I have made more mistakes building "easy" projects than I would like to admit. Building my DCB1 I inserted some LEDs backwards -- not one of a set, but all of a set. When I built a BIB Salas regulator for another circuit, I shorted the outputs of the regulator (not to mention how I butchered the case). In my folded build I inserted one pair of 369s backwards. I mean, the outline was printed on the circuit board and i inserted both transistors backwards! Then I shorted out the raw power supply. So I know it is so easy to literally put one component in the wrong way and make a brick.
But Rick, right now I am listening to a record that I have owned for decades, and it sounds better than I ever remember. And I know my turntable/arm/cart are not 100% dialed in yet. Maybe 95%, but not quite there. This phono preamp will never be the limiting factor, and is completely worth the effort. If I can be of any help just ask; I have received so much help from folks on this forum over the years that I know I am in arrears and want to pay some back.
But Rick, right now I am listening to a record that I have owned for decades, and it sounds better than I ever remember. And I know my turntable/arm/cart are not 100% dialed in yet. Maybe 95%, but not quite there. This phono preamp will never be the limiting factor, and is completely worth the effort. If I can be of any help just ask; I have received so much help from folks on this forum over the years that I know I am in arrears and want to pay some back.
Salas I truly appreciate your efforts and help here, but I initially wasn't that keen to pursue this. After all, my folded sounds wonderful right now, so this is truly "gilding the lily", or fixing a problem that doesn't exist.
BUT: I almost certainly have too low a load resistance for my cartridge, as you pointed out earlier. I installed a pair of 100R Z-foils at R1 and left out the DIP switch and other resistors, intending to use my Ortofon cart which I subsequently destroyed, and 100R is certainly low for my Denon (impedance 16R). So now I have two reasons to rebuild it, to fix the load and tweak the gain. I think I will actually do this in the next few weeks! Enough time has elapsed that the cost of the new Z-foils no longer count toward the initial outlay
Nothing more noble than the solitary tinkerer
I wish I was a true tinkerer. I am more a follower of the great tinkerers!
So many great things have been discovered by the tinkerer.
Never give it up!
Best of luck,
I wish I was a true tinkerer. I am more a follower of the great tinkerers!
So many great things have been discovered by the tinkerer.
Never give it up!
Best of luck,
Thanks for more inspiration
I am not afraid of making mistakes. I have much too much experience with mistakes to fear them! What I worry about is when a mistake affects more than the original mistake, alone.
Made good progress with de-soldering last night. I know before it is over I will probably have a few traces I need to replace with wire, no big deal. I had removed the cap at the output of the reg too many times. Using an OBBLIGATO that is too large fot the board so it is underneath and every time I need to get to anything in its vicinity I had to remove it. Last night when removing it up came the trace that goes to R5x - oh, well,, easy enough to fix.
One of my favorite quotes: Do not fear perfection, you will never achieve it.
From the realistic surrealist Salvador Dali. I think of it everyday.
Thanks to all.
I am not afraid of making mistakes. I have much too much experience with mistakes to fear them! What I worry about is when a mistake affects more than the original mistake, alone.
Made good progress with de-soldering last night. I know before it is over I will probably have a few traces I need to replace with wire, no big deal. I had removed the cap at the output of the reg too many times. Using an OBBLIGATO that is too large fot the board so it is underneath and every time I need to get to anything in its vicinity I had to remove it. Last night when removing it up came the trace that goes to R5x - oh, well,, easy enough to fix.
One of my favorite quotes: Do not fear perfection, you will never achieve it.
From the realistic surrealist Salvador Dali. I think of it everyday.
Thanks to all.
Hi Hikari1,
Salas is right and I do have BHL, exactly like yours. What I did?.., I just replaced all stock components: all resisters are Vishay VAR, IRAA caps are Vishay 1837, the rest of caps are Obbligato Gold. I feed it with Salas BIB set to 24V and about 180mA current. I also use Salas's Raw DC board and C-Multiplier in-between Raw DC and BIB. My cart is MC (0.58mV) and I use MC BHL too. It is 12V and built LT317A to feed it with C-Muly prior regulator and same Salas Raw DC. It is nicely sounded but still have some initial noise at high volume (probably Johnson noise from resistors in signal path). General impression is good, but Salas FSP is way more advance in sound. More air, more details, more alive, more defined bass, very clear highs, and tremendous mids.
When I powered up my MM version of the FSP the raw p/s was ok at 46vdc but when connected to the boards I cannot achieve higher than 31.5v between ground and rail before VR2 bottoms out.Between TP1 & TP2 there is 6.5v which does not alter despite turn both VR1 & 2.
All leds are lit(no wrongly installed ones this time) and no smoke released the 9530 sinks are hotter than the 9610 sinks.This is the same for both channels
Any advice would be appreciated.
All leds are lit(no wrongly installed ones this time) and no smoke released the 9530 sinks are hotter than the 9610 sinks.This is the same for both channels
Any advice would be appreciated.
Thanks Salas.I replaced and correctly positioned the 970's and replaced R3X with the 9.1k resistors.
DC in is at 46vdc with rail to ground at 34.8 & 34.7.TP1/TP2 are at 3.3v and 3.148v. Should I have left R3X at 6.2k or am I good to go?tia.
Lowest that I can go is 34.8v on one channel and 35.1v on the other.TP1/2 readings are 3.25v and 3.124v.
Obviously the IDSS of your Q3x Vref biasing JFETs falls somewhere between usual R3x value matches for providing balanced enough target trimming range.
Engage VR1 from this point on and try for 3.6V TP1/2. If it again won't reach you may use 8.2K for R3x pursuing extra DC Rail bottom range but you are not in unacceptable readings area already.
Engage VR1 from this point on and try for 3.6V TP1/2. If it again won't reach you may use 8.2K for R3x pursuing extra DC Rail bottom range but you are not in unacceptable readings area already.
In MC VR1 would make more difference, in MM can be used for better matching mainly. By lifting one leg of R12 you can much extend its influence.
You made the 40dB with 91R R2 version I presume. That one uses the least bias current. For what cart model, and is it drifting comfortably little on TP1/2 readings after warm up?
You made the 40dB with 91R R2 version I presume. That one uses the least bias current. For what cart model, and is it drifting comfortably little on TP1/2 readings after warm up?
Quintessentially British cart maker. Everything in it designed different than the norm.