JSX Hiss, unwanted noise and tube life issues...

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Mon Nov 02, 2009 1:29 am

Sounds Awesome guys... Im currently looking for a Weber BR-4 Bias Rite Probe so I can do exactly that.. Im also ordering some Winged "C" EL34's (Matched Quad), 4x Tung-Sol 12ax7's, 2x JJECC83S's and 2x JJ ECC803S's

Experament a little with the pre-amp tubes to get the exact sound I want. Once Ive set it up Im going to get my amp tech to confim everything is ok.. For piece of mind...Then Im going to document the Bias on the amp every week using the probe, and if things go wrong again Ill have at least something documented...

SO do you guys think I should bias at 60% disapation? Sounds like a plan..

Hey what do you guys think about the image of the solder joints for the power tube sokets? Do they look ok, or do they look like theve got to hot? Can someone check their JSX so Ive got something to compare against?

Cheers.. Everyone...Your all a big help...

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Tue Nov 03, 2009 8:15 am

Well this is what the guys at the JJ factory had to say:
-------------------------------
Dear *****,
Thank you for using JJ tubes!
You correctly write tubes are not sold states and tubes change their characteristics during operation.
It is really impossible to make diagnose from our place but whole case is strange. Of course there can be some tube which after short time causes problems (become noise, microphonic, or just lost power) but it is very rare. And you write all tubes in almost same moment become weak. It is necessary to test operating mode of tubes in amplifier.
We make permanent testing of all of our tubes in several modes (A class, AB high, AB low) and there are very strict rules for holding its characteristics during testing.

From my point of view you should find somebody who can measure voltages (on plate, grid2, grid1) and currents (anode, grid2 or cathode current) in that amplifier. Base on these data we can tell whether tubes work in good condition.
-------------------------------------
So it looks like its very unlikely to be the tubes at fault here... So its very clear that the Bias needs to be correctly done. Thats obvious... So my problems are clearly raliated to either:

1. Peavey Australia and all the Peavey approved amp techs dont know how to Bias a Peavey JSX Head correctly... Hmmm what do you guys think...
OR
2. There is something wrong with the amp.. And the following needs to be tested: voltages (on plate, grid2, grid1) and currents (anode, grid2 or cathode current)

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Wed Nov 04, 2009 3:45 pm

Well Guys,

Id like to thank Roger Crimm (Customer Service)... Sent through the schematics and what not to help trouble shoot my issues... He did say that there may be merit in what I was saying...But unfortunately he cant do much more, even though he would like to.... The distributor in Australia needs to take care of this one...

Well theres also the tube manufacture saying my situation appears to be unusual, and that their tubes should last longer...

Ive also spoken to Bob at Eurotubes.... He feels it might be a biasing issue at fault here.... I feel this is probably true, but I dont think its a case of the people Biasing the amps not knowing what they are doing... If there is an issue with the Biasing I feel its due to some kind of fault...

I got my amp in the hands of FM Audio, an Awesome amp tech here in Adelaide SA.... He has told me the head of the service department from Peavey Australia is going to have a look at the thing so there may be hope yet..... The Peavey guys flying in next week....

Stay tuned for an update...

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Wed Nov 11, 2009 3:41 pm

Well guys here I am again... :cry:

Got word back from the tech, that my amp has been looked at by the head service guy of the Peavey distributor here in Australia. Basicly Ive been told that the distributor feels Im stretching the truth about my useage of the amp and thats why the tubes have had it. You see after so much dissatisfaction the Peavey distributor serviced the amp a little less than 1 year ago, replacing stuffed tubes in it and biasing the amp. So they are saying the tubes lasted one year this time round...

Well, the amp was purchased on 15/10/2007 within 3 -5 months I had it back at the shop, needed a retube.... Including this service and 4 others this took me to this time last year. So in a 12 month period my amp went through 5 sets of tubes in 12 months... I dont know, but that doesnt appear to be normal.... lol

Ive stated that my amp is using a set of tubes every 3 - 4 months... well so far so good... All the retubes were done by approved Peavey amp techs, so I can prove this occoured.... So then the next re-tube the Peavey distributor did the job them selves, around this time last year... I also explained to them that I had been going through treatment for cancer...and fighting for my life...those of you who know...chemo is not an easy thing... I went through an operation and 6 months of chemo... I didnt have to much time omy hands to play guitar let alone through my JSX... Anyway I normally play via a pedalboard into my home studio pc when at home. I told the distributor/tech that Ive used the amp maybe for 2 - 3 months in this last year... But for some reason they dont think Im telling the truth??? Is how you treat customers Peavey? I hope Roger Crimm can assist as Ive sent an email through to customer service and asked for an esculation path to Peavey in the US...No one here can tell me whats wrong with the amp, but no one can explain to me why my amp is killing tubes.... Hmmmmm not good enough for an amp that retails for $3,490.00 AUS...

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Re: JSX Hiss, unwanted noise and tube life issues...

Post by Roger Crimm » Wed Nov 11, 2009 4:04 pm

I have your email, and will be in touch as soon as possible.
Roger Crimm
Service Manager
[email protected]

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Wed Nov 11, 2009 4:45 pm

Your a champion Roger... :D

Thank you and Peavey...

Cheers..

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Re: JSX Hiss, unwanted noise and tube life issues...

Post by Classic30inCincy » Wed Nov 11, 2009 5:03 pm

We're Pullin' For You CastleJoe......Hope Your JSX Situation Solved.

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Blaklynx
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by Blaklynx » Thu Nov 12, 2009 4:37 am

Hey CaslteJoe,

Fellow Aussie here, Melbourne based.

I read the entire post and feel for ya. I'm also sorry to hear of your personal fight. Hope all is well. Hang in there.

OK, having a design and engineering background in the automotive sector, when a problem occurs, say a failure of a component, it doesn't necessarily mean that the component is at fault. Maybe something else caused the component to fail. We analyse everything along the way and each link in the chain is analysed for it's possible failures. Eventually get to the 'root cause' of the problem. In other words, the root cause is what causes the failure of the component.

In your case, you may have to dig deeper and further to find what causes your valves to degrade quickly. Here are some thoughts:
1. Hairline cracks in electronic components. As they heat up, they fail/go out of tolerance and cause fluctuations in the electrical circuit.
2. Hairline cracks in the PCB board tracks.
3. Hairline cracks in solder joints.
4. Electronic components out of spec (any replaced with wrong type that isn't obvious at first look?)
5. Loose components.
6. Ground lines not connected properly.
7. Wires soldered properly.
8. Wires broken internally (a few strands hanging on by a thread?)
9. Any obvious signs of tampering internally?

These are a few examples that you can use and or possibly ask Peavey to consider. In fact, Peavey should take particular interest in your amp as it could be a learning curve for them, too. In the auto industry it's called "Lessons Learnt" and it's taken seriously so the same mistakes don't happen again (not saying that Peavey made any mistake with your amp but you never know).

I think that Peavey should also consider keeping you amp for a few weeks and actually playing it daily to see if they can simulate your problem. A quick test on the bench or two hours playing does not mean the problem will arise. Surely they could give you an amp so your not without one.

Anyway, my thoughts. Hope you find a solution...
======================
Keep your wife happy..... then you can buy what you want.
Peavey JSX
Mesa Rectoverb
Mesa Quad Pre
Mesa 2:50 poweramp
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======================

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Thu Nov 12, 2009 6:11 pm

Thanks guys...

Blaklynx... Real helpful information thanks...Funny before I got ill I was a Systems Analyist / Engineer for an automotive supplier... :-)

Not sure how they would find hairline cracks? Might be easier to swap the unit out.. But its funny how you mentioned tempreture as a factor... I can say this is a posable factor for sure...

Rogers been in contact again, and after consulting with some of his technical peers, has a few ideas... And is now involved and assisting..

Dont get me wrong the experiance Ive had with the Aussie distributor has left me wanting... And disapointment...

But Roger and the rest of the Peavey team are awesome... They have been nothing but helpful.. Just goes to show... So lets hope that this gets sorted....

:)

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Re: JSX Hiss, unwanted noise and tube life issues...

Post by Classic30inCincy » Thu Nov 12, 2009 6:14 pm

CastleJoe---

Peavey Corporate Staff truly cares for customers and works hard to satisfy.

Keep us up-to-date.........

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Thu Nov 12, 2009 8:37 pm

Will do...

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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Wed Dec 09, 2009 7:04 am

Well guys....

Awesome news.... :D

Got a call from Frank yesterday, thats the amp tech from FM Audio here in Adelaide South Australia. Asked if I could go and see him today...

Well went in with a bunch of my gear, guitars, effects quad box and what not. He had my amp sitting there in his work shop with the chassis out.

He spent hours with me to trouble shoot the issues Ive been having and you know what. Found the amp wasnt biased 100% true. Also that there were 3 faulty pre amp tubes V1, V2 and V3. The power tubes were fine though...

No more crackling and popping after replacing the preamp tubes. He also biased the thing to Roger Crimm's instructions... Played through the amp and it was a heap better...

We then tested with effects through the loop.... There was noise being introduced through the loop... He went back to the schematics had a think... Powered down changed some components from the main board...

I plugged back in with effects back in the loop and I kid you not... I nearly creamed my pants.... Not sure exactly what he did... but let me tell you my JSX sounds absolutely amazing now... Better than ever...

I have always said Franks the man here in Adelaide... I dont trust anyone else, and Frank took the time and put in a huge effort to help me out. Completely explained everything that went on and made the technical aspect easy to understand. But best of all he has a musical ear and knows tone... So when I say something like theres some kind of fizzy thing going on in my tone..He doesnt think Im a fool or its in my head. He really listens to you as a guitar player.

The end result was nothing short of miraculous.... I am so happy right now let me tell ya...

And Id like to point out Roger Crimm and Peavey helped out in a real big way and made things happen for me here in Adelaide. And the local distributors picked up the bill so thanks to them also.... :)

Let me just say especially to those on 240vac power. The one thing I learnt today that blew me away is how much the power outlets current can effect the bias of your JSX. Any variation will make your amp run hotter or colder in the power tube stage. Its a fact.... You need to make sure you feed your beast regulated 240vac power thats it....No more bias wows....

Well Ill be send a more personalized thank you tomorrow via email, but thanks again to all. And for all you guys that helped with advice on the forum your a great bunch...

Cheers... :D

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Re: JSX Hiss, unwanted noise and tube life issues...

Post by Blaklynx » Wed Dec 09, 2009 10:46 pm

Hi CastleJoe,

That's very good news. I'm glad it has been sorted out. This is what it's all about.... helping each other. Congrats to Peavey and your mate Frank and everybody else involved for fixing this for you.

All we need now is a complete rundown of what went wrong, so if similar happens to anybody else, we at least have another possible (cause)/fix we can look at.

Well done mate. Now go play to your hearts content and enjoy the beast......
======================
Keep your wife happy..... then you can buy what you want.
Peavey JSX
Mesa Rectoverb
Mesa Quad Pre
Mesa 2:50 poweramp
Marshall JCM800 (original)
Carvin QuadX
Rocktron Piranha
Tech 21 PSA1
Too much other s***
======================

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Fri Dec 11, 2009 3:24 am

Thanks Blaklynx,

Well as far as a run down goes...Here it is....

-The amp needed biasing again, wasnt out by much but enough to make a difference.

- Preamp tubes in V1, V2 and V3 had it. V2 was causing the crackling and popping..

- As far as the fizzy sound I could hear in my tone was to do with diodes in the amps signal chain. These were swapped out for an alternative component. The difference to the tone, that is elimination of fizz was night and day. I have no idea which ones were exchanged? But my tone now is amazing. No more fighting the amp to achieve an awesome tone.

Having said all that there are some real importaint factors for biasing the amp. Especially for us guys in 240VAC land.... When the amp is biased it must have exactly 240vac. That is the current from the GPO must be regulated to exactly 240vac, no if or buts.

The difference this makes to the amps tone is massive. I cant stress this enough. Playing the amp correctly biased and with a perfect feed of 240vac was an amazing experiance. The amp has never sounded so good even from new. (well ex Satriani concert amp anyway)...

There also appears to be a few issues in relation to design that effects the biasing. Well not issues its just different. The power feeb for the biasing section of the board is obtaned from the power valve stage. Which may mean that as the tubes age and current draw changes so does your bias. Which means the overall effect on you bias is greater than you would normally expect. Solution re-bias the amp.

The other thing is, because you must bias the JSX on exactly 240vac, when you plug into the mains at home or at a gig, if the GPO is not putting out exactly 240vac your tone changes as does the bias on the amp. Thats because the Transformer appears to power the filiments of the power tubes first, then the bias section gets its power from it. So any fluctuationin power to the amp effects your power tubes bias. Meaning unless you have exactly 240vac your amp is nolonger correctly biased.

The solution is to purchase an item called a Veratact (I think thats how you spell it?)... Its a unit you plug into the GPO that contains a transformer that allows you to dial in exactly the current you need. Then you power your furman unit from that (if you have one), which then feeds your amp. Or plug your amp directly into the Veratact if you dont have a furman. Thats the only way to garentee you are running the amp correctly biased..period...

So there you have it....Hope this helps guys....

PS> Marshall dont build there amps this way they have another tap on the bias transformer specifically to feed the bias section of the amp. Makes you wonder... But a Marshall doesnt sound like a JSX....

Oh and if you thought your JSX sounded awesome bias it as explained and feed it regulated power and youll cream your pants...trust me....

:D

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CastleJoe
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Re: JSX Hiss, unwanted noise and tube life issues...

Post by CastleJoe » Sat Dec 12, 2009 4:47 pm

Sorry forgot to say:

The power tube sockets were also resoldered as were some other solder joints..

So no its a matter of wait and see how things pan out on the tube life side of things.

But as far as tone goes.... Its amazing....

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