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Messages - vance

#1
Amplifier Discussion / Re: 1988 Randall RG100ES
January 04, 2020, 01:29:58 PM
I have found a couple 2n5484 transistors bad TR1 and TR5 so far. Not sure what effect that would be having on the power section but need replaced
#2
Amplifier Discussion / Re: 1988 Randall RG100ES
January 02, 2020, 02:04:18 PM
The base of Q10 is 43.5 v the emitter is 44.0v
#3
Amplifier Discussion / Re: 1988 Randall RG100ES
January 02, 2020, 09:53:20 AM
Yes they all test good
#4
Amplifier Discussion / Re: 1988 Randall RG100ES
January 01, 2020, 10:17:53 PM
when checking them against the schematic they are all close. So if there is 42v at the base of say Q11 where the schematic says 38v is that enough to cause issues ?
#5
Amplifier Discussion / Re: 1988 Randall RG100ES
January 01, 2020, 06:32:17 PM
i told you wrong....Q11 has 1.4 on base, Q10 has 41.2 on base Q8 has 41.9 as it should, and Q9 has 0.75 as it should ....Q12 has 0.5 on base
#6
Amplifier Discussion / Re: 1988 Randall RG100ES
January 01, 2020, 04:14:56 PM
the base of Q8 looks just like the signal at speaker out, tops only. The base of Q10 and Q11 have 42v on them. The base of Q12 has a small fuzzy ball shape sine wave
#7
Amplifier Discussion / Re: 1988 Randall RG100ES
January 01, 2020, 02:56:05 PM
Ok got my scope and signal gen. Straightened out. Looks like im only getting the tops or pos. Amplitude sine wave from the speaker output. The wave looks correct at the reverb IC 4588
#8
Amplifier Discussion / Re: 1988 Randall RG100ES
December 31, 2019, 10:14:55 PM
E 50.3mv        E 51.2mv        E -42.9v       E -42.9v
C 42.9            C 43.0v           C 0.3mv       C 54mv
B 50.6mv        B 430mv         B -42.9v       B -43v
#9
Amplifier Discussion / Re: 1988 Randall RG100ES
December 31, 2019, 07:54:27 PM
my scope is acting up so cant really go by that right now....but there is signal there
#10
Amplifier Discussion / Re: 1988 Randall RG100ES
December 31, 2019, 04:41:01 PM
the signal at  base of Q8 is same as the effects send. The base of Q9 is much less signal
#11
Amplifier Discussion / Re: 1988 Randall RG100ES
December 31, 2019, 03:59:55 PM
the amp controls all seem to operate as they should.....tone sounds ok and can adjust as normal just no volume. like its not amplifying much at all. Must be some what but very little. I mostly repair tube amps so the SS is kind of newl to me
#12
Amplifier Discussion / Re: 1988 Randall RG100ES
December 31, 2019, 03:55:33 PM
tops are squared off do to clipping i suppose. keeping the same settings on scope the wave is much smaller on 12 then the 8, 10 , 11 ....11 is the largest. Q8 is irregular pattern
#13
Amplifier Discussion / Re: 1988 Randall RG100ES
December 30, 2019, 09:16:56 PM
yes it checks good
#14
Amplifier Discussion / Re: 1988 Randall RG100ES
December 30, 2019, 08:12:00 PM
yes
#15
Amplifier Discussion / Re: 1988 Randall RG100ES
December 30, 2019, 06:08:15 PM
right now im getting 325mv ac out the 8 ohm speaker load. with the master on 10 and gain on 10 i get just enough volume to the speaker to hear it. The two center output transistors are getting slightly warm to touch but outer two are cold