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Messages - lotus1

#1
Tubes and Hybrids / Re: New amp day! Silvertone 1481
December 28, 2017, 08:48:52 PM
Rotate speaker 180 degrees, tightens it right up...they sag over time, try it.
#2
Schematics and Layouts / Re: National GA920P Schematic
December 22, 2017, 07:46:33 PM
Yes, 12" ceramic magnet, no names...sound pretty good tho. Kind of a Gilmour sound...That clear but "warm" thing.
#3
Schematics and Layouts / Re: National GA920P Schematic
December 22, 2017, 05:00:34 PM
Pics.
#4
Schematics and Layouts / Re: National GA920P Schematic
December 20, 2017, 09:36:49 AM
Effected repairs, Had to use a 1ohm resistor instead of .5...It's alive!! Workd again and that very cool sound is being heard again, Once again, Thanks for all. Will try to post pics soon.M
#5
Schematics and Layouts / Re: National GA920P Schematic
December 17, 2017, 11:00:15 AM
Very cool ideas...Thanks..will attempt when I can get some time..Just effected the "repair" so, fingers crossed it'll work. discovered why the funky red wire attachment..the solder pad had lifted when the original repair was done. fixed that a little better. get to try it out a bit later. Than ks all, cool place here. Next up is my peavey session 400 which ate the speaker voice coil. Putting out something ugly. had a wind shear go thru woods around studio took power out while amp was on..we see.
#6
Schematics and Layouts / Re: National GA920P Schematic
December 17, 2017, 07:44:43 AM
More Pics.
#7
Schematics and Layouts / Re: National GA920P Schematic
December 16, 2017, 10:09:19 PM
1/2? Thanks.  Was told the transistors went bad, they were replaced but, resistors, no.and yes, he was lazy... Haven't gone in myself as without a schematic, I don't touch...or help. I will rectify both the resistors and shoddy wiring, will report back. Oh, and the amp was only used with the cabinet it came with, a 2x12...haven't measured cabinet Z yet, so...It does look like the original cabinet. Will post more pics in the morning,Thanks.<
#8
Schematics and Layouts / Re: National GA920P Schematic
December 16, 2017, 08:39:02 PM
Quote from: Jazz P Bass on December 16, 2017, 02:31:02 PM
It may help if you describe where the resistors go.

What points do they attach to?
Resistors burn up when another part of the circuit demands eccess current.
Yes, I understand, Was looking for the schematic but, Here's a couple of pics. It's the red ones connected to the transistor itself. One has the red wird connected directly, not sure why that is. Thanks for the replies, really like this amp, would like to get it running again. Mario
#9
Schematics and Layouts / Re: National GA920P Schematic
December 16, 2017, 09:37:15 AM
Hello, I just discovered this forum and thread. Very cool. Have a question tho. I have a national GA 960P amplifier.I am in need of a schematic or someone who has one as I have 2 resistors that need replacing but, have burned up to the point I can't read values. If anyone has one of this model, would very much appreciate any help. It uses 2SD428 output transistors. Thanks all.Mario