SVT Plate resistor value

[01redcobra]

Got a mid 70's SVT in with 6550 power tubes. Question is, what is the correct value for the plate resistors in these amps? This one had 5 ohm 5 watt, but all the schematics I've found show 10 ohm 5 watt. Being that they are that close in value, will it make a difference either way?

[52 Bill]

Is this one of the black panel MTI versions? I think that there is a version with 5 ohm resistors, but there are additional changes to the circuit as well.

I have see these repaired with mixed values of resistors and they do work. Personally I go for whatever was originally there and as stock as possible. Maybe you can find the correct schematic or at least one that comes closer.

[01redcobra]

This is one from the Magnavox days. All the schematics I've found are showing the 10 ohm and the quality of the schematics are pretty bad. I was surprised to find only two resistors that had been replaced in the past. The other 4 were all original. Of course the 2 newer ones were the ones that are fried. Just wondered to myself if someone replaced them and never changed the tubes

[mozwell]

i hope one of these will help you

[01redcobra]

Nice, thank you! Looks like this may be a V9. Of course it would be the hardest to read. I've attached a pic of the resistors.

[Enzo]

The V9 is just a regular SVT with a different preamp.

Plate resistors fail when the tube fails. If some of your resistors are original it just means a tube never when bad in those sockets.


They are still using 10 ohms even in today's SVT Classic, they just moved them to the cathode side.

5 or 10 ohms is not going to affect the sound either, but in my opinion, the 10 ohms offers a little more protection and helps the tubes share a tiny bit better.

[g1]

That V9 drawing is for V9 and SVT. So your amp would be the SVT of that particular revision. If memory serves, V9 was the guitar version (ouch).