Audio Research D-90

Hi,
I just bought a A.R.D-90 and there is a hum in the right channel.I reversed the inter-connects and still in the right side.I switched the 12ax7's for 12au7's and it got louder.Any ideas or insight? Bill

houseofsound03-06-2009 2:34pm

Showing 8 responses by houseofsound

houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-09-2009 at 05:15am Copy Comment URL Report Comment Edit Delete Newbee,Hevac1, Thank you for the info. I'm new to the tube world and don't know sh-t. I also have a C.J.,but biasing it is a breeze. The person I bought the A.R. from didn't send a owners manual and I don't know how to bias the amp or the tubes. So thats probably the problem. If one or both of you wouldn't mind taking the time,I'd really like to know. I've seen the meters for sell on Ebay,from China but didn't know if that was the answer.Thanks,Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-09-2009 at 03:18pm Copy Comment URL Report Comment Edit Delete Hevac1, Thanks for the help.I have the volt meter but I don't know witch socket holes to check,what the reading should be or how to ajust the bias if it need be.Thanks again,Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-17-2009 at 01:12pm Copy Comment URL Report Comment Edit Delete Hevac1, You must be having the same luck I've been having trying to find that info.A.R. do'es not seem to hospitable in giving info. Thank you for all your help. If any one out there has a manual for a D-90 thay want to sell or make a copy of ,please let me know.Thank you,Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-21-2009 at 04:49pm Copy Comment URL Report Comment Edit Delete Stonedeaf, Thank you for the info.I intend to get the mannual now that I know who to talk to. Your info on the caps is very helpful because the previous owner replaced one cap so i have 8 cans and one little blue cap in this big open area. I'm a beleiver of sound over appearance but the more I look at it the more it bothers me.I'll either replace the one or I'll replace all.Probably all knowing me. I replaced all tubes last week. One of the 6l6's was bad and dumb ass me didn't test it first. It burned 2 resistors. So I had to replace those. I want back and tested the tubes I bought (27)I bought spares and 6 out of the 27 were bad and 3 were weak. So if you ever are thinking of buying from a guy with the initials J.B. that plays a fender,BEWARE. These are so called new Mullards Tung Sol and E.H. tubes. But,I did get new tubes in the amp and it is up and running as I type. I'm running it Byamped with my C.J doing the highs and mids. I think it sounds good but I'd like more back end. My wife says I'm never satisified.Thanks,Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-21-2009 at 09:59pm Copy Comment URL Report Comment Edit Delete Hifigeek1, Thanks for your help.Your right,there are a couple sockets that could be tighter. I got this amp at a good price and I new I'd have work to do on it. My wife likes when I buy fixxer-uppers.She figures if I'm fixxing one I'm not out buying a new one. Leaves her more money to spend on shoes. Thanks to all of you out there for your input. Please keep it coming.I need all the help I can get.I'm one of those that is pretty handy but a master of nothing.Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-22-2009 at 05:36am Copy Comment URL Report Comment Edit Delete HifiGeek1, Did not find relay you described. I beleive my amp is a D-90(revised). Here is my reasoning: I got some print outs with pic.s from www.arcdb.ws.The info is limeted but acording to there info the D-90takes 9-6550's8+1,4-12ax7's,2-6fq7's,2-12at7's. The D-90b Takes 8-5881's,1-6550's,1-12ax7,and 5-6922's The revised D-90 takes 8-5881's or 6l6's,1-6550,4-12ax7's,2-12at7's,2-6fq7's. This is the tube setup mine has. Also the print out i have from the web sight shows pic's of the D-90 and D90b. The D-90b has 8 cans,where the D-90 has 9 can caps.My amp has 9 also. The face plate states it is a D-90. There is no (R) after so it could be someone down the line put the cheeper tubes in. This I don't know,but would like to find out. So my freinds,I'm just asuming and we all know what asuming is the mother of!What do you all think of my reasoning? Stonedeaf, I would love to have your caps. let me know what you need. There's a guy here in town that is retired Mc sevice tech. I talked to him and he seid he'd check them for me but he'll charge me a 6 pack of miller and a pack of smokes.But if his wife see's the beer and cigs. the deals off.Some guy's sure know how to pick um:)My email is marysbikerman@yahoo.com Thanks,Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-24-2009 at 04:21am Copy Comment URL Report Comment Edit Delete Stonedeaf, Thanks for everything. I sent you a letter today.You should get it in a couple days. How do I get a hold of this Leonard from A.R.C.? Just call the number on the web sight and ask for Leonard? HAY,NEWBEE,HEVAC1,STONEDEAF and everyone. Thanks for all the help.I hope I can return the favor some time.Bill
houseofsound OP Details Discussions Posts This discussion Message User 13 posts 03-25-2009 at 04:30am Copy Comment URL Report Comment Edit Delete THANK YOU, HIFIGEEK1. I'M SORRY I LEFT YOU OUT. I DO APPRECATE YOUR HELP. I DID NOT LEAVE YOU OUT INTENTIONALLY. THANKS TO ALL. AND IF ANY OF YOU COMES A CROSS ANY INFO YOU THINK I COULD USE, PLEASE LET ME KNOW. a GOOD BRAIN SURGON WOULD BE GOOD:)BILL

More to discover