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Help - Ampeg vs GK volume issues

I

iandi.bass

May 20, 2009
30
0
#1
So I've got a bit of a problem



Ultimately, I've already got two things in mind:

1) to try and get a replacement shipment of all my tubes

2) take my amp back AGAIN to a tech to get cheked a 4th time...



Heres the situation:


I own a USA Ampeg CL and a GK 700RB


Ive owned the GK head sicne about 05'-06'. Used to be beat up, got it fixed as a backup head 3-4 months ago. Bangs out great. No problems.

The CL I purchased used off craigslist about a year ago, previous owner had it for a few more years. Worked good. After a few months I decided to get some new tubes, previous owner mentioned it might be a good idea, he never changed em, sound started to deteriorate a bit from when i first purchased it.

Bought new tubes off tubestore.com, took it to a tech, they replaced em, checked it, cleaned it, set it, boom. At this point, the head has been looked at 3 times since about july, not including the replacement.

After the tubes were replaced, I tested it and noticed a pretty large difference in sound before-after, and the CL hit a spark or something and **** itself off, with the green/red light flash (signs of something w/ the tube). So I took it back, they told me the amp was working fine, a tube sparked once, but never again. Checked it again, and let it run 15+ hours, never happened again worked fine.

Took it home, got a replacement for one of the tubes that looked bad, fixed it a bit. fine.


Been playing with it like this since around november and I just have not been at all satisfied with the sound.




The past 2 weeks or so, I decided to try my GK head again after having played a small gig with, and the GK head is blowing my Ampeg head out of the water in volume and lowend. Its actually kind of pissing me off that Ive spent so much money on the CL and my little GK is ripping it. Ive got the CL cranked with gain about 5-6 and master around 8-9, and it is barely even doing half of what the GK is doing when volume is at 12'. Really upsetting me.


SO, my question is:


has anyone ever dealt with this? heard something similar?

any suggestions as to what to do? could it be the fuse in the CL? I honestly dont really know to what purposes the fuse serves, whether or not i should get a new one, etc, etc.


thank you very much.
 
#2
I honestly don't know much about tube amps, but I do know that not all tubes are created equal. Just because a tube is (for example) a 12AX7, doesn't mean it performs the same as other similar tubes from a different brand. That would be my first guess for where to start looking. Next step would be to go through the wiring paths with a multimeter looking for bad components. That's about all I can think of right now...hope it helps a little, anyway.
 
#3
Every time an output tube is replaced the bias needs to be adjusted correctly. If a tube has "sparked" it's bad period! You can't tell that a tube is bad by simply looking at it. It has to be tested. Replacing just one tube in a triple without regard to bias can put your whole amp out of whack.

Comparing two differing amps by how much you have to turn them up is pointless. All you are comparing is gain structure. There is no correlation between the position of the level control to how much output the amp is giving.

Unless the CL has fuses in the output tubes cathode circuits, which I don't believe it has, a fuse has nothing to do with your "problem".
 
#4
I've played through Ampeg, but I'm now a GK man. It's like Ampeg is getting all of their business from a reputation they built over 25 years ago, and people just aren't bothering to look at other stuff. For example, I'm a huge Precision fan. Don't want anything else. My main bass is a Precision Elite II. I'm trying to collect them. I go through a GK 1001 RB-II pushing an SWR Workingman's Tower (8x10). I can get any sound I want out of that rig, and it will make your BONES vibrate. It's all I need.

But those are just my opinions, I could be wrong.
 
#5
BassmanPaul said:
Every time an output tube is replaced the bias needs to be adjusted correctly. If a tube has "sparked" it's bad period! You can't tell that a tube is bad by simply looking at it. It has to be tested. Replacing just one tube in a triple without regard to bias can put your whole amp out of whack.

Comparing two differing amps by how much you have to turn them up is pointless. All you are comparing is gain structure. There is no correlation between the position of the level control to how much output the amp is giving.

Unless the CL has fuses in the output tubes cathode circuits, which I don't believe it has, a fuse has nothing to do with your "problem".
Click to expand...

+1
If it was serviced by a competent tech I am sure he already knows this, but it doesn't hurt to check.
 
#7
deeptubes said:
I've played through Ampeg, but I'm now a GK man. It's like Ampeg is getting all of their business from a reputation they built over 25 years ago, and people just aren't bothering to look at other stuff. For example, I'm a huge Precision fan. Don't want anything else. My main bass is a Precision Elite II. I'm trying to collect them. I go through a GK 1001 RB-II pushing an SWR Workingman's Tower (8x10). I can get any sound I want out of that rig, and it will make your BONES vibrate. It's all I need.

But those are just my opinions, I could be wrong.
Click to expand...
don't worry. you are ;) at least about ampeg. first, they built their reputation 50 years ago, not 25. second, saying that people aren't bothering to look at other stuff grossly underestimates people's intelligence. unfortunately, this seems to be the norm when people buy stuff like fender and ampeg and not their favorite brands.
 
#8
DanRJBrasil said:
get a good tech to look at it, that one doesn't seem to be a good one
Click to expand...

Why?? The problem, as I see it, is that quote "Took it home, got a replacement for one of the tubes that looked bad, fixed it a bit. fine".

So we had a set of new tubes that the bias was set up for. The OP then changed one disturbing the bias setting for that triple. You can't blame a tech if the owner interferes with his work!

The only way you can spot a bad tube is if you see it arc or the tube's cracked and the getter has gone white.
 
#10
Success with any particular amp depends on the amp's reliability, its owner, the tech support, and availability of quality parts. (I'm assuming proper physical handling as a given.) If even one of those doesn't hold up, then that amp is not for you. You, the second factor, are the only one in this calculus that appears to be holding up its end of things. That's not enough for amp joy, however, so I'd suggest you part with the amp and take up a different brand, without vacuum tubes, whether or not it's GK. Another (last ditch) alternative is to find a different (and better-performing) tech, preferably one recognized by Ampeg, on the hunch the problem lies with the third and fourth factors. (A good tube-amp tech will know his vacuum tubes and have a highly developed awareness of what's good and what's junk.)

There's plenty more to say about this business but I'll stop right here.
 
#11
iandi.bass said:
(...)

the GK head is blowing my Ampeg head out of the water in volume and lowend.

(...)

has anyone ever dealt with this? heard something similar?
Click to expand...

Sure, unless you're playing on a true Ampeg from the Golden Era, GK's with similar wattage will blow any Ampeg out of the water volume-wise. The 1001RBII runs circles around an SVT4-PRO, same thing with 800RB x SVT-CL. If the tone pleases you, fine, but ALL newer Ampeg amps are severely underpowered IME. The SVT4-Pro being the worst in the family. You pay for 1200W and bring home a 150W amp...
 
#12
What the heck is a tube?:hiding:

JK.

I also agree to take it to a different tech.
You did say that after the fella looked at it..changed tubes...and said it was fine...but it wasnt?

I'd find a new guy...or at least a second opinion.

Or just use it as a conversation piece/coffee table and rock the GK:bassist:
 
#15
allexcosta said:
Sure, unless you're playing on a true Ampeg from the Golden Era, GK's with similar wattage will blow any Ampeg out of the water volume-wise. The 1001RBII runs circles around an SVT4-PRO, same thing with 800RB x SVT-CL. If the tone pleases you, fine, but ALL newer Ampeg amps are severely underpowered IME. The SVT4-Pro being the worst in the family. You pay for 1200W and bring home a 150W amp...
Click to expand...

With all due respect Alex, you are wrong. My G-K 1001RB-II is not as loud as my supposedly underpowered SS Ampeg B4r. And it doesn't compare to my SVT II either (because the G-K can't go down to a 2 Ohm load but the SVT can and the speakers make a huge difference in volume). If you haven't A/Bed something please don't say something and make yourself look like a fool ... :scowl:
 
#19
what was your gain set at? most people don't get that you really have to crank the gain in hybrid ampegs to get full wattage out of them. the vast majority of folks who claim they're underpowered use the input light like it's a clip light, meaning they back off the gain when they see the light flashing. but that light should be on pretty consistently when setting the gain for max clean power. with a fender bass, it's rare that i'll use a 4 pro or 3 pro with a gain setting less than 3 o'clock because it's only past that point where you can hear distortion in the preamp. and that's why some think they're underpowered. ampeg never overrates their amps. if anything, they underrate them imho, and invariably i find that those who think they're underrated don't crank the gain past noon.
 
#20
JimmyM said:
what was your gain set at? most people don't get that you really have to crank the gain in hybrid ampegs to get full wattage out of them. the vast majority of folks who claim they're underpowered use the input light like it's a clip light, meaning they back off the gain when they see the light flashing. but that light should be on pretty consistently when setting the gain for max clean power. with a fender bass, it's rare that i'll use a 4 pro or 3 pro with a gain setting less than 3 o'clock because it's only past that point where you can hear distortion in the preamp. and that's why some think they're underpowered. ampeg never overrates their amps. if anything, they underrate them imho, and invariably i find that those who think they're underrated don't crank the gain past noon.
Click to expand...

I cannot answer this question since it's been a few years since last time I tried to use an SVT4-Pro. I've been using bass amps for many years and tried hard to make this amp sound good and loud. Had help from sound guys, from friends who own them and they always seemed shy and underpowered and completely inadequate for a gig with a loud drummer. OTOH the 1001RBII gets stupid loud real fast...
 

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