SilverSport Posted December 16, 2006 Share Posted December 16, 2006 I have been here listening to my EICO HF-81, Toshiba 3950 through the Quartets and doing chores when I started to get static (like in the "old" days...while changing radio stations) through my right Quartet...any ideas??? I am thinking that it might be a Tube as this is an old unit...some Tubes are new but some are original (1959)...it has been mostly perfect up to now... Thanks, Bill Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 16, 2006 Share Posted December 16, 2006 Start swapping tubes channel to channel. first try V3 and V4 see if the noise follows a tube. Then try the same with V5 and V6, and then V7 and V9 and then V8 and V10. Whever the noise moves you found the noisy tube. If it never moves then you have problem under the chassis. Here is a sheet to make it easy to Identify the V#'s of the tubes. Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 ...and that is why you are the man!...I will give this a check and get back to you all...thanks Craig...AGAIN! Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 Craig, I think I will start with V-5 and V-6 as V-3 and V-3 are new JJ Electronic as are V-7, V-8, V-9 and V-10 (JJ Electronic)... V-5 is old Mullard and V-6 is an OLD (even the glass is rough) Fisher (Great Britain)...the Fisher may have been a transplant from my Dad's EICO HFT-92 Tuner... Just "fired it up" and it is dead quiet on the left speaker and just a bit of Tube sound on the right...no static but I believe the static didn't start until later in my listening session... I'll keep you posted... Bill Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted December 16, 2006 Share Posted December 16, 2006 Another possibility: Oxidized tube pins and/or dirty-loose socket pins. As Craig stated, crackling or popping sounds can indicate also possible problems in B+, heater supply, or AC primary and related connections on sockets, etc. You might power down, allow to cool, and then remove tubes to clean each pin (I use small pieces of Scotchbrite pads), and then carefully swab with isopropyl alcohol. You can also clean the socket connections with DeOxit, but let all of that evaporate thoroughly before power up again. Also as Craig said, this could be related to internal connections within tube envolopes, which means you need to carefully remove the glass, fix the connection, and then re-establish a vacuum using a vacuum cleaner. Very carefully seal with chewing gum ( Juicy Fruit will give the best frequency response), and then give it a whirl. Nah, that's a bad idea. Chuck the tube for a good one. Erik Erik Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 I have an old 12AU7 that looks like new but for the "burn" mark on one side of the Tube...I should toss this one, right??? (orange writing, cannot read the label any more but it says made in USA and I wold wager it is at least from the 1960s but not used much... Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 Erik, thanks...it sounds fine right now...I'll keep an eye on it... Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 okay...just stopped the music and heard the staticy pops in the same speaker as before...powered down and give it a wait...all the Tubes seem to be glowing the same (at least the same as their "counterparts"...since 6 Tubes are new I feel that they are unlikley the culprit (but I'll continue to test if that's what it takes)... Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 16, 2006 Author Share Posted December 16, 2006 Craig, I believe I will be contacting you about getting the EICO HF-81 into the new millenium...I don't think it has been touched since 1959 except for a Tube now and again... Bill Quote Link to comment Share on other sites More sharing options...
Parrot Posted December 17, 2006 Share Posted December 17, 2006 Bill, probably for more than half of its close to 50-year life so far, it wasn't even hooked up. I bet it was stored from the 1970s solid state days until whenever you purchased it. I don't recall when you got it or what the circumstances were, but I'd guess it came out of hiding and was put back to use only in the last five years. Quote Link to comment Share on other sites More sharing options...
scott0527 Posted December 17, 2006 Share Posted December 17, 2006 Bill, I don't think your problem sounds like a tube problem. Good idea to send it for a tune up. On another note, don't assume that new tubes are less likely to fail than old tubes. Although I guess JJ's are pretty reliable, I've had several bum new tubes over the last 5 or 6 years. I don't think QC was/is all that great in the tube factories in the late 90's and early 00's. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 17, 2006 Share Posted December 17, 2006 Sounds like the problem will end up being under the hood. But Erik comment is a very valid one. You may want to give every single tube socket and the pins a good cleaning with Caig DeoXit. The JJ Telsa 12Axx series tubes brand new need a hit with a wire brush when I receive them so never rule out a new tube. Tubes were the most unreliable component in the gear that used them since ithe tube was invented. Just like the only thing that fails in most lamps is the light bulb. Craig Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 17, 2006 Share Posted December 17, 2006 While you are at it, clean and cycle the stereo/mono switch. Rick Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 17, 2006 Author Share Posted December 17, 2006 Parrot...I am the current curator of this EICO HF-81...it was held prior to me by Daddy Dee and prior to him by Dr Bill...before him, the builder and a family friend of Dr Bill's so I believe it has had a happy and healthy use life...perhaps not...either way. Craig and Scott...you are of course correct...I will do this check on ALL the Tubes suggested (it pays to listen to Craig the FIRST time...[]) Rick...I will cycle the selector knob as well (stereophonic to monophonic and back) as well as Deoxit the Tube sockets...and give it another try... I really APPRECIATE you guys walking me through this...I am listening to my MAC1900 (freshened by Terry DeWick) in place of the EICO and I know some will scream blasphemy but as nice as that MAC sounds...I prefer Tubes and specifically that little EICO HF-81. Bill Quote Link to comment Share on other sites More sharing options...
Parrot Posted December 17, 2006 Share Posted December 17, 2006 Parrot...I am the current curator of this EICO HF-81...it was held prior to me by Daddy Dee and prior to him by Dr Bill...before him, the builder and a family friend of Dr Bill's so I believe it has had a happy and healthy use life...perhaps not...either way. Oh, okay, I remember now. You probably have a particularly nice one--didn't Dr. Bill go over it? All in all I'd prefer having one that had been used regularly to one that had not. Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 17, 2006 Author Share Posted December 17, 2006 ...Okay...I just applied DeOxit (contact cleaner) to the switches and Tube sockets...I will give that 24 hours to dry before firing up the amp so that I don't fire up the house... Output Tubes for Channel 1 and Channel 2 (V-7, V-8, V-9 and V-10) are all new looking JJ Electronic and the pins are all shiney... Phono Stage, I don't and probably won't ever use...Original Fisher made in Great Britain Tubes (V-1 and V-2/12AX7) Drivers (V-5 and V-6/12AX7) are one each Mullard and a Fisher, both Great Britain manufacture...should I switch these with the 12AX7s from the Phono Stage so these match or keep the "mismatched" Mullard and Fisher...(Fisher glass is rougher/dirty and older...may be my substitute from another amp, I can't remember) Pre-Amp (V-3 and V-4/12AU) are new looking JJ Electronic Rectifiers (V-11 and V-12/EZ81) are original I am told and are dark looking EICO labeled "Made in Great Britain" tubes... Is it okay to clean these as some seem to feel rough to the touch I believe from dust-dirt of nearly 50 years... Thanks, Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 17, 2006 Author Share Posted December 17, 2006 Yes, I believe this is a particularly nice unit to begin with and it has a special place with me, the first Tube amp that I bought and a nod to my Father who had an EICO HFT-92 (now I do...currently not using though) AM/FM tuner...also, do you recommend leaving the Tube "burn guards" (aluminum covers on some of the Tubes) on or off??? Thanks again, Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 17, 2006 Author Share Posted December 17, 2006 ...sorry...NOT JJ Tesla but JJ Electronics...I have corrected my posts... Bill Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 17, 2006 Author Share Posted December 17, 2006 ...of course I couldn't wait and after triple checking to see that this was dry after the DeOxit cleaning, I hooked it all back up and started the amp...same static sound in the right speaker...doesn't seem to follow the Tubes (I still haven't switched ALL of them about...) so it will have to go to Craigs spa for an update... [:'(] Bill Quote Link to comment Share on other sites More sharing options...
Parrot Posted December 17, 2006 Share Posted December 17, 2006 DeOxit evaporates fast. The metal covers around some of the tubes are to cut down on noise from interference, so you should leave those in place. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.