Zaphod Beeblebrox Posted May 25, 2011 Share Posted May 25, 2011 (edited) Altronics have reduced prices for two of the best (IMO) kit amps available today. The pricing is: Silicon Chip 20 Watt Class A amp (Altronics part number: K5125) $499.00. (A $100.00 reduction) Silicon Chip ULD (100 Watt) Class A/B amp (Altronics part number: K5155) $499.00 (A $250.00 reduction!) The ULD part means; Ultra Low Distortion. IMO, it is the one to buy. Particularly at the price. The pricing on these items is very keen indeed. These are kit amps in the truest sense of the word. A fair amount of assembly is required, but the result is, IMO, one of the best kit amps (particularly in the case of the ULD amp) that can be built at any price. Historical note: The Class A amp and the ULD amp were published in 2001. Sometime later, Silicon Chip published the design for ULD amp Mk II. IMO, thise was a backward step. IMO, the orginal ULD amp is a more sophisticated, better sounding design. Next month's Silicon Chip magazine (July 2011) will showcase a new and improved ULD amp. No details have been released, except to suggest that the designer has addressed some of the shortcomings associated with the ULD MkII. Either way, the ULD amp sold by Altronics is a bargain. Edited May 25, 2011 by Zaphod Beeblebrox Brain fart Link to comment Share on other sites More sharing options...
LogicprObe Posted May 25, 2011 Share Posted May 25, 2011 Get both for a great bi amp set up! Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 25, 2011 Author Share Posted May 25, 2011 Get both for a great bi amp set up! Not in my opinion. Better to grab two ULD amps. The 20 Class Amp is a beaut. The ULD amp is better. Link to comment Share on other sites More sharing options...
pete_mac Posted May 25, 2011 Share Posted May 25, 2011 Mr Beeblebrox, is the ULD amp currently on special the older ULD, or the ULD mk II? If it is the mk II, can these be appropriately modded to address the backwards-steps taken in the change from mk I to mk II? Link to comment Share on other sites More sharing options...
LogicprObe Posted May 25, 2011 Share Posted May 25, 2011 Not in my opinion. Better to grab two ULD amps. The 20 Class Amp is a beaut. The ULD amp is better. But then you'd be wasting substantial watts! Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 25, 2011 Author Share Posted May 25, 2011 Mr Beeblebrox, is the ULD amp currently on special the older ULD, or the ULD mk II? If it is the mk II, can these be appropriately modded to address the backwards-steps taken in the change from mk I to mk II? As I stated, it is the ULD amp. The ULD MkII is a fundamentally different design. It cannot be altered to ULD topology. I also stress that the superiority of the ULD amp over the MkII is MY opinion. Others may not share my opinion of such things. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 25, 2011 Author Share Posted May 25, 2011 But then you'd be wasting substantial watts! With the Class A amp, you'd be wasting Watts. The power consumption of the ULD amp is substantially lower than the 20 Class A amp. Link to comment Share on other sites More sharing options...
Cyber_Murphy Posted May 25, 2011 Share Posted May 25, 2011 Great 'heads-up' ZB.. If only the Ultra-LD was available as individual modules (like the Class A is) that way you wouldn't need to buy the complete kit.. The only reason I say this is because I don't use the pre-amp board/volume/multiple input facility/speaker protection. I use mine as a straight power-amp,, and if it was available as seperate kits, I would definately build the amp boards again :-) Cheers.. CM Link to comment Share on other sites More sharing options...
fat Posted May 26, 2011 Share Posted May 26, 2011 If I wasn't such a gumby with a soldering iron I would get one. Paying someone to build it would not be worth it I wouldn't think Link to comment Share on other sites More sharing options...
New Sensations Posted May 26, 2011 Share Posted May 26, 2011 Mr Beeblebrox, is the ULD amp currently on special the older ULD, or the ULD mk II? If it is the mk II, can these be appropriately modded to address the backwards-steps taken in the change from mk I to mk II? Pete - if you have the soldering iron skills (which you do), I reckon this would give a tremendous sound for a relatively very little outlay. Link to comment Share on other sites More sharing options...
pete_mac Posted May 26, 2011 Share Posted May 26, 2011 As I stated, it is the ULD amp. The ULD MkII is a fundamentally different design. It cannot be altered to ULD topology.I also stress that the superiority of the ULD amp over the MkII is MY opinion. Others may not share my opinion of such things. Thanks mate... just wanted to be sure Pete - if you have the soldering iron skills (which you do), I reckon this would give a tremendous sound for a relatively very little outlay. I know... damn tempting. I wonder if I can glue a Sansui badge on the front of it? Link to comment Share on other sites More sharing options...
pete_mac Posted May 26, 2011 Share Posted May 26, 2011 (edited) Hmm... any idea how these amps run with nominal 4 ohm impedance speakers? I have one pair that I *think* are a relatively 'easy' 4 ohm load with no nasty dips, but I can't be certain. EDIT: I think I found my answer on diyaudio.com. 4 ohm loads are not recommended. Edited May 26, 2011 by pete_mac Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 26, 2011 Author Share Posted May 26, 2011 Hmm... any idea how these amps run with nominal 4 ohm impedance speakers? I have one pair that I *think* are a relatively 'easy' 4 ohm load with no nasty dips, but I can't be certain.EDIT: I think I found my answer on diyaudio.com. 4 ohm loads are not recommended. I've tested them into 4 Ohm (resistive) loads and listened to them through 4 Ohm speakers. No problems in either case. Link to comment Share on other sites More sharing options...
pete_mac Posted May 26, 2011 Share Posted May 26, 2011 Hmmm.. thanks for the feedback (one again!!!) Link to comment Share on other sites More sharing options...
LogicprObe Posted May 26, 2011 Share Posted May 26, 2011 With the Class A amp, you'd be wasting Watts. The power consumption of the ULD amp is substantially lower than the 20 Class A amp. I meant output watts, not input watts! Link to comment Share on other sites More sharing options...
joz Posted May 26, 2011 Share Posted May 26, 2011 Not in my opinion. Better to grab two ULD amps. The 20 Class Amp is a beaut. The ULD amp is better. Where do you think the ULD A/B is better in this case? Thanks. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 26, 2011 Author Share Posted May 26, 2011 I meant output watts, not input watts! Then I have no idea what you're talking about. The 20 Watt Class A amp consumes more power than the ULD amp. Therefore, it is more efficient to use the ULD amp. The 20 Watt Class A amp has less power output than the ULD amp. Therefore, the ULD amp will cope with a wider range of loudspeakers. If used in a bi-amp system, using drivers of similar efficiency, the ULD amp will clip long after the Class A amp. Many people fail to realise that the AVERAGE power requirements of HF drivers is far lower than bass drivers. HOWEVER, the PEAK power demands of HF drivers can equal that of bass drivers. Therefore, in systems where HF drivers and bass drivers are of similar efficiency, the amplifier power (peak) should be similar. Therefore, the ULD amp makes more sense, more often, in more systems. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 26, 2011 Author Share Posted May 26, 2011 Where do you think the ULD A/B is better in this case?Thanks. The ULD amp is: * More powerful. * Lower distortion. * Cooler running. * Better sounding. Link to comment Share on other sites More sharing options...
joz Posted May 26, 2011 Share Posted May 26, 2011 The ULD amp is:* More powerful. * Lower distortion. * Cooler running. * Better sounding. Yep that answer ticks all the boxes. Ta! Link to comment Share on other sites More sharing options...
LogicprObe Posted May 26, 2011 Share Posted May 26, 2011 Then I have no idea what you're talking about. The 20 Watt Class A amp consumes more power than the ULD amp. Therefore, it is more efficient to use the ULD amp. The 20 Watt Class A amp has less power output than the ULD amp. Therefore, the ULD amp will cope with a wider range of loudspeakers. If used in a bi-amp system, using drivers of similar efficiency, the ULD amp will clip long after the Class A amp. Many people fail to realise that the AVERAGE power requirements of HF drivers is far lower than bass drivers. HOWEVER, the PEAK power demands of HF drivers can equal that of bass drivers. Therefore, in systems where HF drivers and bass drivers are of similar efficiency, the amplifier power (peak) should be similar. Therefore, the ULD amp makes more sense, more often, in more systems. I think that depends a lot on your crossover point. Get two ULD's and one Class A and Tri amp it then! Link to comment Share on other sites More sharing options...
Westy Posted May 26, 2011 Share Posted May 26, 2011 Mhmm very interesting but as someone else stated earlier it would be great to be able to just purchase the amplifier modules and power supply seperately without the preamp, fan, case and all that business. Could anyone confirm if this is the same amplifier module as that used in the ULD http://www.photonage.com.au/100w-class-ab-audio-amplifier-kit-p-10378.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 And is this the powersupply? http://www.photonage.com.au/power-supply-kit-for-k5150-p-9455.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 If so, I think I may be ordering 4 modules to build an active system. Link to comment Share on other sites More sharing options...
Cyber_Murphy Posted May 26, 2011 Share Posted May 26, 2011 Mhmm very interesting but as someone else stated earlier it would be great to be able to just purchase the amplifier modules and power supply seperately without the preamp, fan, case and all that business. Could anyone confirm if this is the same amplifier module as that used in the ULD http://www.photonage.com.au/100w-class-ab-audio-amplifier-kit-p-10378.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 And is this the powersupply? http://www.photonage.com.au/power-supply-kit-for-k5150-p-9455.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 If so, I think I may be ordering 4 modules to build an active system. It's hard to say if thats the same module.. Silicon chip did detail an amp module similar to the UltraLD (as per your link) but when they released the ULtraLD full kit later on, the power amp module was also revised,, this is what I have found from my research anyway,, but I could be wrong.. Also, if not buying the full kit, finding an appropriate transformer will be tricky (2x35V and 2x55V).. You might be better off using 2 seperate transformers, one for the regulated +/-55v rails and one for the un-regulated +/-52.5v rail.. Cheers.. CM Link to comment Share on other sites More sharing options...
Cyber_Murphy Posted May 26, 2011 Share Posted May 26, 2011 (edited) The ULD amp is:* Better sounding. Well,, as someone who has both amps,, I need to say that it's not necessarily better sounding,, not in my system anyway.. Sure, the UltraLD packs a better punch in the mid bass, vocals, electric guitars, and is a very quiet amp But the class A is silky smooth, fantastic in the HF department, great detail, ultra quiet inbetween instruments! Greater soundstage and imaging! The only challenge to this I can think of is that I probably didn't build ultraLD with as much care as I did the class A's,, Eg. mono-blocks, and a better locally made transformer.. but still,, my UltraLD is definately not 'stock' either.. Cheers.. CM Edited May 26, 2011 by Cyber_Murphy typo Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 26, 2011 Author Share Posted May 26, 2011 I think that depends a lot on your crossover point.Get two ULD's and one Class A and Tri amp it then! No. Crossover point makes little difference to the peak power requirements. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 26, 2011 Author Share Posted May 26, 2011 Mhmm very interesting but as someone else stated earlier it would be great to be able to just purchase the amplifier modules and power supply seperately without the preamp, fan, case and all that business. Could anyone confirm if this is the same amplifier module as that used in the ULD http://www.photonage.com.au/100w-class-ab-audio-amplifier-kit-p-10378.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 And is this the powersupply? http://www.photonage.com.au/power-supply-kit-for-k5150-p-9455.html?zenid=0020f4c1e1b722fdd489a1887308b8d7 If so, I think I may be ordering 4 modules to build an active system. Nope. Different amplifier. Not even remotely in the same class as the ULD amp. Link to comment Share on other sites More sharing options...
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