MJ Statistical Regulator PCBs

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thomas
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Re: MJ Statistical Regulator PCBs

Post by thomas » Tue Jan 19, 2016 7:00 am

…. and mine, too. Thanks again for all the work you've put into these….

simon
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Re: MJ Statistical Regulator PCBs

Post by simon » Tue Jan 19, 2016 12:40 pm

Mine arrived safely last Wednesday thanks Nick, today's the first day I've been in to the office since to pick them up. Thanks again for going to all the trouble.

davebms
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Re: MJ Statistical Regulator PCBs

Post by davebms » Fri Jan 29, 2016 8:37 pm

hello all do you have any more kits would like 2 with vertical trimers

thanks dave

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jack
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Re: MJ Statistical Regulator PCBs

Post by jack » Sun Jan 31, 2016 6:13 am

Hi - apologies for delay in replying - I'll be back in the uk tonight - I have a few more kits from this batch - please PM me your address and I'll reply with costs etc.

Cheers
Nick
Ars longa, vita brevis

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Ray P
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Re: MJ Statistical Regulator PCBs

Post by Ray P » Sun Jan 31, 2016 4:23 pm

It lives!

I've been testing my first build of one of Nicks kits. I've tested OK with dummy loads and it checked out fine so I've hooked it up to the target load; looking good so far;

Image

I'm planning to use it to power a Broskie BCF kit. I used 35V zeneers, which the manual say will give 200.9VDC, I'm reading 199.3VDC so pretty damn close (within 1% of what the manual says it should be). I've set the zeneer chain current to 10mA for now to see how it goes over an hour or so. Total load will be 21mA plus whatever zeneer load I dial in.

One thing to look out for when using this regulator to power a valve stage like mine is start-up. I'm not using any switch on delay for the B+ and I noticed that the zeneer load is initially about 30mA before it settles back to 10mA after a few seconds, presumably as the filaments warm up; I think I'll arrange for some switch on delay in the final implementation as the initial peak is likely to stress the components. What do you think Nick?

Ray

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jack
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Re: MJ Statistical Regulator PCBs

Post by jack » Sun Jan 31, 2016 10:26 pm

Looking good!

30mA is fine - well within the zeners' specs - no stress there at all...

You are right in that until the heater is up to temperature and the tube starts conducting, all the current will flow through the zener string...
Nick
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Ray P
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Re: MJ Statistical Regulator PCBs

Post by Ray P » Mon Feb 01, 2016 7:44 am

Thanks Nick, that's reassuring about the zener load at start-up.

I left it hooked up and running for nearly 2hrs and nothing failed. the output voltage, measured with my old Fluke, is now a steady 199.7V (35 zeners). The zener current appears to drift by a few tenths of a mA but not sure how much of this is real and how much is down to the accuracy over time of the Uni-Trend multimeter I'm using.

Anyway, time to hook everything up for a listen...

Ray

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Re: MJ Statistical Regulator PCBs

Post by davebms » Sat Feb 06, 2016 12:37 pm

jack wrote:Hi - apologies for delay in replying - I'll be back in the uk tonight - I have a few more kits from this batch - please PM me your address and I'll reply with costs etc.

Cheers
hello did you get my pm
dave

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Ray P
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Re: MJ Statistical Regulator PCBs

Post by Ray P » Sat Feb 06, 2016 7:57 pm

So my MJ Statistical Regulator is now in service providing 20mA 200V of B+ to a Broskie BCF module.

Image

The project is a 'no-dac' DSD decoder; I'll post some details in the computer audio section a bit later.

Ray

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Re: MJ Statistical Regulator PCBs

Post by little eddy » Sun Feb 07, 2016 11:14 am

For those that installed these I have a couple of questions?

Is there a recommended minimum volt drop across the regulator - if I dropped into my amp as-is, it would see around 107V but could put a larger filter network feeding it?

What is the maximum power dissipation of the regulator without a heat sink? I am presuming the transistor to the side of the board is the one that sees most of the load and would need cooling. Will be running a total current of around 30mA so with supply the MJSR would need to dissipate around 3.2W.

Feels like I need to step down the supply voltage a bit more, perhaps as well as a heatsink.

Thanks,

Mike.
TD-125/RB250/MC25FL & 'Snail' phono, NAS/SBT with CS4398 DAC, 41MP pre & MoFo Power, still messing with OBs.

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Ray P
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Re: MJ Statistical Regulator PCBs

Post by Ray P » Sun Feb 07, 2016 11:49 am

Nick has said a minimum drop of 15V across the MJSR but to avoid too much more (he gives a range of 15-25V in the manual) - I'm dropping about 18V across mine (Vin 218V, Vout 200V give or take the odd millivolt).

I'm using mine with a total load of 35mA, 20mA to the load and 15mA through the zeners. The board gets a warm, nothing extreme. Nick's manual specifies the maximum output current as 200mA.

Looks like you need to burn some more volts in the pre-filter?

Ray

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Ray P
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Re: MJ Statistical Regulator PCBs

Post by Ray P » Sun Feb 07, 2016 11:53 am

jack wrote:Looking good!

30mA is fine - well within the zeners' specs - no stress there at all...

You are right in that until the heater is up to temperature and the tube starts conducting, all the current will flow through the zener string...
I decided to use a front panel switch to manually delay applying B+ for an arbitrary period of time - better for the valves that way.

Ray

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Re: MJ Statistical Regulator PCBs

Post by little eddy » Sun Feb 07, 2016 2:38 pm

Ray P wrote:range of 15-25V in the manual - I'm dropping about 18V across mine ... using mine with a total load of 35mA. Looks like you need to burn some more volts in the pre-filter?
Ray
Thanks. So no dissipation issue if I target around 20/21V @ 30mA.
TD-125/RB250/MC25FL & 'Snail' phono, NAS/SBT with CS4398 DAC, 41MP pre & MoFo Power, still messing with OBs.

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jack
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Re: MJ Statistical Regulator PCBs

Post by jack » Mon Feb 08, 2016 9:51 am

davebms wrote:
jack wrote:Hi - apologies for delay in replying - I'll be back in the uk tonight - I have a few more kits from this batch - please PM me your address and I'll reply with costs etc.

Cheers
hello did you get my pm
Yep - apologies for the delay in handling this - its been a mad, mad, week since we got back - I'll reply tonight.

Cheers
Nick
Ars longa, vita brevis

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jack
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Re: MJ Statistical Regulator PCBs

Post by jack » Tue Mar 15, 2016 9:56 am

Just a'wondering - anyone used any of these for anything yet :)
Nick
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