NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 jazman I welcome your comments completely. I can't wait to see how your heresy's fare with the HF-81. I'm using Original Mullard EZ-81's that match perfectly and test well in the good with no leakage on my EICO 667 Tube Tester. I'm sure there is a problem with my 81 that is causing this harshness like I said before this is by no means a fair comparison of the Amps. If you do a search you will find a thread where I posted picture's of the rats nest of a wiring job someone did to the one I have and I'm sure that's where most of the problems will still be found. It needs a gutting and it will get it. What is the complete tube compliment your using jazzman ?? Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Here's a link to the pictures I posted in another thread. Linkage Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Okay been tracing the Voltage readings and just basically looking everything over before I start the rewire job and think I found one of the major culprits. While having the amp on and testing I noticed I was getting a heavy vibration from something in the amp very audible. I traced it to the Multi section Can Cap. It tests fine and voltgaes are just fine going into it but its making some god awefull noise. Anyone no a good place to score one of these ? The value is 20 mfd @400V dual 40/40 mfd @ 350. Mobile !! who has these little jewels. Craig Quote Link to comment Share on other sites More sharing options...
jazman Posted March 26, 2002 Share Posted March 26, 2002 Craig, All my tubes are Mullards. I did however find 60s Brimar EZ81s very enjoyable in the Eico. I purchased them from Tube World along with some other NOS tubes. My Mullard EZ81s were harder to find. I'll try to get the Heresys connected tonight. Hopefully the noisy cap you discovered is the problem. Klipsch out. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 26, 2002 Share Posted March 26, 2002 http://www.nmr.mgh.harvard.edu/~reese/electrolytics/#rebuildIt could be a option if you can't source a multicap can. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 jazman/Mike I can almost bet its at least a big part of it. The Cap itself buzzes like its a alarm clock LOL !!! The amp also has lots of hum and hiss so I bet that's where the problem is. It goes to show you that you can't alway's trust test instruments because they all say its a good Cap (at least not open or shorted). HH Scott out (how you like that jazzman LOL !!!!!) Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Mike That's a great link. I think I can come up with a new unit that will do the job but having it rebuilt or rebuilding myself is a good option. This message has been edited by NOS440 on 03-26-2002 at 04:52 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 26, 2002 Share Posted March 26, 2002 Craig, I have to say that these usually dont go bad, at least compared to the PS caps underneath, which ALWAYS need replacing at a certain point, usually sooner than later. So that cap was buzzing???? Strange. How about the transformers? Buzz from these? For a source for these, you can try http://www.angela.com/catalog/ kh This message has been edited by mobile homeless on 03-26-2002 at 04:56 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 26, 2002 Share Posted March 26, 2002 If you do source a 20-40-40 mfd 400-350-350, please post where! I may buy a couple for general purpose. This could be a tricky one to source. This message has been edited by mike stehr on 03-26-2002 at 05:06 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 26, 2002 Share Posted March 26, 2002 Pony up the ducats and buy a Mallory! http://www.audioclassics.com/query.php3?query=mallory&srch=only&cat=Parts There are subs for these, btw. kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Mobile It is definitly coming right from the Can Cap its wild ! It also seems to get louder and louder as you let it run. I'm not sure why but its doing it. All the voltages are in line on every tube throughout the amp. So I think its the first culprit and replace the wiring is a must. My scott's make a faint noise like this coming from there rectifier tubes but this is 3 times as loud as that. You can feel the vibration on the can. HH Scott out This message has been edited by NOS440 on 03-26-2002 at 05:11 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 26, 2002 Share Posted March 26, 2002 To be honest, it does sound like that CAN is leaking. Is your transformer running a lot hotter? kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Actually the amp runs cool. I've shut it down until I can find a replacement. I'm not sure if its leaking or getting ready to take off like a rocket. I know one thing for sure it can't be good and is mostly why the amp sounds so harsh. I'm now cleaning the crud off it and making it presentable. I have to pickup some semi gloss black for it. What do you use ? Craig This message has been edited by NOS440 on 03-26-2002 at 06:31 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 26, 2002 Share Posted March 26, 2002 Get Krylon Satin (semi-flat) black. As Allan Songer reports, this does work great. I used it on my first EICO. Rustoleum Semi-flat works well also. kh Quote Link to comment Share on other sites More sharing options...
SOUNDJUNKIE Posted March 26, 2002 Share Posted March 26, 2002 Craig, If you can(no pun), run a low freq(100Hz) signal into both channels playing and measure the AC on both caps. Does the noisy one have a higher AC component, if so, is going south. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Soundjunkie At this time I can't (no pun intended) LOL !! I just scored a scope the other day and a function generator is next on my list. Besides the hum I'm talking about isn't coming out of the speakers (although there is allot of hum/hisses coming out of them). What I;m saying is the Can is buzzing and vibrating by itself without any input or speakers hooked to the amp. Mobile Thanks for the paint tipp.I had read it somehwhere on the forum but forgot who and what duh !! Craig the massive cleaning fool !! I'm even polishing the chassis somewhat !! This message has been edited by NOS440 on 03-26-2002 at 09:52 PM Quote Link to comment Share on other sites More sharing options...
SOUNDJUNKIE Posted March 26, 2002 Share Posted March 26, 2002 Maybe this guy has some caps for cheap. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1715163800 Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 26, 2002 Author Share Posted March 26, 2002 Those would be a nice buy but will most likely end up near $200 and without know what the values are I or anyone else is taking a long shot at whether there worth anything to a Tube audio hobbyist. You could end up with a bunch a useless junk. Nice link though !! Craig Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 27, 2002 Share Posted March 27, 2002 Would lowering the capacitance to 20uF be that big of a deal? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 27, 2002 Author Share Posted March 27, 2002 Mike I'm not sure I sent a email off to Mdeneen to see what he thinks would be the best replacement option. He was out of town all day and said he would look at it tomorrow. Its no big hurry. I've been rerouting the rats nest for the last 3 hours and it looks like I've got at least 5 or 6 hours more rerouting to go. I polished up the chassis it turned out pretty good considering the sorry cruddy shape it was in. I'll post some pictures and soon as I get all the wiring to my liking. Craig Didn't see Mdeneen reply this thread went to 2 pages onmy PC. This message has been edited by NOS440 on 03-27-2002 at 09:23 AM Quote Link to comment Share on other sites More sharing options...
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