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Ampeg SVT 7 Pro - Cutting out ???

#22
daimler said:
Hi Sharkey,

i've got exactly the same issue as you, and the distributor here in Aus will not (understandably) do the warranty repair as i bought online from Canada.
Yet Ampeg CS are saying the disty should do the repair and that they have international warranty agreements.

What did you end up doing?

I have noticed that it seems some posts have been deleted from threads concerning this issue, lots of talking about Ampeg CS and people responding to people having these issues but the posts with people detailing the issue seems to be gone.
Can anyone comment on this?
Click to expand...

Comment: Very odd indeed :hmm:
 
#23
Any mass produced piece of electronics is going to have the odd lemon slip through, what is important is the way the way the warranty is applied and to have decent customer services available. Ampeg seem to be doing alright on this score. The option is to pay significantly more for a hand produced and individually tested product. Since Ampeg is by consensus one of the biggest amp producers the amount of failures will be higher, but I would expect that proportionately it is no different to any other mass produced head at a reasonable price per watt. Again, it is the customer service which for me will make or break the product and Ampeg have finally got this right again. It is one of the reasons why I buy from the authorised dealer rather than import my own into the Southern hemisphere.
 
#24
When the limiter circuit on my SVT-7 would kick in the volume would occasionally drop to nothing. It only happened at 4ohms and when I was trying to push it. Though the tone was AMAZING I returned the amp for this reason. GC couldn't find anything wrong with it but it happened more times than I have fingers on different days, in different venues that all my other tested amps worked fine in (Genz, Eden, TC, Markbass). luckily I had an RH450 at the same time so I was never without a back up. I now gig a Genz Benz 9.0 proudly without backup and without worries.

I remember reading on a couple other SVT7 threads that this was not uncommon and others had reported the same issue. I am afraid it is not a lemon issue, hopefully it was only an early production issue, all I know is it will be hard for me to ever trust an ampeg SVT-7 ever again.

my recommendation:
If the protection limiter circuit is a problem for you like it was for me the problem isn't going away..try to get rid of the amp. If the online store wont take it back get on the horn with ampeg, maybe PM the ampeg rep that was answering concerns in the earlier SVT-7 threads. Not sure if ampeg will react like the smaller more customer friendly companies but there is a chance that having voiced your problem publicly might encourage ampeg reps to solve your issue publicly. Genz, TC and Source Audio get mad props for this here on TB.
 
#27
Understand what U R saying there Jimmy, but "9 o'clock" ain't exactly PUSHING this beast?????? That MASTER VOLUME control works ALL the way round nearly- so flat out seems near 4 o'clock.
I've run mine at ALL levels- not flat out for a LONG period, but for 5 mins at FLAT OUT(GAin at about 3 oclock & master at 5 oclock) into a 4 ohm cab. Sure I wasn't playing 16ths, I was just noodling away but not only did the amp go fine, it was VERY F*&^%* LOUD!
& I did play very gently & listened intently to my speakers :-)

This NEEDS to get sorted PROPERLY IMO.
 
#28
GB, etc deserve their rep for CS too!
I REALLY hope Ampeg come to the party on this.
With a prob I had with my GB amp, GB pm'd me via here (after I asked a question-I didn't even know I HAD a prob yet.) & sent me a replacement part free.
I realize these SVT-7's might have to go back, & just hope Ampeg live up to the expectations I (for one) have of them.
 
#31
Welll.......... I DO NOT do any support whatever on the Loud designs.... that's their problem..

But, I HAVE had a bit of a squint at a 7 pro schematic and I noticed that according to the revision list, they seem to have started out with a regular opto-coupler limiter, but by the time of the schematic I saw, it had been replaced by a clipping-type limiter.

Seems that I remember the rev level being at C-something.*

In any case, if the limiter was the issue, and it is "possible" (depending on design) for it to overshoot and cut output, that since it is GONE in the current revision, that will not be the issue at all.

A clipping type limiter should be an "absolute" limiter, preventing the level from going over "X" regardless.

Many class-D modulators have a real problem with excess level, and can indeed shut down briefly (cut out) if overdriven, so it is entirely possible that the opto limiter was unsuited to the modulator used in the 7 PRO. Explaining any more would be telling things I ought not to, so I'll leave it there.

Anyhow, it seems that a clipping-type limiter should take care of the issue nearly 100% if overdrive-related modulator shutdown was the problem.

* The rev level is interesting, since back when Loud still had the SLM crew, it was pretty much told to us that "thou shalt have thy design perfect at the third layout and parts list prior to production" and that "thou shalt need no revisions after production or thy head shall be struck with heavy objects".

But, revisions with letter codes usually indicate revisions after "release" i.e. in production.... and "A" would be the release version. So "B" and "C" would be changes during production.

You-all may consider that bad, but I think it is good..... they do the best possible pre-production, and after that they fix it as soon as they find it.... What's good is that they get stuff out there sooner, instead of taking forever to try for perfection....

no matter WHAT you do, you will never GET it perfect.... so you may as well ship it when you can find no further faults..... And you keep your customers from being hurt by any that are found later. That's what a warranty is for......
 
#36
larrison said:
husky123, I was waiting to hear your results after rehearsing with your band...how did it go? From the sounds of your post sounds like maybe you experienced the shut down.
Click to expand...

Oh no I didn't have a shutdown problem. I don't think I pushed the head too hard (didn't need to). I had the gain on one of my basses at about 3 o'clock (passive DiMarzio Area J's) and never really turned the master past 10 o'clock. This was 4 ohms through 2X15's.
 
#39
rummy said:
I think the point is that with a new functional amp, one shouldn't have to work around to avoid a problem...
Click to expand...
Well here's the thing...all amps have their limits. And just because the knob has a little more play in it doesn't mean you're not exceeding its limits. If it's shutting down, there's a very good chance you're exceeding its limits, so rather than blame Ampeg (or any manufacturers) for a protection circuit that's keeping you from toasting your amp, people should actually consider the idea that they're trying to run it harder than it's designed to run.
 

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