Full Range Posted July 5, 2016 Share Posted July 5, 2016 I popped in to Nigel's on the way to work this morning and had a look at the amplifier. It was not running at the time so I could drool over it without electrocuting myself. It's an excellent build and that is a fantastic enclosure. I'd be very interested to find out what it sounds like after it's been run in a bit. Mark Nigel normally runs my amp builds for a few days to make sure all the settings are correct and then puts them against his First Watt J2 and the other Pass Labs amps he has So you have a small window of listening to it before it's collected 1 Link to comment Share on other sites More sharing options...
Guest BobbyD Posted July 5, 2016 Share Posted July 5, 2016 Very nice build Nigel. I love the simplicity of design and layout and sure it will sound stunning as 25 W class A should. Looking forward to Pauls feedback...... Link to comment Share on other sites More sharing options...
Green Wagon Posted July 5, 2016 Author Share Posted July 5, 2016 Nigel normally runs my amp builds for a few days to make sure all the settings are correct and then puts them against his First Watt J2 and the other Pass Labs amps he has So you have a small window of listening to it before it's collected Yeah no. To much to do currently sorry. Link to comment Share on other sites More sharing options...
Guest scumbag Posted July 5, 2016 Share Posted July 5, 2016 Nigel, you need to start doing crap work, that way people won't get you to do projects like this and your windows will be much bigger I'm sure an opportunity will avail at some point in the future! Link to comment Share on other sites More sharing options...
Green Wagon Posted July 5, 2016 Author Share Posted July 5, 2016 More a combintaion of lots of stuff all hitting at the same time. And I'm getting old Link to comment Share on other sites More sharing options...
Full Range Posted March 16, 2017 Share Posted March 16, 2017 A quick update on this amp build Due to the 104db sensitivity of my system, it was discovered that one of the components was making the M2 hum The iron PCB transformers are very sensitive and noted by Nelson Pass but that's what makes this amp special and gives it that unique sound signature After trying a variety of earth schemes as it's normally the cause in such matters, it was eventualy discovered that my toroidal was not a good match with this amp even though it was high quality audio grade 500VA I ordered a custom made Noratel 240V - 300VA - 2 X 18 V with a flux ring seal from the local Australian distributor RF Waves After a month it arrived from the Noratel Factory in Europe That was 2 days ago Yesterday I fitted the new toroidal and after turn on - the hum was no more - gone in an instant Its now so quiet you would think the amp is not turned on So I will upload a few photos of the build for now, showing a few changes and additions for now and after a week or so I will revisit and post a review Also warm thanks to @Green Wagon for all the help and guidance 3 Link to comment Share on other sites More sharing options...
acg Posted March 16, 2017 Share Posted March 16, 2017 Damn hum. Link to comment Share on other sites More sharing options...
Full Range Posted March 16, 2017 Share Posted March 16, 2017 4 minutes ago, acg said: Damn hum. In the end it was a simple swap over of a component that in itself is of a high quality build The test that proved it was the toroidal, was to remove the first toroidal and connect it up again 1 mt away with extended leads I have really learnt a lot during this process and my internal knowledge base is always hungry for more @acg When are you coming to visit me 1 Link to comment Share on other sites More sharing options...
Full Range Posted March 16, 2017 Share Posted March 16, 2017 Oh I forgot this photo where it shows the M2s place in relation with the other amps and components M2 is the one with the blue power indicator light in the centre Sorry you can't see the Nakamichi Control amp Link to comment Share on other sites More sharing options...
Guest scumbag Posted March 16, 2017 Share Posted March 16, 2017 32 minutes ago, Full Range said: Oh I forgot this photo where it shows the M2s place in relation with the other amps and components M2 is the one with the blue power indicator light in the centre Sorry you can't see the Nakamichi Control amp A thing of imposing beauty. Link to comment Share on other sites More sharing options...
acg Posted March 16, 2017 Share Posted March 16, 2017 2 hours ago, Full Range said: In the end it was a simple swap over of a component that in itself is of a high quality build The test that proved it was the toroidal, was to remove the first toroidal and connect it up again 1 mt away with extended leads I have really learnt a lot during this process and my internal knowledge base is always hungry for more I fear that I will be chasing hum when I get my 6 channel amps built. The power supply is in a separate chassis altogether and the chokes for the active crossovers will be encased in very thick steel so they don't pickup hum from the AC heaters/filaments. Hopefully I will be able to sort it out easily enough if/when it happens...but I don't like any noise at all from my speakers. 2 hours ago, Full Range said: @acg When are you coming to visit me To be honest, I am just putting all my spare (and some not so spare) time into getting my project done. I really would like to come down the hill to meet you and have a listen to your horns...we will see...I just want to get some noise happening in my room first...maybe this winter I will get down to see you. 1 Link to comment Share on other sites More sharing options...
Full Range Posted March 16, 2017 Share Posted March 16, 2017 @acg I can help with a some very good, & some very demanding test tracks if you like Specifically chosen and compiled by me for horn systems 1 Link to comment Share on other sites More sharing options...
Full Range Posted March 24, 2017 Share Posted March 24, 2017 As promised I have come back to update the First Watt M2 Amplifier thread with a review Components used in this test Pre - Nakamichi CA5 II Source - Cyrus CD8 SE Garrard 401 Bluesound Node Medium - CD , Record & Digital sources Speakers - Klipsch La Scala ( Highly Modified ) Sensitivity min 104db Album - Pink Floyd - Dark Side Of The Moon My brutal mixed track test CD A variety of Records of all genres Warmed the M2 up for about 1 hour I have put the M2 through its paces sometimes returning to play again the same record or CD the next day for balance The M2 is extremely precise, but with a presentation that is more reserved with sharp targeted control that has an emphasis on instrument separation and vocal areas of the recording. In playback the M2's signature is warm at low to medium volume levels however its not holding anything back when the volume is increased. The M2 only gives the listener whats required from the recording to get the job done. Its very analytical and has excellent 3D presentation in high sensitivity speakers The M2 portrays the feeling and tempo of the music genre beautifully, by emphasizing a slightly more controlled and a warmer feel coupled with a wider presentation Extremely sharp on changing passages but with a little more warmth, prat is still there in abundance with enough volume Treble - Is very clean and clear with lots of hang time and controls the full spectrum until it trails off Midrange - Is where the M2 shines and it shines on vocals and softer instrumental passages, beautiful separation but also precisely knitting together congested and melding sounds togetherBass - Abundant but with a little less thump than my F6 on the other hand the M2 has more control through the whole range Summary Warm without losing any prat with knife sharp instrument separation Good with all genres I listened to Add volume and you would think a larger amp was driving this system 4 Link to comment Share on other sites More sharing options...
tcressida Posted April 3, 2017 Share Posted April 3, 2017 DIY just like home cooking u can use the best ingredients, nice job n looking good too . 1 Link to comment Share on other sites More sharing options...
Guest scumbag Posted April 3, 2017 Share Posted April 3, 2017 2 minutes ago, tcressida said: DIY just like home cooking u can use the best ingredients, nice job n looking good too . You can be assured that Paul only uses the best and freshest ingredients. Link to comment Share on other sites More sharing options...
Full Range Posted April 3, 2017 Share Posted April 3, 2017 I have found that you must look at any build in a holistic way and above all try and see components working as a team Building and tweaking crossovers has given me an appreciation and understanding that both capacitors and resistors have a sound signature getting this combination right can achieve nirvana in an audio component The M2 is a lovely amp So much so that I end up turning on the system and start listening to something on a daily basis Link to comment Share on other sites More sharing options...
dewdrop Posted May 17, 2018 Share Posted May 17, 2018 On 01/06/2016 at 7:33 PM, Green Wagon said: Before we start, I would like to say, Many thanks to Nelson Pass for his generosity in freely sharing his designs with the world. I also need to thank 'Tea-bag' from diyaudio for his time and effort in designing and making available the boards seen here. Ok this is no where near complete. But I think the owner is wanting to see some pics displayed. Expect gradual updates. Eventually. SO. Paul has been bitten by the Pass bug. Bought a second hand Decky F5, Got me to change it to an F6, And has now decided he wants a fresh M2. After much discussion, the plan was enacted, parts were ordered, parts have arrived, parts are being assembled. I present the pics below as a 'work in progress'. Just a few boxes of parts. And some of those boxes contain several deliveries. Not all of the parts, just enough to get started on the various boards. Selected positions will use Audio Note Tantalum Non-magnetic resistors. Boards for the actual Amp modules. Boards for the power supply section. CRC filter fed by fast diodes with snubber caps. Underside, populated, cleaned, ready to go. Top side. Mounted onto the heatsinks. Neat trick from a gent on diyaudio. Using smaller TO220 heatsinks as a way of spreading the mounting screw pressure across the transistor. Also happens to give a tiny bit of heatsinking to the top side of the output transistors Although not needed, I've 'thermally coupled' the input jfets for fun. In this design they are acting as input buffers only. Amp module and heatsink assembly ready for assembly into a case. Back panel. Inside the floor of the case is a sub floor. Yeah this shall be a BIG amplifier. 5 Rack unit. EDIT 1. 2-6-2016 Front panel now has the power switch. Back panel, I wasn't happy with the speaker terminals being so damn close together.(Pre punched panel) Quick chat with owner, New holes to move the outer terminals and we'll find some blanks to fill the holes. Just waiting for the transformer before I decide how to position the rectifier and filter boards. Then the wire up can commence.. Stay tuned................... EDIT 2. 30-6-2016 Ya, Ve now have transfoomer frum Germaany. Build can resume... Is Goot, Has nice solid plastic foot. Shall keep windings raised of floor for air flow and extra insulation. Ya, 500 of them VA's just for fun. Now I can haz sort out interior placement and stuff like. Filter board placed, drilled, screwed down. Transformer positioned, bolt hole drilled (need to get bolt). Rectifiers positioned but I will make a little plate for them to sit on to make sure they get proper heat transfer to the bottom plate. Looking at the build of this transformer, I'm impressed. It's really bloody nice. It's a Sedlbauer 'Sealed' from it_tronics on ebay. 'Sealed' means it handles higher temps (60 ambient vs normal 40 ambient), has 1250 self resetting thermal breakers in the primaries, and has the potted core. For $161 to my door from Germany in a week, well, You'd have to be nuttier than squirrel poo not to short list this beast. EDIT 5-7-2016 So close I pulled several midnight shifts to get her done. Time of birth 10 am 5-7-2016. Actually It was fired up last night about 10pm, but first up was a slow variac rise for testing (no smoke:D ) But I did need to swap out one resistor on both boards to 'center' the dc offset. Once that was done it was time to let it stablise, offset is now under 3mv. Both channels are so close you'd think they were matched. So far the massive heatsinks are doing their job very nicely. Just over luke warm so far. Some final pics. And No, I won't tell you what it sounds like. It's fresh and needs some serious break in. I'll let Paul give his impressions as he finds them..... Hi Nigel, Could you share your BOM list used to build the M2? I need some help especially on the PSU parts. TIA. Link to comment Share on other sites More sharing options...
Full Range Posted May 17, 2018 Share Posted May 17, 2018 46 minutes ago, dewdrop said: Hi Nigel, Could you share your BOM list used to build the M2? I need some help especially on the PSU parts. TIA. Here is the BOM But this is based on the design and boards supplied by Tea Bag Links available on his Group buy area along with build instructions Link to comment Share on other sites More sharing options...
Full Range Posted May 17, 2018 Share Posted May 17, 2018 @dewdrop For the M2 BOM Link - https://docs.google.com/spreadsheets/d/1ZZavX5UjpKlB7kEhH9YMSXkL0s0l0HVg6NHbedx5RN8/htmlview Thread link for the group buy and other relevant links to build Tea Bags design ect http://www.diyaudio.com/forums/group-buys/286699-gb-pass-m2-clone-boards-120mm-ums-spacing-tea-bag.html 1 Link to comment Share on other sites More sharing options...
dewdrop Posted May 18, 2018 Share Posted May 18, 2018 Thanks Nigel, I have downloaded the BOM list but I do not have the power supply cap details - hence I wanted to just get whatever you did. Link to comment Share on other sites More sharing options...
Full Range Posted May 18, 2018 Share Posted May 18, 2018 7 hours ago, dewdrop said: Thanks I have downloaded the BOM list but I do not have the power supply cap details - hence I wanted to just get whatever you did. The details are on the link I posted - you need to read the details a couple of times The BOM is located at the bottom But here is the link to the PSU section - http://www.diyaudio.com/archive/blogs/tea-bag/923-dual-rail-power-supply-power-amplifier.html Link to comment Share on other sites More sharing options...
dewdrop Posted May 19, 2018 Share Posted May 19, 2018 Thanks Nigel. I read at the top of Teabag's blog that it is meant for F5T and F6 designs, means that the capacitance for the former is more. I know that I can always opt for the same for M2 but it will also mean my inrush current will increase and result in side effects. Link to comment Share on other sites More sharing options...
Full Range Posted May 19, 2018 Share Posted May 19, 2018 8 minutes ago, dewdrop said: Thanks. I read at the top of Teabag's blog that it is meant for F5T and F6 designs, means that the capacitance for the former is more. I know that I can always opt for the same for M2 but it will also mean my inrush current will increase and result in side effects. Note - I am not Nigel I am the fellow builder and the owner of the amp We opted for larger 27000uF caps (as per photo) over the recommended 22000uF I went through the BOM and discussed with Nigel the critical areas of the signal path and opted for specific changes in brand & materials of some components Using Harris/Vishay Transistors and Audio-note non magnetic resistors in R1,R2,R3,R4 Paul Link to comment Share on other sites More sharing options...
dewdrop Posted May 19, 2018 Share Posted May 19, 2018 (edited) Apologies Paul! Thanks for the photos, much appreciated! I will love to put the AN tantalum resistors per your recommendation. Edited May 19, 2018 by dewdrop Link to comment Share on other sites More sharing options...
Full Range Posted May 19, 2018 Share Posted May 19, 2018 8 minutes ago, dewdrop said: Apologies Paul! Thanks for the photos, much appreciated! I will love to put the AN tantalum resistors per your recommendation. Above all Make sure as it’s very critical the Jfets you purchase are matched pairs Link to comment Share on other sites More sharing options...
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