Nope,Sharkythefrog said:
I went for the full monty, so each NCD has it's own power-supply. For a dual-mono setup this means :
- Two NCD1's
- Two PSU boards
- Two Softstart / Filter combo's
- Two 42v/1000VA (each) trafo's
And yes, I am rather desperate about cases. I can't find anything to suite my need for design on one hand and acceptable price on the other hand.
I suppose that in the end I have to learn to do some CAD/CAM (Catia/AutoCad) and design my on...... and find some company to make a case out of a solid block of aluminium.
Cheers, Eric.
Shocking Haha..... JUst what a newbi like to se as an answer post after a few hour on the town.
Why don´t You try a 200 litres oilbarrel as a case. .... That is I guess, about what You need to all that stuff
Could be a chick komplement to the rest of Your interiour....
The WAF (if applicable) would not be extreamly high but . . . .
I guess that is about all that it is to get out from this amp....
Wish You a really good luck, and I guess Auto.. didn´t have the size of case You are looking for. Solid aluminum...why not.
What kind of pre will You use to this massive setup?
Why don´t You try a 200 litres oilbarrel as a case. .... That is I guess, about what You need to all that stuff
Could be a chick komplement to the rest of Your interiour....
The WAF (if applicable) would not be extreamly high but . . . .
I guess that is about all that it is to get out from this amp....
Wish You a really good luck, and I guess Auto.. didn´t have the size of case You are looking for. Solid aluminum...why not.
What kind of pre will You use to this massive setup?
You don't need 4 separate trafos for a dual mono setup, you need four separate windings. Considering most trafos come with two identical windings, like Eric's 2x42V giants, you'll end up using one physical trafo per channel.
The other option (which isn't an option for NCD) is to use a center tapped trafo, where the whole trafo is one winding of twice the required voltage, but with an extra output in the middle. Connect the center tap directly to ground, and you'll have positive and negative voltage while using only one bridge rectifier. But as I said, it's not an optimal solution, and not an option for the NCD power supply.
Here's a CAD of my upcoming amp, a four channel stereo amp to be fed by an active crossover. I'm running dual mono, but feeding both high and low amps per channel off the same 1300VA trafo. It still has separate caps (2x15000 uF 4-pole Jensen for bass and 1x15000 uF for highs), separated by a 1 Ohm resistor at the high amps. As you might have guessed, it'll be machined from 10mm aluminium with 3mm top and bottom.
The other option (which isn't an option for NCD) is to use a center tapped trafo, where the whole trafo is one winding of twice the required voltage, but with an extra output in the middle. Connect the center tap directly to ground, and you'll have positive and negative voltage while using only one bridge rectifier. But as I said, it's not an optimal solution, and not an option for the NCD power supply.
An externally hosted image should be here but it was not working when we last tested it.
Here's a CAD of my upcoming amp, a four channel stereo amp to be fed by an active crossover. I'm running dual mono, but feeding both high and low amps per channel off the same 1300VA trafo. It still has separate caps (2x15000 uF 4-pole Jensen for bass and 1x15000 uF for highs), separated by a 1 Ohm resistor at the high amps. As you might have guessed, it'll be machined from 10mm aluminium with 3mm top and bottom.
wtfaidh said:
Hi Eric,
Since you are quite close to Belgium, why don't you try the Hexateq cases ( www.hexateq-av.com ) ? I have ordered the stereo one and i am also preparing a true dual mono designbut with smaller trafos (500va each) and everything fits nicely. You could order two boxes and go dual mono also with the cabinets...
Once i complete the amp i will post some pictures.
Bye,
Nicholas
Polarity switch? Nah, too much work After reading some of your posts on absolute polarity, I'm convinced that it makes a difference, but I don't want to think about that when I'm listening to music.
I'm using a relay source selector in my preamp, and a DACT CT2 passive attenuator. Works like a charm on my ZAPpulse 2.3SE amp now. The active crossover on the new one will pretty much work like an active pre-amp though, don't know how much that will affect the "passiveness" of the DACT.
After reading some of your posts on absolute polarity, I'm convinced that it makes a difference, but I don't want to think about that when I'm listening to music.I'm using a relay source selector in my preamp, and a DACT CT2 passive attenuator. Works like a charm on my ZAPpulse 2.3SE amp now. The active crossover on the new one will pretty much work like an active pre-amp though, don't know how much that will affect the "passiveness" of the DACT.
Sharkythefrog said:
Oilbarrel he, migt not be a bad idea.... Wait, let me call Shell.. ;-)
Pre : Passive switching for the time being...
marmatsouris said:
Hi Nicholas,
I'm tempted but since treir price for a single dual-mono case is more expensive as the amps combined, I'm inclined to look for another solution first.... but thanks anyway!!
novec said:
Ok Novec, so there are two +cables and two -cables out from each one of these trafos, right...
Wery nice CAD-drawing of the probably very nice coming amp.
wtfaidh said:
Eric, Did You look at Autocostruire, maybe two of them will do. I don´t know about the stability compared to what You are looking for...
Hi,
I am using this accu Preamp.
Rudy
Accu Preamp: Fettle (www.machmat.com)
Amplifier: Zappulse 2.3SE monoblock, Amplimo torrod transformer 2000Va 2 x 42 Volt. 2 x 47.000µF 80 Volt type Mundorf M-Lytic HC. Weight 1 Monoblock 28 Kg.
CD Player: Denon DCD-3560 LClock XO 2 and analogue-digital upgrade by d.r. Feikert.
DVD Player: Marantz DV17
Speakers: ACR Isostatic RP-400
Attachments
Eric, thank You for this question.
The NCD1 is going up in price, because of the extensive testing work involved. Therefore the price is now €299 instead of €249.
However for less critical applications, we now make a 'NCD1e' version with less adjustment, cheaper opamp, and another output coil. The THD of this version is higher, but idle power consumption is lower. The basic PCB is the same, so the instructions are also the same. Performance is comparable to the best competitors of Class D modules, but not as high as NCD1.
All the best from
Lars
The NCD1 is going up in price, because of the extensive testing work involved. Therefore the price is now €299 instead of €249.
However for less critical applications, we now make a 'NCD1e' version with less adjustment, cheaper opamp, and another output coil. The THD of this version is higher, but idle power consumption is lower. The basic PCB is the same, so the instructions are also the same. Performance is comparable to the best competitors of Class D modules, but not as high as NCD1.
All the best from
Lars
Hello Eric
In the 'e' version we will use a low cost opamp, that will do the job and nothing else. After all it's very simple for the user to upgrade it. And this way we can keep the price down, where everyone can be in, just for the fun of DIY amplifier construction.
As said earler, the LM4562 unfortunately does not perform as well in a NewClassD amplifier as the original LM6172, with regards to THD. When it comes to sound, it may be different.
We are just in the process of upgrading or 'listening lab' (this weekend actually) with new better loudspeakers, source, cables etc. So before too long i will be able to offer some more insight to the sound as well. In the future we will use the one that sounds best, of course. I expect also some users here on the forum will provide some comparative listening results, as we are aware several in here have got chips to play with.
In the 'e' version we will use a low cost opamp, that will do the job and nothing else. After all it's very simple for the user to upgrade it. And this way we can keep the price down, where everyone can be in, just for the fun of DIY amplifier construction.
As said earler, the LM4562 unfortunately does not perform as well in a NewClassD amplifier as the original LM6172, with regards to THD. When it comes to sound, it may be different.
We are just in the process of upgrading or 'listening lab' (this weekend actually) with new better loudspeakers, source, cables etc. So before too long i will be able to offer some more insight to the sound as well. In the future we will use the one that sounds best, of course. I expect also some users here on the forum will provide some comparative listening results, as we are aware several in here have got chips to play with.
Now i have done some more testing on the LM4562. And like i promised here are the results of that.
My conclusion so far is, that i would have to say the LM4562 is by far the best sounding opamp of the tested samples.
Compared to LM6172, the LM4562 has more warmth, but still you notice more small details in the music. It just comes better out in the room, and you tend to notice the music more, and the sound system less.
A Great opamp!
Of coruse i can't say if the LM4562 sounds better in any sound system, and with any kind of music. But with the system we used, and the music used, the difference is clear.
I would very much appreciate any inputs posted here, from those of you who also had the opportunity to compare LM4562 with LM6172.
So what are we doing about it? Well we are going to make a time limited offer, where anyone who buys the NCD1 will get two sets of opamps, the LM6172 installed, and the LM4562 to pop in, for free. So based on the listening tests that will come out in the next months, we can take an informed decision which opamp will be in the NCD1 in the future. The offer is valid for the next 100 sets of NCD1 sold, starting now.
Have a great Saturday! All the best from
Lars Clausen
My conclusion so far is, that i would have to say the LM4562 is by far the best sounding opamp of the tested samples.
Compared to LM6172, the LM4562 has more warmth, but still you notice more small details in the music. It just comes better out in the room, and you tend to notice the music more, and the sound system less.
A Great opamp!
Of coruse i can't say if the LM4562 sounds better in any sound system, and with any kind of music. But with the system we used, and the music used, the difference is clear.
I would very much appreciate any inputs posted here, from those of you who also had the opportunity to compare LM4562 with LM6172.
So what are we doing about it? Well we are going to make a time limited offer, where anyone who buys the NCD1 will get two sets of opamps, the LM6172 installed, and the LM4562 to pop in, for free. So based on the listening tests that will come out in the next months, we can take an informed decision which opamp will be in the NCD1 in the future. The offer is valid for the next 100 sets of NCD1 sold, starting now.
Have a great Saturday! All the best from
Lars Clausen
Indeed measurments alone doesn´t make it! I used to trim some preamps for best square-wave performence, but in the end, I found that there was no correlation between a "beautiful" step response and the listening impression. It´s said that some audio designers only measures their creations.Never listening to what you achieve , seems rather stupid. It´s about music reproduction, isn´t it?.
Of Course!
Sound is the only important feature of an amplifier.
However many use THD as a 'paper measure' of the sound quality, since they are not always able to hear the amplifier in question. Therefore we have set the goal to be the world's best in THD and sound.
However with LM4562 it would seem we have to make a choice, and the winning feature is: Sound!
Sound is the only important feature of an amplifier.
However many use THD as a 'paper measure' of the sound quality, since they are not always able to hear the amplifier in question. Therefore we have set the goal to be the world's best in THD and sound.
However with LM4562 it would seem we have to make a choice, and the winning feature is: Sound!
Hi Lars!
I really appreciate that you took the time to compare the op-amps! Some designers had rejected the one with the slightly higher THD. Some say that certain sorts of harmonic distorsion can enhance the sound , but there is no real evidence for this, quite the contrary, lower distorstion always seems to be better. But there may well be a treshold, under which other known parameters, -and maybe unexplored phenomena , is of greater importance.
One parameter of importance , may very well be the damping factor, of a power amp at different frequences.
Maybe the best amp, is the one which has suffcient low distortion in all known (and uknown) regards, and has properties like low phase shift, linear output impedance and so on, ablility to drive real world loads(like loudspeakers and cables)
I really appreciate that you took the time to compare the op-amps! Some designers had rejected the one with the slightly higher THD. Some say that certain sorts of harmonic distorsion can enhance the sound , but there is no real evidence for this, quite the contrary, lower distorstion always seems to be better. But there may well be a treshold, under which other known parameters, -and maybe unexplored phenomena , is of greater importance.
One parameter of importance , may very well be the damping factor, of a power amp at different frequences.
Maybe the best amp, is the one which has suffcient low distortion in all known (and uknown) regards, and has properties like low phase shift, linear output impedance and so on, ablility to drive real world loads(like loudspeakers and cables)
I'm quite sure audible difference can be visualized during testing, it's more of a matter how test is conducted, which may not be of traditional means, and may also depend on capability of equipment. Is there a way to test the transconductance characterists of devices and its effect on load impedance over a bandwidth?
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