LC proposal regarding the GND and safety earth stuff schemes.
In your stereo cabinet with recommended 2xPSU you have nearly all bits and pieces for dual mono. So instead of stereo cabinets is there a chance a smaller footprint mono cabinet with PSU and amp x 2 will do the job with better sonics and GND+safety (one for left and one for right without touching each other). Same asked over your VSSA thread post #3284.
In your stereo cabinet with recommended 2xPSU you have nearly all bits and pieces for dual mono. So instead of stereo cabinets is there a chance a smaller footprint mono cabinet with PSU and amp x 2 will do the job with better sonics and GND+safety (one for left and one for right without touching each other). Same asked over your VSSA thread post #3284.
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Here is the grounding scheme as recommended for VSSA @ post 1700.
http://www.diyaudio.com/forums/vend...lateral-mosfet-amplifier-170.html#post3543127.
http://www.diyaudio.com/forums/vend...lateral-mosfet-amplifier-170.html#post3543127.
Somebody in this thread mentioned a nice DIY surfacemount preamp kit but I can't find it for the life of me.
I think LC mentioned this kit. I thought I had bookmarked it but no it seems not...
Anybody know the name of this DIY preamp kit I think LC suggested?
BTW what PSU solution are people going with?
I think LC mentioned this kit. I thought I had bookmarked it but no it seems not...
Anybody know the name of this DIY preamp kit I think LC suggested?
BTW what PSU solution are people going with?
Ooo yeah SQ will jump up hehe
Have you seen those thermally biased MOSFETs Morris Kesler is using in the new ATI current feedback piece IE AT6000 series?
I think the tradename on them is "Thermaltrak".
ON Semiconductor
NJL0281D NJL0302D NJL1302D NJL3281D
Audio Transistors
http://www.onsemi.com/pub_link/Collateral/NJL0281D-D.PDF
http://www.onsemi.com/pub_link/Collateral/NJL3281D-D.PDF
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For PSU I will try two of these (eBay ID 111351759002) as the price seems fair to give them a try. I also have a Coldamp PSU and an SMPS800. Both delivering approximately +/-60V. As a last resort I also have toroids, bridges and caps, but as suggested, best would be an SMPS. Will see...
Member supernet suggested he used a 10k pot directly from the output of the CD player, while Danny_66 suggested two different kits in post 305 as being better than PGA kits found on eBay as suggested by androa76 in post 302
LC recommended RelaiXed in post 634
I have some kits at hand, so I have some different choices to experiment with. As my brother will use LPs additional to CDs and computer files, I will implement probably something like 5x amplification before a 10k volume control.
Cheers!
Edgar, look very carefuly and compare it to stereo connection sch from First One user manual and you will see they are 100% the same.
As we experimented with GND wiring for best results, my advice is to remove all three green wires and connect only main GND pin from SMPS to earth bolt.
OK! New drawing. If I remove all 3 green wires from my first drawing, I also remove chassis earthing (chassis not connected to mains gnd). Is this your advice?
Hypex seems to recommend to disconnect mains earth, and employ double insulated construction techniques. Coldamp does not recommend this..
Attachments
In this present drawing chassis earthing is OK since earth bolt is connected to chassis and to mains earth. Also SMPS GND is connected to this bolt.
Still dual mono, one SMPS per channel, is better sounding solution.
Mostly SMPS1200A400, Hypex. Also chassis offered and ordered by many has predrilled fixation holes prepared for this SMPS.
Exactly.
Super, hardly wait to get some feedback.
Yes, nice SMD preamp, will be tested by me too, soon.
Two of these???
Hi Gianni
As promised no SMPS debate from me here anymore or at least for some time. There are millions SMPS out there, who knows of which kind of quality, so testing and comparing should be done prior any comments. For me the reference SMPS is well known, for any new type all testing procedure should be repeated all over again, for which I don't have time at the moment.
So please buy and compare otherwise one would never know what's in his hands. The same validates for me too.
Regards, L.C.
P.S. Also one major point of this thread is what I don't want to be missed - overlooked is that I want to set the level of sound quality of all assembled First One amplifiers, so the GB members would get the most out of their investments in exactly the same manner what we already have here.
Hi Gianni
As promised no SMPS debate from me here anymore or at least for some time. ---------------------
Regards, L.C.
P.S. Also one major point of this thread is what I don't want to be missed - overlooked is that I want to set the level of sound quality of all assembled First One amplifiers, so the GB members would get the most out of their investments in exactly the same manner what we already have here.
I agree with this - the alternative is to have a cat chasing his tail --[
]---and every variation from LC's advised standardised version having greater potential for trouble and consequent dissatisfaction.
.....P.S. Also one major point of this thread is what I don't want to be missed - overlooked is that I want to set the level of sound quality of all assembled First One amplifiers, so the GB members would get the most out of their investments in exactly the same manner what we already have here.
Good intensions LC and first step where you calibrate and quality test the modules before shipping fulfill the intension and impressing
. Next step must be to get as much buyers as possible to get recommended PSU's, wiring scheme setup and box/heatsink to control screening and termals is within reference.
Edit: brianco
A most honest attitude.P.S. Also one major point of this thread is what I don't want to be missed - overlooked is that I want to set the level of sound quality of all assembled First One amplifiers, so the GB members would get the most out of their investments in exactly the same manner what we already have here.