TEAC Model 5 Power Supply

[ilyaa]

hey everyone -

got this TEAC Model 5 mixer on the bench trying to decide what to do with it -

thing is, whoever had it before me 'externalized' the power supply (maybe for noise reduction/performance) - unfortunately for me, that means there is NO power supply in here. i snooped around for anyone selling one for parts but no luck -

looking at the schematic it shouldnt be too crazy to build one - but am wondering if there are any suitable meanwell or other brand ones that would fit the bill?

looks like i need +/- 15V at about half an amp, +15V at about half an amp, +6.3 and +5V at 300mA or so.

if i built one i could probably use modern science and technology to put together something simpler than the orig - any suggestions?

PS is on pg. 87 of attached schematic

[nickb]

My guess is that the transformer died and they could not get a replacement as it has four secondary windings. To get the equivalent function you would need to use three off the shelf transformers that commonly have a single center- tapped secondary. That might be a size and /or mounting nightmare before you're even out of the starting gate. Then you have to design and make the rectifier and regulators all while keeping the noise down. In a nutshell it's not a trivial task.

On the other hand you might be able to find ready made ones that fit the bill but if they are not linear you might find yourself dealing with difficult noise issues. Again mounting and space will be concerns.

It seems to me you have a good solution with the external PSU and anything else is just creating work.

[ElectroWinder]

Although there are youtube videos on how to identify the voltage setting component of a smps and swap it out to set your own desired voltage, it is extremely dangerous as there is 300 to 400 volts in the front section of a smps

For the positive voltages, you could purchase a 24v smps and use individual voltage regulators mounted on heat sinks to get the required positive voltages - but the negative 15v is going to be the problem - you will need a center tapped transformer for that - maybe something in the range of 18-0-18 to 24-0-24 and a positive 15v regulator and a negative 15v regulator on heatsinks as this from https://www.eleccircuit.com/power-su...-ic-7815-7915/

[ElectroWinder]

Having now looked at the teac schematic, you could simply build the +6.5v and +5v section yourself straight from the schematic using a mains transformer with 9V ac output

[ilyaa]

okay hows this:

found one of these i had used for a project some time ago - https://www.mouser.com/ProductDetail...KOH0Z1PQ%3D%3D

should be good for the +/- 15V, right??

and this will probably be fine for the lower voltages, correct? https://www.ebay.com/itm/PHILMORE-TR...AAAOSwbfRcoPCz

just wondering - those weird ICs (uA723) in the Model 5 power supply seem a bit overkilly - a simple regulator will do probably, for the +6.3 and +5? seems like i could make the Model 5A power supply pretty easy (usings a 7805, etc) - any thoughts?