Another AD30HTC problem here

anthonyf516 · Post by **anthonyf516** » Sat Apr 04, 2009 7:25 am

hello everyone,

my name is anthony, and i am new to the forum. i have an ad30htc head. i love the amp. it is great for recording. unfortunately though, i have had a problem recently. i have read through the forum to no avail to try and see if anyone had a similar problem.

recently i was playing through the amp on channel 2, everything is great. when i switched to channel 1 i noticed the lack of volume. it was very very low. i wouldnt be able to get the amp to my tech for at least a week, so i turned it off. two days go by and i play through channel 2 again, everything is fine. channel 1, still nothing. i play through the amp today, and now both channels have very low output...

i understand that i could easily change the tubes because of the cathode bias. what else could this be if not the tubes? the output tubes seem to light up (checked in a dark room)

any help would be greatly appreciated and thank you in advance if you are able to help.

-anthony

Simon Wicks · Post by **Simon Wicks** » Sun Apr 05, 2009 12:39 pm

Hi Anthony! Welcome to the forum

First thing to try is swapping the pre-amp tubes for the two channels. If the channel 1 pre-amp tube is knackered then putting it in channel 2 will quieten the channel and vice versa. That should be the problem. The fact that only one channel is quiet kind of limits your problems to something most likely easy to fix. If you find swapping the tubes works, replace the duff one and maybe keep another pair on standby for when this happens again.

anthonyf516 · Post by **anthonyf516** » Sun Apr 05, 2009 10:49 pm

Simon Wicks wrote:Hi Anthony! Welcome to the forum

First thing to try is swapping the pre-amp tubes for the two channels. If the channel 1 pre-amp tube is knackered then putting it in channel 2 will quieten the channel and vice versa. That should be the problem. The fact that only one channel is quiet kind of limits your problems to something most likely easy to fix. If you find swapping the tubes works, replace the duff one and maybe keep another pair on standby for when this happens again.

at first channel one was very low... then after a bit of playing channel two, that went low as well. i guess i will try and change all four pre amp tubes and see what happens. could there be something with the power tubes? i didnt think it would have anything to do with the power tubes because at one point channel one was out, but two seemed to be fine before it went out as well.

i guess ill just pick up some 12ax7s and see what happens. for pre amp tubes, they dont need to be matched pair correct? just pop them in and go?

stratplayer1997 · Post by **stratplayer1997** » Mon Apr 06, 2009 1:13 am

Correct, preamp tubes can just be swapped out. You might want to pick up some power tubes just to have them.

anthonyf516 · Post by **anthonyf516** » Mon Apr 06, 2009 5:49 am

i just ordered some new 12ax7s and some el84s. thank you for the help, and i will let you guys know if my problem was resolved or not.

wearerobots138 · Post by **wearerobots138** » Mon Apr 06, 2009 6:27 pm

Hi Anthony, I am also a first time poster. I am glad that you posted your question because I am currently experiencing the EXACT SAME PROBLEM with my AD30. I bought mine used a while ago, and it was working fine but then one day the volume just cut out. The tone is still there, but there is no volume. I changed out both the preamp tubes and the power tubes, and the problem stayed the same. I finally took it to a shop, where they "serviced" it for a month; they told me that I had some bad soldering. When I got it back, it worked fine again for about 30 minutes, and then it crapped out again. I realize that my problem could have something to do with the fact that I run it full volume-full gain, but I thought these things were designed to handle that.

Simon Wicks · Post by **Simon Wicks** » Mon Apr 06, 2009 7:42 pm

New stock tubes often fail out of the box. They arent as well made as they used to be back when tubes were in everything.

I'd expect a simple replacement of your tube compliment should solve your problems.

anthonyf516 · Post by **anthonyf516** » Mon Apr 06, 2009 10:40 pm

im in agreement with the quality of new old stock tubes compared to new tubes, but i have never had a problem with new svetlana or sovtek tubes (well a few years ago when the sovtek tubes were decent)

i have some jj tubes coming my way from thetubestore.com. im excited and hopeful.

anthonyf516 · Post by **anthonyf516** » Tue Apr 07, 2009 4:14 am

wearerobots138 wrote:Hi Anthony, I am also a first time poster. I am glad that you posted your question because I am currently experiencing the EXACT SAME PROBLEM with my AD30. I bought mine used a while ago, and it was working fine but then one day the volume just cut out. The tone is still there, but there is no volume. I changed out both the preamp tubes and the power tubes, and the problem stayed the same. I finally took it to a shop, where they "serviced" it for a month; they told me that I had some bad soldering. When I got it back, it worked fine again for about 30 minutes, and then it crapped out again. I realize that my problem could have something to do with the fact that I run it full volume-full gain, but I thought these things were designed to handle that.

what got me was that one channel had very low volume, but the other channel would be just fine. then after a couple days both went.

wearerobots138 · Post by **wearerobots138** » Thu Apr 09, 2009 1:05 pm

Yea, one of my channels ran fine for a while before it gave out on me too, and now both are about at the same volume (or lack there of). If one channel was running fine for a while then I'm having a hard time understanding how it's a tube issue...if it's a tube issue it seems like both channels would die down at the same time. Have you had any success since changing your tubes out? I currently have sovteks running in mine.

anthonyf516 · Post by **anthonyf516** » Thu Apr 09, 2009 6:16 pm

wearerobots138 wrote:Yea, one of my channels ran fine for a while before it gave out on me too, and now both are about at the same volume (or lack there of). If one channel was running fine for a while then I'm having a hard time understanding how it's a tube issue...if it's a tube issue it seems like both channels would die down at the same time. Have you had any success since changing your tubes out? I currently have sovteks running in mine.

well it could be the preamp tubes. each channel has its own preamp section, but they run off the same power tubes.

the tubes were just delivered today, so i will hopefully be able to get to it tonight. might be a day or so until i can get into my studio to hook it up, but i will let you know.

anthonyf516 · Post by **anthonyf516** » Sat Apr 11, 2009 10:25 pm

replaced the preamp and power tubes and everything is working fine. i played for an hour straight, and there doesnt seem to be any problems. thank you everyone for your help.

i forgot how great this amp sounds through a marshall 4x12.

Thanks!

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