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Post by DRZ on Apr 1, 2007 5:32:52 GMT -7
I will ask YOU the experts for some data so I can try and resolve this blown fuse/rectifier/output tube problem that seems to be popping up way to frequently.
I have had problems with Sovtek 5AR4 rectifiers in the last year or so. prior to this the Sovtek was a stout rectifier that would last a good 5 to 6 years and in many cases much longer. As for the EL-84's well that again is a crap shoot, the JJ EL-84 which is the re-labeled as a Groove Tube EL-84-S is the MOST reliable EL-84 I have found and this is from extensive testing. BUT premature failures do happen with the fragile EL-84's from time to time and there is nothing that can be done about that.
So with your help and maybe a POLL set up by Lefty, I would like to know: 1 ) Have you blown a HT fuse ? 2 ) Was the rectifier the the cause ? 3 ) What model Z was it ? 4 ) Circa of amp or serial number ? 5 ) Type of rectifier and date code at bottom of tube ?
Thanks this info once collected will help me in my ever present search to sell the BEST amps I can produce.
DR.Z
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Post by John on Apr 1, 2007 6:53:12 GMT -7
I'd also like to ask the Doc if he could post in this forum, what fuses all the amps use. Perhaps a chart in the "News From DrZ" section.
I think we all have varying degrees of electrical knowledge and I think it would beneficial to have an 'idiot proof' chart so we could walk into the Home Depot and say "I want this fuse".
I'm just a little short in confidence about what fuse to ask for. And I'm very concerned that if I purchase the wrong type, and blow a fuse while playing at my local dump (wired by the owners grandmother), that my wrong replacement fuse could damage the amp.
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Post by Lefty on Apr 2, 2007 12:56:42 GMT -7
I think those who have experienced this problem should just fill out questions 1-5 and submit to Doc.
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Post by billyguitar on Apr 2, 2007 13:00:13 GMT -7
I've never had a tube blow and haven't blown a fuse since 1990, knock on particle board! My Maz 38 wore out a set of El-84s in about 6 months of light gigging. Retubed with JJs and it sounded great again.
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Post by dongiesen on Apr 2, 2007 20:43:42 GMT -7
Not that the fuse chart is a bad idea but hopefully if one still has the origional fuses in their amp they can remove and read the info from the fuse itself. I guess it gets deeper than that though as something had to trigger it to blow as stated in the above posts etc etc and the Doc seems to be on top of solving some problems to the besty of his ability and reputation. So far I have had zero problems and couldn't be happier
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Post by (8^D) on Apr 2, 2007 22:41:38 GMT -7
I think the fuse chart would be a good idea - mostly to benefit those purchasing used items. Same with tube chart - a quick resource to ID what was stock/OEM in the amp and verify if a previous owner changed anything. Seems as more Z's appear on the used market there's been an increase in posts about failures, tubes, etc that could be traced to non stock/recommended aftermarket items being installed in the amps.
RE: Recs/fuses blowing, 3 years of gigging, 4 different amps. Have had socket/mechanical issues, but no tube/fuse issues.
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Post by nitehawk55 on Apr 3, 2007 3:54:30 GMT -7
I think the fuse chart would be a good idea - mostly to benefit those purchasing used items. Same with tube chart - a quick resource to ID what was stock/OEM in the amp and verify if a previous owner changed anything. Seems as more Z's appear on the used market there's been an increase in posts about failures, tubes, etc that could be traced to non stock/recommended aftermarket items being installed in the amps. RE: Recs/fuses blowing, 3 years of gigging, 4 different amps. Have had socket/mechanical issues, but no tube/fuse issues. Another reason there should be downloadable owners manuals for each amp model . No problems with my Maz 18 so far . Replaced original rectifier with a NOS Mullard so not likely to .
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Post by Rockville on Apr 3, 2007 5:00:42 GMT -7
I guess it gets deeper than that though as something had to trigger it to blow Always remembering of course that fuses can blow even when there is no fault due to ageing or a mechanical defect in the fuse itself. If the fuse is replaced with another fuse of the correct rating and it still blows then you may need to look a bit deeper. I apologise in advance for stating the obvious.
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Post by hdahs143 on Apr 3, 2007 5:30:11 GMT -7
Happened once and it was the NOS rec tube I installed at fault, not the Sovtek the amp came with. Has since been replaced with a Mullard with the Sovtek as a backup.
Tubes crap out occasionally. It's just the nature of the beast.
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Post by dei305 on Apr 3, 2007 7:34:58 GMT -7
Doc, Here ya go, So with your help and maybe a POLL set up by Lefty, I would like to know: 1 ) Have you blown a HT fuse ? Yes 2-Amp 2 ) Was the rectifier the the cause ? Don't know 3 ) What model Z was it ? MAZ 18JR Reverb 1-12 4 ) Circa of amp or serial number ? M-8624 5 ) Type of rectifier and date code at bottom of tube ? 03
A couple of weeks ago, I unplugged the amp and moved into a different room. I plugged the amp into the outlet and the power light didn't come on. I checked the 2 amp fuse and it was blown. I checked the rectifier and outputs. Nothing was broken or cracked. I replaced the fuse with a new 2 amp slow blow. I then re-installed the same rectifer tube, turned on the amp..no problem..then I installed the same output tubes..no problem. The amp has been fine since..its been played and gigged. Thanks for investigating this problem Doc. Rick
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tnaluv1
New Member
Music is the best..... FZ
Posts: 49
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Post by tnaluv1 on Apr 3, 2007 14:53:54 GMT -7
Hi Doc, I got a Carmen Ghia head from a cat on ebay a couple of weeks ago. Model #7610 with a 15th Anniversary sticker on it. When it arrived, I plugged it in and played it for a couple of hours and turned it off. When I came back to play it I turned it on and the fuse blew. I took it to the shop and plugged in a new fuse and it blue. So it went to the tech. He replaced two parts. One is a little white rectangle that has XICON 5W 10K J printed on it. The other is a little orange blob that says10PS-D22+10% on the first line and .0022 then a 2 in a circle then 1000DC. He said the solder joint was weak, and that is why he needed to replace the parts. The fuse hasn't blown in about two weeks. But I do get a pretty loud hum that I didn't notice before. But as I said, I only got to play the amp for a short while before the fuse issue. I read elsewhere on these boards to replace tubes and such, so I will start to do that, though I'm not exactly sure where to start with that process. The rectifier tube says- JAN 5Y3WGTA Philips ECG 8552 34167 USA ADR. Hope that helps. I hope I can get rid of the hum and hear what this little baby can really do! Thanks, Alex Lusht mindignitionchannel.com
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Post by myles on Apr 3, 2007 15:05:50 GMT -7
As a side note.... if you buy a new Z amp and if the EL84s have ANY issue within three months you can give GT a call at 1-800-459-5687 and the entire set will be replaced, not just the offending tube.
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tnaluv1
New Member
Music is the best..... FZ
Posts: 49
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Post by tnaluv1 on Apr 3, 2007 17:42:04 GMT -7
As a side note.... if you buy a new Z amp and if the EL84s have ANY issue within three months you can give GT a call at 1-800-459-5687 and the entire set will be replaced, not just the offending tube. Yup, after it's all been said and done, I wish I would have bought a new one! Peace, Alex
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luke
Full Member
Mini
Posts: 109
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Post by luke on Apr 3, 2007 18:46:53 GMT -7
1) Blew 2 amp fuse
2) Replace the rectifer , 2 amp & 1/2 amp fuse problem corrected
3) MAZ Jr. NReverb Head Serial o-18068
4) Original Sovtek 5AR4
Luke Landgraf
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Post by zone47 on Apr 4, 2007 0:04:59 GMT -7
My amp is an 06 Prescription ES head. I can't say for sure it was the rectifier tube that took the BUSS 3A fuse out, but I am 99% sure it was. I have a Mercury 2000 tube tester that supposedly test for shorted tubes. All the tubes tested ok after the blown fuse, but someone here suggested changing the Rec tube anyway, so I ditched the Sovtek and installed an old RCA 5AR4. So far the amp is working and sounding great. The other tubes I am running just for reference are (4) JJ EL84 power tubes, (2) blackplate RCA 12AX7s and (1) miniwatt EF86 I have no idea why I had a Sovtek in there in the first place ..... it was hiding in the back there. The code on the Sovtek is 05 10. SN of the amp is Q6365 I threw the fuse away so I have no more info on it other than it was a Buss automotive type wire (fast blow) fuse. The other .5 amp fuse looks to be a slow blow ( has the wick looking conductor ). Hope the info is useful. I appreciate all the good information and support on this message board. PS. not to bash Sovtek, but I had a 5881 short out and take out the fuse on a Marshall JTM45 RI amp I had. I've had 3 12AX7s just give up vaccum and die.... and now this 5AR4 prob.... so I am not much of a Sovtek fan. -Joel
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Post by cementman on Apr 4, 2007 10:52:24 GMT -7
i have had three bad jj 5ar4 rectifier tubes,,, i will not use them, on the other hand all the sovteks have been great...
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Post by jzguitar on Apr 6, 2007 17:02:34 GMT -7
I had a JJ 5AR4 blow in my Mazerati combo. Blew the fuse. Looked like a little lightning storm inside the tube! I've had a Mullard in there for over a year now with no problems. I keep a GT Solid State rectifier in my bag for a spare. Not sure of any codes on the tube (chucked it out long ago). The amp is an '04.
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Post by Jim @94 Amps on Apr 6, 2007 17:42:02 GMT -7
1/2A, 1A, and 2A fuses should be MDL slo-blow buss fuses
3A should be AGC normal-blow buss fuses
any other types may not function as required
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Post by LittleBlindShakey on Apr 6, 2007 19:44:29 GMT -7
Doc, Hope this helps. 1. Yes, 3AMP 2. Yes 3. Maz 38 Sr. 1x12 combo w/reverb 4. P5628 5. Don't know as I tossed the bad tube but it was the original tube.
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Post by zdogma on Apr 13, 2007 14:29:02 GMT -7
I just blew the 2 AMP fuse in my 2002 Z28 when I installed a new pair of GT 6V6S output tubes. The rectifier is a Mullard 5AR4, and doesn't seem to be the cause.
I think it a was just a bad set of output tubes.
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Post by foxx on Apr 17, 2007 17:55:25 GMT -7
Hey Doc, here's what I know.
1 I blew both fuses 2 Yes 3 Mazerati combo 4 O 9166 5 Original Sovetk #n/a
May your amps improve.
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rgb
Full Member
Posts: 158
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Post by rgb on Apr 19, 2007 6:11:22 GMT -7
I had this issue with my 2004 Maz 18 Jr. I don't have it anymore, so it'll be tough to get you all the info you're requesting, but I'll do what I can.
1) Yes 2) Yes 3) Maz 18 jr 1x12 combo w/verb 4) 2003 or 2004.....can't be sure 5) GZ34.... I think it was a Sovtek
I retubed it completely with JJ's and had no problems after, but sold it shortly after that. Haven't heard any complaints from the buyer. I noticed a degradation in sound quality in the weeks before the rectifier failed, but didn't know what it was until I retubed and got the good tone back. Original tubes were only about a year old with moderate use.
The rectifier would spark inside and the fuse would blow right after turning it on....I think it was ok on standby, but sparked a couple of seconds after switching off of standby, and the fuse would blow.
Hope that helps!
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yarmo
Junior Member
Posts: 69
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Post by yarmo on Apr 19, 2007 8:57:32 GMT -7
1 ) Have you blown a HT fuse ? 2 ) Was the rectifier the the cause ? 3 ) What model Z was it ? 4 ) Circa of amp or serial number ? 5 ) Type of rectifier and date code at bottom of tube ?
Route 66 owner here!
1 ) Yes; 2 ) I 've been told so yes; 3 ) Route 66 4 ) Q - 10541 5 ) Sovtek 5AR4
P.S. The fuse blew twice IIRC. It was within 2 weeks of buying the amp brand new and you guys kindly sent a new one instead of trying to fix it via telephone. The one I received is running beautifully.
Again, I'd like to thank you for the too-kind gesture since I reside in Canada and it was during the Christmas holidays!! Thanks a million!!
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buster
Junior Member
Posts: 73
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Post by buster on Apr 20, 2007 10:36:33 GMT -7
I replaced a GE rect. tube in my Maz Sr. with a chinese one from my Fender Deluxe R.I. just to see how it would sound. The fuse ( I can't remember which one though I think it was probably the mains) blew. I replaced the fuse and put the GE rec tube back in and it was fine. I put the chinese rec tube back in the Deluxe and it was fine and is still there. I have a sovtek rec tube in the SR now as it sounds superior to the GE. Tried a JJ but the pins were loose and though the amp turned on, no sound came out. In summary 1) yes 2) yes 3) Maz Sr 4) M 5340 5) Fender made in China P/N 041400(part#?) No date code that I can find Hope this helps Buster
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Post by rwitcher on Apr 29, 2007 17:42:27 GMT -7
Looking to learn about Dr Z amps and cabinets and help direct my son down the right path. He wants a DrZ amp. Prescription ES with cabinet 2X12's, I think. I'm completely uneducated in this area and am looking for guidance so that I steer him in the right direction. I'm a musician, but I don't play guitar. He plays a Les Paul Studio Plus or a Strat and he's been playing for several years through a Marshall, but is really impressed with the Dr Z sound. Starting from square one, where do I begin my research. What do I need to make sure I look for, where can I get a good deal, what options do I need to consider? He's definately headed for some studio work, he's serious and I must say I'm impressed with how far he's come so quickly.
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Post by ronzoni on May 9, 2007 10:34:51 GMT -7
Hi, I own a Maz 38 Sr. that I got used- I think it's 3 or 4 yrs old and it has the orig. rectifier tube and fuses. No problems. I run it dimed with an Airbrake all of the time (10 hrs. a week) and I replace the power tubes about every 6 months or when I hear em fade. Love it.
Ronzoni
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Post by myles on May 9, 2007 16:22:44 GMT -7
Hi, I own a Maz 38 Sr. that I got used- I think it's 3 or 4 yrs old and it has the orig. rectifier tube and fuses. No problems. I run it dimed with an Airbrake all of the time (10 hrs. a week) and I replace the power tubes about every 6 months or when I hear em fade. Love it. Ronzoni Change the output tubes after one month and see how much they faded that you didn't even notice
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Post by ronzoni on May 16, 2007 10:03:08 GMT -7
Thanks, Myles. I just got a set of GT EL 84s and I'll put em right in to see. Any ideas on pres that'll personalize things a bit? I heard the GT 12ax7M is a cool tube. What positions would I hear it best in? Thanks a lot
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Post by myles on May 16, 2007 12:53:55 GMT -7
Thanks, Myles. I just got a set of GT EL 84s and I'll put em right in to see. Any ideas on pres that'll personalize things a bit? I heard the GT 12ax7M is a cool tube. What positions would I hear it best in? Thanks a lot Personally ... I do not like the 12AX7M in any of the Z amps. It is too dark.
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Post by billyguitar on May 16, 2007 12:55:05 GMT -7
When I first changed the EL84s in my Maz 38 I couldn't believe the difference! So much improvement. The really, really, really goodness went away pretty quick but the plateaued state they settled in at was still a huge improvement over the 6 month old tubes that were in it.
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