Nice.
I'd think you'd have felt that right down your spine and I expect it would have even blurred your vision ?? 🙂
Yeah extended periods of such high SPL is very bad, and I should have worded that more carefully. I guess you did use soft clipping though? A few hours at a Metallica concert and your ears ring about two days, don't think you could even hear a piano after!
If soft clipping is in fact "that" effective at reducing damage I think it should be law for live concerts, where they tend to crank it up well beyond what it should be, especially when more than a few bands are playing, each with a bigger ego than the next (they keep turning it up louder and louder, and I do mean "loud", nothing clean about it).
Anyway, I'd sure like to see one of your projects some day!
SEIJI, since you have that many modules would you be willing to bridge the UCD400's and report back? Seems you have a most difficult load to drive, and it's not at all hard to bridge them.
Regards,
Chris
I'd think you'd have felt that right down your spine and I expect it would have even blurred your vision ?? 🙂
Yeah extended periods of such high SPL is very bad, and I should have worded that more carefully. I guess you did use soft clipping though? A few hours at a Metallica concert and your ears ring about two days, don't think you could even hear a piano after!
If soft clipping is in fact "that" effective at reducing damage I think it should be law for live concerts, where they tend to crank it up well beyond what it should be, especially when more than a few bands are playing, each with a bigger ego than the next (they keep turning it up louder and louder, and I do mean "loud", nothing clean about it).
Anyway, I'd sure like to see one of your projects some day!
SEIJI, since you have that many modules would you be willing to bridge the UCD400's and report back? Seems you have a most difficult load to drive, and it's not at all hard to bridge them.
Regards,
Chris
Hello,
As that's the speaker belong to a friend of mine in his home, just want to try out how good the UCD modules............
I am really concern about how the UCD perform once my very own speaker arrive from Japan.....................
As that's the speaker belong to a friend of mine in his home, just want to try out how good the UCD modules............
I am really concern about how the UCD perform once my very own speaker arrive from Japan.....................
classd4sure said:
Hmm..I've one idea about it, if we are sure, that input of the UcD ok (not clipped), maybe this drum track contain very low frequency events, and "cracks" =overvoltage protection sounds..though it's almost impossible. Actually, UcD clipping is quite neat.
ghemink said:
Mine sounds extremely detailed and solid even at very high volumes.
To be fair though the Sowter output transformers made a big difference to the sound so they may be helping.
Funny thing is I can stick the tube amp on an 8ohm load and feed it a square wave and it remains perfectly flat at near full output, even a sine wave doesn't clip until at full output.
I've never approached full volume through the speakers yet😀
BTW The bass quality actually sounds deeper and tighter than any of my diy classAB amps, not all tube amps sound mushy and warm😉
UcD problem
Deje vu all over again! This sounds just like the problem with the tube preamp we worked on in another thread. The basic problem was that the preamp was letting through so much low freq trash it would trip out the DC protection circuit. The proper cure would have been to fix the preamp but a sub optimum solution was to use much smaller coupling caps and limit the amps LF input. .1uf worked and he was going to try .47uf but we never got a report back. Sure sounds like the same sort of thing going on. Tube preamp circuits rarely have regulated supplies and being single ended they have virtually no power supply rejection. When the power amps draw power from the line it can pull the line voltage down enough to effect the preamps output. I even had a case where turning the volume up caused the whole system to go into LF oscillation. Plugging the power amps into a separate circuit solved the problem, well not really, but at least it made it work. AC power regulation was later installed for a more proper fix.
Roger
Deje vu all over again! This sounds just like the problem with the tube preamp we worked on in another thread. The basic problem was that the preamp was letting through so much low freq trash it would trip out the DC protection circuit. The proper cure would have been to fix the preamp but a sub optimum solution was to use much smaller coupling caps and limit the amps LF input. .1uf worked and he was going to try .47uf but we never got a report back. Sure sounds like the same sort of thing going on. Tube preamp circuits rarely have regulated supplies and being single ended they have virtually no power supply rejection. When the power amps draw power from the line it can pull the line voltage down enough to effect the preamps output. I even had a case where turning the volume up caused the whole system to go into LF oscillation. Plugging the power amps into a separate circuit solved the problem, well not really, but at least it made it work. AC power regulation was later installed for a more proper fix.
Roger
Re: Re: Re: UCD AD400 VS el34PP
Yes, I would be interested in that drum recording. I'll mail you later from home. My woofers are not an easy load for my UcDs. I use dipole woofers that need a lot more power at low frequencies than other systems would. Each speaker has two 8 ohm woofers in parallel, so nominal 4 Ohm load. I can pump out 25Hz at 40V peak-peak easily (was in some of my CDs and monitored the output with a scope). Of course 40V peak/peak is still far away from clipping. I have not gone higher as my ears/room etc would start to fall apart (and excursion of the woofers may be limiting as well).
Many posters gave hints of what could be wrong. So please check it. So problem could be with low frequency signals coming from the tube pre-amp which may cause power supply pumping which would shut-off the UcD module. Another issue could be that the power supply is on the high side, close to the shutdown point of the amp, then only a small amount of power supply pumping could cause the protection to trip.
Do you have a scope or some friend that has one and can work with it? I just can`t believe that the UcD does not work for you as it should really be able to deliver the power without any issues.
I would first check the power supply voltage with a multimeter and then try another pre-amp to see if it still occurs.
Hope you get it working as so many people raving about the UcDs can not all be wrong, there must be some technical issue that explains this.
Best regards and good luck
Gertjan
SEIJI said:
Yes, I would be interested in that drum recording. I'll mail you later from home. My woofers are not an easy load for my UcDs. I use dipole woofers that need a lot more power at low frequencies than other systems would. Each speaker has two 8 ohm woofers in parallel, so nominal 4 Ohm load. I can pump out 25Hz at 40V peak-peak easily (was in some of my CDs and monitored the output with a scope). Of course 40V peak/peak is still far away from clipping. I have not gone higher as my ears/room etc would start to fall apart (and excursion of the woofers may be limiting as well).
Many posters gave hints of what could be wrong. So please check it. So problem could be with low frequency signals coming from the tube pre-amp which may cause power supply pumping which would shut-off the UcD module. Another issue could be that the power supply is on the high side, close to the shutdown point of the amp, then only a small amount of power supply pumping could cause the protection to trip.
Do you have a scope or some friend that has one and can work with it? I just can`t believe that the UcD does not work for you as it should really be able to deliver the power without any issues.
I would first check the power supply voltage with a multimeter and then try another pre-amp to see if it still occurs.
Hope you get it working as so many people raving about the UcDs can not all be wrong, there must be some technical issue that explains this.
Best regards and good luck
Gertjan
I think you are on the right track. You and I both know it isn't the amp, unless something is tripping it, or cutting in the soft clip.
He needs a 'scope on the output.........a DMM on the protection lead..........and it would not hurt to look at the PSU rails.
Jocko
He needs a 'scope on the output.........a DMM on the protection lead..........and it would not hurt to look at the PSU rails.
Jocko
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