meagain Posted May 20, 2007 Share Posted May 20, 2007 Yea! I got my VRDs back. Haven't spent much time listening yet, mostly just a bit last night. Had new caps put in, new kt88's - so I guess that has to settle in for a bit. Not sure what to expect with cap burn in so I hope the changes will be OK. Wanted to give a shoutout to Craig for testing/tweaking them for me. Thanks Craig! (hugs) Soooo.... What would this be called....... When I fired up one amp, there's this crackling sound which fades away after a bit. This morning I swapped all tubes between amps and the startup noise moved to the other speaker. I'm assuming the culprit is in one of my new kt88's I ordered online cuz the little tubes are what I used before and were fine. Is this called something? What would cause a tube to do this? I've not experienced this before. IDK why a tube would crackle upon startup, then chill out. I'd think if it was bad, it would continue to be bad? Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted May 20, 2007 Share Posted May 20, 2007 Yeah, you have a slightly noisy tube there somewhere. But don't assume...yet. Roll ONE TUBE AT A TIME from amp to amp. Since you suspect the outputs, start with one of those. Take the right output on the right amp, for example, and reverse it with the same tube in the same slot on the other amp. If it's not that tube, keep going with the other slots until you find it. Sometimes a tube will show noise on the "ramp up" of power as the juice to the amp flows on power up. I would seek to replace those, even if it isn't a problem during normal operation......especially if they are new current production stuff - just get the questionable tube swapped out for good stock and you should be good to go. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted May 20, 2007 Share Posted May 20, 2007 Dam Tube Thingy's nothin' but ... trouble .....[] Quote Link to comment Share on other sites More sharing options...
Deang Posted May 20, 2007 Share Posted May 20, 2007 I guess you had these tubes waiting for when the amps showed up? IOW's, these aren't the tubes used in the amps when he had them on his bench. When you get new tubes, you should clean all of the pins with denatured alcohol (I use Q-tips). A little bit of crackling isn't all that unusual during warmup with new tubes (unless is sounds like a damn lightening strike). Quote Link to comment Share on other sites More sharing options...
seti Posted May 20, 2007 Share Posted May 20, 2007 Dam Tube Thingy's nothin' but ... trouble .....[] Duke is right so in an effort to help other forum members I am willing to take poession of all tubes and tube gear Quote Link to comment Share on other sites More sharing options...
meagain Posted May 20, 2007 Author Share Posted May 20, 2007 I found the suspect tube (Valve Art KT88). Dean - Right. Craig told me my KT88's I sent to him were bad so I ordered a new quad. Will try the alcohol thing & make sure all the pins are OK and straight. I wouldn't say it sounds like a lightning strike, but I'd say it's pretty loud? Enough to freek me out when I first heard it. Worried an amp got banged wrong in shipping, etc. After the crackling sound died down, I put my ear at the speaker and heard minute irregularities - little jogs, pops. But only if I put my ear close. I've no clue what this would do to music. After it settles, if I can't hear it from listening position - is it still not OK? Duke - I hear ya. Quote Link to comment Share on other sites More sharing options...
markgod Posted May 20, 2007 Share Posted May 20, 2007 It is safe to assume that you have checked the bias on the suspect tube? To rule out the rediculous , no offense meant. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted May 20, 2007 Share Posted May 20, 2007 "I wouldn't say it sounds like a lightning strike, but I'd say it's pretty loud? Enough to freek me out when I first heard it. Worried an amp got banged wrong in shipping, etc. " Sounds like you need your pins retensioned. Some tubes vary in pin thickness...so if you swap out tubes that have thicker pins for tubes that have thiner pins...they don't fit as tight. Eventually they relax into the correct position...but you could have some one retention your sockets. I use a wooden tooth pick...other folks use speacil tools for this. Quote Link to comment Share on other sites More sharing options...
meagain Posted May 20, 2007 Author Share Posted May 20, 2007 It was just tensioned. I think it's just a screwed up tube. And really bad luck. Quote Link to comment Share on other sites More sharing options...
garymd Posted May 20, 2007 Share Posted May 20, 2007 ValveArts have fat pins so that's probably not the culprit. When I switch to the Pentas, I have to tighten all the sockets again. All tubes will make a little noise. I'd be suprised if it made a difference while playing music however. Still, you might as well have them send you a replacement. So how do they sound now after Craig's tuneup? Quote Link to comment Share on other sites More sharing options...
HarryO Posted May 20, 2007 Share Posted May 20, 2007 Quote Link to comment Share on other sites More sharing options...
Moderators dtel's wife Posted May 21, 2007 Moderators Share Posted May 21, 2007 It was just tensioned. I think it's just a screwed up tube. And really bad luck. Meagain, You seem to have cornered the market on "bad luck".[] Quote Link to comment Share on other sites More sharing options...
NOSValves Posted May 21, 2007 Share Posted May 21, 2007 Lisa, Did you just swap the KT-88's and the noise moved? I bet you have a KT-88 that has a cold solder joint inside the tube (you are one lucky lady). What you need to do to determine what tube has the problem is to switch tubes one at a time. When the sound moves you found the noisy tube. Or you do have one usable spare you could also place it in the amp with the noise, one tube at a time until the noise at start up is gone. If this is a cold solder joint on a KT-88 it will get worse and fail sooner or later. No rush to do this so just swap the tube out when you fire up the amps each day and then if the noise is still present swap the next one at your next listening session. Then return the noisy tube for a replacement. Use your spare while waiting for the replacement. By the way another simple way to find the noisy tube is to just tap the tube with your finger nail while it's making the noise at start up and it will usually have an effect on the sound. The tube will not be hot at cold start up so you won't burn your finger. Craig Quote Link to comment Share on other sites More sharing options...
meagain Posted May 21, 2007 Author Share Posted May 21, 2007 Craig - Yes, I swapped tubes and the noise followed, then I narrowed it down to a KT88. I didn't try the tap/jiggle test. I was thinking I could perhaps deal with it but today I fired them up and felt 'maybe' the length of time the crackle happens is long enough to make me delay turning on a CD, etc. Today it 'seemed' to go on for a bit longer than yesterday and just when I thought it was done, it spewed out a few more crunchy sounds. But if you're saying this is often a cold solder and will get worse - that sucks. One of my concerns is I bought these as a matched quad and I've no clue which pair this is from or what numbers were attributed to it. I didn't write the box numbers on the tubes. I guess I'll have to get with the seller to figure it out. Craig - How would biasing work if I used that one old KT88 that was borderline trash can worthy? This makes me nervous - putting in a crappy old tube with good ones. Gary - I can't really judge the sound yet. I'm running the bias pretty low which seems to effect the sound. Also, new caps & power tubes that need to break in. I worked up the nerve to bias to .70 for a listening spell and thought it sounded pretty good but I was thinking it was more bright or more towards the sound of my SS AVR on the high end, maybe the midrange was a bit more forward than the bass? Not sure, it's hard for me to remember minute details of sounds from a few weeks back before I shipped them. They have the Sonicap Platinums in them which apparently require a long burn-in time. Plus the new KT88's.... basically, I guess I can't judge anything yet. Not sure what specifically to expect when things are burned in. But I think it sounds pretty good. One thing though, the system seems quieter when not playing music. I think maybe that's from sending my Peach tubes to Craig for testing and possibly putting a slightly better tube in the V1 slot? IDK. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted May 21, 2007 Share Posted May 21, 2007 Short term the mismatched tube will mean just about nothing just bias it to match the others (your being anal again []). If the quad you ordered is a matched quad then all the numbers on the box should be fairly close. The tube seller just needs to know the numbers of the 4 tubes and send you something in the ballpark. You don't need to know which tube it is out of the four. VRD's don't absolutely require matched output tubes. It's better to buy a matched quad simply because if you order singles the tube sellers will give you the left over junk that they could not match. I purchased 20 singles once thinking I could just match them up myself. I ended up sending them all back they were so far off the charts one way or the other. Craig Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted May 21, 2007 Share Posted May 21, 2007 That crackling noise is part of the glorious charm and spacious sound that tubes impart of thier signals. As many tube fans always says "You never hear tube amp makers claim that thier product sounds just like solid state". Quote Link to comment Share on other sites More sharing options...
oldbuckster Posted May 21, 2007 Share Posted May 21, 2007 My Scott made that noise once, and hasn't done it since then.......................Craig, I like the sound of those J.J.Tesla's...Thanks for the info.....As hard as I try to find fault with the Scott...............I Can't.........Nice Unit........ Quote Link to comment Share on other sites More sharing options...
garymd Posted May 21, 2007 Share Posted May 21, 2007 Craig - Yes, I swapped tubes and the noise followed, then I narrowed it down to a KT88. I didn't try the tap/jiggle test. I was thinking I could perhaps deal with it but today I fired them up and felt 'maybe' the length of time the crackle happens is long enough to make me delay turning on a CD, etc. Today it 'seemed' to go on for a bit longer than yesterday and just when I thought it was done, it spewed out a few more crunchy sounds. But if you're saying this is often a cold solder and will get worse - that sucks. One of my concerns is I bought these as a matched quad and I've no clue which pair this is from or what numbers were attributed to it. I didn't write the box numbers on the tubes. I guess I'll have to get with the seller to figure it out. Craig - How would biasing work if I used that one old KT88 that was borderline trash can worthy? This makes me nervous - putting in a crappy old tube with good ones. Gary - I can't really judge the sound yet. I'm running the bias pretty low which seems to effect the sound. Also, new caps & power tubes that need to break in. I worked up the nerve to bias to .70 for a listening spell and thought it sounded pretty good but I was thinking it was more bright or more towards the sound of my SS AVR on the high end, maybe the midrange was a bit more forward than the bass? Not sure, it's hard for me to remember minute details of sounds from a few weeks back before I shipped them. They have the Sonicap Platinums in them which apparently require a long burn-in time. Plus the new KT88's.... basically, I guess I can't judge anything yet. Not sure what specifically to expect when things are burned in. But I think it sounds pretty good. One thing though, the system seems quieter when not playing music. I think maybe that's from sending my Peach tubes to Craig for testing and possibly putting a slightly better tube in the V1 slot? IDK. I run my VRDs at about 65 or 66 most of the time. When I bias at 70, I can't hear any difference. Might as well prolong the tube life. You can really tell a difference between say 66 and 70??? Quote Link to comment Share on other sites More sharing options...
Deang Posted May 21, 2007 Share Posted May 21, 2007 Someone might ask since you can bias each tube individually with the VRD's, why do you need matched tubes? Quote Link to comment Share on other sites More sharing options...
meagain Posted May 21, 2007 Author Share Posted May 21, 2007 I like them over .71 I will say I had them at .57 on Saturday and couldn't listen to it. If something else was at play besides bias, then IDK. But that was a bad number. Quote Link to comment Share on other sites More sharing options...
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