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Post subject: Power vs. Pre-amp tube toubleshooting help needed
Posted: Sat Feb 19, 2011 5:09 am
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Joined: Sat Dec 11, 2010 5:56 pm
Posts: 14
Location: Salem, Virginia
I have a HR DeVille 212. I have noticed that I no longer have clean, solid tone and that everything coming through the amp (no effects) is muddy and fuzzy and I have significantly reduced output. I figure this is one of those "well duh" you need to replace your tubes but being a newbie to tube amps, I'm not certain how to approach the troubleshooting. Would it be the pre-amp tubes most likely (assuming the problem is with the tubes)? I have taken all of them out and looked at them but it is apparently not the same as looking at a burned out light bulb...LOL Any input is greatly appreciated. Thanks


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Post subject: Re: Power vs. Pre-amp tube toubleshooting help needed
Posted: Sat Feb 19, 2011 10:20 am
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Joined: Tue Jun 29, 2010 1:20 pm
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Hi Fatoldsun,

Great amp, I have the HRDvl 4x10 and the HRDlx and they do have clean solid tone...normally. The problem could be a number of things, but is likely bad output tubes or solder joint problems. If the amp is stuck on the drive channel (drive but no clean, red drive light on), then it is likely solder joint problems. If the channel switching works normally, then it may be a tube problem. You can't usually tell if the tubes are good or bad by looking at them, but sometimes it shows.

Sounds like it may be time to replace the output tubes. Without checking everything else out in the amp, ie power supplies, solder joints, etc, a loss of output as you've described can indicate bad output tubes. The only way to know for sure is to try some new tubes, and/or have the tubes tested. Tube testers don't always show the tubes condition, they are mostly a pass of fail test, and may not be able to tell what the tube should sound like. You should properly bias any new output tubes when installed. The preamp tubes can just be replaced without any adjustment.

The most common problem with your amp and some of the other HRd amps, is poor solder joints. The amp should be gone through by a good tech and all solder joints should be touched up while you are at it, which may save some heartache down the road. The easiest ones to touch up are on the smaller circuit boards at the bottom of the chassis where the tubes plug in, as those are exposed. The tube socket connections should definitely be touched up, as that could also be the trouble with loss of output that you are experiencing. Just a thought. :idea:

Here is a great site about the HRDlx, but also pertains to the HRDvl.

http://www.justinholton.com/

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Post subject: Re: Power vs. Pre-amp tube toubleshooting help needed
Posted: Sat Feb 19, 2011 3:38 pm
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Joined: Sat Dec 11, 2010 5:56 pm
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Location: Salem, Virginia
Thanks shimmilou

That website was helpful and what I realize between you and the website is that I am not qualified (or probably capable) to work on the amp. I have located a qualified tech in the area and will be taking it in. Once I find out the problem, I will re-post here to let everyone know. Thanks again for your assistance.


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