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Quick question - GK 1001RB-II - Pop when powered on?

L

lowend range

Inactive
Jul 29, 2010
126
0
The Empire State
#1
I purchased a used but mint condition GK 1001-RBII which is plugged into one of my Mesa 4x10 roadready cabinets (old style)

Is it normal to hear a loud "thud" or pop when the red light turns blue? I know a lot of amps specifically leave out whatever that part of the circuit is called so it pops, (SWR comes to mind) but I never read anywhere about GK amps doing it....

Any help or answers? (I tried it with the mute button on as well, and it still does it)

Thanks.
 
#2
I don't believe my 1001RB-II has popped or anything. I turn it on, red light, then it turns blue and you hear the bass signal loud and clear. So long as it doesn't take away from the overall functionality, I think you're okay. If it gets any worse though, you may want to have it checked.
 
#5
Marton said:
Mute the amp when it warms up ?

Maybe my 700RB-II do it, I don't know, it's always muted when I power it up.
Click to expand...

I tried it muted as well, it still makes a very audible, kind of loud thump in my speakers.

johnk_10 said:
i just checked mine and my 1001RBII makes the tiniest (almost completely inaudible) thump when the light switches from red to blue.
Click to expand...

Hmmm.... I think I may have to have mine looked at. Mine is much louder.
 
#6
I've got the 700RB-II. I always start it up with the mute button engaged, and it does make a slight but noticeable dull pop type sound when the red power light turns blue. I bought this amp new a couple of years ago, it gets turned on daily, it's been gigged frequently, and this sound has been there since day one. Never bothered me, hasn't gotten any worse, and I believe it's a normal starting up type of thing.

If you have any doubts about your amp, just give GK a call. You'll more than likely get connected to a real person within moments and get the info you need.
 
#8
lowend range said:
I purchased a used but mint condition GK 1001-RBII which is plugged into one of my Mesa 4x10 roadready cabinets (old style)

Is it normal to hear a loud "thud" or pop when the red light turns blue? I know a lot of amps specifically leave out whatever that part of the circuit is called so it pops, (SWR comes to mind) but I never read anywhere about GK amps doing it....

Any help or answers? (I tried it with the mute button on as well, and it still does it)

Thanks.
Click to expand...

Contact [email protected], this is an easy fix.
Bob
 
#16
Yes, the schematics for this amp are well done and the amp is well made. I have set the bias as per the instructions and the problem remains.

Here is an oscilloscope waveform of the amplifier's output to ground. The ~300ms, +50Vpulse happens the moment the red LED goes blue. As you can imagine, the speaker jumps.

1001rb_signal.jpg


You can see that just before the pulse the output it slightly negative. After the pulse settles the DC level on the ouput is zero. The amp then works perfectly and can put out 400W into 4ohms no problem.
 
#17
I just bought a GK 700RB II used a couple of weeks ago and it made the loud pop ( or bang ) when it powered up and changed from a red to blue LED . I sent it to a repair shop through Long & McQuade and when it came back it now only makes just the slightest little pop sound. When I recieved it from the shop it came with a cash register type print out that listed two parts replaced . The parts listed are as follows:

"Replace leaky Q11 , 14 "

SKU# 0800631 YSL PART MJE340T0126 NPN TRAN

SKU# 0800632 YSL PART MJE350T0126 PNP TRAN

Looks to me like they changed those two transistors , nothing else is mentioned on the slip .

Hope this helps somebody .
 
#18
Jammin Johneboy said:
I just bought a GK 700RB II used a couple of weeks ago and it made the loud pop ( or bang ) when it powered up and changed from a red to blue LED . I sent it to a repair shop through Long & McQuade and when it came back it now only makes just the slightest little pop sound. When I recieved it from the shop it came with a cash register type print out that listed two parts replaced . The parts listed are as follows:

"Replace leaky Q11 , 14 "

SKU# 0800631 YSL PART MJE340T0126 NPN TRAN

SKU# 0800632 YSL PART MJE350T0126 PNP TRAN

Looks to me like they changed those two transistors , nothing else is mentioned on the slip .

Hope this helps somebody .
Click to expand...

Thanks for sharing this.:)

Also anyone searching this thread as of today [email protected] is the current contact.
 

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