower...
No no, I didn't get replacement drivers, I got entirely new units, and those too had defective drivers, in an even worse capacity, as they produced some horrible midband distortion in certain frequencies.
I'm using a Dynaudio C4 now. It's so much better than the Sonus faber that I'm even embarrased to admit it, as it's about half the price of the Sonus... Problem now is that the DarTZeel amp is not coping too well with the 88db sensitivity of the Dynaudio...
I'm using a Dynaudio C4 now. It's so much better than the Sonus faber that I'm even embarrased to admit it, as it's about half the price of the Sonus... Problem now is that the DarTZeel amp is not coping too well with the 88db sensitivity of the Dynaudio...
Noted in Stereophile review of the C4: "the combination of -46 degrees and 5.1 ohms at 73Hz will rule out the use of amplifiers that are not happy with low impedances". The Dartzeel only does 160W into 4 ohms, not much current drive, not happy ...
Frank
Frank
Instantaneous current can be reasonable, but looking at the manual there is a current limiting circuit, a crowbar, which limits RMS current at 7A -- this is only as good as a gainclone, a power IC. The circuit topology only uses one pair of output bipolars per channel on SQ grounds, and there's only so much you can do with that sort of componentry ...
Frank
Frank
Yes, it does only 160W into 4 ohms, and the C4 is indeed 4 ohms...
BUT, that said, it plays better, with more grunt, more punch, than a 800W Mark Levison 432, a fine amplifier in its own right.
I'm not into technical things, I just know what works by listening. And the DarTZeel is unbeatable so far.
I've also peeked at the manual, and I see this: "By using one single pair of output devices, and by not limiting the output current, we are able to obtain unbeatable dynamic reproduction."
Also, the crowbar acts (by blowing fuses):
When one of the following elements and/or signals, ora combination of them is detected, namely:
- An output DC voltage drift greater than 2 volts at speaker terminals;
- A permanent output current greater than 7 amperes, while the power supply impedance is on Hi and output voltage swing is no greater than 60 Voltsp-p;
- A permanent output current is greater than 14A;
- A peak, transient output current greater than 25A and longer than 25ms;
So, given than I get better dynamics and better punch than a beefy 800W unit, I don't think it's being limited to 7A...
Oh, and almost forgot to mention... It's running now on 220V, and, so far, no blown fuses!
alexandre
BUT, that said, it plays better, with more grunt, more punch, than a 800W Mark Levison 432, a fine amplifier in its own right.
I'm not into technical things, I just know what works by listening. And the DarTZeel is unbeatable so far.
I've also peeked at the manual, and I see this: "By using one single pair of output devices, and by not limiting the output current, we are able to obtain unbeatable dynamic reproduction."
Also, the crowbar acts (by blowing fuses):
When one of the following elements and/or signals, ora combination of them is detected, namely:
- An output DC voltage drift greater than 2 volts at speaker terminals;
- A permanent output current greater than 7 amperes, while the power supply impedance is on Hi and output voltage swing is no greater than 60 Voltsp-p;
- A permanent output current is greater than 14A;
- A peak, transient output current greater than 25A and longer than 25ms;
So, given than I get better dynamics and better punch than a beefy 800W unit, I don't think it's being limited to 7A...
Oh, and almost forgot to mention... It's running now on 220V, and, so far, no blown fuses!
alexandre
Which tells you that there's power and then there's power. The DartZeel wins because the designer put the major work in to get all the little things right, if you don't do that properly then all that extra power is effectively wasted, especially in terms of getting good sound. For a start, I'm sure the power supply has been better sorted out ...
In spite of what I said earlier, that level of current is fine provided you don't have a particularly vicious, "audiophile" speaker. It's not the amperage that counts, it's how cleanly the power supplies within deliver the flow when needed through the circuitry to the speakers. No nasty glitches, in other words ...
Frank
joe,
I've replaced the Dynaudio C4s with Dynaudio Temptations. And what a difference!
The C4s were fairly hard to drive indeed. Seems like they go all the way down to nearly 2 ohms, so that's what was killing the poor DarTZeel amp
With the Temptation, I can hear the same music, louder, and the amp's "eyes" never, ever blink, which means there's more headroom.
Not to mention the incredible sound quality I'm getting with the Temptations.
So, if you're interested in the DarTZeel power amp, check your speaker's impedance curve. If it goes too much below 4 ohms, you'll likely have trouble. The Temptations go only down to 3,6 ohms, so I guess that's why everything's great now.
alexandre
I've replaced the Dynaudio C4s with Dynaudio Temptations. And what a difference!
The C4s were fairly hard to drive indeed. Seems like they go all the way down to nearly 2 ohms, so that's what was killing the poor DarTZeel amp
With the Temptation, I can hear the same music, louder, and the amp's "eyes" never, ever blink, which means there's more headroom.
Not to mention the incredible sound quality I'm getting with the Temptations.
So, if you're interested in the DarTZeel power amp, check your speaker's impedance curve. If it goes too much below 4 ohms, you'll likely have trouble. The Temptations go only down to 3,6 ohms, so I guess that's why everything's great now.
alexandre
Can anybody take a look at these measurements of the CR-1's from Stereophile and have any idea how the Dartzeel NHB-108 might do on these speakers?
http://www.stereophile.com/content/tad-compact-reference-cr1-loudspeaker-measurements
Thanks in advance.
http://www.stereophile.com/content/tad-compact-reference-cr1-loudspeaker-measurements
Thanks in advance.
joe,
You're in luck! Quoting...
"My estimate of the CR1's voltage sensitivity was 87.5dB(B)/2.83V/m, which is both about average and slightly above the specified 86dB. The CR1 is specified as being a 4 ohm load, but the speaker's impedance remains above 7.5 ohms throughout the upper midrange and treble, dropping to 4 ohms only between 40 and 225Hz (fig.1). Though there are some swings in the value of the electrical phase angle, the extreme values occur, as usual, when the magnitude is high, mitigating the effect of the increased current demand. There is one exception, at 34Hz, where there is a value of 5 ohms and –48° capacitive phase angle, which will put strain on an amplifier with limited current delivery."
I don't think you'll have much a problem, at least not with the impedance curve...
Now, the sensitivity... How big is your room? If it's fairly big, you'll need to crank the amp to go loud enough, as 86dB is a fairly low sensitivity. In that case, you can expect the integrated to heat up considerably, and, after many consecutive hours of operation (at loud volumes), it might switch off to cool down a bit
BTW, if you're going for the power amp, try to arrange a listening session with the DarTZeel pre as well.
alexandre
You're in luck! Quoting...
"My estimate of the CR1's voltage sensitivity was 87.5dB(B)/2.83V/m, which is both about average and slightly above the specified 86dB. The CR1 is specified as being a 4 ohm load, but the speaker's impedance remains above 7.5 ohms throughout the upper midrange and treble, dropping to 4 ohms only between 40 and 225Hz (fig.1). Though there are some swings in the value of the electrical phase angle, the extreme values occur, as usual, when the magnitude is high, mitigating the effect of the increased current demand. There is one exception, at 34Hz, where there is a value of 5 ohms and –48° capacitive phase angle, which will put strain on an amplifier with limited current delivery."
I don't think you'll have much a problem, at least not with the impedance curve...
Now, the sensitivity... How big is your room? If it's fairly big, you'll need to crank the amp to go loud enough, as 86dB is a fairly low sensitivity. In that case, you can expect the integrated to heat up considerably, and, after many consecutive hours of operation (at loud volumes), it might switch off to cool down a bit
BTW, if you're going for the power amp, try to arrange a listening session with the DarTZeel pre as well.
alexandre
Hi Alexandre,
Thanks! I'm thinking about going for the NHB-108 amp not the integrated although I may not be able to resist one of them also. I found a used model "A" in nice shape with all the updates and I think I'll give it a shot. I don't have the speakers yet (on order) but my room is a decent size bedroom and I am not a head banger. I don't crank the music, well maybe on occasion
Joe
Thanks! I'm thinking about going for the NHB-108 amp not the integrated although I may not be able to resist one of them also. I found a used model "A" in nice shape with all the updates and I think I'll give it a shot. I don't have the speakers yet (on order) but my room is a decent size bedroom and I am not a head banger. I don't crank the music, well maybe on occasion
Joe
Similar threads
