6.3VAC to 6.3VDC LDO supplies MIC5156 based tube amp upgrade

[v4lve lover]

I replaced them with unpolarized caps a while ago. Measure the bridge and get some unpolarized replacements 47uF 25V

 

[Bas Horneman]

Thanks. I got you mixed up with another user it seems. My apologies. Thought you had left the forum.

 

[Ryssen]

Anyone have a Bom they wanna share?

 

[Bas Horneman]

https://www.diyaudio.com/community/...56-based-tube-amp-upgrade.382265/post-7515640
This post has virtually all the values.

I got some stuff from the local surplus store. You can use through hole resistors easily on the pads. Everything bog standard really.
You need the adjustable version of the mic https://nl.mouser.com/ProductDetail/998-MIC5156YN

If you are using the "through" hole version get this pot: https://secure.reichelt.nl/nl/nl/pr...den-staand-10-k-ohm-64y-10k-p2716.html?&nbc=1. The smd board cleverly allows "all types"

Heatsink: https://secure.reichelt.nl/nl/nl/ko...-sk-129-38-1-p228064.html?&trstct=pos_1&nbc=1

So sorry no bom.

 

[Bas Horneman]

I replaced them with unpolarized caps a while ago. Measure the bridge and get some unpolarized replacements 47uF 25V

Swopping polarity will work as well. Swopped the polarity around on the boards I bought from you. And then there is 8 volt accross them with negative probe on negative pole and positive probe on positive pole.

 

[platon.rado]

if you can't find 47uF nonpolar then you can use two 100uF normal polarised electrolytics in series with their negative legs joined, per side.

 

[Bas Horneman]

Polarised work fine if connected the right way. Removed these. Shows that polarity is reversed.

 

[Bas Horneman]

Fixed.

 

[platon.rado]

ok

 

[v4lve lover]

Im building a new batch of ten of these boards, Pm or leave a message here when interested, price €32.50 each excluding postage.

 

[Ryssen]

Ive built 5 of these with pcbs from jlp.But I cant get past 6v with a 6sn7 at the output.Its he same on all boards.I have 6,55v at the big elyts.
I use IRF840 is that of any dissadvantage?

 

[Bas Horneman]

What rectifiers are you using?
Pictures might help to spot causes.

 

[v4lve lover]

IRF840 is unsuitable, try IRL540

 

[Ryssen]

I found the fault.

I found out that the experiment cables that I use between the trafo and the 6,3v module are to thin that I get a voltage drop.
I took another pair and paralleled and I now get 6,3v dc out.
The rectifier is SB560.

​

 

[Bas Horneman]

c1 and c2 are the wrong way around still. Check my post 87 and 88.

 

[zoom777]

I found the fault.


I found out that the experiment cables that I use between the trafo and the 6,3v module are to thin that I get a voltage drop.
I took another pair and paralleled and I now get 6,3v dc out.
The rectifier is SB560.

​

So the IRF840 is doing fine in this circuit? I have also purchased them for this board.

 

[Ryssen]

As far as I can see they work fine,lets wait for V4lv lover has to say about them.

 

[Ryssen]

c1 and c2 are the wrong way around still. Check my post 87 and 88.

Will change to unpolarized.But it still working as it is.I think they are a part of a voltage doubler.

 

[Ryssen]

Have been using the module for about 2 days with IRF840,and everything seems fine,no blown caps and spot on 6,3v.

 

[v4lve lover]

IRF840 is not reccomended, its got too high on resistance.

C1 and C2 change to unpolarized UVP series 100uF 25V