lespaul678 Posted November 28, 2020 Share Posted November 28, 2020 I have a Line 6, Bogner, Spider Valve HD100 and I'm replacing the tubes on it. I need advice on biasing the amp after replacing the tubes. I didn't see anything in the manual about what to set the bias to. Does anyone know? Quote Link to comment Share on other sites More sharing options...
psarkissian Posted November 30, 2020 Share Posted November 30, 2020 Use ONLY the specified tubes and bias. This is NOT an all analog tube amp. Shock hazard is great, replacement and bias should be done by a trained Line 6 authorized service technician. It hurts when you get zapped. Quote Link to comment Share on other sites More sharing options...
lespaul678 Posted November 30, 2020 Author Share Posted November 30, 2020 Thank you for your concern. I appreciate it. I do have the exact replacement tubes, but you did not answer my question. You're supposed to bias an amp after replacing the tubes and I do not see the number in the user manual for what to set the bias to. I need that number for the HD100 Valve, Spider, Bogner amp head. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted November 30, 2020 Share Posted November 30, 2020 Bias is not in the manual because they don't want people getting zapped. There may still be some info about that in the Knowledge Base or HD100 Facebook group page. The Knowledge Base has it as +35mV(dc) +/- 2mV. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 28, 2021 Share Posted April 28, 2021 That is for FX loop or separating out the pre and power stages as some people do. It's a typical feature in all kinds of amps and even stereo system. There's a digital board with patches and effects, that sends the audio signal to the tube amp board. The amp board sends a signal back to the digital board. It keeps the signal from going out of wack and blowing something. I can't get anymore specific and deeper than that. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 28, 2021 Share Posted April 28, 2021 If I seem vague, it's because your getting into circuit level questions I can't get into with an end user. Proprietary NDA stuff. Not allowed to get any deeper than I already have. Need to use the specified tubes, or it runs the risk of ending up on my repair bench,... and I'm trying to avoid that. Being a service tech here at Line 6, I speak from lots of experience with these amps here. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 28, 2021 Share Posted April 28, 2021 I do know, I'm just not allowed to get into with someone other than a Line 6 authorized service tech. Sorry. Quote Link to comment Share on other sites More sharing options...
silverhead Posted April 28, 2021 Share Posted April 28, 2021 40 minutes ago, psarkissian said: I do know, I'm just not allowed to get into with someone other than a Line 6 authorized service tech. Sorry. No need to apologize for adhering to your NDA, imho. There are things you know that you can’t share publicly. Not difficult to understand. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 28, 2021 Share Posted April 28, 2021 Yes, true. Also don't want people probing in these amps, as they are touchy due to the hybrid analog/digital nature, and there is that high voltage hazard risk. I imagine you've been zapped a number of times too. It's not like our amp is in Aspen Pittman's tube amp book. He was a cool guy, founder of Groove Tube and a total tube amp nut. I miss him. Quote Link to comment Share on other sites More sharing options...
ParkerFlyMajik Posted April 29, 2021 Share Posted April 29, 2021 Apparently, he took his toys and went home. I have 7 DT amps, so I have a feeling the local service center is going to know my first name pretty soon. ;-) Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 29, 2021 Share Posted April 29, 2021 Seven amps,... very good. Quote Link to comment Share on other sites More sharing options...
ParkerFlyMajik Posted April 30, 2021 Share Posted April 30, 2021 20 hours ago, psarkissian said: Seven amps,... very good. I'm extremely happy with the results I get from the Helix>DT combination. I was late to the party so I started with the DT25 HD a few years ago and wanted to try its big brother so I ordered a refurbished DT50 HD from Line 6 (sadly the only one that doesn't work... something in it died). After that I just started acquiring them whenever I found a great deal (cheap and barely used) so now I have 3x DT50 HDs & 1x DT50112 and 2x DT25 HDs & 1x DT25 112. Also, 2x DT50 4X12 cabs which I love. I hope to keep these amps running for a long time (that is, unless L6 comes out with a new version... :-) ) I also own a PC+ 112 & 212, just because I may want to gig again someday and I've found they are gig friendlier. Quote Link to comment Share on other sites More sharing options...
PaulTBaker Posted April 30, 2021 Share Posted April 30, 2021 nice! what a great look! I also love the DT25. I have two of them. One bricked trying to upgrade to 2.0 to use with the helix. I did change the tubes (correct tubes!) and set the bias a few times. Very Very Carefully! My problem was the DT25, at least in my case, was/is so fragile. I bought a PC 112+ and used it this past weekend. I am really happy with that for gigging. It is much lighter and feels more sturdy. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted April 30, 2021 Share Posted April 30, 2021 I think I've seem that photo on the DT group FB page. Very good. Quote Link to comment Share on other sites More sharing options...
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