Mikett said:
Mike,
Problems,
1/ the ALW' site schematic is not the same as the AOS ones. That bom can not be used with the aos boards.
2/ ESP project P06 the schematic show different pin layouts between OPA637 and NE5532 I don't think OPA637 can be just a drop in with the P06 pcbs.
Back to the drawing board...
The Butcher
Yes, you're quite right the ALW has an extra transistor in there for alittle tweak. The BOM is still largely the same though. His chart of substitutions will come in handy.
As for the 627/637 I thought initially that they were available as duals but it looks like not. But considering that you were concerned about the cost, those Ics are going to run easily over $100 by themselves. In that price target you'd better be sure you want them. Otherwise just stick with more reasonably priced ICs and keep trying till either you find one you like or they become available as a dual package. You could always try creating a dual package from two singles as an experiment. But again at $50+ a pop I'd be sure that they'd work and sound they way I want first.
I think techdiy has some good prices on ics & trans for the super regs.
As for the 627/637 I thought initially that they were available as duals but it looks like not. But considering that you were concerned about the cost, those Ics are going to run easily over $100 by themselves. In that price target you'd better be sure you want them. Otherwise just stick with more reasonably priced ICs and keep trying till either you find one you like or they become available as a dual package. You could always try creating a dual package from two singles as an experiment. But again at $50+ a pop I'd be sure that they'd work and sound they way I want first.
I think techdiy has some good prices on ics & trans for the super regs.
Well Mike... thats ok .. I thought as you suggested if I could use the ESP P06 pcb then it would be nice. I already have 4 opa637 and all the parts at hand and ready to solder..but.....so now I am just stick to my original notion and copy this http://www.diyaudio.com/forums/showthread.php?postid=300426#post300426
using P2P
The reason I bought 4 opa637 is just in case I blow up a couple of them while testing.
I wrote up the BOM for the aos S.reg boards from the schematics, just need to make sure what I already have at hand before ordering the rest of the parts. Hopefully the S.reg boards will be here sometime next week. Cost management.. ah yes.. when I got the quote I misundertsood that just the S.reg pcbs cost $66US and to me that is a bit much..but now I paid only $33US for them and it is bearable.
The Butcher
.. I thought as you suggested if I could use the ESP P06 pcb then it would be nice. I already have 4 opa637 and all the parts at hand and ready to solder..but.....so now I am just stick to my original notion and copy this http://www.diyaudio.com/forums/showthread.php?postid=300426#post300426using P2P
The reason I bought 4 opa637 is just in case I blow up a couple of them while testing.
I wrote up the BOM for the aos S.reg boards from the schematics, just need to make sure what I already have at hand before ordering the rest of the parts. Hopefully the S.reg boards will be here sometime next week. Cost management.. ah yes.. when I got the quote I misundertsood that just the S.reg pcbs cost $66US and to me that is a bit much..but now I paid only $33US for them and it is bearable.
The Butcher
Got the 4 pcb from aos. Just order the rest of the parts last night. I am having trouble with the super reg regulator pcbs. I ordered the AD825 but I have no idea which opa321p to order from DigiKey
There is no support from aos so I am also having trouble as to how to hook up the silly thing and it is getting expensive.
So far I have spend $33US for the pcbs. The parts for the reg is around $80cdn without the 4@opa321.
The rest of the PSU has not been design yet...will post some pics tonight
P2P done for the phono preamp except the loading cap and resistor because I am yet to know what cable to use from the TT to the phonostage.
AndrewT,
The 250pf is the total capacitance including the cables from the Pearl spec sheet.
There is no support from aos so I am also having trouble as to how to hook up the silly thing and it is getting expensive.
So far I have spend $33US for the pcbs. The parts for the reg is around $80cdn without the 4@opa321.
The rest of the PSU has not been design yet...will post some pics tonight
P2P done for the phono preamp except the loading cap and resistor because I am yet to know what cable to use from the TT to the phonostage.
AndrewT,
The 250pf is the total capacitance including the cables from the Pearl spec sheet.
Excuse me for interrupting the chat here, folks... but I understand that the butcher isn't giving much attention to the enclosure (if any at all)...
There WILL be a shielding ( == conductive) enclosure, right? Otherwise there will be a lot of RF noise to worry about, rather then the quality of the supply regulation.
Just my 2 cents
Jennice
There WILL be a shielding ( == conductive) enclosure, right? Otherwise there will be a lot of RF noise to worry about, rather then the quality of the supply regulation.
Just my 2 cents
Jennice
Jennice,
Thanks for the advise. I am yet to decide on a remote supply or same enclosesure with the phono stage, but I hear you. You are getting to know the Butcher's style
In either case I will take your adivce to have a shield for them. I bought some self adhesive copper sheet, great stuff so I can just line the inner surface and the bottom plate to what ever material end up as the case. There is a nice aftershave hard cardboard box from Dunhill that I can use..
Thanks for the advise. I am yet to decide on a remote supply or same enclosesure with the phono stage, but I hear you. You are getting to know the Butcher's style
In either case I will take your adivce to have a shield for them. I bought some self adhesive copper sheet, great stuff so I can just line the inner surface and the bottom plate to what ever material end up as the case. There is a nice aftershave hard cardboard box from Dunhill that I can use..
Onvinyl said:
Hi there,
Do you mind tell me what transformer you are using with the regulator? EI core or toriod? dual secondary or center tap? What rating and voltage?
I am thinking to use the 40VCT EI center tap 5A with the BrianGT bridge rectifier pcb 8@MUR820. But I think I need to drop some more volts?
The type and size of transformer is not a huge critical factor as its effect is diluted by the regulator. You can go to some pretty high voltages by using the 317/337 preregulator since the voltage rating is the differential voltage (40-42V) and will drop the voltage to just a few above the desired above voltage. Thus a 40Vct is no problem at all, bringing about 28V down to 15V or so. Just attach a heatsink on the preregs.
Trying out the layout inside. The problem is not sure how the super regulator supposed to be connected. The bridge rectifiers are BrianGT pcbs MUR850 the caps are 50V 10000uf per rail. The transformers are 40VCT 5 amp each center tap but I will only use half of each so I needed 4 altogether. I think this PSU is bigger than my high cap LM3875 GC! Way overkill monster phono stage!
It is bigger than my turntable Size matter or not?
It is bigger than my turntable
Size matter or not?Attachments
Mikett said:
The one difference which a transformer can make (particularly for a phono-preamp) is the energy it radiates itself -- EI cores and torroids have different patterns.
The other difference is that attibutable to from the tank circuit formed by the secondary inductance, the diode's capacitance AND the capacitance between primary and secondary windings. The ringing can be dealt with by placing a RC across each diode, or across the diode bridge. If you don't have the equipment to measure the transformer inductance, try using 10nF and 220R in series.
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