|
Post by miller on May 25, 2014 15:17:33 GMT -7
I have started noticing a white noise coming and going. Almost like it is in a cycle. I bought this amp new 2 years ago and use it all the time. Does this sound like a tube problem? At first I just thought I had the reverb up to loud but after turning it down I am still getting the loud white noise cycle. Had a gig last night and our sound man even noticed it coming through the PA so I know it isn't a dirty power problem since it does it everywhere I take it. Any suggestions would be great!!
|
|
|
Post by miller on May 25, 2014 15:18:11 GMT -7
Also, I am not a new member. I just can't remember my password and my old email isn't used anymore!!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 25, 2014 15:45:04 GMT -7
Are the tubes also two years old? If so then yes you are in need of some new tubes. Get them from a reputable dealer if possible.
|
|
|
Post by miller on May 25, 2014 16:09:27 GMT -7
Yes, the tubes are the ones that came with the amp. I purchased the amp in November of 2012 and I don't know how long it had been on the shelf either.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 25, 2014 16:34:26 GMT -7
Yes, the tubes are the ones that came with the amp. I purchased the amp in November of 2012 and I don't know how long it had been on the shelf either. At least change the power tubes with a closely matched set from a reputable source. I'd change them all. Imho.
|
|
|
Post by miller on May 26, 2014 6:01:30 GMT -7
My stock EL84's are JJ's. What are some suggestions? Just go back to the same ones or try Groove Tubes? I love my Z but I have always wanted it to have just a bit more punch. I have noticed that when looking at tubes, especially Groove Tubes they come ratings of High, Medium and low. What is the difference? Output?
Also, what is the large tube that is not in line with the rest? Amp diagram says SAR4. Does it need replaced as well?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 26, 2014 6:45:30 GMT -7
My stock EL84's are JJ's. What are some suggestions? Just go back to the same ones or try Groove Tubes? I love my Z but I have always wanted it to have just a bit more punch. I have noticed that when looking at tubes, especially Groove Tubes they come ratings of High, Medium and low. What is the difference? Output? Also, what is the large tube that is not in line with the rest? Amp diagram says SAR4. Does it need replaced as well? The 5AR4 is your rectifier tube and yes I'd replace it. Buy a NOS rectifier if you can find one and have the coin. NS rectifiers are hit and miss. I bought an RCA 5AR4 three years ago and it's still going strong. I don't see it dying any time soon. NOS preamp tubes are a sound investment as well. As far as EL84's go I use and love TAD EL84 STR's. The Groove Tube rating is related to early, normal or late breakup. I buy my tubes from Mike at KCANOS. Buy with confidence from him. Doug's Tubes is another great source. Be careful when changing tubes. Make sure the power is disconnected and handle the tubes with care. It's an easy fix and your MAZ will sound killer after it's done.
|
|
|
Post by mickey on May 26, 2014 7:36:09 GMT -7
Enuggles is quite right. An NOS rectifier is a good idea, I got my Mullard via eBay, though I checked the seller out thoroughly first. Been in the amp probably three years without any issues. I also use JJ EL84's in my Maz, always sound fine, and provided that you buy from a good source as already stated they should be fine. I always specify the distortion rating equivalent to Groove Tubes #6, as that is what the Doc used to put in the amps when mine was made in '05, and again they always sound fine. I know some users really like the TAD's, but again buy them from a reputable dealer as I have heard of one or two instances where they have blown quickly in a Maz.
You say you want your Z to have more punch; it will when you change the tubes.
|
|
|
Post by miller on May 26, 2014 8:00:50 GMT -7
Thanks for all the suggestions. I am going to order tubes today. But I am slightly confused and am sure one of you can set me straight.
The diagram in my amp head showing the tubes going left to right like this. ECC 83, ECC 83, 12AT7, 12 AX7, 12 AX7, and then the four EL84's plus the rectifier tube.
This is what I got when I pulled all the tubes one at a time to check what they were. Here they are in the same order. JJ ECC 83, Ruby 7025/SS 12AX7A, JJ ECC 81, Sovtek 7025 12AX7WB, Sovtek 12AX7LPS. Then the four JJ EL84's.
So what is up with all of that. Is the Ruby 2AX7A being used as a ECC 83? Is a 12AT7 the same as the JJ ECC 81? What is the difference between the Sovteks? One is a WB and the other is LPS?
|
|
|
Post by headshrinker (Marc) on May 26, 2014 8:24:00 GMT -7
ECC83/12AX7/7025 are all the same tube. The ECC 83 is the European designation, the 12ax is United States and originally 7025 was a quieter version of the ECC 83 and 12 AX. Probably not true these days. The ECC 81 and 12AT are also the same. The WB and LPS designate construction differences for the same tube. Generally folks like the LPS in the spot it is because it's the phase inverter and most folks feel it sounds/ works better there. In fact any of the same tube can go anywhere. You can even sub a ECC83/7025/12AX for the ECC 81/12AT. I do it in my Maz. I think it gives the reverb a bit more oomph. Generally I think that if you like the way your amp sounds don't change the preamp tubes except maybe the lps until they blow. They last a real long time. I would change the power tubes. I wouldn't mess with the rectifier either, but a lot of folks do put in NOS ones and they will likely last longer, but I'm of the if it ain't broke don't fix it school. Your power tubes are likely used up by now. Don't toss them though as they will work as backups in an emergency. Hope that helps some.
|
|
|
Post by miller on May 26, 2014 8:50:49 GMT -7
I think I will see if the power tubes fix the problem and go from there.
|
|
|
Post by headshrinker (Marc) on May 26, 2014 9:08:10 GMT -7
If you are ordering tubes you might want to order one 12AX7 too. That way if the power tubes don't fix it then you can use the 12AX to sub for the preamps. Start with the first preamp tube and sub the new one. If it fixes it you found your bad tube. If not put the old one back in and go to the next one. As I said before you can use it to see if the 12AT is the culprit too. If it turns out to be that one you can then order a 12AT or if you like it leave the 12AX in there. I would always have at least one extra 12AX on hand.
|
|
|
Post by mickey on May 26, 2014 14:29:58 GMT -7
Check this out if you haven't already: drzamps.com/tube_info.htmlThe Doc uses EL84EH's now as I believe he had issues with inconsistency with the JJ's, though as I stated above I've personally had no problems with them.
|
|
|
Post by miller on May 29, 2014 10:05:21 GMT -7
Well, I put new power tubes in today and it did not cure the problem. I ordered a 12ax7 as well. I started changing them out and the middle small tube out of the 5 was the culprit. It is an ecc81 or AT7 and I replaced it with the ECC83/12ax7. Although it did cure the mystic reverb popping sound there is still a little thud every once in a while. Almost sounds like a door being shut across the house. Just a small faint thud every so often.
|
|
|
Post by BritInvasion on May 29, 2014 10:13:39 GMT -7
You might want to try an NOS 12AT7 in that slot. I replaced the ones in my Maz8 and Maz18 with them and now the reverb is very quiet. Cost around the same as a new production tube but will last much longer and perform properly.
|
|
|
Post by fishman on May 31, 2014 14:02:05 GMT -7
Dr Z has a phone....call them up and put this to bed....
|
|