Thanks for very kind report Rick. The amp R&D phase was so long it has to have some qualities hehe
Enjoy, L.C.
heeeee Redjr, I am following this very active "lazy cat" for a while now.....and his first one is moving up to the first place, in my short list. But I know (yeah big brother is watching you..hihihihi) that you finished building the PA03 recently. I finished mine just a week ago. Sooooo
here comes the question: (and I know that you already mentioned it), but can you tell a little more about the differences you experienced. Many thanks in advance. Daanm.
I have a 2x40AC 800VA toroidal transformer,which is ok i think atleast as a starting point for this amplifier.Also have a 3U case,which measurements are W 406mmxH 133mmxD 250mm.Looking a heatsinks for this case.
These are maybe best option,which i found.
SK56/100/SA FISCHER ELEKTRONIK - Heatsink: extruded | TME - Electronic components
Other choice is Dissipante03/300N 3U case,which about 70€ more than first choice after the taxes and postage.
Any opinions or choices for the heatsinks or case?
These are maybe best option,which i found.
SK56/100/SA FISCHER ELEKTRONIK - Heatsink: extruded | TME - Electronic components
Other choice is Dissipante03/300N 3U case,which about 70€ more than first choice after the taxes and postage.
Any opinions or choices for the heatsinks or case?
Hi, LazyCat.
Do-you think a SMPS1200A400 could be large enough to drive two M modules in a 2 ways active speaker (crossover ~1-2 KHz) ?
Thanks.
Welcome aboard.
Press57, I have been researching the same thing. I have got a lot of help on this thread. So, if You have not already, go back in this thread about 4 pages and You can get some information that may help You choose a case for your situation.
I think the case You have could work, but You would need to find a way to mount the heatsinks outside (for best air flow). You can mount the heatsinks inside, but You may need fans to help with airflow, depending on where your amp will be.
I hope this helps
Press57, I have been researching the same thing. I have got a lot of help on this thread. So, if You have not already, go back in this thread about 4 pages and You can get some information that may help You choose a case for your situation.
I think the case You have could work, but You would need to find a way to mount the heatsinks outside (for best air flow). You can mount the heatsinks inside, but You may need fans to help with airflow, depending on where your amp will be.
I hope this helps
Thanks, fluid
And the awesome drawing! I would have never known about those steel rails, if You had not mentioned it.
I have found the Chinese Vender many of You have been using, he seems to have some nice heatsinks, if I wanted to fabricate my own chassis. I am leary of the importing fees, as products from China can have duties up to 27%.
redjr, You have ordered these, what were your fees?
I am leaning towards the Dissipante 2U 300 with All Aluminum. As the SMPS has their own thick metal shield underneath, I am not sure if I need the inner base plate, still thinking on that one. I do not want to go too small and make it a nightmare to wire this amp up!
And the awesome drawing! I would have never known about those steel rails, if You had not mentioned it.
I have found the Chinese Vender many of You have been using, he seems to have some nice heatsinks, if I wanted to fabricate my own chassis. I am leary of the importing fees, as products from China can have duties up to 27%.
redjr, You have ordered these, what were your fees?
I am leaning towards the Dissipante 2U 300 with All Aluminum. As the SMPS has their own thick metal shield underneath, I am not sure if I need the inner base plate, still thinking on that one. I do not want to go too small and make it a nightmare to wire this amp up!
3U chassis is simply too high, 2U would be better choice, just watch for the heatsink to be 0,5 K/W or less. If the whole chassis is made from Al, than all panel's surface will be inside Rth equation too, helping dissipate excessive heat.
Your mains transformer is OK, but I do allways prefer to have lower power but separate PSU for each channel - dual mono amplifier.
When amp is in a position to grip drivers directly there's no better choice to make a speaker, you get very easy load, extra dB of sensitivity and playing with electronic active crossover, whether analog or DSP, is a lot more fun. So yes SMPS1200A400 would be sufficient, if not, you could add one more in no time.
Well, there is pro and con, don't you think ?
The pro is it reduces the problems of ground loops. The con, the stereo image stability during transients ?
I'm used to CFA, with poor PSRR. So, the con was an important criteria. With a CFA with good filtering on VAS and input stages, the con does not matters any more ?
Just stay a little advantage, when an instrument is located only at a side of the stereo landscape, left or right, it will beneficiate of double caps value with a single PSU with double power than two monos.
Both should be the same, so trimm TR3 CW on the one with lower temp. Make half a turn CW each time and wait it stabilizes, proceed until heatsink reaches 35°C.
I didn't find imaging problems with dual mono, on contrary it was always better than single PSU version. We even make complete GND isolation from the chassis and between channels, so called GND lift, to get best stereo imaging. So more isolation between channels and GND by using dual mono with GND lift, the better, brings most out of it. I'm sure you'll try some day.
Don't be fooled it's just our caprice from experimenting point of view, no, it's perfectly scientifically justified.
Let's assume you are in a case where you don't need the full power of the modules (say 1 to 10W continuous), I mean other than on short music impulses where you indded need some current reserves to feed, say, real life 3-4 Ohm speakers, and given the SMPS seems good at storing lot of energy for short impulses.
Is there then any real benefit of going the cost of 2 SMPS with the First One?
Where does the second SMPS really makes a difference in real life? Is it all the time even at a few watts that it sounds better (elthough I would have though at that stage there is no vltage drop and a single SMPS might even be more equal for 2 channels), or only if you constantly need over 100W continuous with some bursts on top of it, eg very loud playing or driving very difficult loads?
I Struggle to understand the benefits of the 2nd SMPS in applications where current is needed on short bursts only - I know for example that in that specific case 2 SMPS are overkill when working with a class D amps due to the way they work together, I wonder if it is the same here.
I wouldn't want to compromise the music quality for an extra SMPS of course, but if there are some applications where the second SMPS doesn't have any real added value it could IMHO be good to point it as the SMPS are fare more costly than the First One.
Claude... thinking loud
Is there then any real benefit of going the cost of 2 SMPS with the First One?
Where does the second SMPS really makes a difference in real life? Is it all the time even at a few watts that it sounds better (elthough I would have though at that stage there is no vltage drop and a single SMPS might even be more equal for 2 channels), or only if you constantly need over 100W continuous with some bursts on top of it, eg very loud playing or driving very difficult loads?
I Struggle to understand the benefits of the 2nd SMPS in applications where current is needed on short bursts only - I know for example that in that specific case 2 SMPS are overkill when working with a class D amps due to the way they work together, I wonder if it is the same here.
I wouldn't want to compromise the music quality for an extra SMPS of course, but if there are some applications where the second SMPS doesn't have any real added value it could IMHO be good to point it as the SMPS are fare more costly than the First One.
Claude... thinking loud
Press57, I have been researching the same thing. I have got a lot of help on this thread. So, if You have not already, go back in this thread about 4 pages and You can get some information that may help You choose a case for your situation.
I think the case You have could work, but You would need to find a way to mount the heatsinks outside (for best air flow). You can mount the heatsinks inside, but You may need fans to help with airflow, depending on where your amp will be.
I hope this helps
Thanks,yes i have been followimg this thread and got an idea to use that old case.I can "maybe" mount the heatsinks outside,but i´am now more leaning to get the Dissipante case,because the heatsinks are not same size as the case sides and a price difference is not so much.
Thanks.Yes 2U is adequate,but i maybe however get the 3U just in case for a possible later use.I´m not also sure about,how my power supply will work.I have this or almost same power supply from Connexelectronic it´s with six Nippon Chemi-Con KMH 10000Uf 100V caps.
hypex power supply
Hi
For using the hyepx power supplies with the FirstOne amp, do we need the Cable set from hypex? for example https://www.hypexshop.com/DetailServlet?detailID=3900 OR https://www.hypexshop.com/DetailServlet?detailID=4227 based on the power supply?
How are you connecting the amp and power supply?
Thanks
Ani
Hi
For using the hyepx power supplies with the FirstOne amp, do we need the Cable set from hypex? for example https://www.hypexshop.com/DetailServlet?detailID=3900 OR https://www.hypexshop.com/DetailServlet?detailID=4227 based on the power supply?
How are you connecting the amp and power supply?
Thanks
Ani
If we can see the technical benefit, concerning noise and ground loop on this point, we don't, concerning stereo image.
My point was simple: If an amp has his gain affected by the power rails variations during transients, both will be affected in the same way if we use an unique PSU for both amps and the image will remain stable.
This said, when a rail variation occurs, each amp have to compensate-it immediately via its feedback. Less parasitic signal in the feedback signal (errors to be compensated) better it is.
Remain a pure financial aspect: As the Hypex SMPS is twice the price of each module, it is very expensive, as many of us are used to balance the price of the PSU VS the one of the amplifier itself. Well, if we add the price of the heat sink to the one of the module ;-)
Btw: I'm very surprised by the poor documentation of the Hypex SMPS: No datas about noise and ripples, both AC and switching frequency leaks...