Members surlybastard Posted February 20, 2011 Members Share Posted February 20, 2011 I've got a Traynor Custom Special 100 H (not the H2) with KT77's currently dying a slow death. I want to switch them to EL34's, but I've never had to re-tube and re-bias an amp myself before. I've figured out where all the test points, ground and bias pot are, I just wanted to check in and see if anyone else has changed the bias on one of these and if they have any advice or direction? The manual says to set the bias to 25mV, that strikes me as being very cool. Any opinions? Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted February 20, 2011 Members Share Posted February 20, 2011 It's cold, but that's not necessarily a bad thing.. I believe Mesa has their EL34 amps set fixed at 25mV per tube and they sound great. I'd start with the manual recommendations and go from there. Hotter bias does not necessarily mean a better tone. The only thing that a hotter bias is guaranteed to do is shorten the tube life, the rest is personal preference. Link to comment Share on other sites More sharing options...
Members surlybastard Posted February 20, 2011 Author Members Share Posted February 20, 2011 I have heard that Traynor does bias this particular amp colder than most. My amp has had the particular KT77's in it for just over a year, and I usually play it at lower volume. Does that seem like a shorter lifespan than I should expect given those conditions? Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted February 20, 2011 Members Share Posted February 20, 2011 I have heard that Traynor does bias this particular amp colder than most. My amp has had the particular KT77's in it for just over a year, and I usually play it at lower volume. Does that seem like a shorter lifespan than I should expect given those conditions? one year is average, not great not bad. What makes you think you need new tubes? What are the issues you are noticing? Link to comment Share on other sites More sharing options...
Members buddhapaugh Posted February 21, 2011 Members Share Posted February 21, 2011 I had KT77's before and they seem to have a shorter lifespan.... most EL34 type tubes have shorter lifespans than other tube types (specifically 6L6). Link to comment Share on other sites More sharing options...
Members Zhorellski Posted February 21, 2011 Members Share Posted February 21, 2011 I have heard that Traynor does bias this particular amp colder than most. My amp has had the particular KT77's in it for just over a year, and I usually play it at lower volume. Does that seem like a shorter lifespan than I should expect given those conditions? **We recommend adjusting the zero signal bias to +75 mV +/-10mV DC at each of the testpoints. Bias adjustment should be done with the amplifier configuration in the 50 Watt mode(YCS50) or 90 Watt mode (YCS90). Please refer servicing to qualified personnel.** Copy this from my Traynor ycs50 manual. Link to comment Share on other sites More sharing options...
Members surlybastard Posted February 21, 2011 Author Members Share Posted February 21, 2011 one year is average, not great not bad. What makes you think you need new tubes? What are the issues you are noticing? In the 100w mode I've started to notice a crackling and faint hum coming from the speaker that isn't affected by anything I do (volumes or any other setting). The amp is silent in 30w mode. I've contacted Yorkville and done the obvious troubleshooting and we're down to tubes at this point. So before I send it off to a tech or Yorkville (I'm in Canada so I can send it back to them) I wanted to rule out the tube problem since 9 times out of 10 that's what the issue is but I'm trying to save some $$$ by doing the swap myself. Link to comment Share on other sites More sharing options...
Members surlybastard Posted February 21, 2011 Author Members Share Posted February 21, 2011 I had KT77's before and they seem to have a shorter lifespan.... most EL34 type tubes have shorter lifespans than other tube types (specifically 6L6). Do you re-tube your YCS-100 yourself? Any advice for newbie at this? Sorry for the open ended question, if I owned a DSL 100 there's a million youtube videos and forum posts of guys re-tubing and biasing that amp, I'm a little on my own working with this particular amp since not a lot of people own it Any advice or direction would be appreciated. At this point my plan is to use the KT77's as my guinea pig, so I can get a feel for what the test points tell me and how the pot works. Thanks! Link to comment Share on other sites More sharing options...
Members surlybastard Posted February 21, 2011 Author Members Share Posted February 21, 2011 **We recommend adjusting the zero signal bias to +75 mV +/-10mV DC at each of the testpoints. Bias adjustment should be done with the amplifier configuration in the 50 Watt mode(YCS50) or 90 Watt mode (YCS90). Please refer servicing to qualified personnel.**Copy this from my Traynor ycs50 manual. Ya my manual has a similiar sentence, except it suggests 25mV +/- 3mV Link to comment Share on other sites More sharing options...
Members kd77 Posted February 21, 2013 Members Share Posted February 21, 2013 I have a similar problem, my ycs100h works good in 100 watt mode but it goes silent when i switch to 30 watt class A mode, did swapping out the power tubes fix this problem for ya? Link to comment Share on other sites More sharing options...
Members gt5litre Posted February 22, 2013 Members Share Posted February 22, 2013 What did Yorkville say to do, what bias should the amp/ tube be adjusted to? Link to comment Share on other sites More sharing options...
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