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Messages - Jazz P Bass

Pages: 1 ... 9 10 [11] 12
151
Tubes and Hybrids / Re: Peavey VTX Classic 212 65w Need Help???
« on: January 04, 2018, 01:16:08 AM »
Right On, Enzo.


153
Schematics and Layouts / Re: Trainor Bass Mate Solid State amp repair.
« on: December 29, 2017, 02:41:06 PM »
I was totally confused by that reply myself.

" Not seeing anything too familiar in any of those Schematics,, Thanks for posting any way,, It's going to be another fly by the seat of my pants repair,,, "

Oh, well.

154
Schematics and Layouts / Re: Trainor Bass Mate Solid State amp repair.
« on: December 28, 2017, 11:00:00 AM »
http://traynoramps.com/downloads/servman/sm_trayint.pdf

The full part number of the output transistor is '2SC2233'.
No need for the 'Y'.

155
Schematics and Layouts / Re: National GA920P Schematic
« on: December 16, 2017, 05:12:13 PM »
Wow!

Those two schematics are totally different.

As the OP is searching for a schematic that uses 2SD428 (TO3 mount) the schematics may or may not be of help.

Maybe the Gibson G30 is closer.

156
Schematics and Layouts / Re: National GA920P Schematic
« 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.

157
Amplifier Discussion / Re: Capacitor conducting DC?
« on: December 14, 2017, 10:56:20 AM »
The only 100uf cap on the drawing is for the battery.

What problem are you troubleshooting?


158
Amplifier Discussion / Re: Heatsinks for your poweramp
« on: December 11, 2017, 10:45:07 AM »
Those are nice Ic's.

Good to know that they are robust enough to survive being 'hooked up wrong'.

Any idea what mistake you made?


159
Amplifier Discussion / Re: Heatsinks for your poweramp
« on: December 10, 2017, 01:55:41 PM »
The LM386 is Not simply an opamp.
It is a power amplifier in it's own right.

The quiescent current with a 12Vdc supply is in the milliwatts.
So that wont make you say ouch.
The power dissipation of the package is 500 milliwatts (1/2 watt).
Again, no need for a heatsink.

If the device got that hot, it is hooked up wrong.
Most probably it is now bad.

160
The Newcomer's Forum / Re: New here - JC-120 #492020 - chasing down info
« on: December 05, 2017, 12:56:52 AM »
Good Luck!

161
Yeah, there is not too much if anything 'out there'.

Layout drawing?

Hmmph.

162
The Newcomer's Forum / Re: Londoner L100A
« on: November 05, 2017, 11:25:04 AM »
Yeah, that's a 'ground' buss.

Not too sure about the slave.

163
The Newcomer's Forum / Re: TDA 2030 Guitar amp build oscillation problem
« on: October 05, 2017, 02:02:40 AM »
I would have to question where you purchased the TDA2030 ic's.

That ic is no longer in production.

LM1875 is.

164
The Newcomer's Forum / Re: TDA 2030 Guitar amp build oscillation problem
« on: October 01, 2017, 12:00:41 PM »
Understand that the reason for the capacitor on the output is because the power supply is a single polarity.

Therefore the output will 'sit' at 1/2 of the supply voltage.
Which is Volts dc.

The cap is not needed on a dual supply because the output 'sits' at 0 Vdc.

165
The Newcomer's Forum / Re: HH MA150 blowing mains fuses
« on: September 30, 2017, 10:45:26 AM »
HH MA150 schematic:

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