• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Ampeg SVT-VR hum problem

#41
Well, that places it earlier, in the preamp. I'm not completely clear at what point which control is turned.....

The thing to do is to find which controls affect it the most.... Sounds like you mean that MID and possibly LOW controls affect it. but there is always some background, and it is difficult to know what is amplifying background hum, and what is bringing in NEW hum, if anything.

Then again, while the amp should be quiet, you have to make a choice as to whether it is loud enough to affect use, and be worth taking to the shop, or not.

I actually am not sure what the deal is, it sounds on the clip as if the background is being amplified and affected by many/most of the tones...... And not so much like some specific part of the circuit is bringing in hum.

if that is so, it must be originating with the first or second tube, and getting the lowest hum versions MIGHT be a fix.... but you messed around with swapping tubes, and you say that didn't do much/anything.

I don't think it is a long-distance fix candidate..... it may be that a tech (a good one, not s burnt-parts finder) could look and see right away that something is not correct.

if you stand 2 meters away, is the hum annoying with controls in "normal playing" positions?
 
#43
after listening to your clip, its hard to say how loud the noise/hum actually is. IME, all of them that i've tried (6-7) have a fair amount of noise/hum that is acceptable, and one your's, the noise is following the tone control adjustments, which is normal for an SVT. but again, its really hard to tell how loud your's is without a reference to go by.
 
#44
Jerrold Tiers said:
Well, that places it earlier, in the preamp. I'm not completely clear at what point which control is turned.....

The thing to do is to find which controls affect it the most.... Sounds like you mean that MID and possibly LOW controls affect it. but there is always some background, and it is difficult to know what is amplifying background hum, and what is bringing in NEW hum, if anything.

Then again, while the amp should be quiet, you have to make a choice as to whether it is loud enough to affect use, and be worth taking to the shop, or not.

I actually am not sure what the deal is, it sounds on the clip as if the background is being amplified and affected by many/most of the tones...... And not so much like some specific part of the circuit is bringing in hum.

if that is so, it must be originating with the first or second tube, and getting the lowest hum versions MIGHT be a fix.... but you messed around with swapping tubes, and you say that didn't do much/anything.

I don't think it is a long-distance fix candidate..... it may be that a tech (a good one, not s burnt-parts finder) could look and see right away that something is not correct.

if you stand 2 meters away, is the hum annoying with controls in "normal playing" positions?
Click to expand...


I did find another possible problem in the instrument input board and leads going to the preamp board. With or without a bass plugged in and the volume of either channel turned up to 12:00 or higher, when I tap on the input board or wires leading to the preamp board with a chopstick there is a loud thump/popping noise. Tapping on the preamp board does not make the noise. Is this normal?

I will order some low noise tubes to experiment. I got a slightly better tone, but about the same noise running a JJ ECC83 in V1 and a Mullard ECC82 in V2.

While standing 2 meters away playing normal volume/controls the hum is not annoying. After reading about other owners claiming their amps are very quiet, it got me worrying about my amp noises. Maybe I can live with it.

When I play a passive USA P bass into a SVT 810E with the amp tone controls at 12:00 and no ultra-low on, the sound starts breaking up at about 11:00. Is this normal?
 
#46
johnk_10 said:
after listening to your clip, its hard to say how loud the noise/hum actually is. IME, all of them that i've tried (6-7) have a fair amount of noise/hum that is acceptable, and one your's, the noise is following the tone control adjustments, which is normal for an SVT. but again, its really hard to tell how loud your's is without a reference to go by.
Click to expand...

I did find another possible problem in the instrument input board and leads going to the preamp board. With or without a bass plugged in and the volume of either channel turned up to 12:00 or higher, when I tap on the input board or wires leading to the preamp board with a chopstick there is a loud thump/popping noise. Tapping on the preamp board does not make the noise. Is this normal?

Thanks for the help!
 
#47
tube circuits often have quite lively circuit boards in them, so i think that it is normal.

i did find that using a NOS triple mica 5814A (12AU7A equivalent) to replace one of the 12AU7's made mine a bit quieter too. especially the second 12AU7 (front the left if looking at the preamp from the front panel).
 
#48
gumbystuff said:
While standing 2 meters away playing normal volume/controls the hum is not annoying. After reading about other owners claiming their amps are very quiet, it got me worrying about my amp noises. Maybe I can live with it.
Click to expand...

That might be a plan......... Amps vary, tubes vary, and it does not sound as if you have a problem in the power amp...... Power amp problems could cause hum and could be destructive, but yours is not the source of hum, evidently, so you are in the clear there.

That hum sure sounded loud on the clip.......
 
#49
So the new SVT VR I picked up has the same problem. It's a fairly high pitched buzz, most noticeable if you crank up all the highs (so Ultra Hi engaged and treble up max) but noticeable always, and probably enough so that it'd be annoying.
Plugged a bass into the Power Amp In socket on the back and it was completely gone, just fan noise (which after reading a few posts about them being loud, is actually quite acceptable, perhaps they've fixed it?)
So this means what? A problem in the Pre Amp? Needs new tubes or what? Obviously I'm not just going to buy a set of new tubes at my cost to install in a brand new amp!
Steve
 
#51
I had a similar problem with my VR. There was a hum on one channel, I was able to listen to the hockey game clear as a bell on the other channel. I decided to return the amp because it had other quality issues related to the cabinet. Like you, putting more money into a brand new amp doesn't sit very well.

Unfortunately it seems like you've got to factor in a new set of good pre-amp tubes into buying one of these amps. If you want a VR, it is worth the investment. Once you get it working, it is a great amp.
 
#52
Isn't there a three month warranty on the tubes? I agree this amp is worth persevering with and if it is a tube fault apparently this can often happen in shipping. I was recently reading about the high percentage of tube returns for this, and it is something over which manufacturers have little control. That said, perhaps dealers should have a spare set of tubes in stock so that they can do a swap and establish whether this is the problem.
 
#56
Tim1 said:
2007/8 Loud Management + Jimmy = Red Flag + Bull :hiding:
Click to expand...
i know, it's been 2 years since they canned him. i should lighten up and get over it. but the way he so totally crapped all over ampeg's history and didn't even care still makes me sick enough that he'll always be "the idiot that nearly destroyed ampeg" to me.
 
#57
JimmyM said:
i know, it's been 2 years since they canned him. i should lighten up and get over it. but the way he so totally crapped all over ampeg's history and didn't even care still makes me sick enough that he'll always be "the idiot that nearly destroyed ampeg" to me.
Click to expand...

+1 for each of us who helped bring Ampeg out of the hole starting in 1986.

I have stories that I shouldn't tell, but they sure don't contradict Jimmy.
 
#58
Jerrold Tiers said:
+1 for each of us who helped bring Ampeg out of the hole starting in 1986.

I have stories that I shouldn't tell, but they sure don't contradict Jimmy.
Click to expand...
the few stories you have told were enough. i wasn't personally affected like you were, but at least now you've moved into a much bigger growth field that's pretty darn exciting if you ask me, and he's got the stink of failure on him.

btw, i just found out that the rumor that he went to behringer was wrong. he now works for some company in vancouver that specializes in corporate turnarounds. i don't know who's looking for anyone to take a thriving company and turn it into crap, but there you go.
 
#59
There certainly still is a huge brand loyalty for Ampeg out there. It still is the automatic backline for touring acts over here.
One other thought - many (probably the majority) of bassists don't even know Talkbass exists, probably don't even know that Loud took over from SLM and buy on brand name alone. It is this loyalty that Loud initially took advantage of, and if we at Talkbass (read Jimmy and Jerrold in particular) had some small part in influencing the management change and attitude turnaround then well done us.
 
#60
:D i think it was more just having creative people in charge instead of soulless bean counters that caused their attitude turnaround. that and a marketplace that voted with its dollars against loud's previous approach. i don't think we pointed out anything they didn't already know, quite honestly.
 

Latest posts

Top Bottom
Back