nzlowie Posted February 17, 2018 Share Posted February 17, 2018 Tonight I thought I'd throw my Pass ACA onto the mid-hf horns..... dam these little amps are pretty good. Hard to believe such a simple little amp can sound so good.... but then it's designed by Nelson Pass! Anyone else using these? 2 Link to comment Share on other sites More sharing options...
Upfront Posted February 17, 2018 Share Posted February 17, 2018 Tonight I thought I'd throw my Pass ACA onto the mid-hf horns..... dam these little amps are pretty good. Hard to believe such a simple little amp can sound so good.... but then it's designed by Nelson Pass! Anyone else using these?Currently using mine on a pair of supertweeters. You've convinced me to give it a run on my paper horns..... when they're finished. 2 Link to comment Share on other sites More sharing options...
nzlowie Posted February 17, 2018 Author Share Posted February 17, 2018 Should have known you would have built a pair of these! Built mine age's ago but haven't used them much as I have to rebuild the case as the heatsink is too small. Going to build new cases and change the output cap to something a lot smaller and add a filter cap to the input, we don't need these to run below 500hz so why feed them that range. Link to comment Share on other sites More sharing options...
Upfront Posted February 17, 2018 Share Posted February 17, 2018 How old is the kit? Does it have the latest mod? Mine (12 months old) only gives 5-6w instead of the 8w the original ones did. Link to comment Share on other sites More sharing options...
mwhouston Posted February 17, 2018 Share Posted February 17, 2018 Can you guys post a schematic. Link to comment Share on other sites More sharing options...
nzlowie Posted February 17, 2018 Author Share Posted February 17, 2018 How old is the kit? Does it have the latest mod? Mine (12 months old) only gives 5-6w instead of the 8w the original ones did. Mine is about 2 years old now, I thought the only mod was an extra bias? resistor that lifted it from 5 to 6 watts.Yes mine have this. Schematic link here. http://www.diyaudio.com/forums/diyaudio-com-articles/214808-amp-camp-amp-1-a.html Link to comment Share on other sites More sharing options...
Upfront Posted February 18, 2018 Share Posted February 18, 2018 You could be right mate. My memory of it was that it was originally an 8w kit and the mod took it down to 5-6w but improved sound quality. It's now part of the design. Could be wrong. I originally bought the boards quite a few years ago but didn't get around to building it. My ever patient wife bought me the kit for Christmas last year. Link to comment Share on other sites More sharing options...
Upfront Posted February 18, 2018 Share Posted February 18, 2018 Can you guys post a schematic. From googleI think it's the latest. Link to comment Share on other sites More sharing options...
mwhouston Posted February 18, 2018 Share Posted February 18, 2018 8 hours ago, nzlowie said: Mine is about 2 years old now, I thought the only mod was an extra bias? resistor that lifted it from 5 to 6 watts.Yes mine have this. Schematic link here. http://www.diyaudio.com/forums/diyaudio-com-articles/214808-amp-camp-amp-1-a.html Thanks. Link to comment Share on other sites More sharing options...
Guest scumbag Posted February 18, 2018 Share Posted February 18, 2018 Not very DIY - more self assemble but this grabs my eye - https://diyaudiostore.com/products/amp-camp-amp-kit?variant=21206375620 Link to comment Share on other sites More sharing options...
Upfront Posted February 18, 2018 Share Posted February 18, 2018 Not very DIY - more self assemble but this grabs my eye - https://diyaudiostore.com/products/amp-camp-amp-kit?variant=21206375620 Built in and listening in an afternoon. Good fun. Link to comment Share on other sites More sharing options...
btd Posted February 19, 2018 Share Posted February 19, 2018 (edited) Built the base model a couple of weeks ago. After trying the various up grades, 24v, adding R15, up specking R12, adding larger heatsinks to cope with it all, it`s now all back to the base model. I did keep my home made heatsinks. Not large enough for the 24v model but more than enough for the 19v. I went back to the basic model as I could not justify the 40% increase in power for the increase in output. 5.13 watts against 6.36 watts. (that and don`t have any spare laptop power supplies) Added the B1 pre to keep it all in the Pass family. A very nice sounding little unit. Now I just have to build a box. Tony Edited February 19, 2018 by btd 4 Link to comment Share on other sites More sharing options...
Upfront Posted February 19, 2018 Share Posted February 19, 2018 Built the base model a couple of weeks ago. After trying the various up grades, 24v, adding R15, up specking R12, adding larger heatsinks to cope with it all, it`s now all back to the base model. I did keep my home made heatsinks. Not large enough for the 24v model but more than enough for the 19v. I went back to the basic model as I could not justify the 40% increase in power for the increase in output. 5.13 watts against 6.36 watts. (that and don`t have any spare laptop power supplies) Added the B1 pre to keep it all in the Pass family. A very nice sounding little unit. Now I just have to build a box. Tony Cool! Cases are always a pain in the bum. What speakers do you run with it Tony? Link to comment Share on other sites More sharing options...
btd Posted February 20, 2018 Share Posted February 20, 2018 10 hours ago, Upfront said: Cool! Cases are always a pain in the bum. What speakers do you run with it Tony? I don`t find the case building that hard, once I stop procrastinating over the style I want. The electronics is my downfall. If I did not follow the paint by numbers or dot to dot approach I would be lost. Speakers used are generally some old VAF DC7`s (93 db, series II I think). Though today I have had it driving some Infinity RS4B`s comparing it to some other amps. One day I want to try some DIY horns. Tony from the 1/2 dun shed. 1 Link to comment Share on other sites More sharing options...
nzlowie Posted February 20, 2018 Author Share Posted February 20, 2018 Ordered a couple of new cases today to put the ACA's in, the nice ones I built originally got way too hot as the heatsink wasn't efficient enough.Before fitting them I'm going to fit an extra cap on the input and lower the value of the output cap to effectively make a high pass filter so I can eliminate the coil and cap from my passive xover. Lowering the output cap also allows me to use a nice poly prop cap which should help sound quality as well.If this works as it should I'll do the same with the second pair of amps for the tweeters.Roll on the weekend. 1 Link to comment Share on other sites More sharing options...
Upfront Posted February 24, 2018 Share Posted February 24, 2018 I turned my gear on this morning and heard a pop. Turned out to be a psu from my ACA amp. Any suggestions for a new post supply for them? Mean well comes to mind. Or build a pair? Link to comment Share on other sites More sharing options...
Guest scumbag Posted February 24, 2018 Share Posted February 24, 2018 Would this suit?? https://www.allo.com/sparky/19v-power-supply.html I'm not sure what the PSU requirements are for your unit. I used one of these units on my NUC to replace the standard PSU. Link to comment Share on other sites More sharing options...
Upfront Posted February 24, 2018 Share Posted February 24, 2018 The originals supplied with the unit at 19v 2.4a so what you've suggested would work not a problem. Wondering if I should go to a 4a version. Pondering. Link to comment Share on other sites More sharing options...
Guest scumbag Posted February 24, 2018 Share Posted February 24, 2018 The Meanwell ones would probably be of comparable quality to the Allo one - and may have more options in regards to amperage. I guess having more headroom wouldn't hurt? Link to comment Share on other sites More sharing options...
Upfront Posted February 24, 2018 Share Posted February 24, 2018 The Meanwell ones would probably be of comparable quality to the Allo one - and may have more options in regards to amperage. I guess having more headroom wouldn't hurt? Headroom is exactly why I was thinking about making one. I have the regulators. Just need a transformer really.https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F323066636557 Link to comment Share on other sites More sharing options...
nzlowie Posted February 24, 2018 Author Share Posted February 24, 2018 The originals supplied with the unit at 19v 2.4a so what you've suggested would work not a problem. Wondering if I should go to a 4a version. Pondering. I've got a few spare Lenovo plug packs if you like I could send you a couple, these are 65w or 3.25 amp. 1 Link to comment Share on other sites More sharing options...
Upfront Posted February 24, 2018 Share Posted February 24, 2018 I've got a few spare Lenovo plug packs if you like I could send you a couple, these are 65w or 3.25 amp. Thamks mate. I'll send you a pm. Link to comment Share on other sites More sharing options...
mwhouston Posted February 25, 2018 Share Posted February 25, 2018 No need to say these SMPS are not intended for audio. They can be very noisy. Great to test out gear but may introduce hash into your system depending where they are used. Link to comment Share on other sites More sharing options...
nzlowie Posted February 25, 2018 Author Share Posted February 25, 2018 No need to say these SMPS are not intended for audio. They can be very noisy. Great to test out gear but may introduce hash into your system depending where they are used. Don't know about them being noisey, these are what I use and with the 114db horns they are dead quiet! 2 Link to comment Share on other sites More sharing options...
mloutfie Posted February 25, 2018 Share Posted February 25, 2018 On 18/02/2018 at 8:34 PM, scumbag said: Not very DIY - more self assemble but this grabs my eye - https://diyaudiostore.com/products/amp-camp-amp-kit?variant=21206375620 They're never in stock after the initial sale. I've been looking for an amp camp kit for a while now Link to comment Share on other sites More sharing options...
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