pH

Master Room reverb 4194 VR chip
« on: February 27, 2012, 01:49:27 PM »
I have a MicMix Master Room XL-210 spring reverb on my bench that isn't working, I suspect the voltage regulator chip might be the culprit. Problem is that it uses a SG4194CJ chip that is listed as obsolete. Anyone familiar with these? I can't seem to find anything that would work in its place, nor can I find a schematic for the unit.

http://www.datasheetcatalog.org/datasheets/120/354845_DS.pdf

-Paul


pucho812

Re: Master Room reverb 4194 VR chip
« Reply #1 on: February 27, 2012, 09:00:16 PM »
try nte.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Harpo

Re: Master Room reverb 4194 VR chip
« Reply #2 on: February 28, 2012, 11:35:19 AM »
If you don't need the +/-V tracking and can't source the original, a 78xx/79xx substitution should bring it to life again. Resistor value of (Ro / 2500) will give you the ballpark number of DC voltage/rail for xx. Just an idea...
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams

pH

Re: Master Room reverb 4194 VR chip
« Reply #3 on: February 28, 2012, 01:13:21 PM »
Not being much of a SS guy I'm not sure how I'd go about a substitution. I'm more from the simple tube PSU farm.
Any over-explanation would be greatly appreciated.

Harpo

Re: Master Room reverb 4194 VR chip
« Reply #4 on: February 28, 2012, 05:27:20 PM »
rough drawing to fit in 4194 socket.
Value of xx will be about resistor value connected to 4194-pin10 / 2500.
FI value of Ro about 6K would suggest a 6000/2500 = 15, so use 7815 and 7915.
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams

pH

Re: Master Room reverb 4194 VR chip
« Reply #5 on: February 28, 2012, 10:15:17 PM »
Goodness.

Amazing, this place.

Thanks a ton Herr Harpo.
-Paul

mobyd

Re: Master Room reverb 4194 VR chip
« Reply #6 on: March 02, 2012, 06:26:30 PM »
Goodness.

Amazing, this place.

Thanks a ton Herr Harpo.
-Paul
If you don't end up using Harpo's (very impressively drawn) setup, I have a bunch of XR4194s and could send you one FOC.
Cheers
M

pH

Re: Master Room reverb 4194 VR chip
« Reply #7 on: March 30, 2012, 12:45:16 PM »
Hey MobyD,
PM'd you about getting a couple of those 4194s from you.

pH


 

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