| Author | Message | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Greetings, The time has come for me to replace the cap's in my 212 HD130. The amp seems to be making a bit more popping sounds and I don't want to fry the transformers. There's a local amp tech by the name of Marty Pincus who I'm probably going to have do the work, as the lead routing and tight spacing of the filter caps, and others, has caused me to question my capabilities. Anyway, I found a distributor that is located 25 minutes away from me, where I can drive to pick up what's needed for the cap job. (At least they'll have the 100uF filter caps.) The caps they're selling are their own "ARS" brand. I've read that most people have had no problems with them and I just wanted to hear if anyone here has a take on them. Opinions on "ARS" caps? BTW: I'd really like to have either Ed Goforth of Terry Loose work on the amp, but shipping these heavy chassis seems fraught with danger. Marty has performed work on an Epi amp that I have and is highly regarded by local musicians, so he's probably a fine choice for the work. Anyway, any guidance is appreciated. Thanks. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
No opinion on ARS but I have used some of Webers branded caps with no problems. They could even be the same one. I think theirs say Elion or something like that. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks Mike. I should be dropping the amp over at the tech's today sometime. I told him that "ARS" would be fine. He mentioned "F&T", which I believe are highly regarded for MM amps. I said that either one would be fine but I couldn't find "F&T" part numbers for the smaller cap's. I believe that they had one that was a 22uF x 450V (500V?) instead of the 20uF x 450V, which he said would be fine. So it sounds like he'll be using "F&T"s instead of the "ARS". We'll see. I can't wait to have this amp freshened up, as I love its tone. The MM just suits my playing/vocal style a bit better than my '89 RI Marshall Bluesbreaker combo. I play and sing pretty clean. Not much bluesy breakup in either instrument (Voice or amp) is best for me. I'll report back on the results of the work. I'm expecting to pay around $200 (WAG)or so, providing he doesn't have to supply any tubes. He'll test the Sylvania 6CA7's that are in it. I've got my fingers crossed that they're still good, as the consensus seems to be that they're the best tube for the MM. Thanks again for your response. 210HD 130 w/12ax7 212HD 130 w/12ax7 | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
My tech gave has given me an estimate of $300 labor for replacing the filter caps, perhaps the two caps on the bias board(?), cleaning and tightening all tube sockets, input sockets, etc. I'm in L.A. and 6 years have gone by since I've seen $150 estimates for cap jobs. Is $300 labor exorbitant for the above mentioned work in today's market? It seems like it might be. If it is, how much over LA market prices is it? Many thanks. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Geez,, that guy must REALLY think highly of himself. I'd sure look around. I know LA LA is high but damn. That's just LABOR? Too bad you're not around here! Anyway, that's just nuts. Even at $100 an hour, that's three hours for a cap job and tighten the sockets! No way. Hell, you can BUY the amp(almost) for THAT! | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks Mike. I thought that he was more than a little high. I told him that I figured it might be that much, tops, including the parts. He does know what he's doing, and he does tout himself as being a perfectionist. He also says he's "going through" the amp entirely, scoping everything, etc. I told him I just wanted the caps replaced but he's gone a bit "ape shit" on it. As I said in my original post, I'd have preferred to take it to Ed Goforth or Terry L., but didn't want to ship the heavy chassis. I suppose it probably would have been cheaper to have done it but it still would have the risk of shipping (which sounds significant). Tough, and painful, call. BTW: The tech says that the amp is only putting out about 100W on the high setting. He says it might be the power tubes so I'm ending up replacing all of those 6CA7's that he tested anyway. Any common decreased output problems? I knew that he'd be high, but not this high. I suppose I could pick up the amp before he replaces the cap's but I'd probably end up paying him $100 for shop time. He was reminding me about how much time he's spent testing the tubes, etc. While it's true that I can buy the amp for that much, it wouldn't have new filter caps in it. I'm just trying to make myself feel better. ;0/ Thanks for your input. I appreciate it. | ||
| Christophe (vignau) Username: vignau Registered: 06-2011 |
Its a good time to learn how to solder ! and handle security around  | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
I have done a fair amount of soldering, but not in with the type of lead routs, etc., that are involved in these amps. As I said in the earlier post, I had considered doing the work myself but decided on discretion, as I didn't want to be the first to mess up the inside of a previously clean amp. Yes, it's costing me more than I thought, but I'll have a good amp that will live to play many other days. I'm not sure what you were referring to with the "handle security around" statement. Translation? Thanks. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
BTW: My experience,and the suggestions for me to have done this myself are more "cries for help" for someone to put together a tutorial on replacing the filter caps. I've been on youtube, and seen a few tutorials, but they don't deal with de-soldering the leads and working with axial type capacitors and their lead routing/soldering. If I got to watch someone do it, I'd almost surely attempt it myself. I know that there are worries about liability due to the high voltage in MM amps, etc., but disclaimers and waivers should suffice to eliminate such worries. A tutorial would have saved me a bunch of $ here. FWIW. Regardless, I appreciate all the help I get here. Thanks guys. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
This ongoing experience has prompted me to delve into the cap job a little deeper. I now see that the fiber board under the filter caps just contains what I'd call solder junctions that is used as a common connecting point for the wires/leads. It's not so daunting. Live, pay, and learn. I think I'll replace the filter caps on my 210 myself now that I'm seeing things more clearly, etc. Speaking of my 210 HD130...it has Mallory 100 uF X 450V filter caps but they are covered with a transparent blue vinyl rather than the silver like that in the 2X12. I guess those too are original? It also has an orange Sprague TVA1311 on the bias board that appears to be original. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I don't think that the blue ones are original-they didn't start making them look like that until late 80's/early 90's. I think those have been replaced. Does your bias board have any other caps on it? It should. They should all be silver on THAT vintage amp. I would be GLAD to help you with the long distance advice on doing it yourself, if you wish. Those prices are nuts. Radio shack soldering pencil(all you need)- 10-12 dollars. Some rosin core solder, maybe $5.00. That's REALLY all that you need plus the ability to email pics so that we can help. I've been doing this for %&$*&# years and let me tell you, the MECHANICS are not that tough. It ;s the diagnostics that require help and experience. This is a mechanical repair that CAN be taught. Let me know if I can help. I have a 130 watt amp chassis that is have been using for a picture aid for people that I can sho you as you go, if you want. I keep it down in the shop just for that purpose. I just haven't gotten around to fixing it because honestl, I don't need an amp THAT loud anymore. It spends it's life as a photo model. What a job! Anyway, let me know if I can be of help. Mike. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks Mike. I'll be taking you up on your generous offer once I get a set of filter caps for the 210. I have some of the under-chassis electrolytics coming next week. I might change those and order the filter caps as soon as my wallet recovers from the shock of the pro repair. BTW: I have noticed that the prices on MM amps have been climbing a bit, no? That makes the big spend a bit more palatable. Thanks. 210 Filter Caps under pie-tin http://home.earthlink.net/~bmw4re/Filter Caps210.jpg | ||
| Christophe (vignau) Username: vignau Registered: 06-2011 |
Brian you said: I'm not sure what you were referring to with the "handle security around" statement. Translation? Thanks I was thinking about the high voltages that can remain in caps. Take care of it and use proper procedure to unfill them from any voltages. I did all the cap job on my 210HD130, took me something like 2 hours, not more. rebias your amp after doing the cap job. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks for the clarification, Christophe. Yes, I'm very cautious about working inside my amp and make sure that the caps are sufficiently drained before making contact with things. I appreciate the warning. Salud. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
So, before I placed any order for the filter caps for my 210, I figured I'd investigate as to whether Sprague used date codes on their caps. I read somewhere that they did so I went to check it out. If there is something to this stuff, it tells me that the 20 uF X 450's are from '76 and the 100 uF's from '80. Sort of a large gap, no? Regardless, I also noticed something that I hadn't before. I'm guessing that the white substance around the base of the lead on the 20 uF cap indicates physical leakage. No? http://home.earthlink.net/~bmw4re/Filter Caps210_2.jpg | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
BTW:I was only able to order the F&T's in 22 uF rather than 20 uF. My tech said that it shouldn't make much of a difference being that they have a 10% tolerance anyway. I just hope their value is to the downside. Any comments regarding using the 22 uF instead of a 20 uF? Thanks. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Yes, those are leaking. NOT a good sign. YOu picked the right time to replace. 22uF won't mean squat in the long run. Some of those caps must have been replaced at one time or other. | ||
| Christophe (vignau) Username: vignau Registered: 06-2011 |
22?F will behave the same as 20 ?F, its the same with Marshal amps designed with 50 ?F/500V. The standart value now is 47?F, so you cannot find 50 and 47 is fine | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Thank you, gentlemen. I was hoping that the value wouldn't make that much difference. I ordered all of the filter caps and may be prevailing upon you for some tips for installation. I have been frustrated in the past using my little 30W Weller iron and have been considering buying a station of some sort. How about if I use a soldering gun for removal of old solder? Is there much danger in overheating anything with the gun's heat while removing? I was once warned about using it when I replaced the output jack on my early '86 G&L ASAT. I ended up resorting to it anyway. All ended well, so I guess all's well. I suppose that I can use the little iron for installing the new ones. Any input is appreciated. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Honestly, I use nothing BUT a 30 watt iron for almost everything but soldering chassis grounds. I have three of them on my bench at one time, all different lengths. Yeah, that's stupid but sometimes longer IS better! Anyway, other than soldering the INITIAL spot on a pot case for a ground, it's plenty. For that, I use a couple of old Weller 100/140 watt. If I have to solder to the chassis, I use one of those old stick type irons that's probably 1500 watts and takes a half hour to warm up and even longer to cool down! Don't use THAT much. A 30 watt pencil is wonderful unless you just don't like cords on you pencil. I still do. Hey, I'm freaking old, ok! | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
I'm with Mike on this,a 30 watt pencil with lots of different ends usually gets most jobs done. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
I've now successfully replaced the two caps on the rectifier board and am moving on to the one on the driver board. What's the best procedure/process to use to remove the cap leads from those eyelets on the board? Do I need to remove the solder first using solderwick or some other sort of remover or can I heat the existing solder and pull out the lead? Would I then be able to reuse the existing solder in the eyelet? I'm guessing that I'll need to do the same thing in order to replace the filter caps. Thanks for any help. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
BTW: My tech tested the 3 Sprague 150 uF X 50 V caps, along with the F&T filter caps, and they were all well within spec/tolerance. The JJ E34L's that I got from Eurotubes checked out for the most part (no shorts, leaks, etc.). However, there was one tube that had a much higher mutual conductance reading than the others. They read: 1450, 1750, 1800, & 2200 mohs (?). My tech said that he'll place the 1450 so that it works with the 2200 in order to compensate for the disparity. Maybe that's why Eurotubes "matched" them that way in the quad? Comments? | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
FWIW: My tech tested the caps in front of me on a B&K capacitor checker. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Doubt if Eurotubes did that. They matched them so that they all had the same(or close) current draw AT A CERTAIN VOLTAGE. Bob's pretty good at that but I doubt if he actually CHECKS the tubes for conductance. He burns them in and then matches them for current draw. Mike. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
My tech said the same thing, that Eurotubes probably checked them for the current draw. He also wasn't alarmed by the difference, so it mustn't mean that much and is to be expected. I had requested a "middle number" on the current draw, as my tech had given me a dangerous bit of "little knowledge". The quad was marked a 40, which the guy at Eurotubes said was somewhere in the middle of what they had. | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Well, the eagle has landed. Fired the 210 HD130 up using a current-limiter, and it glowed brightly before gradually tapering off. The amp sounds incredible, and that's with even having pretty marginal tubes in it right now. There's like no hum at all. It's so quiet when idling. Many thanks to Mike Kaus for his help during my first attempt at recapping an amp. Thanks to Steve Kennedy for starting and running this site. It's a great resource. Only one bonehead move that had me worried. I'd forgotten that I'd borrowed the 12AX7 to use in my Marshall that had it's one if it's 12AX7's go south. Note: Without PI tube, amp makes no sound. I was scared for a moment. Maybe I should be more scared because I forgot it at first. Doh!! I used F&T's for the filter caps and Spragues for the rectifier and driver caps. I didn't replace the ones on the main PCB. I'll consider doing those as part of another project. Oh another thing: When I first plugged in, the amp was giving my some hum and static sounds that seemed string/guitar related. I'd read something here that switching the ground switch over might fix it. It did. Yay! | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Expectant father filming delivery. Exciting current-limiter video.  http://www.youtube.com/watch?v=mPGenWcSc cM | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Well, I picked up my 212 HD130 from the tech yesterday. It sounds great. But, truth be told, it never sounded bad before. Just a bit noisy. His component replacement work, as far as lead bending, routing, and soldering was excellent. All of the identifying print on all of the caps was facing dead-nuts straight up. There was a noticeable difference between the straight orientation of his large filter caps and mine, but my work appears pretty comparable on the bias and rectifier electrolytics. He pointed to the fact the he didn't like hard bends on the leads, but rather sweeping bends. Good thing he didn't check my work.  Just before I left, he mentioned that he hadn't checked the fuse, but didn't think that he'd have to since I sort of knew what I was doing (Hmmm....?) It turns out that the fuse was a 250V 10 amp! I had thought about checking this in my 210, but I hadn't with the 212. I'll grant that he's a very good amp tech, and is certainly knowledgeable. Anyway, after putting the amp in my Jeep, I asked him what I owed him for the job, sort of figuring that he might back off of the original estimate, seeing that I now had personal experience about how much work went into it, but nothing doing. He stuck to the $300 labor charge that I'd agreed to (with some reluctance). He then told me that he'd lowered his prices some because of the economy. I kid you not.  It's worth noting that now that I know how to replace filter caps, there are a couple of guys I know, who also know this tech, who need their caps done in a couple of Fenders. I've now told them that it's not that difficult to do. This is something that I wouldn't have been able to tell them if the high prices of this tech didn't force me into getting in and doing it myself. Life is interesting how it works sometimes. | ||
| Christophe (vignau) Username: vignau Registered: 06-2011 |
"if the high prices of this tech didn't force me into getting in and doing it myself. Life is interesting how it works sometimes" I did experienced that many times, the last time was for my transmission on my '77 Formula Firebird. The good thing is when you do that, you are sure the job is well done. many time I had to DIY on my Pontiac following technician intervention. With the years, I know now 98% of the car  | ||
| Brian M. Watson (mrroundel) Username: mrroundel Registered: 06-2007 |
Christophe: Yup, I work on my own cars ('99 BMW 528i and ''98 Jeep Grand Cherokee w/6cyl) as well. I have rebuilt a Mopar V8 (318) that was in one the '68 Barracudas I used to own, by myself. I have not attempted a transmission. Generally, unless it really is voodoo, you don't need to be a voodoo doctor to do it, right? Thanks for your responses. Salud. | ||
| MrRoundel (mrroundel) Username: mrroundel Registered: 06-2007 |
BTW:The tech who serviced the adjusted the tube bias using the scope and watching the wave form until it clipped, then backing it down. He says he that he always biases amps relatively cool. I'm wondering if I should trust but verify on that one, using my bias probe set? What would you do? | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I ALWAYS bias amps on the cool side but DON'T use the scope to bias. There are always people who argue both ways. I won't take a side. I use the cathode current that is measured from pin 8 to ground and YES, I know it includes a little extrat current from the bleed over from the other sides of the tubes but it's close enough. 22-23mA of current from the tube inclusive is fine with THAT much plate voltage. OR, if you are measureing off of the internal resistor, .44-.46V at the point Y connection. | ||
| MrRoundel (mrroundel) Username: mrroundel Registered: 06-2007 |
In looking at the schematic, I'm a bit confused about which caps I actually replaced in my HD130's. I'm seeing that I probably replaced the 150uF cap #'s C38 (Driver board) and the two (C46,C47)on the rectifier board. If the bias caps are the two that are on the main circuit board, neither I, nor my tech, replaced those. It sounds like those bias caps (C31,C32?)are important. What am I risking by not replacing those? The caps on the main board must be the ones that my tech was saying were going to be difficult to get at, as I see that posted here. So I might just let it go for a while. I just want to know the risks. Thanks. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
C47 is the bias supply cap. 31 and 32 are for the supply voltage sources for the op amps. | ||
| BrianW (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks Mike. Are either one of those caps, 31/32, responsible specifically for supplying the reverb circuit? The reverb is still out on this amp. I tried switching around the op amps and using a known good tank, however it's still not working. I'm not sure about how to check for shorts in the reverb cable. I can say that neither side is open. Thanks again. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
31 and 32 are caps in the + and _ supply for the op amds and anything SS. You need to see if there is +16 and -16 coming out but it sounds like another problem. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Geez, can't type for squat. Sorry, had to leave quick. Anyway, those caps are in the supply side for the IC stuff so If you have the preamps working, those caps are OK. I'D still replace them but hey, who am I! Anyway, reverb doesn't work, check to make sure you have +and - 16 volts on the IC and then start looking at the reverb path. You could have a cap shorted out in the reverb stream somewhere taking the signal to ground or it could be as simple as the jack at the send/receive jacks shorted. Just going to have to start tracking it from front to back. Check for voltages at pins 7 and 4 to see if they are receiving voltage first. Mike. | ||
| BrianW (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks, Mike. I apologize for my lack of what's probably basic knowledge of electronics. That said, if there is a short at the jacks, would the input and output have continuity between them? Is that what you're referring to? And I should remove op amps 5 and 6 to check for +&- 16V voltage? Note: When I was playing a bit louder than usual the other day the amp "farted" a bit when picking smartly and on low notes. Any chance that this could be because I've got the old tubes in there, despite them checking o.k., if not a little weak in the mutual conductance? I placed the tubes so that there was a weak with a strong for both sets, i.e. biased at 13.4mA-23.1mA-21.1mA-13.4mA. I guess I'll pull the chassis again to check those pins and jacks. Thanks again. Note: I usually play vintage '80's G&L ASATs (ASAT III mostly) with Leo Fender designed MFD single-coils. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
No, you're not looking for continuity at the jacks. THose tubes are pretty far apart to be matched. Not enough to be dangerous but could give you some odd harmonics. I would suggest running a signal through and tracing it through with a scope to see what's happening. If you don't have access to one(and who does unless you work on this stuff) you might build yourself an audio probe and try to trtack the signal through that way. You can check the IC voltages with them in or out. I can almost guarantee though that that ISN'T it or the preamp wouldn't be running. I guess it's possible to have an interuption to ONE IC but unlikely. More likely the caps around the reverb circuit. One probably went up. The signal gets picked up off of the treble pot and is fed through the reverb circuit so I would, if it were me, start looking around the reverb IC's for shorted caps. Other than that, you are going to have to track it through the circuit with either a scope or a probe. If you are into building stuff, here's some info on it. http://www.el34world.com/Hoffman/tools.h tm http://www.tedsforums.com/forum/index.ph p?topic=8797.0 Mike. | ||
| BrianW (mrroundel) Username: mrroundel Registered: 06-2007 |
Thanks for the links, Mike. I'd taken a break from messing with amp innards so I haven't checked where you suggested. However, moments ago I removed the chassis from the 210 and tried to check the points you suggested. After removing op amps 6 & 7, I noticed that the sockets are marked differently at the front (aligment guide side) pin. The #7 has a #7 in the front but the #6 looks like it's marked "0" at the front. If you're saying check pin 7 of ic 7, how does one test the socket? My probe doesn't seem to be pointed enough to make contact? Do you extend it with a needle or something? I checked the reverb tank sockets at the circuit board. I'm guessing that I check the center? Should that read infinity if not shorted? Thanks. Many thanks. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Infinity if not shorted. I usually uses either a paper clip if it has large legs or a straight pin if the small ones. |
Tue, 03/25/2014 - 09:35
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