ADA Depot - A Forum To Support Users of ADA Amplification Gear

Let's Get Technical => Troubleshooting Problems => Topic started by: rabidgerry on January 22, 2017, 12:41:30 PM

Title: MP-1 got Noisy...
Post by: rabidgerry on January 22, 2017, 12:41:30 PM
Well so much for the clips, my MP1 has a problem  :dunno:

Making some strange "earth fault"  style noise.

 
Title: Re: Re: Bobby Gustafson's sound? (Overkill - The Years Of Decay)
Post by: MarshallJMP on January 22, 2017, 02:46:12 PM
That's why we are here to solve problems  ;D

Send me an email with some details.
Title: Re: Re: Bobby Gustafson's sound? (Overkill - The Years Of Decay)
Post by: rnolan on January 23, 2017, 04:28:34 AM
Hey RG, knowing you, you've checked all the usual culprits (leads, isolated the MP-1 to be sure etc) but just checking/asking.
Title: Re: Re: Bobby Gustafson's sound? (Overkill - The Years Of Decay)
Post by: rabidgerry on January 23, 2017, 04:38:18 AM
oh yeah RN, I know it's just the MP1 as my other preamps are fine.

Strange, it's like an earth fault sound trying to compete with the proper sound.  I actually forgot I had this issue a while ago but I got distracted and since I haven't played my MP1 in a while I forgot it was still happening.  I recently had the idea to allow me to switch preamps using a footswitch in my home studio setup which is why I got back on the MP1 and it was then I noticed.

I'll make a clip MJMP when I get home and let you hear it.  Bear in mind I last did the MDRT and noise mod to the MP1.  I never quiet finished the noise mod as I still have some electrolytic caps to replace on the tube board.
Title: Re: Re: Bobby Gustafson's sound? (Overkill - The Years Of Decay)
Post by: rnolan on January 23, 2017, 06:24:36 AM
Hey RG, yeah I figured, your pretty thorough  :thumb-up: . My smell (for what it's worth) is it's input jack(s) related (hey don't ask me why.... :dunno: it's a feeling I guess).  Unless there are dependencies on the tube board because of the noise mod you've almost finished (and I doubt it  :dunno: ).
Title: Re: Re: Bobby Gustafson's sound? (Overkill - The Years Of Decay)
Post by: rabidgerry on January 23, 2017, 07:11:26 AM
It could be.  I must try the rear jack and see if it's the same.

Mind you I think when I first discovered this issue I tried that.  Lets see when I get home.
Title: MP1 noise
Post by: rabidgerry on January 23, 2017, 10:05:04 AM
Ok as relates to something I mentioned in the thread about getting the Overkill guitar sound, my MP1 got an issue.

Sounds ground/earth noise issue.  Last thing I did was noise mod.  There are some electrolytic caps I needed to replace to finish the job but my understanding of things was that it should stuff have been ok without doing these, indeed the worked ok (If I remember correctly) for a while after the mod.


Gonna post a clip to let yaaaaaaaaaaall hear it.  :'(
Title: Re: MP1 noise
Post by: rabidgerry on January 23, 2017, 11:25:41 AM
Rockmaster 00:00 - 00.57  Have played a riff with sudden start and stops hearing the level of noise in between and after playing.  Also towards the end I have little bit where I hit string gently and let them fade out so you can hear what level of noise I am getting with the noise reduction working from my FX unit.

Reason the noise reduction is on as this is the usual set and forgotten setting I use and never ever need to change.

MP1 00:58 -   02:25 is me playing similar riff to before but note the noise between.  Can I just say it's way worse when playing than it has turned out recording.

Ok included are little segments before the actual riff to let you hear the noise.  This isn't normal for me, it's usually dead quiet like the rockmaster.  After the riff playing I do a little bit where I allow strings to ring out and also after this some hands on, hands off strings to let you hear the difference in noise.  Again this is not normal.  With that noise reduction on it should be quiet just like the rockmaster.

02:25 til the end is the tube clean channel, should I be getting this much gain from the clean channel?  Please note the noise present like before despite much much less gain.  This is pretty much me playing about with the volumes and od1 and od2 controls and nothing on the EQ.

see attached
Title: Re: MP1 noise
Post by: MarshallJMP on January 23, 2017, 02:40:29 PM
How is this setup?
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on January 24, 2017, 12:49:23 AM
four cable method man.  Same as always.  It never made that noise before.

Will try my 3tm as well and see if it's the same in the same setup.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on April 24, 2017, 08:08:43 AM
Bringing this up again as now I have another stock MP1 without the noise mod and it doesn't make the same noise problem as the MP1 that I modified.

And this is using the 4 cable method that I use for everything

So stock:

Stock MP1 - No excessive noise issue
Modified MP1 with Noise Mod and MDRT - Excessive noise
Peavey Rockmaster - No excessive noise issue

Stock MP1 Boosted - No excessive Noise
Modified MP1 with Noise Mod and MDRT - Even worse Noise
Peavey Rockmaster with onboard boost engaged - No excessive noise issue

Now I reckon something has gone wrong with my wiring when I was modifiying the unit.  It worked ok for a while, but it doesn't work ok now, it has this incessant noise louder or competing with main signal.  Reminds me off the sorta noise you get with a faulty earth.

Any suggestions are most welcome on where to look at with this problem.


Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on April 24, 2017, 02:46:42 PM
That's a 3TM right? (the modded one with the MDRT)
Title: Re: MP-1 got Noisy...
Post by: rnolan on April 24, 2017, 08:59:19 PM
Input Jack ?? Tubes ?? 2 things to rule out from the start.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on April 25, 2017, 12:25:23 AM
That's a 3TM right? (the modded one with the MDRT)

No my man, I modded a stock MP1  (US 120v model) last year, bought the MDRT and noise kit from you.  Obviously for the sound advantages those mods offer but also to have my MDRT then set to 230v so I didn't need to drag a step down TF around.

I actually sent you noise comparisons ages ago but you reckoned it was the 4 cable method.  I'll see if I still have them.

I've 3 MP1's now:

Standard no mods      (bought the other week)
Standard MDRT/Noise Mod      (the faulty one)
3TM    (bought of an English guy who had you mod it for him

Input Jack ?? Tubes ?? 2 things to rule out from the start.

I'll check, does rmind me if that kind of noise Richard.  I think I get the same from front and back inputs, I must check this evening.

(the latest MP1 I got only has the front input so will mod the back one at some point)
Title: Re: MP-1 got Noisy...
Post by: rnolan on April 26, 2017, 05:25:16 AM
Hey RG, if the input jack and tubes check out ok (ie ruled out) then I'd check your solder joins from when you did some of the noise mod (and maybe finish the last couple of caps you still had left to do ??). Maybe check the earthing around the MDRT you installed  :dunno: . Now correct me if I'm wrong but doesn't the MDRT install also involve changing bit(s) on the tube board ?? if so have a good look at that and also how it connects to the main board. I'm just thinking aloud here (hopefully in a constructive way)... Oh and maybe check your power plug earth (could be that simple ?  I'm assuming you through on an Irish plug when you did MDRT ?)  Also make sure the MDRT is installed nice and tight and not inadvertently touching the case except at its mount points (can cause hum (vibration))
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 13, 2017, 07:58:06 AM
time to fix this issue!

I tested front and back inputs they sound the same still have the noise.  Still have to check the tubers.

I cannot recall where I left off in the noise mod  MJMP I shall need your help on what it is left I have to do.  I'll send you a photo of the caps I have left over.
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 13, 2017, 01:44:36 PM
Well also send me a pic of the mp-1 pcb this way I can see both.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 14, 2017, 12:12:12 PM
(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%2016.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%2016.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%2012.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%2012.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%205.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%205.jpg.html)



(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%204.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%204.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%201.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%201.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%209.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%209.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%203.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%203.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%208.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%208.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%202.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%202.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%2010.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%2010.jpg.html)

(http://i86.photobucket.com/albums/k114/themetalmartyr/ada%20mp1%2011.jpg) (http://s86.photobucket.com/user/themetalmartyr/media/ada%20mp1%2011.jpg.html)
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 14, 2017, 12:30:57 PM
Ok, seems you need to replace C8,C2 and C1 on the tube board, also C16,12,13,7 and 6 on the tubeboard.

Then on the mainboard all the small caps near the voltage regulators (near the MDRT).
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 14, 2017, 12:52:59 PM
Just out of curiosity, those caps which I know I need to replace, they wouldn't cause the noise I'm getting right?

The noise is now so loud no guitar can be heard.
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 15, 2017, 04:26:56 AM
Well if one of those big caps on the tubeboard is busted you could get hum.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 15, 2017, 07:25:39 AM
When you say big caps?  I replaced the big ones near the tranny so they should be good.  Or do you mean one of the smaller ones that I have yet to swap out?

The noise is actually insanse now I must record it and let you all hear it.
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 16, 2017, 06:26:45 AM
I mean the caps on the tubeboard, not the mainboard.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 17, 2017, 10:50:00 AM
ok as the guide stops pretty suddenly it seem I have about 10caps I have no clue what to do with.  I started taking them out thinking I could just match them up with the right values...............WRONG!

you're going to have to help me out MJMP.  Will email ya.
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 17, 2017, 02:34:00 PM
Okay, I remember now, I gave you some extra caps not mentioned in the manual.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 19, 2017, 12:22:04 PM
emailed you mjmp the caps you give me and hopefully you can tell me where they go.  Soon as I get those installed, we shall see if the noise is still there.  If the noise is still there, further investigation will be needed :thumb-up:
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on June 19, 2017, 02:44:13 PM
I send you the new updated manual but except for some caps the rest was also explained in the old manual.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on June 20, 2017, 04:20:17 AM
I was hoping to update the manual also.

I'll do up a draft FINALLY, now I have some time to do other things than make an album :)  I have my life back again  :lol:
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on July 01, 2017, 03:26:14 AM
So replaced the caps on the tube board and tested.

Strangely the insane noise I was getting the last time I tested, which was louder than the actual guitar signal"!!!!  is gone....................

seems a bit strange to me as this noise was crazy loud.  I wonder did opening and taking the guts out move something back to where it should have been?  The caps alone don't seem entirely responsible for the fix.

Who knows perhaps they are.  MP1 sounding f**king awesome!  Gonna rehearse with it today.

Will replace the last few caps tomorrow ones situated at the MDRT.
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on July 01, 2017, 04:11:16 AM
Well it could be, if one (or more) high voltage caps were bad then you get hum.
Title: Re: MP-1 got Noisy...
Post by: Iperfungus on July 01, 2017, 08:19:02 AM
So replaced the caps on the tube board and tested.

Strangely the insane noise I was getting the last time I tested, which was louder than the actual guitar signal"!!!!  is gone....................

seems a bit strange to me as this noise was crazy loud.  I wonder did opening and taking the guts out move something back to where it should have been?  The caps alone don't seem entirely responsible for the fix.

Who knows perhaps they are.  MP1 sounding f**king awesome!  Gonna rehearse with it today.

Will replace the last few caps tomorrow ones situated at the MDRT.

 :thumb-up: :thumb-up: :thumb-up:

Times for some good luck!
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on July 01, 2017, 11:32:22 AM
Well it could be, if one (or more) high voltage caps were bad then you get hum.

May be that's what it was MJMP.  Now I've only done those on the tubeboard so would that still apply to those?

It was a crazy earth/ground type hum that was throughout the sound, then it got so bad you couldn't even hear guitar.  I really hope it was.  I'll complete the mod (it's only taken a year  :lol:) tomorrow!

I dam well forgot totake it to practice with me.  So I had to use the Rockmaster, which was having output issues.  However, I put in the old tubes again and I got all the output back!!!!!!!!!!!!!!!!  f*ck those tubes I bought they musta have been total shit.

I need some juicy harmonically rich, nice mid rangey tubes with nice gain!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The Chinese dirt tubes in the MP1 with MDRT and noise mod sound fantastic.

Then my stock MP1 - No mods has some tubes in there that are also great (not sure what?). 

Quietness is very similar to the modded version and the stock one, however the trim pots in the MDRT MP1 could do with being turned down a little since now there is more voltage and all that good stuff giving me more gain.

Thanks Iperfungus  :thumb-up: always need the luck
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on July 01, 2017, 04:54:02 PM
Got this problem before, those caps are getting old + they get a much higher voltage on them so they wear out, and at point it's over and out. So now you're good for at least 10 years.
Title: Re: MP-1 got Noisy...
Post by: rabidgerry on July 02, 2017, 03:00:38 AM
can't really reply to that any other way than  :thumb-up:

So the MDRT perhaps speeded up the death of those caps, ok makes sense  :)
Title: Re: MP-1 got Noisy...
Post by: MarshallJMP on July 02, 2017, 04:53:43 PM
can't really reply to that any other way than  :thumb-up:

So the MDRT perhaps speeded up the death of those caps, ok makes sense  :)

Yeah since the MDRT is putting 40V more then the original tranny.