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Post by ducmike on Sept 10, 2005 4:46:08 GMT -7
I am getting a strange undertone on all notes with my RT66. I thought it was my poor muting at first, but now I that is not it. It does it with all my guitars. It is a noise lower than the note. I read a thread on TGP that it could be power tubes, so I installed a new set of KT66's (shuguang) and still there. I also had read that it could be the spring tube retainers, is this possible? Also, my stock EF86 and the 2 Bugleboys I have seem to be microphonic, you can clearly hear it through the speakers when I tap them. This is my first ef86 amp, so I don't no if that is normal with them. I have tried different speakers in my cab too. I have also tried diff. guitar and speaker cables. I love the tone, but this is starting to drive me nuts. I might call KCA and get a Dario ef86 to see if that helps.
Thanks in advance for in help. Mike
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Post by Laroosco!! on Sept 10, 2005 7:16:01 GMT -7
How old is your 66?
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Post by cheycaster on Sept 10, 2005 9:27:39 GMT -7
That sounds like filter caps to me. My 70 marshall Super lead 100 W did the same thing and I replaced everything under the sun too but it was still there. In '88 Guitar Player mag came out with a cover story called "AMPS!" and it described my Super lead to the "Tee" about the funny out of tune lower ghost notes no matter if you played clean or honkin' iton. Hope this might help!! cheycaster
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Post by ducmike on Sept 10, 2005 10:35:47 GMT -7
The signature tag on the chasis is dated Feb. 2004. That seems a little early to give up the Ghost (sorry for that). I guess I need to email the good Dr.
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Post by taswegian on Sept 11, 2005 15:15:06 GMT -7
Just a side note, remember a Rte 66 has to be rebiased if you change the power tubes.
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Post by ducmike on Sept 11, 2005 15:48:46 GMT -7
I did rebias the new tubes, but the problem existed with the old tubes too. I'm hoping that the ef86 might be the problem, but I don't want to by another one just to find out that they are all slightly microphonic. It seems that I have read that is the case.
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Post by taswegian on Sept 11, 2005 16:49:28 GMT -7
This is my first ef86 amp, so I don't no if that is normal with them. No this isn't normal with them. I have a Rt 66 and I don't get any ghosties...just thick rich overtones, sometimes a beautiful octive. I installed a GEC british military grade EF86. I know Mike at KCA has some in stock kcanostubes.com/content/estore_details.asp?product=142I wouldn't know what to tell you about the problem but it would seem very unfortunate that all your EF86's were microphonic. Good luck with it.
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dewman
Junior Member
Posts: 86
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Post by dewman on Sept 12, 2005 0:23:32 GMT -7
Had a similar problem with a 1989 Marshall Bluesbreakers. It turned out to be actually two problems, bad filter caps and rattling spring retainer clips. Replaced the filter caps, charged them up slowly on a variac, part of the problem fixed. However the majority of the ghosting and in some cases rattling (like a voice coil rub with some notes) was taken care of by putting a dab (a lot) of lock tite sealer on each KT66 retainer spring, letting it dry and then reinstalling the tubes. At certain volume levels the springs were bouncing against the KT66s and being somewhat microphonic at high volumes, were translating into a whole host of sounds from rattles to ghost notes. All this as well depended on what guitar I was playing and where on the neck. Anyway, although my spring clips look like crap, the high temp silicone lock tite provides a cushion and doesn't let the springs rattle against the glass anymore. I saw on Ebay some high temp silicone rings ('tube dampeners') for about 10$ that are supposed to cut down on microphonics. Don't know if they would help either. I tried several things to dampen the springs, such as cutting a piece of fuel line tubing (high temp friendly) for each spring, tygon tubing, etc., but the glob of high temp lock tite (from Lowes or Home Depot) did the trick and hasn't shown any ill effects due to heat. I have the combo bluesbreaker which doesn't have really enough room for KT66s, so with a couple of spacer washers and the lock tite I have a really nice sounding amp which can be cranked with no more ghost notes. The retainer clips are fairly cheap (a few bucks) and easy to install (drain the caps first!) so if it doesn't work then you can replace the originals. I'll pay close attention to this problem as I have recently ordered a Route 66...hope this helps.
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Post by ducmike on Sept 12, 2005 5:18:41 GMT -7
Thanks tasweigan, all 3 of my ef86's are clearly microphonic when tapped. And thanks to dewman for the input too. I was thinking the spring retainers could be the problem. I'll get a new ef86 and some retainer clips before I bother Dr.Z. I love the tone and I will send it in for service if I need to, this is "THE" amp for me.
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Post by taswegian on Sept 12, 2005 7:21:38 GMT -7
Yeah they are really cool aren't they. I don't think people know how good they are until you use them in a live context. Listening to it in a shop you might go "oh yeah, a little bit more of this and a bit more of that" but when you get it going with the band it's just "oh yeah"! I've heard (figuratively speaking) Miles say EF86's are a "crap shoot" so maybe it's as simple as that! Hope it's healthy soon because they are just too good an amp to be playing "sick"!
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Post by ducmike on Sept 12, 2005 7:42:27 GMT -7
I haven't played in a band context yet, but I can tell I'll have no problem cutting through. I don't think the problem would be as noticeable in a full band. I think I'll just email Z and see if I can send it in.
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Post by cementman on Sept 13, 2005 9:01:59 GMT -7
i owned a new 66 that had ghost notes. had to send it back to dr z, he said it was filters. now, i have a used z-28 that had a strange noise, when i tapped the ef86 it sounded microphonic, so i put in the other ef86 i had (one a mullard, the other GEC from mike at kca tubes) they both were microphonic, so i put in a different 12ax7/5751 and it went away. for some reason a bad 12ax7 made the ef86 microphonic. i cant say this is a rule of thumb, but that was my experience. i love z amps. however i never bought the smaller ones, which i should have. i have a big 2/12 38 (about 70 lbs) and a z-28 4/10 (65 lbs?) and they sound so good i just cant let them go.
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Post by ducmike on Sept 13, 2005 16:09:53 GMT -7
I have tried a few 12Ax7's too, but i have alot of those so I will try them all and see if it helps. Dr Z did say to try a new Ef86 before I send it to him.
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Post by ducmike on Sept 18, 2005 8:35:05 GMT -7
At the Dr's advice, I ordered a Dario EF86 to replace the microphonic ones. The Dario (from KCA) is dead quiet when tapped. It definatly helped. There is still a ghost note there, but is not as pronounced and noticable. I might still send it to DR Z to have him tighten up the filter caps, but I need alot more time with it like this to decide. The amp seems to have more volume now also. I have a bunch of NOS 12ax7's ( Mullard, Amperex, GE, RCA), but I think I like a GT12AX7-M in the PI the best.
Does anyone know if it is ok to replace the spring tube retaines with the clip style. I think the retainers might be addig a little noise.
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Post by adammkoss on Sept 28, 2005 16:53:03 GMT -7
You might wanna check which notes are worse - Gerald Weber talks about these modulating C#'s (2nd or 14th fret on the B-string), which are more indicative of a filter cap problem. Also, i don't know what "tightening up" would do (unless you electrically "tighten" the circuit, which is pretty much maxed as filtering goes with a gz34), but, whatever you do, DON'T TOUCH the filter caps (or any circuit component for that matter) unless you know what you're doing, unless you wanna discharge ~500 Volts through your being (which won't likely be after doing such). Also, if you play any guitar with true single coils (esp. a stratocaster), look out for Strat Syndrome, where the magnetic pole pieces are too close to the string and causing modulations there. Also, move to different rooms/spaces, as something in the room might be rattling...or you may be experiencing the "phenomenon of the missing fundamental". Probably a million other things - best to send it to the good Dr for a check up
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dewman
Junior Member
Posts: 86
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Post by dewman on Sept 29, 2005 23:46:11 GMT -7
Ditto the strat pickup phenomena. I have seen that a lot. Recently replaced my pickups wih Fralin Blues Specials and the pull was way greater from the magnets and the pickups had to be backed off from the strings. Took a while to diagnose that one. Sounded just like a filter cap warble/ghost note...
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Post by ducmike on Oct 2, 2005 8:14:46 GMT -7
Thanks for the help. I know its not the pups though. I use 4 different guitars, a LP standard, Hamer special and 2 Strats, and it is there with all of them. One of the Strats has TX specials lowered to the pickguard and it is still there. I have a new 2061 style cab coming, and I have a apair of new Scumback speakers here waiting on the cab, I'll wait and try this before I decide to ship it off. I think my current cab with V30's is accentuating the problem.
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Post by lurko on Oct 28, 2005 9:10:13 GMT -7
The ghosting is usually caused by insufficient filtering of the power supply, not microphonic tubes, in my experience. And as I stated in another post, all tubes will "plink" when tapped. They are microphonic only when that plink rings out and begins to slightly feedback.
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Post by ducmike on Oct 28, 2005 9:18:58 GMT -7
I have discovered that I don't here the ghost notes in a live mix. So I have decided not to worry about it. I might still send the amp to DrZ for check up, just to be safe.
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dewman
Junior Member
Posts: 86
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Post by dewman on Nov 6, 2005 21:48:41 GMT -7
a follow up to this thread- I sort of wondered about this problem and played around with my 66 at full click the otherday. With volume at 3 oclock, and treble and bass around the same, the ghost dissonnant overtones were particularly noticeable. I had to rerally crank it to get there,but there is no doubt about it I have them too. It was more pronounced with the Z best can (running at 8 ohms). I have an attenuator on it but it didnt make a difference. The effect was there but way less noticeable when running at 16 ohms into a marshall 1936 cab loaded with two stock greenbacks. Its not a ghost buzzing that I heard at these volumes, but when playing around the 8th - 15th fret it appears as a dissonant tone, almost like a synthesizer is doubling your lead lines. Weird as hell. I A/B'd the guitars I have and it didnt matter. Two other amps I have do not give ghost notes like this, a bluesbreaker and ampeg vt40. I sort of thought that this was a bad filter cap or something of the sort, and it is after all only a significant problem at higher volumes when the amp is pushed. But I heard them man- and it was loud enough to really be noticeable. I switched the EF86 this evening to another one and will see if the amp selfcorrects. In the original post, it wasn't clear what settings these notes are heard, and clearly unless I am opening up for Metallica I probably will not likely play at these volumes. But the notes were clearly ghosted, significantly so at high volumes. It could be a general thing with the EF86 tubes when the sound levels are extraordinarily high??? If you could repost what conditions that you were running the amp at to get those ghosties that would be great. Lowering the amp level did the trick mostly, so it's likely tied to the circuit wiring layout and maybe a microphonic tube .
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Post by ducmike on Nov 7, 2005 7:17:20 GMT -7
Hi dewman, I usually run the amp with trebel at 3:00, bass at noon, and voume from 1:00- 3:00. What you hear is exactly what I hear. I have tried many different EF86's and that's not the problem. DR Z has said it is a characteristic of the amp to some point. He said he could tighten up the filter caps, but it won't gp away completely. I don't hear it in a live situation at all. At the last jam I took it too, Buddy Whittington wailed on my 66 at full volume ( T-max, B-off, V-max) for about 5 songs and I never noticed it at all. And I was listening for it. And Buddy is as good a person as he is a guitar player, a very cool dude.
I'll try playing at a lower volume to see if it goes away. Last night I set it at T-11:00, B-10:00 and V-Noon to try to get a country tone with a Strat. I will pay close attention to the ghosting when I do this again. BTW, this thing has great clean headroom when you back off the interactive tone controls. I really like the cleans I get this way, though I usually just back off the guitar a little for hairy clean.
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dewman
Junior Member
Posts: 86
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Post by dewman on Nov 7, 2005 12:31:31 GMT -7
Hey ducmike, I thought of your post when I heard it. I was running it through the Z best cab at the same levels. I was sitting or standing right in front of the cab too. I am glad that it isn't noticeable in a band situation though. I'll stay tuned and see if it can be improved. let me know if you hear from the Dr on this one. It goes away when I turn down, and interestingly when I switch cabs, so I am wondering if it is emphasized by the speaker cab. Anyway, you're not crazy, it's there but probably can be made less severe. More on that as I experiment...But let me qualify that I ain't worried about it now, it's just something I experienced when maxing it out the other day. The amp sounds great through and through, it's likely that only under certain conditions these ghosties show up - I am sure that a combination of driving the hell out of it and using the ported cab at those frequencies...The design is awesome, and I love the amp and can't really rag on it at all. I was just saying that I heard them too when pushing the amp real hard. But you know my VT-40 and Bluesbreaker sound like they will blow up when I push them as hard. I guess the 66 is set up so well that I am spoiled when I hear anything except the fundamental notes I am playing. I had a super reverb that sounded like it was choking with all the rattling and ghost notes when pushed at high volumes with humbucking pickups. Sold that one. The marshall is clearly tougher and holds up unless you place everything on 10. My take on it is that it ain't gonna likely show up unless you drive it hard, but I am curious if it has it's origins in the EF86, the circuit, or some alignment of interference set up (or magnified) with the ported cab or the speaker combination. Oh well- guess I have to go play it for a couple of hours to do some more 'research'- good luck.
D
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Post by johnnyl on Nov 7, 2005 14:42:49 GMT -7
Hi guys, sorry to jump forums on y'all but I was interedted in reading this thread. I get some ghost notes (sounds like moaning) w/ my SRZ-65 and zbest too so maybe it's not your ef86. Maybe it does have something to do with driving the hell out of the amp and the ported zbest making that frequency more audible. I did notice it more when using an attenuator too. I've gotten used to the "ghosties" but at first I thought zombies were about to come out of my Zbest... haha...
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Post by ducmike on Nov 7, 2005 14:43:50 GMT -7
I don't really consider it a problem anymore. The way I understand it is that if you dial it out completely ( by filter mods), the amp would no longer be the 66. I think it is a trade off for the ultra touch sensative feel with that punch. I was worried until I played out with it, but not anymore. I took awhile deciding between the RT66 and a Clubman, I liked them both, but the Z didn't flub out when cranked, and I like that it doesn't have a master volume. I thought I had made a big mistake when I first heard the ghost notes. The tone by far offsets the ghost notes.
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Post by ducmike on Nov 7, 2005 14:46:57 GMT -7
I don't really consider it a problem anymore. The way I understand it is that if you dial it out completely ( by filter mods), the amp would no longer be the 66. I think it is a trade off for the ultra touch sensative feel with that punch. I was worried until I played out with it, but not anymore. I took awhile deciding between the RT66 and a Clubman, I liked them both, but the Z didn't flub out when cranked, and I like that it doesn't have a master volume. I thought I had made a big mistake when I first heard the ghost notes. The tone by far offsets the ghost notes. I don't think it is the EF86 either. The Z28, RX, KT45, and the Delta 88 all have EF86, and there doesn't seem to be any ghost complaints with these.
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Post by kledbet on Nov 8, 2005 17:13:16 GMT -7
I have spoken with a guitar tech who tells me that this problem is related to the ef86 tube. This used to be an issue in stereo amps built in the past but was solved with a very small mod to the ef86 circuit. The mod only takes a few minutes and according to him might take care of this issue. I don't know why only some of these amps have this problem. When my 66 comes in I will take it over and see if this small mod will solve the problem while at the same time keeping the 66 tone intact. If it works I will let everyone know about the fix.
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Post by taswegian on Nov 9, 2005 14:29:20 GMT -7
I'm confused, is this a mod to the EF-86 tube or the preamp circut in the 66? I wouldn't be modding the 66 in any way without talking to the Doc first as this may render your warranty null and void.
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Post by kledbet on Nov 9, 2005 16:40:20 GMT -7
I'm not exactly sure what the mod is but from what I remember in my talk with the tech it was real simple, like a resistor across the tube socket... or something like that. I won't mess with the design of the amp, but if 1 resistor will take away those ghost notes I will try it. I can always take it off later. The amp I am getting is used (so there is no warranty) and I asked the seller if it had ghost notes and he said yes. Of course he did not mention this before I paid for it. As we all know the amp is probably the best of its kind around and I would love to be able to not hear my own guitar sounding back at me a 6th lower like I was using a harmonizer. The good Doc has created one of the greatest blues and rock amps ever and I want to make sure no one thinks I am making any kind of put down on him or his amp.
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dewman
Junior Member
Posts: 86
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Post by dewman on Nov 10, 2005 9:46:02 GMT -7
Please let us know what happens. Sounds like this mod is an effort to quiet a small parasitic oscillation with the tubes. The same type of thing is found with some marshalls with valve art KT66's and addition of a resistor is required to stabilize the amp. Often these resistors can squelch dynamics and tone, like the differences between blackface and silverface amps which have the swamp resistors in there to prevent oscillation due to the poor lead dress in the later silverface models. Since it appears EF86 related, that might explain why some people have it and some people dont. The ghost notes were pretty pronounced with the dario miniwatt EF86 that came with the route 66 from DrZ, but a replacement dario from Mike K at KCANOS tubes has quieted the ghost notes down considerably. Let us know how you fared!-Just don't electrocute yourself, discharge them caps!!
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Post by kledbet on Nov 10, 2005 11:44:27 GMT -7
My amp will come in on Friday, but the tech is gone til tuesday. I called him today and here is what he said about the ef86 possible mod. It is a shunt bypass on the plate resistor which involves adding 1 capacitor and 1 resistor. This is suppose to roll off any frequencies over 20,000 htz which can induce the modulation effect in some ef86 tubes. This idea came from a design book on stereo amps where the ef86 tube was linked to extra modulations... this mod was the fix. I asked if it had any affect on tone or dynamics and he said no, but we will have to see about that. The mod will probably be tried when he gets back in town so I will be able to post something by the middle to end of next week. In the meantime I am also going to try 3-5 different nos ef86 tubes and see if that has an effect.
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