I got matched set of 2SK 170BL from Spencer ( I think he said something like 2% match)- also marked actual iDss from his measurements. I got 0 mV offset at Buffer loaction on both the channels. You can ask SPencer what meathod he uses - he is knowledgeable on Fets. Instead of you trying to measure, you can obtain matched sets from him also for your small requirements as he is quite reasonable on matched Fet prices. The other loactions I just used BL market Fets - they work fine
Kannan
The more I listen the more I like...
I am listening to Correnteza by Anna Caram. There are what I took to be water sounds, but now I can hear them as wood blocks. There was a cello in one song, I never heard it before, it is also pretty amazing to hear the little chuffing sounds during the rapid sax solo, or the decay of the crash cymbals. Well back to the listening, going to play with some of my more favorite live tracks now.
I am listening to Correnteza by Anna Caram. There are what I took to be water sounds, but now I can hear them as wood blocks. There was a cello in one song, I never heard it before, it is also pretty amazing to hear the little chuffing sounds during the rapid sax solo, or the decay of the crash cymbals. Well back to the listening, going to play with some of my more favorite live tracks now.
Crt, contacted me, he was on travel, and will do some more labels for the silkscreen layer very soon. 7812, 100nf, 1,2,3,4,5,6,Gnd for the selector.
Weird thing is that on his actual board, and on my Eagle 5.6.0 the Leds don't look like four symmetrical brackets, but appear as full leds with a straight and a round side with those brackets inside them.
Maybe it goes down to the pcb maker's version and/or symbol library?
Tea-Bag can you ask them? I told Crt to maybe try another tell tale symbol for the Leds cathode orientation and we will see.
Weird thing is that on his actual board, and on my Eagle 5.6.0 the Leds don't look like four symmetrical brackets, but appear as full leds with a straight and a round side with those brackets inside them.
Maybe it goes down to the pcb maker's version and/or symbol library?
Tea-Bag can you ask them? I told Crt to maybe try another tell tale symbol for the Leds cathode orientation and we will see.
Attachments
Did you do AB with the Conrad Johnson and Russ's Diamante? Something it misses in comparison? AB is sanity.
Crt, contacted me, he was on travel, and will do some more labels for the silkscreen layer very soon. 7812, 100nf, 1,2,3,4,5,6,Gnd for the selector.
Weird thing is that on his actual board, and on my Eagle 5.6.0 the Leds don't look like four symmetrical brackets, but appear as full leds with a straight and a round side with those brackets inside them.
Maybe it goes down to the pcb maker's version and/or symbol library?
Tea-Bag can you ask them? I told Crt to maybe try another tell tale symbol for the Leds cathode orientation and we will see.
I think the Eagle to Gerber translation does this. It appears on all Gerber file output. I think even the one we sent direct to them from CRT (he in the end outputted to GERBER, but I am not sure if I deleted the specific message that forwarded that data from him from you. We likely need to use a different symbol, or the masses will have to get over it.
I think you will fine those missing brackets are on the Documentation layer 51. This layer is for printing (documentation) purposes and not used for the silkscreen. If you need them to be on the silkscreen then they should be moved to level 21.
Eagle uses layer 51 on lots of the components so it is not a good idea to routinely ask for layer 51 to be included on the silkscreen, especially on 2 layer PCBs. BTW: Level 51 is usually used when the graphics overlap the pads.
Attached is my Eagle menu for easy selection of layers. Change .txt to .scr.
Eagle uses layer 51 on lots of the components so it is not a good idea to routinely ask for layer 51 to be included on the silkscreen, especially on 2 layer PCBs. BTW: Level 51 is usually used when the graphics overlap the pads.
Attached is my Eagle menu for easy selection of layers. Change .txt to .scr.
Last edited:
Uriah/Andrew T - I bought a bag of 2SK170 from ebay and used that method (ie 9V - and FWIW, I think thats what Nelson recommends on an article on PASSdiy). I got values from about 7 to 11 with most clustered around 8-9mA.
Uriah, I'm sure they'll be fine if the original doc from Nelson specifies 5-10mA.
Fran
EDIT: couldn't find that sch for matching, but here is the line from teh b1 pdf:
Uriah, I'm sure they'll be fine if the original doc from Nelson specifies 5-10mA.
Fran
EDIT: couldn't find that sch for matching, but here is the line from teh b1 pdf:
Last edited:
Longer Review
DC B-1 now fully broken in with 20k switching attenuator. More words, same conclusion: I am amazed how good it sounds.
Direct Coupled B-1 Buffer with Shunt Regulator by Salas
Trying to write about a piece of equipment always makes me realize that I am not an audio review poet. And then another thing happens, I shake my head and wonder how changing just one element somewhere in the middle of the chain would make any difference at all.
I believe "throwing away very, very little gain" is the most important reason why the B-1 Buffer is such a good component in my system. So assuming you start with a good strong signal from your source component most of what your volume control/switcher needs to do is not mess it up. The other really important role for this stage is to transmit the signal through the cable into power amp pretty much intact.
Right now my source is a PS Audio DLIII Digital Link DAC, modified to be non-inverting. The DC B-1 is just a few dB below full "gain" at my favourite listening level. The power amp is a DIY EL34 PP tube amp. Speakers are DIY open baffle. The DC B-1 prototype replaced a "regular" B-1.
Most of the time the DC B-1 sounds pretty much like every other extremely good preamp, but even then it doesn't put me on edge at all. World peace ... I'm kidding of course, but there is an uncanny sense of calm about good recordings playing through the DC B-1, more so I believe than I have ever heard. The S/N ratio among other things must be otherworldly. I'm sure somebody will find a piece of equipment that is good enough to measure it accurately. It certainly doesn't add any kind of distortion. Another surprising effect: different recordings sound more different. The DC B-1 taught my system a broader spectrum of sounds than it had ever played.
And then somebody smacks a snaredrum, or something else that makes a lot of noise before the sound falls away with a nice long resonant decay and reverb tail. Getting that close to the recording could be like work and trigger the kind of listening that comes with editing or mixing music, but with this DC B-1 that just isn't what happens to me. I just enjoy myself and the feel of being pulled into the music.
Next up for critical listening were sounds the could be dangerous to your health on many pieces of audio equipment: operatic soprano, large choir, applause, the list goes on. Applause is nearly impossible to get right on loudspeakers and in small rooms, so forget about that one even though the DC B-1 helped and took some of "rain on a tin roof listened to from the inside" out of the experience. Large choral sections were amazing with individual voices often recognizable, and operatic soprano didn't get that nasty shrill vibration unless is was happening in the singers mouth and throat.
It is also very easy to hear pitch, vocal inflections, pedal on piano, autotune [sorry about that one it can't be helped], cymbals that really sound like cymbals. What's best though is all that variety of tonal color, the ability to make slow engaging, and the calm that radiates from music playing through the DC B-1.
Soundstage: yes. For those few recordings where I know the room, the microphones used, the musicians and their instruments, distances and the intent at the time it was all mixed - thumbs up. For every other recording: I like what I hear, locations are stable and there is a good sense of depth.
This writeup might make it sound like the DC-B1 turned my home system into a monitoring setup, but somehow it didn't. All that detail and depth was just too much at ease, too relaxed to make it overwhelming.
I have no clue how a buffer/preamp could possibly be any better. To me it exists outside of any discussion over tubes vs. sand. Yes, I'm glad there is a tubed power amp between my DC B-1 and the speakers. That amp amazingly does allow the B-1 to shine through.
DC B-1 now fully broken in with 20k switching attenuator. More words, same conclusion: I am amazed how good it sounds.
Direct Coupled B-1 Buffer with Shunt Regulator by Salas
Trying to write about a piece of equipment always makes me realize that I am not an audio review poet. And then another thing happens, I shake my head and wonder how changing just one element somewhere in the middle of the chain would make any difference at all.
I believe "throwing away very, very little gain" is the most important reason why the B-1 Buffer is such a good component in my system. So assuming you start with a good strong signal from your source component most of what your volume control/switcher needs to do is not mess it up. The other really important role for this stage is to transmit the signal through the cable into power amp pretty much intact.
Right now my source is a PS Audio DLIII Digital Link DAC, modified to be non-inverting. The DC B-1 is just a few dB below full "gain" at my favourite listening level. The power amp is a DIY EL34 PP tube amp. Speakers are DIY open baffle. The DC B-1 prototype replaced a "regular" B-1.
Most of the time the DC B-1 sounds pretty much like every other extremely good preamp, but even then it doesn't put me on edge at all. World peace ... I'm kidding of course, but there is an uncanny sense of calm about good recordings playing through the DC B-1, more so I believe than I have ever heard. The S/N ratio among other things must be otherworldly. I'm sure somebody will find a piece of equipment that is good enough to measure it accurately. It certainly doesn't add any kind of distortion. Another surprising effect: different recordings sound more different. The DC B-1 taught my system a broader spectrum of sounds than it had ever played.
And then somebody smacks a snaredrum, or something else that makes a lot of noise before the sound falls away with a nice long resonant decay and reverb tail. Getting that close to the recording could be like work and trigger the kind of listening that comes with editing or mixing music, but with this DC B-1 that just isn't what happens to me. I just enjoy myself and the feel of being pulled into the music.
Next up for critical listening were sounds the could be dangerous to your health on many pieces of audio equipment: operatic soprano, large choir, applause, the list goes on. Applause is nearly impossible to get right on loudspeakers and in small rooms, so forget about that one even though the DC B-1 helped and took some of "rain on a tin roof listened to from the inside" out of the experience. Large choral sections were amazing with individual voices often recognizable, and operatic soprano didn't get that nasty shrill vibration unless is was happening in the singers mouth and throat.
It is also very easy to hear pitch, vocal inflections, pedal on piano, autotune [sorry about that one it can't be helped], cymbals that really sound like cymbals. What's best though is all that variety of tonal color, the ability to make slow engaging, and the calm that radiates from music playing through the DC B-1.
Soundstage: yes. For those few recordings where I know the room, the microphones used, the musicians and their instruments, distances and the intent at the time it was all mixed - thumbs up. For every other recording: I like what I hear, locations are stable and there is a good sense of depth.
This writeup might make it sound like the DC-B1 turned my home system into a monitoring setup, but somehow it didn't. All that detail and depth was just too much at ease, too relaxed to make it overwhelming.
I have no clue how a buffer/preamp could possibly be any better. To me it exists outside of any discussion over tubes vs. sand. Yes, I'm glad there is a tubed power amp between my DC B-1 and the speakers. That amp amazingly does allow the B-1 to shine through.
Very nice description. I am glad that you guys like it. I should give some explanations about it I guess. The way I developed it and voiced it I mean.
The extra transparency is due to the lack of coupling capacitors, the calmness of the extra information that owes not to come out stark, and be expertly mixed, is the specific shunts and values.
Such a simple concept as the regular NP B1 owed to get simplest possible I thought, so I gave it a go. Saw that it lent itself to no caps. ZenMod was first to mention about losing the input one. Having messed with many of those capacitor buggers, I knew that no caps means max info, I also knew that 4 really good coupling caps mean big spending. So I got rid of those 4 darn expensive filter$.
I was messing a lot with the simplistic phono during that period, and I had voiced shunts for powering circuits with such JFETs, so I had most ground work done, and I just tuned those you have now for it. They will gel best with this one. For other applications will be very good, but not as good as for this one. Roughly half its sonic signature is the regs.
DCB1 was made p2p, got voiced in my diy system, replaying vinyl 90% of the time through the simplistic njfet riaa, in comparison with my 6V6 trioded tubed buffer with regulated psu. Which has all that calm resolution stuff but sounds more alive ''you are there'' for dynamics, golden tone and presence. Sorry, jfets can't do that, they are always a bit darker and mushier than comparably silent valve circuits. The two preamps present the same balance & info, different esoteric tone and dynamics, DCB1 is 30 times less expensive, lighter, smaller, no time consuming, or troublesome though. And takes no extensive lethal HV P2P expertise. Pick your persuasion. Both were driving my design diy 31dB gain 2X20W KT88 PP triode amp to 95dB 3 way column speakers that I designed too.
As for measuring its noise floor mentioned, here you are, see it attached. 0dB=1VRMS. The GB pcb version I will measure it again for you when I get the pcb copies here and get em done. The scope stuff has been shown from Ferds before. Same as I got. Refer to those posts.
The thing with applause is down to stereo, and mass choral distinction is down to the transducers bottleneck and room acoustics. 1-5kHz distortion shows up a lot of 3rd and IMD in many of them if pushed for any real level on a massive choral score, plus geometrical faults in the wave launch and local diffraction can mess it up more. There are some that can do it well though. Large format modern studio monitors and custom large diy mainly. Lynn Olson discussion class stuff, long ribbon arrays, some panels. All open back.
In low level auditions, decent FR OB, can go the extra mile VS the common boxed insensitive two way due to better wave launch geometry, much more area in high mids than a tweeter, lack of crossover, and no messing with 1st msec in a box. Near field monitoring can help a small box 2 way for such a program if good on diffraction, bcs it keeps it under low power demand.
The extra transparency is due to the lack of coupling capacitors, the calmness of the extra information that owes not to come out stark, and be expertly mixed, is the specific shunts and values.
Such a simple concept as the regular NP B1 owed to get simplest possible I thought, so I gave it a go. Saw that it lent itself to no caps. ZenMod was first to mention about losing the input one. Having messed with many of those capacitor buggers, I knew that no caps means max info, I also knew that 4 really good coupling caps mean big spending. So I got rid of those 4 darn expensive filter$.
I was messing a lot with the simplistic phono during that period, and I had voiced shunts for powering circuits with such JFETs, so I had most ground work done, and I just tuned those you have now for it. They will gel best with this one. For other applications will be very good, but not as good as for this one. Roughly half its sonic signature is the regs.
DCB1 was made p2p, got voiced in my diy system, replaying vinyl 90% of the time through the simplistic njfet riaa, in comparison with my 6V6 trioded tubed buffer with regulated psu. Which has all that calm resolution stuff but sounds more alive ''you are there'' for dynamics, golden tone and presence. Sorry, jfets can't do that, they are always a bit darker and mushier than comparably silent valve circuits. The two preamps present the same balance & info, different esoteric tone and dynamics, DCB1 is 30 times less expensive, lighter, smaller, no time consuming, or troublesome though. And takes no extensive lethal HV P2P expertise. Pick your persuasion.
Both were driving my design diy 31dB gain 2X20W KT88 PP triode amp to 95dB 3 way column speakers that I designed too.As for measuring its noise floor mentioned, here you are, see it attached. 0dB=1VRMS. The GB pcb version I will measure it again for you when I get the pcb copies here and get em done. The scope stuff has been shown from Ferds before. Same as I got. Refer to those posts.
The thing with applause is down to stereo, and mass choral distinction is down to the transducers bottleneck and room acoustics. 1-5kHz distortion shows up a lot of 3rd and IMD in many of them if pushed for any real level on a massive choral score, plus geometrical faults in the wave launch and local diffraction can mess it up more. There are some that can do it well though. Large format modern studio monitors and custom large diy mainly. Lynn Olson discussion class stuff, long ribbon arrays, some panels. All open back.
In low level auditions, decent FR OB, can go the extra mile VS the common boxed insensitive two way due to better wave launch geometry, much more area in high mids than a tweeter, lack of crossover, and no messing with 1st msec in a box. Near field monitoring can help a small box 2 way for such a program if good on diffraction, bcs it keeps it under low power demand.
Attachments
It is now up and running. Music is playing. Very different than the old Harmon Kardon pre amp I have been using. Very nice. It will of course need some burn in for real listening impression. I just jumpered the input selector to get sound going. I have been pushing the envelope with the wife and now need to focus on our trip this afternoon, but no issues I have found worth mentioning.
Actually I am surprised at how much punch and power it has. Driving a gainclone, I am hard pressed to get of the second detente in the pot. I think I may need a higher impedance pot. Thanks for this great layout and support. This will undoubtedly result in many a nicely built B1.
Isn't the potentiometer mounted backwards ?! It looks like this on the pics.
BOM is to be revised before the closing of the sign up so to include proto testing suggestions. We already know more compatible Leds, connectors, a comp cap for some chattering relay probability, maybe Mosfet and 7812 small sinks for those feeling it may not have enough air in their enclosure etc. The original building thread with schematics is there
Yes, Jean Paul,
The pot is inverted. It just makes the positioning of the wiper backwards. All clockwise is low volume. I learned that after it was installed and running. Not perfect yet, but still functional. Proof of board and concept was the goal. Perfection and tweaking to come when more time is at hand. Maybe that will solve my volume issue as well. I guess that is another note to add to the assmebly guide is that the pot is mounted to the bottom of the board, not the top.
The pot is inverted. It just makes the positioning of the wiper backwards. All clockwise is low volume. I learned that after it was installed and running. Not perfect yet, but still functional. Proof of board and concept was the goal. Perfection and tweaking to come when more time is at hand. Maybe that will solve my volume issue as well. I guess that is another note to add to the assmebly guide is that the pot is mounted to the bottom of the board, not the top.