altecman Posted August 21, 2019 Posted August 21, 2019 Just acquired a AEM 6000 Amp & 6010 Preamp and was wondering if anyone had the kit or AEM articles. It would be nice to have a copy so that I can do a once over before applying power.
Addicted to music Posted August 21, 2019 Posted August 21, 2019 I don’t have the article. But I still have the kit. Someone else with the article might chime in and post it here. The kit would be over 30yrs old and it will need a recap. Hence the reason i don’t use mine anymore. The Hitachi mosfet output device are literally indestructible. For the 6000 power amp you can see that it has a speaker protection pcb on both sides, I can’t remember if the soft start was on the protection or on a separate pcb. Depending on the transformer used the article specified a 50-0-50VAC 300W. I used 500w. The filter caps are spec at 100VDC 10,000uf and with 240V it should run rail voltages 75-0-75 vdc. The best you can do is visually inspect further to ensure nothing is damaged and that there are no wiring defect. Turned it on and make sure you measure the speaker outputs to ensure that DC is zeroed. If not, there are 2 potentiometers, one for bias and the other to adjust for DC offset on the output. The article will explained procedure. Also on switch on those relays should “click” and if they do it means that it hasn’t detected DC on the output of the amp, but even after this stage I recommend you use a MM to ensure there is no DC on the output. The same go for the preamp, turn it on and resure that there are no DC on the output RCA b4 you go live plugging it in. 1
altecman Posted August 21, 2019 Author Posted August 21, 2019 Hopefully someone will come to my aid. The trannies in mine look about 500va, too small for 300va. The twin capacitor block looks enormous. Not much room left inside the enclosure, As a kit amp it would have been Australia's most ambitious diy project at the time. Would you consider selling your kit.
Addicted to music Posted August 22, 2019 Posted August 22, 2019 21 hours ago, altecman said: Hopefully someone will come to my aid. The trannies in mine look about 500va, too small for 300va. 500VA 50-0-50 weighs around 4-5kg. I think you are right looking at the pic you provided... that smaller transformer would be used to power the preamp and looks to be a 150-300VA in that pic in your post. 21 hours ago, altecman said: The twin capacitor block looks enormous. Not much room left inside the enclosure. The caps I used are 100VDC 15,000uf x 4 per channel. I can’t see the soft start pcb in you pic, don’t quote me on it but the soft start circuit has a 10 ohm 5w resistor in series to the mains that’s on a time constant circuit where a relay is used to bypass this resistor, If you were to used the specified 10ohm 5 watt, the ends of that resistor glows brightly through the ceramic and didn’t last long, even if you used 100VDC 10,000uf. I had to use 20 ohm 10 watt in parallel of memory for reliability. 21 hours ago, altecman said: As a kit amp it would have been Australia's most ambitious diy project at the time. Would you consider selling your kit. The project was written by David Tillbrook for a Magazine called “Australian Electronic Monthly”. It was sectioned over many months.... The 6010 preamp was released and the 6000 power amp followed. He also released a 100W version using common Hitachi devices... A company called Eagle Electronics in South Australia advertised heavily on the kit, however it ended badly because they could not sourced the heavy gauge u channel bracket... Eagle Electronics then filed for bankruptcy so the kits without these u channel brackets were not supplied to people like myself. I had to sourced it from Jaycar because they also sold the the kit in pcb form with the u channel brackets.. my boss at the time also built 6000 and it was a real item back in the mid 80s that made me off load the Naim gear I had.... this kit has been discussed several times here on this forum, you just have to do a search. 21 hours ago, altecman said: Would you consider selling your kit. The last time I turned it on, it was working correctly, however I haven’t turned the preamp on for a while. If the price was right, yes I would let mine go to someone who may appreciate it.
altecman Posted August 22, 2019 Author Posted August 22, 2019 Just had another look and saw that the twin power supply comprises each of 8 x 4700uF 100v black Elna caps., was this an upgraded version? I also see a metal partion separating each side down the middle. What surprises me is that the single power fuse on the back is 3 amp circuit breaker, wouldn't this be too small with all that sudden surge when powering up those large trannies and all those caps. I went and turned it on and a big puff of smoke came out of that circuit breaker. Hopefully it just shorted due to all that abuse. What do you mean about the u channel brackets, can you tell if my amp has them. What price were you looking at?
Rockman Posted August 22, 2019 Posted August 22, 2019 I have the magazines here somewhere & was going to build the kits. I had built the 5000 series kits & bought a kit from Eagle Electronics here in Adelaide to convert the 5000 series power amp to the 6000 series topology. I met & spoke with David Tilbrook, at Eagle one Saturday when they were promoting the amps & the speaker he designed using Philips drivers. I also have a 6000 series preamp kit which I grabbed that Altronics were offering at reduced price near the end. Both kits plus another 5000 series pwr amp kit all remain unbuilt as I got involved with Hafler gear around that time as well as Audio Amateur projects.
Addicted to music Posted August 22, 2019 Posted August 22, 2019 (edited) 1 hour ago, altecman said: Just had another look and saw that the twin power supply comprises each of 8 x 4700uF 100v black Elna caps., was this an upgraded version? No it’s not an upgrade version. 100VDC 10,000uf wasn’t exactly easy to find. I was lucky that I was able to sourced 100VDC 15,000uf From Semikon when they had a retail outlet here. Huge capacitors like this are even harder to find today, Electronics these day are shrinking in size and reducing power consumption, big storage caps at those values no one will keep. They have to be a special order and there is a waiting period. 1 hour ago, altecman said: I also see a metal partion separating each side down the middle. The AEM6000 was designed to have completely separate left/right channels with separate power supplies but incorporated in a single chassis. The Left/right channels are totally isolated. 1 hour ago, altecman said: What surprises me is that the single power fuse on the back is 3 amp circuit breaker, wouldn't this be too small with all that sudden surge when powering up those large trannies and all those caps. I went and turned it on and a big puff of smoke came out of that circuit breaker. Yes, if you do not have a soft start circuit this is what it would do, wear out main switches and circuit breaker contacts, Capacitors when fully discharged represent a short to the mains, they increase there impedance to the mains as it charges up. 1 hour ago, altecman said: . IWhat do you mean about the u channel brackets, can you tell if my amp has them. What price were you looking at? For heat transfer efficiency it was designed with separate pcb. You can see the main pcb hanging of the output devices “hitachi mosfet “ pcb. The u channel is one piece and is mounted on the main heat sink. It looks like your amp modules have been mounted upside down as I cannot see the top of the Hitachi Mosfets. 1 hour ago, altecman said: IWhat do you mean about the u channel brackets, can you tell if my amp has them. What price were you looking at? Will have to discussed this privately... Edited August 22, 2019 by Addicted to music
altecman Posted August 22, 2019 Author Posted August 22, 2019 6 hours ago, Rockman said: I have the magazines here somewhere & was going to build the kits. I had built the 5000 series kits & bought a kit from Eagle Electronics here in Adelaide to convert the 5000 series power amp to the 6000 series topology. I met & spoke with David Tilbrook, at Eagle one Saturday when they were promoting the amps & the speaker he designed using Philips drivers. I also have a 6000 series preamp kit which I grabbed that Altronics were offering at reduced price near the end. Both kits plus another 5000 series pwr amp kit all remain unbuilt as I got involved with Hafler gear around that time as well as Audio Amateur projects. It would be great if you could find the articles.
altecman Posted August 22, 2019 Author Posted August 22, 2019 Looking at the componentry it seems that reasonably good bits were used. I have to get rid of those skeleton style trim pots, looks like it's going to be a pain to get into. Just found some track damage on the top of the left board. I think the damage was caused by the very large wiring. I would think if such welding styled cable should be used that large copper binding posts should have been used. When I remove the boards I will use small copper nut and screws. Whilst I'm there I'll remove all that solder flux. Gee I wonder if I've bit off more than I can chew LOL. I wonder where that blue ground wire is going too, it looks like it just broke off somewhere? So many grounding points.
Auracle Posted August 23, 2019 Posted August 23, 2019 Was the pre-amp kit also called the "ultra fidelity" pre-amp? If so, I believe I may have a photocopy of those articles in a box somewhere. Will have to have a look when I get home. You are welcome to them as I don't think I will be building any more amps in my lifetime.
altecman Posted August 23, 2019 Author Posted August 23, 2019 (edited) Yes, the preamp is what you said, so excellent if you still have the articles, thanks Edited August 24, 2019 by altecman
altecman Posted August 25, 2019 Author Posted August 25, 2019 (edited) Just replaced the circuit breaker and switched it on, then a puff of smoke came of of one of those current inrush thermistors, you can see the little exits holes on either side. The terminal strip must be a sort of soft start. I think I'd better wait for the articles before proceeding as I don't want to totally stuff up the amp. When I get all the info I'll totally strip and rebuild. Cheers Edited August 25, 2019 by altecman
Addicted to music Posted August 25, 2019 Posted August 25, 2019 1 hour ago, altecman said: Just replaced the circuit breaker and switched it on, then a puff of smoke came of of one of those current inrush thermistors, you can see the little exits holes on either side. The terminal strip must be a sort of soft start. I think I'd better wait for the articles before proceeding as I don't want to totally stuff up the amp. When I get all the info I'll totally strip and rebuild. Cheers Not sure why that was used or the intention here, the article didn’t discussed the use of varistors, thermistors or polyswitches of any sort. You need to traced these to see where the go, then we can work out why the builder put these in place.
Addicted to music Posted August 25, 2019 Posted August 25, 2019 I started to build this when I was in my early to mid 20s back in the early to mid 80s. It took me many years waiting for parts to arrive was the biggest issues. David Tilbrook was way ahead of his time, I learnt of the AEM6000 article more on Electronics than I did at school, because he taught me more on why passive components are used and where, a little different then contantly setting up transistor circuits and using formulas to calculate gain etc. Even some of the teachers at tech school said that this was outside the boundary of what’s required in Diploma of Electronics..... when I started to build this amp, I wanted to build something that last and last it did! I turned this tho on this morning and guess what? After around 25yrs this thing still works, sounds pretty good to me and was driven by a Topping D50..... The photos will show many components here including the original Hitachi mosfets and also the jfet device that David intended to use which was a NTE461 device, all original all working! You cannot get these anymore, but I’m sure you can find equivalents. The NTE 461 was a dual device that was criticise matched..... 1
altecman Posted August 25, 2019 Author Posted August 25, 2019 (edited) Very nice. I see you have the gold axial ROE caps too, was there a reason why axial caps were used instead of radial. I had another look with the mirror and saw I have the u channel bracket. Edited August 25, 2019 by altecman
Addicted to music Posted August 25, 2019 Posted August 25, 2019 3 hours ago, altecman said: Very nice. I see you have the gold axial ROE caps too, was there a reason why axial caps were used instead of radial. I had another look with the mirror and saw I have the u channel bracket. They were supplied as is that was in the kit from Eagle Electronics.... so my guess is that the radial were not available..... There are also items that were supplied with the kit and I just wanted better! You can see that the white square ceramic are metal plate resistors, I used these to reduce parasitic inductance. Note the Teflon tape that was used underneath, it’s there to prevent the pins of the metal plates from shorting out the traces on the top of the pcb. There are 2 adjusting pots like I said in the previous post, notice the blue Bourne 10 turn sealed and how it’s positioned, it’s for servicing in case I need to adj the DC offset. The other pot is yellow and it’s also sealed multi turn. Those green resistors are vitreous metal wire and are high temp tolerant.
altecman Posted August 26, 2019 Author Posted August 26, 2019 Getting a copy of the 6010 preamp article sent to me, thanks for that. Just need a copy of the 6000 amp before stripping it down. Cheers
altecman Posted August 30, 2019 Author Posted August 30, 2019 While I wait for the article on the amp I was wondering if anyone had the kit assembly instructions for both the amp and preamp. It would be great to get a copy of these as it would make life a lot easier when I pull them apart for a total rebuild. Cheers
gvwrighty Posted February 19, 2020 Posted February 19, 2020 Altecman, if you've received your copy of the original articles, would you be able to forward me a copy? I'd really appreciate it. Thanks
pohtaras@hotmail.com Posted April 11, 2020 Posted April 11, 2020 Hi Guys, I am new to this forum. Many years ago, I built the AEM 6000 amp modules along with status monitors and surge cuurent limiter and recommended power supplies. Addicted to audio mentioned that Altecman's 6000 amp modules were mounted upside down in the case on the main heatsinks. (Can't see the tops of the Hitachi Mosfets). Looking at the original article from AEM Septeber 1986 the pics show that Altecman's mounting is correct.. Mosfets not showing. Any clarification on this matter would be appreciated. Thank you.
Leinster Lad Posted May 21, 2020 Posted May 21, 2020 I am getting ready to refurbish my old ETI-477 / Series 5000 amp, and was just browsing here..... I found a copy of the AEM6000 schematic if anyone is interested ? There is also a company called Connex Electronics https://connexelectronic.com/ who do a complete AEM 6000 "clone" which is on their web site. Lots about this over on the DIYaudio website. They also do soft starts, power supplies and speaker protection. I have no idea where they are located and have no affiliation with them at all. Just sharing the info. AEM6000_Audio_Amplifier_Module.pdf Power_SoftStart_v4.pdf Speaker_Protection_Circuit.pdf
pohtaras@hotmail.com Posted May 15, 2021 Posted May 15, 2021 Hi Guys, Would anyone have a copy of the original article for the AEM 6504 status monitors as used in the AEM 6000 power amp. I have built everything Modules, power supplies, surge current limiter and status monitors. However I am having some issues with my status monitors and I can't find the original article relating to them. Would anyone have a copy of the original articles for these status monitors. Schematics, pcb layout and wiring. Any help would be greatly appreciated. Regards, Peter.
pohtaras@hotmail.com Posted June 4, 2021 Posted June 4, 2021 Hi Milan, Thank you for your reply. I managed to source some scans of the original articles. So all good now. Thank you. Peter.
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