Steel as magnetic shielding
Steel is needed to minimize magnetic (as opposed to EMI) effects. If you purchase an Antek transformer, you can also purchase a purpose-made steel case that the toroid fits in for magnetic shielding. Other brands "may" offer steel bands around the circumference of the toroid to achieve magnetic shielding.
You could use mu-metal, which is a special form of steel, but it is very expensive and as I understand it, mu-metal looses its properties if it is worked/formed, and must be re-annealed after forming/working to re-establish its shielding properties.
Steel is needed to minimize magnetic (as opposed to EMI) effects. If you purchase an Antek transformer, you can also purchase a purpose-made steel case that the toroid fits in for magnetic shielding. Other brands "may" offer steel bands around the circumference of the toroid to achieve magnetic shielding.
You could use mu-metal, which is a special form of steel, but it is very expensive and as I understand it, mu-metal looses its properties if it is worked/formed, and must be re-annealed after forming/working to re-establish its shielding properties.
To those who already have the B1 Kit:
May I ask if it emits any heat at all (PCB, Nutube, other parts)?
I am asking because I plan to put it in a chassis without any hole vents in it (to minimize any sound/vibrations going in, as well as for aesthetics).
But if it emits even just a little heat, then I'll be forced to put in a few hole vents in the casing.
May I ask if it emits any heat at all (PCB, Nutube, other parts)?
I am asking because I plan to put it in a chassis without any hole vents in it (to minimize any sound/vibrations going in, as well as for aesthetics).
But if it emits even just a little heat, then I'll be forced to put in a few hole vents in the casing.
I have my B1 Korg inside the case of a Naim NAC 62, which is completely enclosed. No ventilation is necessary. In fact, it is better to not have any holes in the case because they may allow acoustic feedback and ringing from the NuTube.
For the small amount of heat produced by a little SMPS, there is still enough heat transfer with an un-ventilated case.
For the small amount of heat produced by a little SMPS, there is still enough heat transfer with an un-ventilated case.
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The thermal rquilibium will however be different depending on the ambient temp. In winter my room is at 68F while in summer it could get to 80F.
I wonder how much the distortion strata and THD changes as the cases heat up. Not sure but the Nutube THD could change quite a bit with a case internal PSU which generates heat especially a shunt type.
nash
avdesignguru ,
thanks so much for guiding me through this project. It's really helpful. Well Mean sounds good. I've been using LED PSU for small tube pres. So, it makes sense to me. And I love to use putty myself.
I am also reading your post about F6. And Jim pointed out that F6 might be an easier build than F5 for me.
So I just ordered a pair of Jensen from the Ebay...Cable solution. I grabbed the last pair. I am about to order a F6 board.
avdesignguru and Jim, thanks for your help. And Mr. Nelson Pass, if you are reading this, I want you to know that I am so thankful.
thanks so much for guiding me through this project. It's really helpful. Well Mean sounds good. I've been using LED PSU for small tube pres. So, it makes sense to me. And I love to use putty myself.
I am also reading your post about F6. And Jim pointed out that F6 might be an easier build than F5 for me.
So I just ordered a pair of Jensen from the Ebay...Cable solution. I grabbed the last pair. I am about to order a F6 board.
avdesignguru and Jim, thanks for your help. And Mr. Nelson Pass, if you are reading this, I want you to know that I am so thankful.
I have the F6 & Korg b1 Nutube combo and I really like it. Now I have taken de schiit saga out of the chain and replaced it with a muses volume control. I have been going through all my "test" records and to my surprise it did change soundstage and higher frequencies quite a lot. Soundstage is much more accurate and higher frequencies sound cleaner and less fuzzy to me.
Very happy to inform that the muses volume control is a big step up in favor of both a schiit saga (relay stepped attenuator) and a dact type stepped attenuator.
FYI, am still on triad PS.
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Cable Solutions is a good vendor. I bought my last pair of F6 Jensens from them and saved a bit on freight over direct purchase from Jensen.
You will need the matched input JFETS and I recommend buying them from DIY store as well. I found I did not need output Mosfets to be matched. I did need to go to the next higher voltage zener to achieve desired bias.
Is the Mean Well you are using the same as the MeanWell power supply used in the ACA 1.6?
Thank you.
ACA is a 120 watt supply. I used a 25 watt Mean Well GST25U24-P1J, equivalent to the Triad specified by Mr. Pass.
.
I too am building the same amps...B1+F6. Exciting
How about something like the one below. I've used it for various projects...no need trans. The ripple is 120mv ish. It's a little lower than the GST25U24-P1J which is about 150mv. This may be inconsequential as Mr. Nelson made the provision to make it lower so....
MW Mean Well RS-25-24 AC to DC Power Supply Single Output +24V NIB 50/60Hz 1.1A | eBay
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For my aca.. I made an on off DC circuit breaker after the cap reserviour.. Works very well.
Sounded very good very quickly
The Reports on the Muses Volume Control is quite satisfying, my gut instinct has been driving me toward a Muses, it was a interface in a system I was feeling compelled to put into use,
especially when my caught up in the COVID 19 Lock Down Korg B1 is finally produced.
The Local HiFi Group now have five built, and the Modular Design has become the favoured design.
My intention is to Trial My Slagle AVC vs a Promethius TVC and a Tocos Pot'.
I also have a DACT but, I have been advised the Stepped Attenuator can have a few operational issues to be overcome, so the DACT was removed from the line up for Volume Control Trials.
A Muses Volume Control has been on my mind for a Long Time, and with the Korg B1 to become a owned, and I am feeling it will be an End Game Pre',
I was very interested in the idea of using The Muses.
I don't do DIY Electronics, anything that requires a understanding of Schematics and Soldering is avoided by myself as a hands on task.
This has never discouraged me from venturing into the wonderful world of
Unique Produced Devices, as my system is built from such products.
To achieve such a set up, it generally means I rely on support from those that are in possession of a full understanding of the requirements to produce the devices I am interested in.
As a request, I am going to inquire if there is anybody available who could produce for me a Muses Volume Control, that when produced, it can be set up in its own Casing, to be used as a Module to be connected to a
Second Casing/Module that will have the Korg B1 PCB housed inside.
If there is any help available to support this request, can I be PM'd
especially when my caught up in the COVID 19 Lock Down Korg B1 is finally produced.
The Local HiFi Group now have five built, and the Modular Design has become the favoured design.
My intention is to Trial My Slagle AVC vs a Promethius TVC and a Tocos Pot'.
I also have a DACT but, I have been advised the Stepped Attenuator can have a few operational issues to be overcome, so the DACT was removed from the line up for Volume Control Trials.
A Muses Volume Control has been on my mind for a Long Time, and with the Korg B1 to become a owned, and I am feeling it will be an End Game Pre',
I was very interested in the idea of using The Muses.
I don't do DIY Electronics, anything that requires a understanding of Schematics and Soldering is avoided by myself as a hands on task.
This has never discouraged me from venturing into the wonderful world of
Unique Produced Devices, as my system is built from such products.
To achieve such a set up, it generally means I rely on support from those that are in possession of a full understanding of the requirements to produce the devices I am interested in.
As a request, I am going to inquire if there is anybody available who could produce for me a Muses Volume Control, that when produced, it can be set up in its own Casing, to be used as a Module to be connected to a
Second Casing/Module that will have the Korg B1 PCB housed inside.
If there is any help available to support this request, can I be PM'd
hello
I developed a Muses Volume and Input selection module
and build it into my Korg Nutube Preamp.
I called the whole module „PCU“ Preamp-Control-Unit.
In the photos you can see the structure of the preamp.
On the left the muses and digital board. On the right the input module with four inputs and next to it an input-expansion-board with two inputs. The PCU Modul is controlled via two encoders, alternatively with an Apple remote control, in the future also with an IOS app. I’ll make a description of the „PCU“ and post it here. I think I need a day to do that, so I could post the description here tomorrow, Sunday.
Juergen
I developed a Muses Volume and Input selection module
and build it into my Korg Nutube Preamp.
I called the whole module „PCU“ Preamp-Control-Unit.
In the photos you can see the structure of the preamp.
On the left the muses and digital board. On the right the input module with four inputs and next to it an input-expansion-board with two inputs. The PCU Modul is controlled via two encoders, alternatively with an Apple remote control, in the future also with an IOS app. I’ll make a description of the „PCU“ and post it here. I think I need a day to do that, so I could post the description here tomorrow, Sunday.
Juergen
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