You will need to connect the circuit ground to chassis or it will hum. Are you using the PassDIY pcb? The mounting holes all have connection to ground, use one metal standoff and the rest nylon, and make sure the metal standoff touches the metal of the chassis. (Remove any paint or anodization) Also make sure every panel of the chassis is electrically conductive to each other.
I would then insulate every connection, RCA, barrel, switch, etc… but the potentiometer body must touch chassis.
I would then insulate every connection, RCA, barrel, switch, etc… but the potentiometer body must touch chassis.
Hi. Sorry. I've not been around for a while. I'll try to post some pictures in the next few days. The Omron G6K 5V relays are controlled from the PIC with a standard transitor switch/flyback diode arrangment.
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Hi. Sorry. I've not been around for a while. PCB is my own design taking the B1 schematic and adding a PIC microcontroller to drive the input switching relays under the control of a tactile switch on the front panel. PSU for B1 and PIC (5V) is located near the front panel. The PIC is tucked up near the transformer. The back half of the board is the B1.
I used Kicad to work it up and had the PCBs made by Seeed Studio.
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Hello again.
Almost all of the parts for my B1 are here.
I’m not happy with one component though and I hope someone can help…
Ideally I’m looking at a design almost like in the first post. Just two round knobs. But I couldn’t find a two position rotary selector. Instead I got a rather big switch which I, now that I have it here, don’t like at all….and it is not black nor could I find a nice black one.
I’d rather have two black knobs, one for input and one for volume.
For volume I got the EIZZ 24 pos. step attenuator.
Does anyone know of a nice two position rotary switch OR is it possible to block one position from the 3-pos rotary switch from EIZZ???
Please, I do not want more than two positions!!
Thank you
Almost all of the parts for my B1 are here.
I’m not happy with one component though and I hope someone can help…
Ideally I’m looking at a design almost like in the first post. Just two round knobs. But I couldn’t find a two position rotary selector. Instead I got a rather big switch which I, now that I have it here, don’t like at all….and it is not black nor could I find a nice black one.
I’d rather have two black knobs, one for input and one for volume.
For volume I got the EIZZ 24 pos. step attenuator.
Does anyone know of a nice two position rotary switch OR is it possible to block one position from the 3-pos rotary switch from EIZZ???
Please, I do not want more than two positions!!
Thank you
Lorlin 2 section/6 positions, shorting type
ask in Iron Pre thread for exact type No.
it can be limited (indentation set/inherent toothed washer) to any number of positions
of course, if you insist on kosher, search for anything Elma or Switchcraft .... or whatever
ask in Iron Pre thread for exact type No.
it can be limited (indentation set/inherent toothed washer) to any number of positions
of course, if you insist on kosher, search for anything Elma or Switchcraft .... or whatever
Thank you
CK1040 would be the desired type then.
Since not available I’ll get CK1060, a little harder to solder but otherwise same
CK1040 would be the desired type then.
Since not available I’ll get CK1060, a little harder to solder but otherwise same
Hello!!
One knob is still missing and I’m thinking about making some kind of description on the panels, but other than that I’m quite happy.😊
The RCA are sh*t and the log pot is not ideal at the top end but very nice at my usual listening volumes.
One one side there is a phono tube pre from project, on the oder side a digital streamer. Output into active transmission line speakers.
What I find especially pleasing is, if I switch from analog to digital, the volume level is exactly the same. But I guess that’s not the achievement of the buffer.
Thanks for your help in the process
One knob is still missing and I’m thinking about making some kind of description on the panels, but other than that I’m quite happy.😊
The RCA are sh*t and the log pot is not ideal at the top end but very nice at my usual listening volumes.
One one side there is a phono tube pre from project, on the oder side a digital streamer. Output into active transmission line speakers.
What I find especially pleasing is, if I switch from analog to digital, the volume level is exactly the same. But I guess that’s not the achievement of the buffer.
Thanks for your help in the process
Attachments
Me again,
I do experience a little but annoying humm sound, what I think is the 50Hz from mains.
Anyone any advice on how to find that and how to get rid of?
On the audiofile attached you can hear when I remove or replug the DC Plug. It is enough to just hold the "-" from the plug to the socket and the hum is there...
Oh, I can't attach an audio file...
I do experience a little but annoying humm sound, what I think is the 50Hz from mains.
Anyone any advice on how to find that and how to get rid of?
On the audiofile attached you can hear when I remove or replug the DC Plug. It is enough to just hold the "-" from the plug to the socket and the hum is there...
Oh, I can't attach an audio file...
for start, confirm with ohmmeter that entire case (including front) is in contact with GND of power supply
Yes, every panel and the housing of the pot is connected to „-„ of the power supply.
The noise gets introduced when I connect the „-„ pole with the power supply and stays after pushing the plug in completely.
Are there any requirements to the power supply? Reading Mr. Pass file on the B1 almost anything should go, right?
The noise gets introduced when I connect the „-„ pole with the power supply and stays after pushing the plug in completely.
Are there any requirements to the power supply? Reading Mr. Pass file on the B1 almost anything should go, right?
UPDATE:
I connected my adjustable power supply from my workstation @ 24V and … no hum…
guess I have to update my wall adapter…can someone recommend a decent one? But not the overpriced ifi please.
i do own some of the Peter Daniels PCB‘s but I really want to avoid implementing that kind of power supply for this as I don’t want 230V inside the housing. (Everything except my power speakers is low voltage)
I connected my adjustable power supply from my workstation @ 24V and … no hum…
guess I have to update my wall adapter…can someone recommend a decent one? But not the overpriced ifi please.
i do own some of the Peter Daniels PCB‘s but I really want to avoid implementing that kind of power supply for this as I don’t want 230V inside the housing. (Everything except my power speakers is low voltage)
You connect your dac directly to the amp and listen to an audio cd. Nice.
Now you connect the B1 between the dac and amp and listen to the same cd. Wonderfull.
I started with the B1 as a covid lockdown project. Then upgraded to DC B1 with a single comon supply. Very much better SQ than B1. Then upgraded to dual supply for each channel. Hear the offset null of each channel could be adjusted to zero, independantly. Even better SQ.
Now I can hear micro details. The treble is super clean and the shhhhh noise of voices clearly audible. Then incorporated an output transformer to one channel. Sound became analog type in that channel with a little more gain. When adjusted properly with the balance control you can enjoy the sound of both worlds. Pure digital sound in one and the antique mellow sound in the other. The transformer adds tube like sound.
Next upgrade would be a TVC.
Have listened to many expensive branded setups but my B1 beats them all in the wonderful world of music.
Thanks Papa for the wonderfull gift to us diy audiophiles!
Now you connect the B1 between the dac and amp and listen to the same cd. Wonderfull.
I started with the B1 as a covid lockdown project. Then upgraded to DC B1 with a single comon supply. Very much better SQ than B1. Then upgraded to dual supply for each channel. Hear the offset null of each channel could be adjusted to zero, independantly. Even better SQ.
Now I can hear micro details. The treble is super clean and the shhhhh noise of voices clearly audible. Then incorporated an output transformer to one channel. Sound became analog type in that channel with a little more gain. When adjusted properly with the balance control you can enjoy the sound of both worlds. Pure digital sound in one and the antique mellow sound in the other. The transformer adds tube like sound.
Next upgrade would be a TVC.
Have listened to many expensive branded setups but my B1 beats them all in the wonderful world of music.
Thanks Papa for the wonderfull gift to us diy audiophiles!
Hi everyone,
I’m experiencing an issue with my balanced B1 buffer and could really use some advice from those with more experience. The problem is that the right channel plays at a lower volume (about 3-5 dB lower) compared to the left channel.
Here’s some context:
Thanks in advance!
I’m experiencing an issue with my balanced B1 buffer and could really use some advice from those with more experience. The problem is that the right channel plays at a lower volume (about 3-5 dB lower) compared to the left channel.
Here’s some context:
- The buffer has worked great for years.
- A few years ago, I replaced the stepped attenuator with a Muses volume control system from Meldano, which also required changing the power supply from a simple 18V wall wart to a SilentSwitcher (15V).
- At first, I thought the issue was with the volume control, but after testing with different potentiometers (both the Muses system and a TKD), I’m now fairly confident that the problem lies within the B1 buffer itself.
- Two B1 boards from DIY Audio R0 (2008), populated with components per the original B1 article.
- One SilentSwitcher (15V) powering both boards.
Thanks in advance!
we can overlook everything, without seeing pics 
it's easy to determine; for each phase same measurement
inject sine, 400Hz to 1KHz, even laptop headphone out will do, approx 1V
then measure with DVM Set to Vac
-at input jack
-after selector
-at pot input
-at pot output
-at buffer input
-at buffer output
-at output jack
with that table you'll be able to check all function blocks and wiring
for JFet buffer - suspicious one, it's enough to measure voltages for both JFets at D, G, S
all measurements ref. to GND (black probe at GND)
post here
it's easy to determine; for each phase same measurement
inject sine, 400Hz to 1KHz, even laptop headphone out will do, approx 1V
then measure with DVM Set to Vac
-at input jack
-after selector
-at pot input
-at pot output
-at buffer input
-at buffer output
-at output jack
with that table you'll be able to check all function blocks and wiring
for JFet buffer - suspicious one, it's enough to measure voltages for both JFets at D, G, S
all measurements ref. to GND (black probe at GND)
post here
Thank you very much for your advice—it’s highly appreciated!
Following your guidance, I was able to narrow down the issue. It seems that the problem is not with the B1 buffer after all. When measuring the voltage coming out of the volume control, I found that one of the four channels outputs 0V, while the other three measure 1.8V.
This strongly suggests that the issue lies with the volume control rather than the B1 buffer.
Thanks again for your support and for pointing me in the right direction!
Following your guidance, I was able to narrow down the issue. It seems that the problem is not with the B1 buffer after all. When measuring the voltage coming out of the volume control, I found that one of the four channels outputs 0V, while the other three measure 1.8V.
This strongly suggests that the issue lies with the volume control rather than the B1 buffer.
Thanks again for your support and for pointing me in the right direction!
Many pages and posts.
Does someone want to point me to the (final) circuit of the preamplifier ?
Elias
Does someone want to point me to the (final) circuit of the preamplifier ?
Elias
Hello Elias,
if you mean the nice article from Nelson Pass?:
https://www.firstwatt.com/wp-content/uploads/2023/12/art_b1_man.pdf
Cheers
Dirk
if you mean the nice article from Nelson Pass?:
https://www.firstwatt.com/wp-content/uploads/2023/12/art_b1_man.pdf
Cheers
Dirk
Hi Eliias,
DC B1 by Salas
http://www.diyaudio.com/forums/pass-labs/145201-building-symmetrical-psu-b1-buffer.html
Just build with the given LM317 symetrical dual supply.
So simple. So wonderful!
Srian
DC B1 by Salas
http://www.diyaudio.com/forums/pass-labs/145201-building-symmetrical-psu-b1-buffer.html
Just build with the given LM317 symetrical dual supply.
So simple. So wonderful!
Srian