Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Leevi on January 12, 2011, 02:59:46 pm

Title: Sovtek Mig-50
Post by: Leevi on January 12, 2011, 02:59:46 pm

I found the following schematics for the Sovtek MIG-50 on the WEB.
Which one is the right MIG-50 schematic?

1. http://www.blueguitar.org/new/schem/sovtek/mig-50.pdf
2. http://www.blueguitar.org/new/schem/sovtek/mig-50h.gif

/Leevi

Title: Re: Sovtek Mig-50
Post by: gldtp99 on January 12, 2011, 05:46:20 pm

The Sovtek Mig 50 heads i've serviced most closely matched schematic #1--- not all of them were absolutely, perfectly identical but schematic #1 is the schematic i used...............gldtp99

Title: Re: Sovtek Mig-50
Post by: plexi50 on January 12, 2011, 10:31:26 pm

If i am correct the second schematic is the Mig Midget
The first schematic is the Mig 50

Title: Re: Sovtek Mig-50
Post by: The_Gaz on January 13, 2011, 01:50:39 am

The one on top is the regular Mig, which is more like a Plexi, and the second is the high-gain version (that's what the "H" stands for). The high-gain will have a "HI" and a "LO" input like a 2204 JCM 800. Both schematics should be close, although they were infamous (in my sad small tube-driven world) for using whatever surplus parts they had on hand. In fact, the amps were called "MIGS" because they evidentially used surplus parts from MIG fighter jets1

Title: Re: Sovtek Mig-50
Post by: Leevi on January 13, 2011, 09:35:23 am

Thanks for the replies guys. I believe you that it's the schematic #1 but I wonder how
close it is to Marshall Plexi 50. It seems the only bigger difference are the power tubes (5881s).
/Leevi

Title: Re: Sovtek Mig-50
Post by: plexi50 on January 13, 2011, 10:28:22 am

The Mig 50 was a clone of the Marshall circuit. You just dont have the low impedance jacks and it uses a 500 ohm resistor in place of a choke

The power supply resistor node values are also different. Close enough