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Post by zwarrior on Nov 3, 2010 23:16:27 GMT -7
This is my second Dr. Z. My first was a carmen ghia 112 combo. Which I unfortunately sold on hard times. But I just traded my amp for a RX ES 212 combo, and I love it. I'm currently playing American tele's and HSS Strats. Anyhow, the problem is I've had it for a week and Ijust started noticing this weird noise. I've gigged with it three times so far and no problems. The noise is hard to describe but I will try.
When I play at home(modest volume @2 or 9:00 hi or low input), and I let a note or chord ring all the way out, as it fades in signal strength and volume there is a weird, slightly distorted, harmonic artifact. It sounds almost like ring modulation or a fuzzy octave or harmony that intensifies as the note/chord dies and eventually fade after the note is gone. It isn't super loud, but it is noticeable when you try to play lightly or let a note/chord ring all the way out.
I've tried the obvious.. Cable change, plug straight into the amp, different outlet, different guitar. I am pretty strapped for cash right now so I am hoping to diagnose and mend in the easiest and least expensive way possible just to keep her running for all the gigs coming up. I plan to completely retube this thing when I can afford to. But do you guys have any idea where I should start with this sound?
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Post by texasjoe on Nov 4, 2010 4:14:07 GMT -7
Sometimes speakers can make that noise if you are pushing them to the point when the amp begins to clip. That's why around the outside edge of the speaker they put that black shiny stuff. That is supposed to eliminate that sound. So maybe the RX is putting out so much volume that you're speakers can't handle it? Or maybe it's time to replace them. What speakers are you running with your ES? Also, Ted Weber says that speakers sound better without that stuff on them so it's totally possible you're speakers don't have that.
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Post by zwarrior on Nov 4, 2010 8:14:40 GMT -7
they are 70th anniversary g12h's. It is doing it at lower volumes. It is a a lot harder to detect with the amp loud. I literally have the volume between 2-4 (or 9:00 and 11:00) and the overdose off, in either the hi or low input.
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Post by frank4001 on Nov 5, 2010 6:43:37 GMT -7
I would check the EF86 tube. They are known to go microphonic...If it is you may get away with a cheap fix. You should probably check all the pre-amp tube anyway. There are some rubber band like rings you can put around the tubes...I forget what they are called but sometimes they work...sometimes not.
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Post by zwarrior on Nov 5, 2010 7:19:03 GMT -7
I would check the EF86 tube. They are known to go microphonic...If it is you may get away with a cheap fix. You should probably check all the pre-amp tube anyway. There are some rubber band like rings you can put around the tubes...I forget what they are called but sometimes they work...sometimes not. Do you think it is more than likely a pre-amp tube? I took them all out and re-seated them, and the amp seems ok now. No noise after that. I got the former owner on the phone and he said he had the amp retubed 8 months ago, and used the amp on a pretty light gig schedule and a lot of rehearsals. 2 questions... 1. What is a good rule of thumb for how long to go between servicing the tubes? I am in a working band. We do an average 3-3hr. gigs a week, playing rock and groove music. This is my amp. I have no back-up or second choice. 2. Is there another name for the EF86? Can't find an EF86 in stock near here. Just curious. 3. I lied this is the last question.. Does the Brake Light work well for this amp for gigs? (it doesn't have MV) Does the Brake light hurt the amp in any way? (transformer, etc..)
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Post by frank4001 on Nov 5, 2010 12:58:58 GMT -7
Pre-amp tubes, especiall Ef86's make noise...Sometime if you play it in certain spot like too close to a wall or something will set them off. Get those tube things I was talking about..I think some the Dr.Z's come with them now. Look on the KCA tube web-site. Mike is a very good guy to work with. Pre-amp tubes should last a long time. that amp may eat power tubes though. Call Mike, he knows the amp and the tubes. Brake-Lite? Not for me....You can send the chassis to Dr.z and he'll put a Master on it....I'd do that.
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Post by zwarrior on Nov 6, 2010 6:31:42 GMT -7
All fixed, Re-seated that EF86 and put those rubber tube guards on preamp tubes. All noises gone. Thank you very much for your help. I can't be without this amp long enough for the MV mod. So brake light is a bad idea?
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Post by rcrecelius on Nov 11, 2010 10:06:04 GMT -7
All fixed, Re-seated that EF86 and put those rubber tube guards on preamp tubes. All noises gone. Thank you very much for your help. I can't be without this amp long enough for the MV mod. So brake light is a bad idea? The Brake Lite is good up to 45 watts...now the RxES is a 45 watt amp but it has been known to produce 60+ watts wide open...so if you're cranking it to get tube saturation, the BL will not holdup...I used a BL with mine when running the amp semi clean(vol up around 1 oclock) and it did fine.
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