Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - vance

#16
Amplifier Discussion / Re: 1988 Randall RG100ES
December 30, 2019, 02:41:19 PM
350mv with signal
#17
Amplifier Discussion / Re: 1988 Randall RG100ES
December 30, 2019, 09:50:05 AM
Here is a pic of schematic
#18
Amplifier Discussion / Re: 1988 Randall RG100ES
December 29, 2019, 03:58:38 PM
i actually tried both ways. Im getting signal to the output but its not amplifying like it should. voltages on the Q14, 16, 13, 15 are
E 51mv , B 51mv, C43v
E 52mv, B 438mv, C 44v
E - 44v, B - 44v, C 53mv
E -44v, B - 44v, E 53mv

TIP 32  43v, 1v, 43v
TIP 32 53mv, - 43v, 0v
TIP 31 - 1v, 43v, 447mv

juction of the R48, R49 is - 17.4v

The trim pot dosent change the voltage at all
#19
Amplifier Discussion / Re: 1988 Randall RG100ES
December 27, 2019, 07:23:28 PM
I appreciate the reply...i did realize that and insulated them. Still have very low output out the speaker out . I did notice when hooking up the scope probe when i would attach the ground clip to the neg. of speaker output the volume would actually get a little louder. So thats where im at. The Tip 32 transistors test good. Not sure whats up with the low output at this point.
#20
Amplifier Discussion / 1988 Randall RG100ES
December 26, 2019, 03:17:30 PM
Picked up a randall rg100es from local pawn shop. someone had removed all 4 output tansistors. I bought replacements my issue is the board isnt labled at all for components. I installed the transistors and done what testing i could before i powered it up. Voltages seem ok from what i can make from the schematic. Im not getting any volume out the speaker outputs. I can hear it faintly and shows a weak signal on scope. It works through the signal out jack into another amp. One question i have is were the original power transistors 2n6254 insulated between the transistor and heatsink? Any help with getting this amp going would be greatly appreciated.