Yep. I made some improvements in the input section, which lowered the noise and THD+N by about 2 dB. I also improved the 1+5.5 kHz IMD at 1 W.
As I pointed out in my most recent newsletter, the sale pricing will go away once I have modules in stock. My current estimate for when that will happen is on November 18. It could be a few days before or a few days after.
The sale is my reward to those who are willing to support me by helping to put a dent in the rather large credit card bill before it comes due.
If you're on the fence, you may want to get off the fence and onto a computer to place your order. 🙂
Also note that since you're in Canada, I can take payment via eTransfer in CAD at the current exchange rate. That'll save you a 3-4% exchange fee, plus you get a better exchange rate. Just toss me an email if that has your interest. You can do that through the Contact Us form on my website or by adding @neurochrome.com to my user ID here.
That should give you about ±24 V rectified, which will give you 100 W into 8 Ω give/take. The 3U x 300 mm Dissipante or Mini Dissipante from ModuShop would be a good chassis for such an amp.
I also recommend using the Intelligent Soft Start (ISS). The ISS limits the inrush of the transformers, which extends the service life of your transformers and also prevents nuisance blows of the mains fuse. The ISS is currently on intro sale. Same deal as with the MOD686: Sale will end when boards arrive in stock (by early December in case of the ISS).
Yep. That should work well.
I originally went with connectors on the MOD686 because people requested them. They were tired of connecting/disconnecting the screw terminals during prototyping. But, humans being humans, the first question after I changed to connectors is, "why didn't you use screw terminals?" I can't make everybody happy all the time I guess. 🙂
Tom
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Tom,
What are the dimensions of the 686 board,please? I can't see that on your webpage........but that might just me being obtuse.
cheers
t
What are the dimensions of the 686 board,please? I can't see that on your webpage........but that might just me being obtuse.
cheers
t
Spring-cage, not screw terminals. https://www.phoenixcontact.com/onli..._P-15-03/c252a030-3764-4828-a692-d0ba1dd45a27
https://www.phoenixcontact.com/onli...Rsk5-d_QPMnfBo/#Z7_82KCHG41MGCF90QL9V1UF79NV5
What confuses me, though, is if people were tired of using screw terminals during prototyping, what else were they going to use? Re-soldering? Wire nuts???
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On the website it says:
Dimensions: 212 × 65 × 40 mm W × D × H
That's probably for the complete module, so the PCB should be close to 212 x 65 mm.
Alligator clips
https://www.amazon.ca/WGGE-WG-026-P...ocphy=9000792&hvtargid=pla-568154706689&psc=1
Built in fusing
Well, they wanted connectors so they could plug/unplug a few times during the build. I don't know if people build on a piece of plywood first and then move the amp to a chassis. Any other amplifier module on the market uses connectors. I'm sure OEMs prefer them as well. Recall, I'm not marketing exclusively to DIYers.
If you really really don't want the connectors, you can always solder wire directly to the bottom of the PCB. I don't recommend trying to remove the connectors as you'll likely destroy the PCB in the process.
Tom
Tom, how does the rev 1.1 measure up against the benchmark amp? Have you taken the numbers crown back?
Tom, I signed up for your newsletter months ago but I've never received a newsletter.
Been listening to my Mod-686 for the past week and added in your 8x2 pre yesterday - hopefully get time to do a write up this week on my thoughts!
Been listening to my Mod-686 for the past week and added in your 8x2 pre yesterday - hopefully get time to do a write up this week on my thoughts!
I have a single ended pre I'd like to try with the Modulus 686. Is there any benefit to use Tom's Universal Buffer between the pre and the 686 to go from single ended to balanced rather than to just use a single-ended to pseudo differential cable?
We're neck-and-neck. The AHB-2 is lower noise. The 686 provides higher output power than each channel in the AHB-2. Benchmark doesn't specify IMD of any kind for the AHB-2.
That's odd. Try signing up again and/or checking your spam folder.
You can sign up for my newsletter here: Neurochrome Newsletter
Traditionally I've averaged a newsletter every two months, so I won't drown you in spam.
Tom
Can you point me to a specific product data sheet from this category? I am unable to see specific specs anywhere -- I'm probably not familiar with their product organisation sitemap.
Are you referring to this one? 1700053 | Phoenix Contact, FRONT 2.5-V/SA10 5mm Pitch, 1 Way PCB Terminal Strip | RS Components
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Oh, I see what the problem is. The product filters are not persistent through the site URL, so even after I filter for spring-cage connections the link doesn't give the right search results.
Here are a few examples:
https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=1904558&library=usen&tab=1
https://www.mouser.ca/ProductDetail/Phoenix-Contact/1904558?qs=71zq8cT40IRQNJUy17xiUQ==
https://www.phoenixcontact.com/online/portal/ca?uri=pxc-oc-itemdetail:pid=1933998&library=caen&tab=1
https://www.mouser.ca/ProductDetail/Phoenix-Contact/1933998?qs=6i0QExrCb7MiXKwjl/FnoQ==
If you search for product series ZFKDSA on Mouser you should get the results you're interested in. Wago also makes these, and as a matter of fact, I believe they are the ones who invented this style of terminal connector (they call it "CAGE CLAMP").
Here are a few examples:
https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=1904558&library=usen&tab=1
https://www.mouser.ca/ProductDetail/Phoenix-Contact/1904558?qs=71zq8cT40IRQNJUy17xiUQ==
https://www.phoenixcontact.com/online/portal/ca?uri=pxc-oc-itemdetail:pid=1933998&library=caen&tab=1
https://www.mouser.ca/ProductDetail/Phoenix-Contact/1933998?qs=6i0QExrCb7MiXKwjl/FnoQ==
If you search for product series ZFKDSA on Mouser you should get the results you're interested in. Wago also makes these, and as a matter of fact, I believe they are the ones who invented this style of terminal connector (they call it "CAGE CLAMP").
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No worries. The TDPT series is similar, but they use a "push-in" connection instead of a "spring-cage" connection. I think the only difference is that the push-in connection requires solid wires, or pin terminals/wire ferrules on your wire, whereas spring-cage terminals will accept bare stranded wire.
1017503 Phoenix Contact | Mouser Canada
https://www.phoenixcontact.com/onli..._P-15-02/868cc764-43df-41cb-9e7d-c2429d2efe8c
I've used my amps with both a pseudo-differential cable and with XLR cables. I don't perceive any differences as long as the cables are short. Some (fewer than 1% I think) have had issues with hum when using pseudo-differential connections. That hum has gone away when converting to balanced signalling.
I think a lot depends on the complexity of the overall system. Stereo builds rarely have issues. Multi-channel builds seem to attract more issues, maybe because you get many more opportunities for ground loops.
Tom
That is the reason that I've gone balanced. There is ten channels feeding my Linkwitz LX521.4's. Four amps in each of two boxes and two amps in a third. Feeding that lot from an active crossover single ended was a recipe for hunt the hum. So went balanced from the get go. And have had no problems - plug it together and away you go.
Craig
Craig
After several months of delay and waiting, I'm getting some of the parts for my stereo power amp build. Will take me a few more months to get the rest. The Modulus-686 modules have been in Bangalore for a few months now. I intend to drive down and get them when the world normalises somewhat.
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Attached the wrong transformer image. This is the right one. Double primaries.
Heatsinks are 40cm long, 17.5cm tall, and 33mm deep from base surface to tips of fins.
Heatsinks are 40cm long, 17.5cm tall, and 33mm deep from base surface to tips of fins.
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