| Author | Message | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
Hi there. I am the lucky owner of a HD 130 head chass. no. 2275-130 EX without reverb, which need new filter caps. As you can see on the pictures, someone did a partial recap but left the filter caps alone. http://i1090.photobucket.com/albums/i368 /Spamon/MusicMan%20HD%20130/DSC01434.jpg http://i1090.photobucket.com/albums/i368 /Spamon/MusicMan%20HD%20130/DSC01427.jpg http://i1090.photobucket.com/albums/i368 /Spamon/MusicMan%20HD%20130/DSC01429.jpg http://i1090.photobucket.com/albums/i368 /Spamon/MusicMan%20HD%20130/DSC01432.jpg The small 20uF filter caps seems in good shape, but both of the 100uF suffer from the "pimple problem". The two 150uF, 50V on the rectifier board seems okay too. Would you advise me to replace the healthy caps now, or wait till they show sign of pimples? And can you tell me why everyone is raving about the Sprague Atom caps, why are they so much better than everything else like Illinois, TAD etc, which is less than half the price. The 100uF, 450V Atom is rated at 65 deg. C, while the other brands are rated 85 or 105 deg. C. After a gig I can't touch the chassis without burning my fingers. That's around 45-50 deg C. From a life span view, I'd guess it would be wiser to use the a higher thermal rated cap than the Sprague. Or maybe I'm wrong... And another question: With the power switch on the back and the high-low switch on the front, what is this arrangement attached to the high-low switch? http://i1090.photobucket.com/albums/i368 /Spamon/MusicMan%20HD%20130/DSC01433.jpg Regards, Henrik Nordskov | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I personally have had no trouble Ilinois Caps but i know others have. They ARE used in a lot of oem applications so how bad could they be. I don't really think that ANY caps are made the way they used to be. I have Illinois caps in my bassman that I use ALL the time-NO troubles. TAD'S have a good rep. I'd use them too. I keep very few Spragues here any more, due to price. I've got a stock of Illinois, Panasonic, Xicon and some Elon's that Ted Weber stocks. Just depends on what's on sale for the sizes I'm out of. Spragues have just gone bonkers on price and I just don't see the need anymore. I've seen spragues cut open and they had somebody elses RADIAL cap inside! I would replace ALL those caps, as well as every electrolytic on the preamp board. Then fan, fan fan! Being an export amp, I have NOT seen any so I'm the wrong one to answer here. I hope Lars drops in as he is familiar with them. Mike. | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
Mike: "I've seen spragues cut open and they had somebody elses RADIAL cap inside!" That's lame! "Fan, fan fan!" I don't get it, please explain. (Bear with me, I'm danish :D) | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I just meant to put a little fan on the back of the amp. Sorry! | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
Ahh.. It has been on my mind for some time, but I never had it done  I actually have a 230V PC fan somewhere, would it be safe to tap across the +46V/-46V bias? That'll give 92V and make it almost noiseless. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I don't think that there is enough current capabilities there to run the fan and the amp. If you're on 230v over there, I'd just put a cord on it and plug it in. If you are 117, I'd still just plg it in. It will run about half speed and be just fine. I built a regular 110V fan into the front of my gigging amp and run it wide open. Used the non used polarity switch and powered it through one side of that. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
By the way, I can't stress how important it is to change the bias cap board as well. | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
By "change the bias cap board as well" you don't mean the ENTIRE BOARD, but only the caps, right?! ;) Some of the caps have been replaced recently including the bias caps (150uF, 50V). I'll replace the remaining: Filter caps 100uF, 450V + 20uF, 450V and rectifier caps 150uF, 50V. The 20uF, 450V are hard to get, I guess 22uF, 500V will do just fine. 150uF, 50V are hard to get too, so I have to go with Panasonic FM radial. Although I'm not sure if the leads are long enough to reach across the PCB. I recall reading that Steve suggest replacing some of the brown 600V PVC caps too. I don't recall which ones  | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Remember that you can always go up in voltage rating. 50v caps are getting rarer but you can get them in 100v. 22uF@500 is fine. If you can see ANY way to get axial caps, do it. Radials doing the "splits" are kind of fragile unless you support them. They look ugly too! | ||
| Lars Verholt (lmv) Username: lmv Registered: 11-2009 |
Tis a small world. I have actually worked on this particular amp as Henrik and I used to play in a band together back in the salad days. Glad to hear it's still playing! I had to sell my own HD 130 when I moved to the other side of the Pond (but I have seen its next owner on this forum). Anyhoo - the Sprauge Atom has evolved into being the standard replacement part for high end gear. They are more expensive because they are simply a higher grade part with a higher life expectancy. If I repair, say, a Fender Twin amp it makes sense to use the accepted standard replacement part unless the owner specifies otherwise. Henrik's amp is one of the original ones with the old style hi-lo primary tap switching. I would think all the electrolytic caps could stand to be replaced. If the amp doesn't hummmm or lacks power, I'd worry more about the internal 150uF caps than the big filter ones. Either way, www.mouser.com has them all and I bet Farnell do too. The little lamp thingie by the neon light is there to cut the voltage down. The neon light is rated at 125VAC. Hils Conny! -Lars Verholt | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
Hej Lars Mikael. Ja, verden er lille. Jeg har skrevet til dig p? din firma mail. If you remember you actually had your fingers in my amp years ago in your moms basement. Nothing dirty here, folks! We replaced the cap on the driver board. I got this amp second hand at a good price. I had a friend pick it up and it turned out that one of the tubes had litterally melted down. There was a hole the size of a dime on the side of the tube and the glass was buckled and bend like a modern glass sculpture. I guess it had been running without a cab. I thought I never had it up and running, but after replacing the tubes, I fired it up and it was playing - no problem. No bias trim, no nothing. How lucky can you be Jeg skal hilse igen Henrik | ||
| Henrik Nordskov (nordskov) Username: nordskov Registered: 04-2011 |
Okay, I have a last couple of questions before I place my order on BanzaiMusic.com. 1. Should I replace all brown PVC caps with ex. Orange Drops? 2. On the treble side of the tone stack I find ceramic caps. Everybody seems to agree that ceramic caps are a no-go in the signal path. How about replacing them with Silver Mica's? WOW! As I took a closer look at the large filter caps, I discovered that the + lead on C44 had come loose from the solder joint due to what seems to be overheating (the solder had partly melted). Where the hell did all that heat come from?! And why couldn't I hear it? | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I personally wouldn't change ANY caps that aren't actually bad. I don't agreae that ceramics are bad. Hell, they were put in at the factory and they worked then, didn't they? There's nothing wrong with the old brown turds. I'd be surprised if the heat actually melted the solder but I guess anything is possible. More likely just a crappy soldering jobTHat came loose. Must have been enough filtering to keep it from humming already. Mike. |
Tue, 03/25/2014 - 09:34
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