Of course the price is very dependant on the number of boards so If I could get a sense of everyone's interest that would be very helpful. As an early estimate 10 boards total will be 20-25USD per board plus shipping and while 30 boards will be at 15USD per board w/shipping.
If this builds some traction I will start a GB thread so we do not clutter the thread.
Nick
If this builds some traction I will start a GB thread so we do not clutter the thread.
Nick
Is that the current mirror reg that you did once when we were discussing in Babo's thread? Just seen your thread. Excellent pre.
P.S. You would be better off with bigger shunt caps across the Zener refs (C1,C15). 1000uF. Its positive, I have experimented with that.
Akrivos!
Yes, that's it - you did a great job!
Good that you mention that so everyone can try, especially on -V because it's just -4.6V and 1000uF/6V3 is physically small and easy to try. The -V branch is more sensitive to changes in PSU than +V.
4 eyes not enough ?
never .......
hey - but Jabukovaca is certainly good in adding at least 2 more eyes .......
i would be interested in one board, though only if you could send me the semiconductors as well. i live in india, and if i had to ship these seperately from overseas the project would be too expensive...i would like to do the project though, about to start an F2 so thinking of this as the pre.
cheers
mymindinside
cheers
mymindinside
Here is a link to a spreadsheet for the GB. I think I was able to add everyone who has shown interest so far but please check and feel free to correct or add to the sheet.
http://spreadsheets.google.com/ccc?key=0AvN-gJHBthcTdGV3MkJMcVVjTi1hSWNMQXFNbVBLQUE&hl=en
Juma I will start a GB thread not to clutter this one any further. Thank you for the design.
mymindinside, one board is all you need for stereo
http://spreadsheets.google.com/ccc?key=0AvN-gJHBthcTdGV3MkJMcVVjTi1hSWNMQXFNbVBLQUE&hl=en
Juma I will start a GB thread not to clutter this one any further. Thank you for the design.
mymindinside, one board is all you need for stereo
Hi Guys,
As some of you know, I am building this preamp as part of a larger project (see http://www.diyaudio.com/forums/pass-labs/156094-b1-active-crossover.html if interested). The first stage of the process is getting a working version of this preamp, with plenty of space in the chassis left over, and later stages will be to put filters in.
I have a question about the regulators. The final version of my project (if I get there...) will have four of these buffers, a stereo pair for high-pass and another for low-pass. I intend to power these from the same pair of regulators (there will also be a whole bunch of other stuff, but this will be powered - that's another issue best discussed on the other thread ...) I understand (from above) that one set of regulators is sufficient for a stereo pair, but I ought to think ahead and build them to be adequate for all four buffers. Will the regulators as give in post #23 be enough? I should add that I expect to have to heatsink a things a little better, which is fine, but I'm trying to calculate whether the shunt current is enough (and failing...) and could do with a little help...
Cheers
Nigel
As some of you know, I am building this preamp as part of a larger project (see http://www.diyaudio.com/forums/pass-labs/156094-b1-active-crossover.html if interested). The first stage of the process is getting a working version of this preamp, with plenty of space in the chassis left over, and later stages will be to put filters in.
I have a question about the regulators. The final version of my project (if I get there...) will have four of these buffers, a stereo pair for high-pass and another for low-pass. I intend to power these from the same pair of regulators (there will also be a whole bunch of other stuff, but this will be powered - that's another issue best discussed on the other thread ...) I understand (from above) that one set of regulators is sufficient for a stereo pair, but I ought to think ahead and build them to be adequate for all four buffers. Will the regulators as give in post #23 be enough? I should add that I expect to have to heatsink a things a little better, which is fine, but I'm trying to calculate whether the shunt current is enough (and failing...) and could do with a little help...
Cheers
Nigel
Nigel, corrected schematic is given in posts #28 and #31. Since you are building 4 preamp modules, you'll have to double the current, so what you need is:
40mA from neg. reg. - 80ma total (shunt burns the same ammount of current as the preamps)
80mA from pos. reg - 160mA total.
You set that with R22 and R23 for pos. reg. and R11 for neg. reg. (half the value of those resistors). Some heatsinking is neccessary - I use the heatsinks from dead PC PSUs - they are large enough and have threaded holes for MOSFETs (Q11, Q9, Q3 and Q7).
40mA from neg. reg. - 80ma total (shunt burns the same ammount of current as the preamps)
80mA from pos. reg - 160mA total.
You set that with R22 and R23 for pos. reg. and R11 for neg. reg. (half the value of those resistors). Some heatsinking is neccessary - I use the heatsinks from dead PC PSUs - they are large enough and have threaded holes for MOSFETs (Q11, Q9, Q3 and Q7).