Thinking out loud regarding that switch on/off noise...
Suppose one would connect the B1K as a source, say on Line Input 1, also using another source or preamp connected Line Input 2.
Let's say that all our grounds are always directly connected regardless the source selection (Line 1 or Line 2) but that of course the hot signal is only connected to the selected source.
Would switch on/off the B1K while having source selection on Line 2, and staying there say for 20s or so, and then selecting Line 1 to play through the B1K save us completely from the big switch on/off noise?
If that woudl work that would save us from switching on and off power amps.
Many thanks for your kind reply
Claude
Suppose one would connect the B1K as a source, say on Line Input 1, also using another source or preamp connected Line Input 2.
Let's say that all our grounds are always directly connected regardless the source selection (Line 1 or Line 2) but that of course the hot signal is only connected to the selected source.
Would switch on/off the B1K while having source selection on Line 2, and staying there say for 20s or so, and then selecting Line 1 to play through the B1K save us completely from the big switch on/off noise?
If that woudl work that would save us from switching on and off power amps.
Many thanks for your kind reply
Claude
Have you noticed if the Nutube appears to offer any perceived improvements in SQ by letting it be used for X? amount of hours through leaving the device switched on permanently.
My Nutube runs best indeed after a couple fo songs, indeed. But then I didn't notice really any improvement.
On the other hand, I prefer to switch it off: 30 000 hours are just over 3 years, plus if it turns out to work like my projector then past 15 000 to 20 000h there will be a slight minus. in quality.
I leave all my systems on permanently (amps, sources etc.) because they don't really wear. Except said projector, A-V computer, turntable and B1 Korg as I feel it is then wasted.
But that's just me
On the other hand, I prefer to switch it off: 30 000 hours are just over 3 years, plus if it turns out to work like my projector then past 15 000 to 20 000h there will be a slight minus. in quality.
I leave all my systems on permanently (amps, sources etc.) because they don't really wear. Except said projector, A-V computer, turntable and B1 Korg as I feel it is then wasted.
But that's just me
I usually leave it on 24/7. But I do shut it down when I know I won't be listening for a few days. And I feel like it's not as good after. Could be psychological, I am not sure.
Pas Labs stuff has "standby" modes which keep the regs and input stage active while keeping the power hungry output stages turned off. Same principle.
I leave my SS phono stage on ALL the time. It's probably been turned off 3 or 4 times in the last 5 years.
That's pretty common and normal. The inner part is isolated from the outer part via plastic or teflon. I wouldn't worry about it.
So I made a second B1 with Korg Triode to drive another newly made ACA.
I too used an Alps 100k pot sitting in the parts bin.
But with the pot wired up, it distorts terribly.
If I remove the pot ground, it is loud as hell (no kidding) but the distortion is gone (well other than it is overdriving the amp).
On my last build I used a Noble 100k pot from the parts bin.
Could the Alps pot be bad? It measures 87k, not 100k by the way.
How could I test that?
Or is it best to just get a 50k pot?
Thanks in advance,
Dan
(BTW, voltages are all a-okay)
I too used an Alps 100k pot sitting in the parts bin.
But with the pot wired up, it distorts terribly.
If I remove the pot ground, it is loud as hell (no kidding) but the distortion is gone (well other than it is overdriving the amp).
On my last build I used a Noble 100k pot from the parts bin.
Could the Alps pot be bad? It measures 87k, not 100k by the way.
How could I test that?
Or is it best to just get a 50k pot?
Thanks in advance,
Dan
(BTW, voltages are all a-okay)
"Probably fake, but not bad."
har har.
The pot is mounted on the chassis which is to ground.
The pot's ground leg of the potential divider ground to chassis.
I think all 4 of the board's mounting holes are to ground. And it is mounted with standoffs that ground to the chassis.
And then there is the ground next to the 24v which I have ground to the chassis.
Are you saying to remove the ground next to the 24v in, or remove the board's grounding via the mounting holes?
har har.
The pot is mounted on the chassis which is to ground.
The pot's ground leg of the potential divider ground to chassis.
I think all 4 of the board's mounting holes are to ground. And it is mounted with standoffs that ground to the chassis.
And then there is the ground next to the 24v which I have ground to the chassis.
Are you saying to remove the ground next to the 24v in, or remove the board's grounding via the mounting holes?
Via the PCB standoffs.
You have a lot of potential for ground loops which is probably what you are hearing. Are you using an SMPS power supply? You don't need to ground the chassis. The chassis only NEEDS to be grounded for safety if you are using a linear supply with a 3 prong power cord. An don't use the chassis as any sort of connection from the pot to the PCB or anything like that. You want the wires to be the path of least resistance...once we start introducing unequal paths to ground is where we start getting ground loops. It's OK for the chassis to be grounded, but it needs to not be the path of least resistance.
Maybe a pic would help? Perhaps I am not understanding what you are doing correctly.
So, i bypassed the (fake ;O) Alps pot and soldered in a potential divider with 47k in series and 3.3k to ground with no other changes (hey, that was what was in the parts bin).
Loud. Beautiful music.
So I must have something going on wrong with my pot. Maybe me. Maybe the pot.
Here's a picture with the lovely potential divider wired up for prosperity.
Just some thoughts on grounding:
1. The power input is grounded to the chassis in addition to the solder lug. I have the lug to chassis in a make shift "star" at the ground post.
2. The power negative on the board is wired to the ground post.
3. The board mounts go to ground via the chassis (all or some) so more grounding there.
4. The signal grounds are all connected to ground via the board.
So a ground fiesta.
But not problem with my last build with a lovely Noble 100K pot.
Odd.
I think I'll wire up my (fake) Alps pot not attached to the chassis.
Yes ACA on the sides.
(apologies for the fake Alps pot references - if this really a thing?)
Dan
Loud. Beautiful music.
So I must have something going on wrong with my pot. Maybe me. Maybe the pot.
Here's a picture with the lovely potential divider wired up for prosperity.
Just some thoughts on grounding:
1. The power input is grounded to the chassis in addition to the solder lug. I have the lug to chassis in a make shift "star" at the ground post.
2. The power negative on the board is wired to the ground post.
3. The board mounts go to ground via the chassis (all or some) so more grounding there.
4. The signal grounds are all connected to ground via the board.
So a ground fiesta.
But not problem with my last build with a lovely Noble 100K pot.
Odd.
I think I'll wire up my (fake) Alps pot not attached to the chassis.
Yes ACA on the sides.
(apologies for the fake Alps pot references - if this really a thing?)
Dan
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It’s hard to make out exactly what’s going on from the pic. But you are running the ACA and the korg off the same PSU? This probably complicated things a bit.
If you want to choose a “star” ground I’d choose the ground power inlet. But “Star” means all grounds return to this point. Yours don’t.
I’d get rid of the ground to the chassis. I’d wire up the pot outside the chassis and see if that works. Then I’d alligator clip it to the chassis as a test. If there is noise I’d isolated the korg from the chassis. One of these will work.
Belt and suspenders (as my boss used to say), I’d make sure the rca jacks and speaker outputs are isolated from chassis.
Also, since the B1 reverses speaker phase and the ACA does as well you need to make sure your speakers are in correct polarity. Which will mean output positive is speaker positive with this combo. You might already know that.
As for the pot, it’s no big deal but the alps pots (especially the blue) is the most counterfeited part in all of diy audio. Yours might be genuine, it was a joke. But don’t worry, the fake ones supposedly sound real good too.
Also, as you may have learned the korg has quite a turn on thump. Typically, I turn keep my preamp on and power amp gets turned on after. In your scenario it’s not possible since the korg and amp are on the same psu. Your speakers might not like this. You might want to figure out some sort of speaker out delay/relay or put the korg on a separate on off switch.
If you want to choose a “star” ground I’d choose the ground power inlet. But “Star” means all grounds return to this point. Yours don’t.
I’d get rid of the ground to the chassis. I’d wire up the pot outside the chassis and see if that works. Then I’d alligator clip it to the chassis as a test. If there is noise I’d isolated the korg from the chassis. One of these will work.
Belt and suspenders (as my boss used to say), I’d make sure the rca jacks and speaker outputs are isolated from chassis.
Also, since the B1 reverses speaker phase and the ACA does as well you need to make sure your speakers are in correct polarity. Which will mean output positive is speaker positive with this combo. You might already know that.
As for the pot, it’s no big deal but the alps pots (especially the blue) is the most counterfeited part in all of diy audio. Yours might be genuine, it was a joke. But don’t worry, the fake ones supposedly sound real good too.
Also, as you may have learned the korg has quite a turn on thump. Typically, I turn keep my preamp on and power amp gets turned on after. In your scenario it’s not possible since the korg and amp are on the same psu. Your speakers might not like this. You might want to figure out some sort of speaker out delay/relay or put the korg on a separate on off switch.
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Diy Nutube preamp with LiFePo4 battery
I finished my best Nutube preamp with the best parts and use Ian Canada LiFePo4 battery. I don't use the volume so I removed the input buffer, the jfets are 2SK170,..... The preamp can playing continue in around 15 hours with 7pcs LifePo4 in serie
The sound really excellent, ultra quiet
Thanks Nelson and Ian
I finished my best Nutube preamp with the best parts and use Ian Canada LiFePo4 battery. I don't use the volume so I removed the input buffer, the jfets are 2SK170,..... The preamp can playing continue in around 15 hours with 7pcs LifePo4 in serie
The sound really excellent, ultra quiet
Thanks Nelson and Ian
