Recently looking through some older LC Audio stuff, it seems the output inductor in one design was a litz wired inductor. Is this good for the NCD? There are a few people trying this out on other designs, and it seems reasonable.
soongsc said:
Hi soongsc,
The LC audio modules started with solid core copper cable and then went to their teflar 2 cable as output inductor wire. The teflar 2 is a multi-solid core silver clad copper wire, not litz wire.
Regards,
Nikos
NCD 4 pole PSU?
Hi,
Just read the cookbook and wondered if the PSU module for the 4-pole PSU still should be fitted with its original caps og if they become obsolete with the added filter caps?
Rgds
Hi,
Just read the cookbook and wondered if the PSU module for the 4-pole PSU still should be fitted with its original caps og if they become obsolete with the added filter caps?
Rgds
Re: NCD 4 pole PSU?
Good question 😉 and another one:
What is the ideal value of these caps?
Granholm said:
Good question 😉 and another one:
What is the ideal value of these caps?
I kind of get a feeling that same cap values are best not used in parallel. Smaller caps of values within 5% are probably better.
Running Red Hot
Hallo,
One mudules seem to run very hot...!! especially the resistor at the connection side.
It also switched off one time. It's still playing, no changes in setup during last month. Suggestions ?
Cheers, Eric.
Hallo,
One mudules seem to run very hot...!! especially the resistor at the connection side.
It also switched off one time. It's still playing, no changes in setup during last month. Suggestions ?
Cheers, Eric.
Nope, that was a dummy load as a safety precaution. This time it's the big (1/2 watt) one at the pcb just after / in front of the blue connector...
Eric: This resistor is supposed to dissapate some power, when there is less load on the amplifier. That's why it gets hot.
It can never burn though, as it is included in the safety system.
My recommendation: Use a proper load, then all is fine.
Resistor load is fine, as long as you use 2 - 8 Ohms.
All the best
It can never burn though, as it is included in the safety system.
My recommendation: Use a proper load, then all is fine.
Resistor load is fine, as long as you use 2 - 8 Ohms.
All the best
Hi Lars,
Thaks for this reply. The NCD is running on Mission 770 speakers for the last couple of weeks....
Not only the resistor is red-hot but the coil as well.
If this is normal behavior, o.k. but than I have to apply forced cooling by means of a small fan wich would be a pitty because of the additional noise and another trafo as well...
Cheerio, Eric.
Thaks for this reply. The NCD is running on Mission 770 speakers for the last couple of weeks....
Not only the resistor is red-hot but the coil as well.
If this is normal behavior, o.k. but than I have to apply forced cooling by means of a small fan wich would be a pitty because of the additional noise and another trafo as well...
Cheerio, Eric.
When you say 'red hot' you hopefully don't mean 'red hot'?
Something like 60 deg C? (Which is normal).
Cheers
Something like 60 deg C? (Which is normal).
Cheers
Well, it is realy hot...!!! I can't keep a finger on it, but i'll put a "K type" sensor on it which is accurate to about 1200 C. should be enoug ;-) I'll keep you informed.
LM6172 vs LM4562
I have been listening to both op-amps in the last few weeks now . I do hear a difference in the NCD1. For what it’s worth, my personal opinion :
- The LM6172 seems to be more harsh but has a lot more dynamics, very suitable for rock & metal.
- The LM4562 seems more “smooth” to my ears and appears more balanced and reveals more details in classical music. It’s simply less fatiguing and due to this quality I enjoy it more when Bach if filling the room…
I do not know if this is specific for either of the op-amps or if it’s specific for the NCD1 which might designed around the LM6172.
A strange side-effect is that the ferrite core stays about 7C lower in temperature with the LM4562 (56-57C) compared to the original LM6172 (63-64C). This works on both modules…
I’ve been listening to commercial amps as well and the NCD1’s stay for sure. The bill adds up to 1.400,=/1.500,= until now and no housing yet but to me it’s every euro worth while…!!!
Cheers, Eric.
I have been listening to both op-amps in the last few weeks now . I do hear a difference in the NCD1. For what it’s worth, my personal opinion :
- The LM6172 seems to be more harsh but has a lot more dynamics, very suitable for rock & metal.
- The LM4562 seems more “smooth” to my ears and appears more balanced and reveals more details in classical music. It’s simply less fatiguing and due to this quality I enjoy it more when Bach if filling the room…
I do not know if this is specific for either of the op-amps or if it’s specific for the NCD1 which might designed around the LM6172.
A strange side-effect is that the ferrite core stays about 7C lower in temperature with the LM4562 (56-57C) compared to the original LM6172 (63-64C). This works on both modules…
I’ve been listening to commercial amps as well and the NCD1’s stay for sure. The bill adds up to 1.400,=/1.500,= until now and no housing yet but to me it’s every euro worth while…!!!
Cheers, Eric.
Volume control
I'm using a passive volume control (simple pot) and no imput switch for my NCD's.
But what to do if I want to use the balanced input instead ?
How do you guys have solved this problem ?
Cheers, Eric
I'm using a passive volume control (simple pot) and no imput switch for my NCD's.
But what to do if I want to use the balanced input instead ?
How do you guys have solved this problem ?
Cheers, Eric
Re: Volume control
The simple way to do it is to use quad pot vr and connect the volume the same way for the negative side as the positive side, I also use a switch to selectably reverse polarity of the inputs. The majority of classic music I have are phase inverted, Jazz are normally not.wtfaidh said:
Volume for balanced
Only problem with using a dual ganged pot for +ve and -ve input is that any non linearities due to tracking will show up on the output due to the differential nature of the balanced input (if I have my theory right!).
I use a scheme with a single pot between +ve and -ve inputs and this setup can be used unbalanced also, by shorting the -ve balanced input and unbalanced hot on the +ve balanced input the pot becomes a standard unbalanced volume control.
Regards,
Dean
Only problem with using a dual ganged pot for +ve and -ve input is that any non linearities due to tracking will show up on the output due to the differential nature of the balanced input (if I have my theory right!).
I use a scheme with a single pot between +ve and -ve inputs and this setup can be used unbalanced also, by shorting the -ve balanced input and unbalanced hot on the +ve balanced input the pot becomes a standard unbalanced volume control.
Regards,
Dean
NCD monos
I just finished my NCD monoblocks and have started breaking them in 🙂
Cheers,
Morten
I just finished my NCD monoblocks and have started breaking them in 🙂
Cheers,
Morten
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Re: Volume for balanced
The scheme you ar using seems quite well. But if someone wants to have a multiple input selector that can be either unbalanced or balanced, then there could be some difficulties. Hmm, a very interesting subject to think about.
This does sound right. If the tracking is not perfect, then the gain on the high half and the low half will not be the same.deandob said:
The scheme you ar using seems quite well. But if someone wants to have a multiple input selector that can be either unbalanced or balanced, then there could be some difficulties. Hmm, a very interesting subject to think about.
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