Guest Posted August 1, 2016 Posted August 1, 2016 Next DIY job to complement the rest of the Lounge work and current system development. 800w RMS (8 ohms @0.05 THD) of Holton Precision Audio kits, a pair of sub amps to drive 4 x Exidos Maelstrom 18's, fun.
mwhouston Posted August 1, 2016 Posted August 1, 2016 Next DIY job to complement the rest of the Lounge work and current system development. 800w RMS (8 ohms @0.05 THD) of Holton Precision Audio kits, a pair of sub amps to drive 4 x Exidos Maelstrom 18's, fun. Golly.
Guest Peter the Greek Posted August 1, 2016 Posted August 1, 2016 Next DIY job to complement the rest of the Lounge work and current system development. 800w RMS (8 ohms @0.05 THD) of Holton Precision Audio kits, a pair of sub amps to drive 4 x Exidos Maelstrom 18's, fun. Senbloodysational!
Guest Posted August 1, 2016 Posted August 1, 2016 Associated stack of amps/chassis, total finished rating of 1750W rms into 8 ohms, 2 ohm stable needs a 25A power circuit. Going to be around 40 hours labor to complete the matching stack of amps DIY Will all be linked to switch on via a trigger in the only amp that gets a button on the front. The chassis's will all get a matching front panel.
mwhouston Posted August 1, 2016 Posted August 1, 2016 (edited) I built this 6V6 SE UL tube amp in 2014 and though I liked the sound it never really excited me. The tubes are all Ozzie made and over 40years old. In fact that was part of the motivation to build Black Lace. One other feature is dual HT+ rails after the first filter cap which is a 4uf Russion military PIO. Each rail has three stages of filtering and has its own 5H choke. On my 99db efficient Beymas though a reasonable hum could be heard. I added 470uf of additional cap to each rail which has dropped the hum to virtually nothing. Today I'm going to improve the filtering more and see if I can completely remove all hum. To hear it currently on the Beymas you have to put your ear inside the driver. So it's very quiet. The sound and sound stage of the amp has also improved which is always the result of dual HT rails - far better imaging and sound stage. I just kept playing one album (24/96 files from my Pi server and XMOS DAC) after the other for four hours. But it did take a whole hour before the amp really started to deliver. Very pleased with progress and the amp so far. Edited August 1, 2016 by mwhouston 5
Newman Posted August 2, 2016 Posted August 2, 2016 Staggered turn on would be a good idea. That wouldn't be Matt's style. 3
Stevesie Posted August 2, 2016 Posted August 2, 2016 Staggered turn on would be a good idea. That wouldn't be Matt's style. Heh, significant household light dimming at amp switch on is strangely satisfying, I find.... 3
selectedgrub Posted August 2, 2016 Posted August 2, 2016 Love it, but what the heck is it? It is a "sub" - marine.
mwhouston Posted August 2, 2016 Posted August 2, 2016 Heh, significant household light dimming at amp switch on is strangely satisfying, I find.... Mate, even my small powered tube amps cause a lamp flicker. 1
mwhouston Posted August 2, 2016 Posted August 2, 2016 (edited) Spent some more time on the PS today for Black Lace today. I may have just reduced the hum a touch more. To hear it you have to stick your head in the 15" speaker cone. The amp sounds even a little clearer. Really enjoying this baby at the mo. Edited August 2, 2016 by mwhouston
Guest Posted August 2, 2016 Posted August 2, 2016 Staggered turn on would be a good idea. Interestingly all the amps have a soft start feature, so no massive inrush current, otherwise there would be a need for a motor start C Curve Circuit breaker installed. Yes the lights old filaments and halogens would dim a bit on "start up" there is 70 Kg of ferrite and copper in the rack Will be a fun job, love building kits as I learn something new about how an amp works every time. If I do have trouble, will stagger start by using different timing components in the controllers (see, may learn something)
Guest Peter the Greek Posted August 2, 2016 Posted August 2, 2016 Damn.....I wish I had the knowledge to build these....awesome stuff
Guest Posted August 2, 2016 Posted August 2, 2016 (edited) Damn.....I wish I had the knowledge to build these....awesome stuff You have done some cool/clever stuff Peter, building a "kit" is not all that hard, and plenty of DIY'ers that will help. Building up a $20, D class 50w x 2 (which comes assembled) can be really rewarding. Finding an old buggered amp, gutting it, making a custom face plate, mounting the module, bla, bla. good fun Edited August 2, 2016 by Guest
Guest Posted August 2, 2016 Posted August 2, 2016 That wouldn't be Matt's style. True, the dimmer the better on start, adds drama
betocool Posted August 2, 2016 Posted August 2, 2016 You have done some cool/clever stuff Peter, building a "kit" is not all that hard, and plenty of DIY'ers that will help. Building up a $20, D class 50w x 2 (which comes assembled) can be really rewarding. Finding an old buggered amp, gutting it, making a custom face plate, mounting the module, bla, bla. good fun Agree 100%. I built some time ago a stereo 50W or so class D amp with a quick and dirty power supply and transformer, without really expecting much of it. But it sounded really sweet, paired with my main speakers. Now when I hear it on my workshop it sounds a bit meh... but that's only because I have two pairs of verge waste refurbished speakers and power it from a laptop Line Out. Meaning... I need a DAC and a new set of speakers for my workshop! * looking for an amanero usb combo board somewhere *
Newman Posted August 2, 2016 Posted August 2, 2016 True, the dimmer the better on start, adds drama Cue scene with weeping angels 1
Guest Peter the Greek Posted August 2, 2016 Posted August 2, 2016 You have done some cool/clever stuff Peter, building a "kit" is not all that hard, and plenty of DIY'ers that will help. Building up a $20, D class 50w x 2 (which comes assembled) can be really rewarding. Finding an old buggered amp, gutting it, making a custom face plate, mounting the module, bla, bla. good fun Thanks! and very interesting/intriguing.......at some point when we get our HT back up and running (now quite some time away), we're going to need in the order of 40-50 channels of active amplification. I've been very interested in using Holton for this. Makes sense to me, I could build a heap of class A amps for the tweeters (and maybe mids) and then a bunch of Class D for the subs etc and just jam them into some large cases/chassis' (suitably designed for interference or whatever......<<<<this for example I know nothing of)
Guest Posted August 3, 2016 Posted August 3, 2016 (edited) Thanks! and very interesting/intriguing.......at some point when we get our HT back up and running (now quite some time away), we're going to need in the order of 40-50 channels of active amplification. I've been very interested in using Holton for this. Makes sense to me, I could build a heap of class A amps for the tweeters (and maybe mids) and then a bunch of Class D for the subs etc and just jam them into some large cases/chassis' (suitably designed for interference or whatever......<<<<this for example I know nothing of) Just ideas and wouldn't be too hung up on class A unless you are a pro and know more than I do about amps, which is not much http://www.ebay.com.au/itm/50W-50W-Audio-TP2050-CLASS-D-AMP-Assembled-Kit-Power-Digital-Amplifier-Board-/191572664415?hash=item2c9a9ee05f:g:PdIAAOSwymxVRZeQ 3 of these = 6 channels, could be mounted on the base of an old gutted out amp, associated RCA sockets/speaker binding posts, mounted in rear of chassis. One of these http://www.ebay.com.au/itm/400W-24V-17A-Single-Output-Switching-power-supply-AC-to-DC-SMPS-/261847204022?hash=item3cf74f40b6:g:J4sAAOSwEeFVKTh4 could be put in with the amps, wired to each amp and mains IEC socket. Rough but ready and I think less than $100 for the main bits. If I was starting out, would do this for a giggle and what the DIY component of Audio is all about for the most part, fun at a rock bottom price. If it went up in smoke, you would find out why and lean from it. Anyway just ideas. Enjoy Edited August 3, 2016 by Guest
Stevesie Posted August 3, 2016 Posted August 3, 2016 Thanks! and very interesting/intriguing.......at some point when we get our HT back up and running (now quite some time away), we're going to need in the order of 40-50 channels of active amplification. I've been very interested in using Holton for this. Makes sense to me, I could build a heap of class A amps for the tweeters (and maybe mids) and then a bunch of Class D for the subs etc and just jam them into some large cases/chassis' (suitably designed for interference or whatever......<<<<this for example I know nothing of) The Hypex UcD modules are pretty easy to work with, though they aren't as cheap as the eBay Chinese stuff. Very well built though, and have a flat impedance/frequency curve that you don't always get with Class D.
Guest Peter the Greek Posted August 3, 2016 Posted August 3, 2016 The Hypex UcD modules are pretty easy to work with, though they aren't as cheap as the eBay Chinese stuff. Very well built though, and have a flat impedance/frequency curve that you don't always get with Class D. All very interesting. Take this thing by Holton for example. They say "With 8 of these device on board it is the equivalent of having 16 x total output devices in the output stage." does that mean you can build an 8 channel amp (or can it be 16?) with it? for $2-3k in parts that seems like a bargain? My interpretation of this is you buy the kit from them, get a few other bits and pieces and a case/chassis and just plug/screw it together? am i missing something?
Stevesie Posted August 3, 2016 Posted August 3, 2016 All very interesting. Take this thing by Holton for example. They say "With 8 of these device on board it is the equivalent of having 16 x total output devices in the output stage." does that mean you can build an 8 channel amp (or can it be 16?) with it? for $2-3k in parts that seems like a bargain? My interpretation of this is you buy the kit from them, get a few other bits and pieces and a case/chassis and just plug/screw it together? am i missing something? That line is just referring to the construction of the Exicon transistors compared to normal ones, rather than any multi channel capability. You still need one board per channel. You are essentially correct re building an amp otherwise - but you do need some understanding of mains wiring/safety, audio signal grounding etc. 1
Guest Peter the Greek Posted August 3, 2016 Posted August 3, 2016 That line is just referring to the construction of the Exicon transistors compared to normal ones, rather than any multi channel capability. You still need one board per channel. You are essentially correct re building an amp otherwise - but you do need some understanding of mains wiring/safety, audio signal grounding etc. Cool, thanks.....my wife is going to spew about this as in another thing to chew up my time at some point! Our electrician is pretty cluey, I'll speak with him
Upfront Posted August 4, 2016 Posted August 4, 2016 Cool, thanks.....my wife is going to spew about this as in another thing to chew up my time at some point! Our electrician is pretty cluey, I'll speak with him Well worth talking to Anthony. He's a member here (aussieamps?). Lovely bloke. He will be able to give you a run down. He makes nice gear.
mwhouston Posted August 5, 2016 Posted August 5, 2016 Picked up all the parts for yet another 180W Class D today. This will be based on the new T4 modules. The front half of the modules is very different to the original T4 but the back half is similar. The module is about 3/4 the size of the original. They have kept the very high end components throughout and retained the super quality audio caps as the input caps. If I go head down bum up I could have it finished tomorrow. Problem is after about four hours over a hot iron my back starts to complain and I need to do something else. By early next week it should be done. Then I have another DSD DAC to build and a 6L6\12AT7 power amp. Busy boy! 3
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