Nice build indeed, a small bandsaw is a safer way of cutting alloy though.
I even use whatever wood cutting blade is on. An edge sander cleans the cut edges nicely and an orbital sander gives a nice finish to larger flat faces if they get marked.
I spray a clear lacquer after to prevent oxidation.
I even use whatever wood cutting blade is on. An edge sander cleans the cut edges nicely and an orbital sander gives a nice finish to larger flat faces if they get marked.
I spray a clear lacquer after to prevent oxidation.
Yeah. I suppose some heat shrink on the mains connections would be nice. However, once the amp is boxed up, it's not like you can get your fingers on the QC connectors.
The SpeakON connectors have little plastic 'walls' between the terminals. You'd have to work hard to get the terminals to short.
Or a table saw. Unfortunately, not everybody (me included) has a full-featured machine shop. I do like to see that the workpiece was properly clamped for the cutting, though.
I cut 6061-T6 aluminum with a chop saw all the time. I use a metal-cutting blade for non-ferrous metals. I think it's a 100 or 120-tooth blade (TCG tooth profile).
Tom
I want to start to thank you for your inputs.
I planned to use non-insulated female blade crimp terminals to use with heat-shrink tubing but was unable to find it in the city where i live. I might change that harness next time i order parts from France.
I use Neutrik NL Faston to connect the speaker cable to SpeakOn.
With the locking function on the NL Faston it would be hard to disconnect the cable from the SpeakOn if desired with heat-shrink tubing covering the Faston. I don’t see how the terminals could get shorted without being deliberately pushed on.
I use this cutting blade specially made for aluminum in my saw and I clamp down the the aluminum really well. I don’t have a bandsaw.
Makita Sagklinga 260mm 100T (Aluminium)
Klas
I planned to use non-insulated female blade crimp terminals to use with heat-shrink tubing but was unable to find it in the city where i live. I might change that harness next time i order parts from France.
I use Neutrik NL Faston to connect the speaker cable to SpeakOn.
With the locking function on the NL Faston it would be hard to disconnect the cable from the SpeakOn if desired with heat-shrink tubing covering the Faston. I don’t see how the terminals could get shorted without being deliberately pushed on.
I use this cutting blade specially made for aluminum in my saw and I clamp down the the aluminum really well. I don’t have a bandsaw.
Makita Sagklinga 260mm 100T (Aluminium)
Klas
I tried the Mod 86 hooked up to my living room system to get an idea of the sound and to decide if I wanted to build a new housing for it or just reuse the one serving duty for the amp that is there now. I just had the amp boards clamped to heat sinks and SMPS-86 laying on a piece of plastic all wired up. After that test I can use some advice. Music played fine and it sounded very detailed however when I got close to the speaker I could hear hiss. Loud enough that during low volume quiet evening listening it would be annoying. I am using the amp with single-ended RCA inputs. Hiss was from both speakers. The amp I am using now is silent. The only change I made was the Mod 86 and a longer RCA cable, all other components were the same (music server, DAC, pre-amp, speakers).
I suspect of course the source of problem is the fact that I did not have a proper case and wires were just laying about. As I build a new case for this what do I need to be careful of to make this amp as quiet as possible? I do have a form factor limitation of 8" x 8" x 4" and the single-ended input, Given that what should I do to ensure this amp is silent in operation?
I suspect of course the source of problem is the fact that I did not have a proper case and wires were just laying about. As I build a new case for this what do I need to be careful of to make this amp as quiet as possible? I do have a form factor limitation of 8" x 8" x 4" and the single-ended input, Given that what should I do to ensure this amp is silent in operation?
The most bare bones amp I've built in recent times had two LM3886DR modules and an SMPS-86 on a piece of aluminum sheet with a heat sink along one edge. It was dead quiet in use. I don't recall doing anything other than connecting the IEC mains protective earth to the aluminum sheet.
That said, if your speakers are very sensitive (say mid 90s dB SPL @ 1 W or above) you may hear a faint hiss if you jam your head into the speaker. I haven't heard of any issues with hiss in actual use, even with high-efficiency drivers.
You can always try to short the inputs to the amp. If you still hear hiss, the noise is from the amp. If the hiss is gone, the noise comes from the source connected to the amp.
Tom
That said, if your speakers are very sensitive (say mid 90s dB SPL @ 1 W or above) you may hear a faint hiss if you jam your head into the speaker. I haven't heard of any issues with hiss in actual use, even with high-efficiency drivers.
You can always try to short the inputs to the amp. If you still hear hiss, the noise is from the amp. If the hiss is gone, the noise comes from the source connected to the amp.
Tom
The speakers I first tried are 88db Fostex ff105wk fullrange. I just tried the amp on the test bench with inputs shorted hooked up to some old Optimus Pro-X7 speakers which I think have about the same sensitivity as the Fostex. Woofer silent but if I put my ear up to the tweeter I do hear hiss. It's faint but audible. Would you expect it to improve once everything is grounded to a case? Right now it is sitting on a piece of plastic.
Thanks Panelhead. I will proceed forward. I have full faith that the Modulus 86 when properly built is fantastically quiet. It's the properly built part that concerns me and I want to catch any errors before I get it in a case where it is harder to correct any issues.
Since you hear hear noise on both channels it is unlikely it is construction error.
I've had builders with compression drivers (100+ dB/W*m efficient) use Modulus-86 with good results, so yeah... They should be quiet.
If you get 10 V out for 1 V in (20 Hz - 20 kHz), undistorted, and you have a low DC offset (typically around ±100 µV if you clean off the flux; ±5 mV if you don't), then the amp modules are working.
Tom
If you get 10 V out for 1 V in (20 Hz - 20 kHz), undistorted, and you have a low DC offset (typically around ±100 µV if you clean off the flux; ±5 mV if you don't), then the amp modules are working.
Tom
Hi dear friend;
Isole days work my mod86...
*İnnner speaker and signal cables are furutech alpha series OCC copper.
*WBT and Neutrik connectors
*Elecaudio OCC copper all power lines
*hammond transformers
*main filters soft start and speaker delay..
*modushop hifi2000 3U case
Thanks Tom...
[/url][/IMG]
[url=https://hizliresim.com/mu725B]
[IMG]https://i.hizliresim.com/mu725B.jpg[/url][/IMG]
[/url][/IMG]
Isole days work my mod86...
*İnnner speaker and signal cables are furutech alpha series OCC copper.
*WBT and Neutrik connectors
*Elecaudio OCC copper all power lines
*hammond transformers
*main filters soft start and speaker delay..
*modushop hifi2000 3U case
Thanks Tom...
[url=https://hizliresim.com/mu725B]
[IMG]https://i.hizliresim.com/mu725B.jpg[/url][/IMG]
Very nice build. Thank you for sharing. The heat sinks are nice and large - and aligned with the vent holes in the bottom. I also appreciate that you covered the mains connections with heat shrink. Nice job on the inductors too!
The "transformers up front" layout is a little unusual (at least judging by the chip amp gallery thread), but I think it works out really well here. The mains/primary wiring is kept as far away from the audio circuits as possible, and there's good spacing between the secondary wiring and the rest of the amp. Excellent!
Which output terminals are those?
Tom
The "transformers up front" layout is a little unusual (at least judging by the chip amp gallery thread), but I think it works out really well here. The mains/primary wiring is kept as far away from the audio circuits as possible, and there's good spacing between the secondary wiring and the rest of the amp. Excellent!
Which output terminals are those?
Tom
My binding posts WBT-0703 Cu Binding Posts
So I ended up re-purposing the case I made for my ACA to house the Mod 86, plenty of heat sink I think (0.5 C/W per side). Full commitment since that was my main amp so no music till I got it going. It was a little harder to bolt in than I first imagined but with a little fab work everything fit. I used the SMPS-86 as a power supply with the thought that if the ACA and it's 8 watts were doing ok the 28 watt Mod 86 would be fine.
With everything in the case and connected up the amp is nice and quite. I am using it with single-ended inputs fed by an AKSA Lender pre with 9db of gain. I built the Mod 86 with the THAT1206 for 14db of gain knowing I would use it in combination with a pre that had some gain also. Speakers are Fostex FF105WKs in a Planet 10 designed box supplemented by a sub.
Early on for real listening impressions but so far it is sounding excellent. I am not much for audiophile language and it would seem wrong to go there with such a simple system but 2 things did stand out (besides running MUCH cooler). The center image is more defined when it should be. Really seems to lock into a single point when the mix calls for that. Second music has a sharper edge, not in a bad way, just cleaner at the beginning and end of notes. However I think the best thing I could say is that as much as I would try to focus on hearing changes from the previous amp I would mostly just end up lost in the music, which is ultimately the goal.
Next on the table is the HP-2. I am going to build it as a Pre/HPA to feed the Mod 86 as well as my Meze Classics. That will be my reference for a precision setup to compare as I have fun in this DIY scene.
Thanks Tom for making this amp available for DIY along with your fantastic documentation and support. Great fun!
With everything in the case and connected up the amp is nice and quite. I am using it with single-ended inputs fed by an AKSA Lender pre with 9db of gain. I built the Mod 86 with the THAT1206 for 14db of gain knowing I would use it in combination with a pre that had some gain also. Speakers are Fostex FF105WKs in a Planet 10 designed box supplemented by a sub.
Early on for real listening impressions but so far it is sounding excellent. I am not much for audiophile language and it would seem wrong to go there with such a simple system but 2 things did stand out (besides running MUCH cooler). The center image is more defined when it should be. Really seems to lock into a single point when the mix calls for that. Second music has a sharper edge, not in a bad way, just cleaner at the beginning and end of notes. However I think the best thing I could say is that as much as I would try to focus on hearing changes from the previous amp I would mostly just end up lost in the music, which is ultimately the goal.
Next on the table is the HP-2. I am going to build it as a Pre/HPA to feed the Mod 86 as well as my Meze Classics. That will be my reference for a precision setup to compare as I have fun in this DIY scene.
Thanks Tom for making this amp available for DIY along with your fantastic documentation and support. Great fun!
Attachments
That's a nice and compact build there. At first I thought it was a standard ModuShop chassis, but it looks like you used two ModuShop heat sinks and added your own front and rear pieces.
It looks like you AC coupled the input. I would suggest adding a little heat shrink so the input connection doesn't short to the mezzanine plate.
I like the setup with the mezzanine plate. I did something similar for my Modulus-286 Kit (LE). I really like the compact look. Nicely done.
Tom
It looks like you AC coupled the input. I would suggest adding a little heat shrink so the input connection doesn't short to the mezzanine plate.
I like the setup with the mezzanine plate. I did something similar for my Modulus-286 Kit (LE). I really like the compact look. Nicely done.
Tom
Yep just started with the Modushop heat sinks and built the rest around it. I wanted something different from a standard box that would integrate with the rest of the living room decor. The caps (.02 uF total) on the input are to provide some low freq roll off to give my speakers a little relief below 130Hz. Thank you, good advice on the heat shrink, I'll put some on for insurance.