Let´s hit the 5000 posts mark for this monster thread!
Do we smell an experiment coming, StigErik ?
It´s been around for a awhile that improvements in the treble will audible impact the bass too.
So it is not unlikely that UCDs on your ribbons will alter the perception of the bass although your woofer systems are unchanged.
Physically speaking, whatever signals that demand more acceleration than what your woofers are configured to produce rely on the ribbons, so whatever is meant by "leading edge" might rely more on the HP section than the LP
+1 exactly my thoughts.
stigerik what do you think?
will you do the experiment?
Well not harmonics but 'impact' part of drum sound can be as high as 3khz in kick drum (sound of beater hitting the drumhead) depending on beater's material and music style (ever listened to Death/trash/speed metal?
).Harmonics are much higher even if very short in duration and not nescesseraly 'harmonicly' related to sustained sound of drumhead: it's percussive material.
So yes i improvement in highs tends to give more focus and tightness to bass sound (not only percussive materials, it happens on bass, double bass,etc,etc...).
Please correct me if i'm wrong, but this is just what is described by Fourier, any signal can be divided in a n number of sine waves. Fast transitions (leading edge of the square wave) need high frequency sine waves so this is handled by the tweeter.
I asked this some time ago and never got an answer. Is this too obvious of a question?
Go and have a look at Bruno's papers on Class D design - you should find it answered there
and it's probably fair to assume that subsequent designs have tried to improve upon performance from his original papers
OK, let me check that I got this right - you have your pre-amp (Maranz) connected to the nc400's with balanced XLR cables. You then use the remote trigger (12V) output of the Marantz to switch the nc400's on/off. Do you use the standby on the SMPS(s) or the nAMPON inputs on the nc400's?
It could of course be that the Marantz produces a transient when turned on/off - have you tried with a different amp? Could there be a DC offset on the Marantz output?
Thanks for responding Julf.
Right, I use balanced XLR. I use the remote trigger to power on. I use a softstart from Hypex. It's switching the power, not the standby or the nAmpon. I don't have another amp to check. With the Squezzebox, cinch to xlr cable, there was no tic.
Maybe it is not the best wáy to switch on the nCore but given the fact that it also 'tics' when I mute the Marantz pre, it shouldn't make a difference I guess?
Do you also get the tic when leaving the nCores on, and turning off/muting the Marantz (so with the remote control cable between the Marantz and the nCores disconnected)? Would you happen to have a 12V relay handy to try a temporary test circuit to use SMPS standby instead of the Hypex softstart module?
(edit: I realize the Marantz control output can only drive 150 mA, but that should still be enough for a small-signal relay)
Look at nc400 datasheet again: "Figure 2: Preferred connection". There is no connection from IEC ground to chassis. Also, check that XLR pin 1 is connected straight to the chassis and also the signal ground from the module should be also connected to the chassis. I did not see those chassis connections in your build.
If I have removed the R141 from NC-400 (and would like to keep it that way), is it possible to match the gain of UCD-400 with the NC-400? That is with UCD-400HG HxR powered by SMPS400 and NC-400 powered by SMPS600.
gain_nc = 4.17*(1+2*Rf_nc/Rg_nc)
gain_ucd = 4.5*(1+2*Rf_ucd/Rg_ucd)
gain_ucd = gain_nc
4.5*(1+2*Rf_ucd/Rg_ucd) = 4.17*(1+2*Rf_nc/Rg_nc)
R141 removed, so
rg_nc = infinity
=> 4.5*(1 + 2 * Rf_ucd / Rg_ucd) = 4.17
<=> Rf_ucd / Rg_ucd = (4.17 / 4.5 - 1) / 2
=>Rf_ucd / Rg_ucd = -0,03666...
=> no can do but it is very close to 0.
SO,
Does this mean that if i set rg_ucd=infinity (remove the R3 altogether) difference in gain will be very negligible and close enough to bi-amp UCD-400HG with NC-400 with R141 removed?
Does that -0.0366 somehow describe the 0.2dB difference in overall gain according to datasheets?
gain_nc = 4.17*(1+2*Rf_nc/Rg_nc)
gain_ucd = 4.5*(1+2*Rf_ucd/Rg_ucd)
gain_ucd = gain_nc
4.5*(1+2*Rf_ucd/Rg_ucd) = 4.17*(1+2*Rf_nc/Rg_nc)
R141 removed, so
rg_nc = infinity
=> 4.5*(1 + 2 * Rf_ucd / Rg_ucd) = 4.17
<=> Rf_ucd / Rg_ucd = (4.17 / 4.5 - 1) / 2
=>Rf_ucd / Rg_ucd = -0,03666...
=> no can do but it is very close to 0.
SO,
Does this mean that if i set rg_ucd=infinity (remove the R3 altogether) difference in gain will be very negligible and close enough to bi-amp UCD-400HG with NC-400 with R141 removed?
Does that -0.0366 somehow describe the 0.2dB difference in overall gain according to datasheets?
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Fair to assume? With hundreds out in the field no one has ever hooked a scope to the output???
Well, the gain ratio is actually 1.0791366906 (4.5/4.17) - so 0.7 dB. Anyway, still not a big difference.
More than happy to do it next time I have my amp up on the workshop desk.
Another way to switch on you amps
At the moment i'm switching the amps on with the power switch at the IEC power inlet. Because I positioned my amps and other audio gear different in my audio rack it is now a bit hard to reach. Therefore I designed a simple circuit that detects the incomming line signal and then switched on the amps. It also switched off the amps when there is no signal for about 15 minutes.
I got the schematics from Elliott Sound Products and designed a little pcb myself using his schematics. I just received the pcb's and soldered the components to it this afternoon. I'll build it soon into my amps and see how this works out. Perhaps this is also a nice solution for you? Because I had to order 10 pcs I have some pcb's left
Hi Audioschipper,
At the moment i'm switching the amps on with the power switch at the IEC power inlet. Because I positioned my amps and other audio gear different in my audio rack it is now a bit hard to reach. Therefore I designed a simple circuit that detects the incomming line signal and then switched on the amps. It also switched off the amps when there is no signal for about 15 minutes.
I got the schematics from Elliott Sound Products and designed a little pcb myself using his schematics. I just received the pcb's and soldered the components to it this afternoon. I'll build it soon into my amps and see how this works out. Perhaps this is also a nice solution for you? Because I had to order 10 pcs I have some pcb's left
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Hi Audioschipper,
At the moment i'm switching the amps on with the power switch at the IEC power inlet. Because I positioned my amps and other audio gear different in my audio rack it is now a bit hard to reach. Therefore I designed a simple circuit that detects the incomming line signal and then switched on the amps. It also switched off the amps when there is no signal for about 15 minutes.
I got the schematics from Elliott Sound Products and designed a little pcb myself using his schematics. I just received the pcb's and soldered the components to it this afternoon. I'll build it soon into my amps and see how this works out. Perhaps this is also a nice solution for you? Because I had to order 10 pcs I have some pcb's left
Does that mute the amps (nAmpon) or switch the psu to standby? This would be very useful for lot of people, at least me
If I ever get to build these, that is.- Status
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