Here are some shots of my NC400 and UCD400 4 channel amp. The left photo is the original donor chassis. One power supply for each generation. OK, the saucers do not need that much HS, but that is what I had....and it fits in w/ the vintage chassis style...
Interfacing to the remote on/off and meter driver circuits was a royal pain...I wish folks would not be so "clever" with their on/off circuits!
I coupled to the meter drivers with a pair of step-down transformers because the Mc circuit has a single ground and I did not want to add a ground-loop to the layout. e.g. dual ground going in, single isolated ground going out.
David
Interfacing to the remote on/off and meter driver circuits was a royal pain...I wish folks would not be so "clever" with their on/off circuits!
I coupled to the meter drivers with a pair of step-down transformers because the Mc circuit has a single ground and I did not want to add a ground-loop to the layout. e.g. dual ground going in, single isolated ground going out.
David
Attachments
"I wish folks would not be so "clever" with their on/off circuits!"
Translation to clarify meaning:
The McIntosh on/off circuit and remote trigger is a AC/DC plus analog/TTL hybrid - quite strange and unnecessarily convoluted, I had to re-design it; the NC 400 is properly and simply done such that the error-lines and power-on triggers "OR" together naturally, so we can easily use one PS for two channels.
HTH,
David
Translation to clarify meaning:
The McIntosh on/off circuit and remote trigger is a AC/DC plus analog/TTL hybrid - quite strange and unnecessarily convoluted, I had to re-design it; the NC 400 is properly and simply done such that the error-lines and power-on triggers "OR" together naturally, so we can easily use one PS for two channels.
HTH,
David
Hello pos,
The 3-driver mid-tower loudspeaker is nearing completion. This will be about my 26th loudspeaker construction since my teens.
The saucer-section (NC) powers the extended mid-range plus tweeter combination. The SS Be 6640 will have a passive fourth-order acoustic cross to the SS 18 W/8531 at about 2400 Hz.
The UCD powers a SS 23 W which will cross actively to the 18 W. Experiments will begin at 100 Hz fourth-order and we will go around and around from there. The slopes, gain, cross frequency, and overlap adjustment is a long process before we can...smile.
The SMPS's are thus horizontally deployed, one for the NS's, one for the UCD's. Vertical deployment gives a few more dB's of headroom, but I did not have time to experimentally verify a hybrid NC-UCD PS configuration under stress. I guess they would be OK.
In my case, my ears begin to noticeably distort at 89 dB, which means we are pushing massive peak-power levels of about... 4 watts! For the 23 W, which is a lot less efficient than the 18 W, we will be blowing titanium voice-coils across the room with those stunning 9 watt peaks! So all these Hypex amplifiers will be just as happy as you please...plenty of headroom!
BTW, the Mc 162 is a mid 90's design. Later generation Mc amplifiers have simpler and better administrative circuits for on/off.
David
P. S. Just kidding, the 23 W voice coils do not give-way at 9 Watts.
The 3-driver mid-tower loudspeaker is nearing completion. This will be about my 26th loudspeaker construction since my teens.
The saucer-section (NC) powers the extended mid-range plus tweeter combination. The SS Be 6640 will have a passive fourth-order acoustic cross to the SS 18 W/8531 at about 2400 Hz.
The UCD powers a SS 23 W which will cross actively to the 18 W. Experiments will begin at 100 Hz fourth-order and we will go around and around from there. The slopes, gain, cross frequency, and overlap adjustment is a long process before we can...smile.
The SMPS's are thus horizontally deployed, one for the NS's, one for the UCD's. Vertical deployment gives a few more dB's of headroom, but I did not have time to experimentally verify a hybrid NC-UCD PS configuration under stress. I guess they would be OK.
In my case, my ears begin to noticeably distort at 89 dB, which means we are pushing massive peak-power levels of about... 4 watts! For the 23 W, which is a lot less efficient than the 18 W, we will be blowing titanium voice-coils across the room with those stunning 9 watt peaks! So all these Hypex amplifiers will be just as happy as you please...plenty of headroom!
BTW, the Mc 162 is a mid 90's design. Later generation Mc amplifiers have simpler and better administrative circuits for on/off.
David
P. S. Just kidding, the 23 W voice coils do not give-way at 9 Watts.
Attachments
nCore noise floor...
Hey nCore builders. A quick question. I have built a pair of nCore mono amps, and while the noise floor is very, very low, it is rather coarse sounding. That is, with the ear a couple of inches from the tweeter (Revelator, no dropping resistors) I can hear a frying egg sound rather than a smooth rushing water/white noise type of floor. Interestingly, when I take my "RF analyizer" (AM radio tuned low with earphone) and place it near the SMPS600, I hear the exact same noise being broadcast by the power supply. It seems this is the inherent noise of the power supply which gets through to the speaker.
My source is very, very low in noise, and is not the source of this. Just wondering if this is normal and if other folks are experiencing it as well.
Hey nCore builders. A quick question. I have built a pair of nCore mono amps, and while the noise floor is very, very low, it is rather coarse sounding. That is, with the ear a couple of inches from the tweeter (Revelator, no dropping resistors) I can hear a frying egg sound rather than a smooth rushing water/white noise type of floor. Interestingly, when I take my "RF analyizer" (AM radio tuned low with earphone) and place it near the SMPS600, I hear the exact same noise being broadcast by the power supply. It seems this is the inherent noise of the power supply which gets through to the speaker.
My source is very, very low in noise, and is not the source of this. Just wondering if this is normal and if other folks are experiencing it as well.
Preamp advice
Dear Ncore owners,
Bruno is probably on vacation and didn't reply to my question about a recommended preamp for the Ncore400. So I am curious which preamps other Ncore owners use and what their listening experiences are. I am using the Metrum Octave DAC and an Emmeline Nighthawk phono amp for analog, both don't have a volume control and cannot be used as preamps. But my Lehmann Linear headphone amp could also serve as a line stage. I would only need to insert a switch to select sources because it only has one RCA line in...
Dear Ncore owners,
Bruno is probably on vacation and didn't reply to my question about a recommended preamp for the Ncore400. So I am curious which preamps other Ncore owners use and what their listening experiences are. I am using the Metrum Octave DAC and an Emmeline Nighthawk phono amp for analog, both don't have a volume control and cannot be used as preamps. But my Lehmann Linear headphone amp could also serve as a line stage. I would only need to insert a switch to select sources because it only has one RCA line in...
This is not normal, you should not hear any noise at all.
Check your cable layout inside the cabinet. And a picture of the internal layout would be helpful.
Thanks...
Further testing has led me to believe the noise is not the nCore, but is actually either present in the source component (and was previously masked by the noise floor of my Pass X150.5) or is the result of an interaction between the nCore and the source. More testing to follow today, and I'll try to put together a wire harness which allows me to "listen" to the source noise floor with headphones.
Looks like the nCore amps at least will be a great tool for evaluating other components!
BTW, my internal layout and wiring is as good as it gets, as discussed on this thread, and the source is true balanced.
Further testing has led me to believe the noise is not the nCore, but is actually either present in the source component (and was previously masked by the noise floor of my Pass X150.5) or is the result of an interaction between the nCore and the source. More testing to follow today, and I'll try to put together a wire harness which allows me to "listen" to the source noise floor with headphones.
Looks like the nCore amps at least will be a great tool for evaluating other components!
BTW, my internal layout and wiring is as good as it gets, as discussed on this thread, and the source is true balanced.
barrows, I agree with StigErik. There is a slight chance it could be your second thought of an interaction between the Ncore and something in you system but it it is more likely coming from some other piece in your system. When assembled right the Ncore noise floor is lower then the system it will be in. Now the synergy of ones system has been changed. IMHO.
Help
Some help required please. I've wired up 1 channel. Not in a case yet so I've connected both nampon and shield to pin 1 of the XLR socket. My cable is the new hypex one not the mogami one and I have blue connected to pin 2 of the XLR and the white wire connected to pin 3. When I power up the red LEDs come on but I just get a regular clicking sound, about one click per second. Any suggestions? Does the clicking tell us anything?
Update: my preamp only has RCA outputs so I am using Sowter transformers to convert the signal to balanced. I disconnected the XLR cable from the sowter / preamp and connected direct to my digital source, a Transporter which has balanced outputs and used it's digital volume control. Result: worked fine!
Any ideas why the sowter transformers would be causing a problem?
BTW, even with 1 channel and a degraded signal because of the digital volume control (it's only on half volume) the sound augers well!
Some help required please. I've wired up 1 channel. Not in a case yet so I've connected both nampon and shield to pin 1 of the XLR socket. My cable is the new hypex one not the mogami one and I have blue connected to pin 2 of the XLR and the white wire connected to pin 3. When I power up the red LEDs come on but I just get a regular clicking sound, about one click per second. Any suggestions? Does the clicking tell us anything?
Update: my preamp only has RCA outputs so I am using Sowter transformers to convert the signal to balanced. I disconnected the XLR cable from the sowter / preamp and connected direct to my digital source, a Transporter which has balanced outputs and used it's digital volume control. Result: worked fine!
Any ideas why the sowter transformers would be causing a problem?
BTW, even with 1 channel and a degraded signal because of the digital volume control (it's only on half volume) the sound augers well!
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