Temperature compensated MAIDA

[jackinnj]

I've noticed that my Maida regulators drift with temperature -- LB47 has a compensated circuit using the LM329 -- here's how to implement -- first the schematic:



Here's a single layer version free for the pickin'

[wirewiggler]

Jack,
Can you send me the file on this, I will try to make one by hand.

Thanks
Bill

[okapi]

Hi Jack,

can i ask what you need the high voltage for?

thanks.

[jackinnj]

Originally posted by wirewiggler
Jack,
Can you send me the file on this, I will try to make one by hand.

Thanks
Bill

PM me your email address. I changed the voltage setting resistor to consist of 2 units -- it's less expensive to use a pair of 3W devices and spread the heat.

Originally posted by okapi
Hi Jack,

can i ask what you need the high voltage for?

thanks.

Tube preamp.

[okapi]

this is the data sheet for the Maida regulator from national (1980).

[jackinnj]

Originally posted by okapi
this is the data sheet for the Maida regulator from national (1980).

The Value of C1 should be 1uF, not 100F -- this is a recurrent problem with Multisim -- but when I translated Multisim to Ultiboard I changed the value to 100nF -- should be 1uF -- thank for pointing out the error. A 1uF pp also has a bigger footprint.

The pass transistors which Maida used are now unobtanium. The TIP50's are rated 500V and are more than sufficient for the task.

[Salas]

I just use a single IRF840 pass element.

[okapi]

Originally posted by jackinnj



The Value of C1 should be 1uF, not 100F -- this is a recurrent problem with Multisim -- but when I translated Multisim to Ultiboard I changed the value to 100nF -- should be 1uF -- thank for pointing out the error. A 1uF pp also has a bigger footprint.

The pass transistors which Maida used are now unobtanium. The TIP50's are rated 500V and are more than sufficient for the task.

unfortunately, i can't take any credit for finding an error. I was just posting the application note so that beginners like myself, who can't figure out a circuit without an explanation, could make also make use of your helpful post.

i believe you have also built the jung super reg, how does the noise level of the Maida with the lm329 compare?

[jackinnj]

Originally posted by okapi



unfortunately, i can't take any credit for finding an error. I was just posting the application note so that beginners like myself, who can't figure out a circuit without an explanation, could make also make use of your helpful post.

i believe you have also built the jung super reg, how does the noise level of the Maida with the lm329 compare?

Janneman, I believe, did the definitive work on the Jung super-reg. I use a smt version of the Jung/Didden in my rework of the Crown IC-150 with wonderful results.

Somewhere in the universe of diyaudio is a comparison of the Last-PAS regulator and my LR8N3 (supertex) regulator. I used a storage-scope, bandwidth limited, to integrate noise over time. I haven't put the temp compensated Maida through these paces.

The LastPAS can be a little wonky with respect to temperature and I found that the current range of HV zeners are more prone to failure than their Pb cousins.

The LastPas is a really quiet, really low impedance supply.

[okapi]

thanks for your replies. Because of this thread i have discovered 3 additional voltage regulators. I was foolish to think i had almost maxed what there was to know about "standard" linear power supplies for audio.

on a side note, i hope the new version of diyaudio moves the power supply forum to its proper place - the home page.