Beer of the Bass Posted April 23, 2016 Share Posted April 23, 2016 [quote name='Dan Dare' timestamp='1461421161' post='3034501'] Not strictly accurate to talk of car stuff not being able to be used because it's only designed to run on 12v. With the exception of hardwired valve amps (which can have internal supply rails running at 500v dc - that's why you don't poke around inside them), solid state circuitry runs at very small voltages. The mains current is stepped right down. PCBs wouldn't tolerate mains voltages. [/quote] Higher powered solid state amps (whether class AB or class D) typically use power supply rails at +/- 50 to +/- 80 volts DC. So not as high as would be found in a valve amp, but not tiny either. Quote Link to comment Share on other sites More sharing options...
luckydog Posted April 23, 2016 Share Posted April 23, 2016 At risk of heading toward the techy long grass, Class D amps have an odd requirement of the PSU: that it can sink as well as source energy to the speaker load. This is because energy returned from the speaker due to non-ideal behaviour of drivers/cabs cannot be dissipated in class D amps, it is returned to the PSU. This is prevalent at lf where drivers/cabs often behave non-ideally. It can all be taken care of with proper design, but might offer some explanation as to what is going on with heft? However, I don't think one can generalise as to amp class and performance: there's good and bad, and plenty of opportunity to interact with cabs in many amps of all classes IMHO. LD Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted April 23, 2016 Share Posted April 23, 2016 [quote name='luckydog' timestamp='1461423634' post='3034539'] It can all be taken care of with proper design... [/quote] Therein lies the rub. Afaik a lot of these amps share the same module which I imagine is bought off the shelf to install into 'many' (patently not all) of these mini/lightweight amps and common sense dictates that they will be bought for (among other things) their cost effectiveness. It is interesting that some folks declare that some/many Class D amps are 'lacking' in something and there is actual science to back up those layman's observations. Quote Link to comment Share on other sites More sharing options...
Passinwind Posted April 23, 2016 Share Posted April 23, 2016 [quote name='Dan Dare' timestamp='1461421161' post='3034501'] Not strictly accurate to talk of car stuff not being able to be used because it's only designed to run on 12v. With the exception of hardwired valve amps (which can have internal supply rails running at 500v dc - that's why you don't poke around inside them), solid state circuitry runs at very small voltages. The mains current is stepped right down. PCBs wouldn't tolerate mains voltages. [/quote] Plenty of tube amps use PCBs without incident, and many switch mode supplies rectify the line supply directly to DC before doing anything else. Quote Link to comment Share on other sites More sharing options...
Guest bassman7755 Posted April 23, 2016 Share Posted April 23, 2016 [quote name='warwickhunt' timestamp='1461424698' post='3034551'] Therein lies the rub. Afaik a lot of these amps share the same module which I imagine is bought off the shelf to install into 'many' (patently not all) of these mini/lightweight amps and common sense dictates that they will be bought for (among other things) their cost effectiveness. [/quote] Well it seems to most common class D modules are the ICE power ones. To put things into perspective, these are not the dirt cheap chinese units you find on ebay - they are quality units with a strong pedigree in a variety of markets [url="http://www.icepower.dk/en/company/"]http://www.icepower.dk/en/company/[/url] Quote Link to comment Share on other sites More sharing options...
luckydog Posted April 23, 2016 Share Posted April 23, 2016 Even with the same module, the PSU that can make a difference because of the oddities of class D ! LD Quote Link to comment Share on other sites More sharing options...
RandomBass Posted April 23, 2016 Share Posted April 23, 2016 Look out for a class H amplifier. The H stands for Heft, of course. Much like the D in class D stands for 'Digital'. Ahem. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted April 23, 2016 Share Posted April 23, 2016 Having played Class D heads extensively for over a decade, and spotted a pattern, I've learned to trust my ears :-) Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted April 23, 2016 Share Posted April 23, 2016 [quote name='wateroftyne' timestamp='1461430903' post='3034618'] Having played Class D heads extensively for over a decade, and spotted a pattern, I've learned to trust my ears :-) [/quote] Ditto... though it takes longer for things to sink in with me! Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted April 23, 2016 Share Posted April 23, 2016 Damn! Wish I'd said '(heat) sink'. Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 23, 2016 Share Posted April 23, 2016 [quote name='warwickhunt' timestamp='1461431270' post='3034621'] Damn! Wish I'd said '(heat) sink'. [/quote] Not a fan? Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted April 23, 2016 Share Posted April 23, 2016 [quote name='wateroftyne' timestamp='1461430903' post='3034618'] Having played Class D heads extensively for over a decade, and spotted a pattern, I've learned to trust my ears :-) [/quote] What's the pattern?... Interested to hear your view as I'm relatively new to class D. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted April 23, 2016 Share Posted April 23, 2016 [quote name='Musashimonkey' timestamp='1461435386' post='3034658'] What's the pattern?... Interested to hear your view as I'm relatively new to class D. [/quote] I'm on my phone and it's a faff to type too much - just do a search for any Class D thread on BC and you'll see the debate. Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted April 23, 2016 Share Posted April 23, 2016 WoT's perspective may be different to mine but I've found that whilst Class D equipped amps patently have as much volume as they are rated at (OK, most of them ). However, when used in a full band setting they suddenly lose presence... heft/punch/kick call it what you like. They have bottom end but it lacks authority when used in anger. I think Dave Funk (Thunderfunk) described it as some amps throw cannonballs whilst others throw doughnuts (there's a hole in it somewhere). Those that favour Class D have argued that the lump of iron in the Class A/B doesn't have anything to do with it; though it is becoming apparent there are reasons why there may be a counter-argument! Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 23, 2016 Share Posted April 23, 2016 [quote name='Musashimonkey' timestamp='1461435386' post='3034658'] What's the pattern?... Interested to hear your view as I'm relatively new to class D. [/quote] Generally the pattern is as follows for me: 1: Get GAS for amp because it looks good and the lightness is a bonus 2: Have a generally favourable initial opinion 3: Become increasingly dissatisfied after several gigs 4: Sell This has been the case with three class D amps, which all happen to have the ICE module. It hasn't put me off though; my current amp is class D and I absolutely love it - the more I push it, the more I love it. It doesn't have the ICE module, so that may be an influencing factor, I don't know. Quote Link to comment Share on other sites More sharing options...
Twincam Posted April 23, 2016 Author Share Posted April 23, 2016 [quote name='RandomBass' timestamp='1461430277' post='3034613'] Look out for a class H amplifier. The H stands for Heft, of course. Much like the D in class D stands for 'Digital'. Ahem. [/quote] Haha I like it What I don't like is this thread has probably unsurprisingly and this is possibly my fault descended into the old class d thing. After a good test today at the neighbours expense I can say class T with it's old school toroidal transformer has heft and is loud! And so does my gf when I turn the volume up I was told off with much heft! Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 23, 2016 Share Posted April 23, 2016 [quote name='Twincam' timestamp='1461437683' post='3034681'] After a good test today at the neighbours expense I can say class T with it's old school toroidal transformer has heft and is loud...And so does my gf [/quote] That's how I read your post! I wouldn't tell her that to her face Quote Link to comment Share on other sites More sharing options...
Twincam Posted April 23, 2016 Author Share Posted April 23, 2016 [quote name='Roland Rock' timestamp='1461438310' post='3034687'] That's how I read your post! I wouldn't tell her that to her face [/quote] Hahaha! Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted April 24, 2016 Share Posted April 24, 2016 (edited) When I think back to my older heavier amps from Ashdown, Ampeg, Trace, Peavey, Laney, Hartke and others I have forgotten for the moment, they quite often printed peak power on the rear as well as the official continuous RMS rating. The peak output was often two or three times the RMS rating and probably allowed for transient peaks for the occasional slappy bit. Maybe this extra energy was available because of the general over engineering of the older heads (big transformers, capacitors etc)? I know cost has always been important but nowadays the race to market the biggest output for the price seems to have led some manufacturers to quote maximum RMS figures but maybe the class D topology doesn't allow the peak capability that we were brought up with? Hence the proliferation of 1000 watt class D heads that possibly give us a similar transient load capacity to the 350 to 500 watt heavyweight heads? Edited April 24, 2016 by Sparky Mark Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted April 24, 2016 Share Posted April 24, 2016 [quote name='Roland Rock' timestamp='1461436970' post='3034672'] This has been the case with three class D amps, which all happen to have the ICE module. It hasn't put me off though; my current amp is class D and I absolutely love it - the more I push it, the more I love it. It doesn't have the ICE module, so that may be an influencing factor, I don't know. [/quote] What's your current head?.. (If you don't mind me asking) Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 24, 2016 Share Posted April 24, 2016 [quote name='Musashimonkey' timestamp='1461495407' post='3035080'] What's your current head?.. (If you don't mind me asking) [/quote] Sure. Glockenklang Blue Rock Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted April 24, 2016 Share Posted April 24, 2016 [quote name='Roland Rock' timestamp='1461496574' post='3035092'] Sure. Glockenklang Blue Rock [/quote] 1000 Watts. Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 24, 2016 Share Posted April 24, 2016 (edited) [quote name='Sparky Mark' timestamp='1461498373' post='3035113'] 1000 Watts. [/quote] That's right. As far as I can make out, it used an Abletec 1000w power module. I agree with you that headroom is required so that it doesn't run out of puff during those deep loud notes. Edited April 24, 2016 by Roland Rock Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted April 24, 2016 Share Posted April 24, 2016 [quote name='Roland Rock' timestamp='1461496574' post='3035092'] Sure. Glockenklang Blue Rock [/quote] Ok now that's fired up my GAS! Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 24, 2016 Share Posted April 24, 2016 (edited) [quote name='Musashimonkey' timestamp='1461499066' post='3035127'] Ok now that's fired up my GAS! [/quote] Haha. It is indeed an absolutely top quality amp, but they cost lots of monies 😕 My review halfway down the second page here http://basschat.co.uk/topic/279448-rock-around-the-glock/page__st__30 Edited April 24, 2016 by Roland Rock Quote Link to comment Share on other sites More sharing options...
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