Members Sordid1 Posted April 2, 2011 Members Share Posted April 2, 2011 Ok so I got a quad of el34eh's in mine. They sound awesome but the only thing I don't get is that when I measure at the test points or the resistors as shown here I get between 25-40mv which would make sense expect according to this thread it should read 100mv???? Did they change the design of this or am I doing something wrong. I'm setting my meter to 200mv dc which should be right I think. Any help would be appreciated, the tubes aren't glowing red or anything I just want to be sure. http://www.musicradar.com/forum/showthread.php?t=66691 _Shane Link to comment Share on other sites More sharing options...
Members Sordid1 Posted April 2, 2011 Author Members Share Posted April 2, 2011 ttt Link to comment Share on other sites More sharing options...
Members hairydangler Posted April 2, 2011 Members Share Posted April 2, 2011 I think you set your multi-meter to the 100mv dc setting. I think this is common practice. Someone correct me if Im wrong please. I always use my Weber bias-rite so I havent had to use my multi-meter yet for biasing. Going out on another limb I would say being 100 watts with probably 4 valves, biasing each valve to about 36 mv should be safe. However I dont know the plate voltage but would guess again at about 460. Im not a tech but heres a free bump to help you get more info. Good luck! Link to comment Share on other sites More sharing options...
Members hairydangler Posted April 2, 2011 Members Share Posted April 2, 2011 I read your link and he describes two ways to measure the bias. Perhaps this measures all four valves? Could be the reason for the 100mv bias he recommends, however in that case it would seem low. Link to comment Share on other sites More sharing options...
Members Sordid1 Posted April 3, 2011 Author Members Share Posted April 3, 2011 I read your link and he describes two ways to measure the bias. Perhaps this measures all four valves? Could be the reason for the 100mv bias he recommends, however in that case it would seem low. That's what I think as well and that would be cold, the problem is when I measure either of these points i'm getting 25-50 not 100????? Link to comment Share on other sites More sharing options...
Members Sordid1 Posted April 3, 2011 Author Members Share Posted April 3, 2011 figured it out nevermind! Link to comment Share on other sites More sharing options...
Members hairydangler Posted April 3, 2011 Members Share Posted April 3, 2011 What was it? Just curious as Ive had an eye on this amp and may need to bias one someday. figured it out nevermind! Link to comment Share on other sites More sharing options...
Members Sordid1 Posted April 3, 2011 Author Members Share Posted April 3, 2011 me being a total idiot. I just had it WAY to low. the weird thing is it still sounded nice. I now have it at 100 and it sounds great. I know that seems really cold but it seems to be perfect in this amp. As far as getting one I would highly recommend it. Definitely sounds better with some different preamp and power amp tubes (the stock power tubes are great but a bit too balanced for this kind of dark amp) but easily my favorite amp to date period. If you are using a strat ele the stock tubes are probably perfect but i'm a PRS guy. Thanks for the help man! Link to comment Share on other sites More sharing options...
Members hairydangler Posted April 3, 2011 Members Share Posted April 3, 2011 I figured thats what it was. Good job! Sounds like its got a decent sweep to get ya back up where it needed to be. Cool. I hope to bias my own one day but really, I should sell a few amps first! me being a total idiot. I just had it WAY to low. the weird thing is it still sounded nice. I now have it at 100 and it sounds great. I know that seems really cold but it seems to be perfect in this amp. As far as getting one I would highly recommend it. Definitely sounds better with some different preamp and power amp tubes (the stock power tubes are great but a bit too balanced for this kind of dark amp) but easily my favorite amp to date period. If you are using a strat ele the stock tubes are probably perfect but i'm a PRS guy. Thanks for the help man! Link to comment Share on other sites More sharing options...
Members Sordid1 Posted April 3, 2011 Author Members Share Posted April 3, 2011 I figured thats what it was. Good job! Sounds like its got a decent sweep to get ya back up where it needed to be. Cool. I hope to bias my own one day but really, I should sell a few amps first! My favorite amp ever period at this point. It does EVERYTHING realy, really well and has it's own sound going too. Build quality is great, these Korean made jobs lately are awesome and as much as I would love to keep everything built us or uk it's really hard to pay double riple for something that doesn't sound as good to me so I didn't Link to comment Share on other sites More sharing options...
Members doomsdaymachine Posted April 3, 2011 Members Share Posted April 3, 2011 I used a bias probe, that measures in milliamps. I was told BY BLACKSTAR, that my HR-60 runs at a plate voltage of 500.. An EL34, E34L, 6L6 & KT77 all run at 25 watts plate dissapation - So, 25 watts divided by 500 = .050, (50 millliamps). Then, the standard formula is to run 70% of that, (x .7) to get you of crossover distortion = 35mA. Link to comment Share on other sites More sharing options...
Members audiodog22 Posted July 19, 2013 Members Share Posted July 19, 2013 I could of sworn that if you use a bias tester for the HT-100 that you should set it at about 37 but since doing it that way above ^ it sets all four so wouldn't it be at 37 x 4= 148 and not 100??? I am confused and SHOULD i BUY a bias tester or just do all 4 tubes? Link to comment Share on other sites More sharing options...
Members audiodog22 Posted July 19, 2013 Members Share Posted July 19, 2013 http://www.amp-head.com/product_info.php?cPath=21&products_id=70 Link to comment Share on other sites More sharing options...
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