Title: HRM "low freq short Post by: mindology on March 29, 2010, 05:27:16 PM hey guys...
I have been periodically experiencing a "break up" like a short on my HRM if there is an abundance of low frequency. For instance, yesterday I turned the tone all the way down on my PRS hollow body and it did it on the clean channel. For that matter.. it does it on both dirty and clean channel... any ideas? Title: Re: HRM "low freq short Post by: mindology on March 30, 2010, 03:52:05 PM I know it seems kinda convoluted, but I am not sure how to describe it.
After thinking about it, it is similar to the sound of a shorting cable.... Mind you, it only does it if I have an overload of low freq. Any ideas? Title: Re: HRM "low freq short Post by: hywelg on March 30, 2010, 05:20:04 PM I've got something similar with my DZ-30 combo only mine comes on only rarely after playing for a while and it will never do it when you get the chassis on the bench. My attempts to provoke what must be a short somewhere have failed so far which is really annoying as it means I can't gig with it. It is the sound you get when you touch the end of a cable just before you plug it into the guitar whilst said cable is connected to the amp.
If you can make it happen at will then I'd suggest (but only if you are competent working with 450+volts) taking the chassis out connecting it up as normal, induce the problem and start chopsticking the pre-amp signal connections. If you are not completely happy to do this then make a thorough note of what to do to replicate it and then take it and the notes to a tech. Title: Re: HRM "low freq short Post by: mindology on March 30, 2010, 05:47:36 PM Yeah.. I contacted Nik about this.. he is getting back to me...
I will let you know Title: Re: HRM "low freq short Post by: mcinku on March 31, 2010, 06:24:20 AM If you ask me this is a cold solder issue.
I had similar experience once... something funky was happening with my amp. In the cab I had issues but on the bench everything was fine. I found the culprit at the end... on the bench amp was not vibrating and it was always fine but in the cab and with speaker working, the amp was vibrating and some funky sounds were happening. ;) Title: Re: HRM "low freq short Post by: ODME on March 31, 2010, 08:57:35 AM When a low frequency exposes something it's generally because it causes a physical vibration that causes the problem to manifest.
Have you tried pounding on the amp with your fist to see if that also causes the problem to happen? It could be a bad solder joint or even a tube that is reacting to vibration. Title: Re: HRM "low freq short Post by: mindology on March 31, 2010, 12:49:49 PM When a low frequency exposes something it's generally because it causes a physical vibration that causes the problem to manifest. Have you tried pounding on the amp with your fist to see if that also causes the problem to happen? It could be a bad solder joint or even a tube that is reacting to vibration. hmm... Never thought of that... I will have to check it out... The funny thing is that I never play in this setting so it does not happen often. however, I don't want it to become a problem..... Any chance that a tube could be contributing? Title: Re: HRM "low freq short Post by: jmernyk on March 31, 2010, 04:18:19 PM Once had a filter cap that would cause that, would work fine but crap out sometimes when the the current demand was high (big low notes). Tricky to find....
Title: Re: HRM "low freq short Post by: mindology on April 01, 2010, 01:29:52 PM so last night... I let the amp run for an hour without playing through it... no short. Could this be an amp "burn in" issue since the amp does not have a total of 10hrs playing time.
Nik suggested that this could be the case, or he told me to let it run---turn it off---- and turn it back on... if the crackle starts to happen again, it is probably a bad solder somewhere. I did this, and no short... so right now I am thinking that it could be taking the "new" off.... what do you guys think? Title: Re: HRM "low freq short Post by: mindology on April 05, 2010, 05:25:14 PM Ok.. so now I am thinking cold solder.. now I need to find someone to help me trace it!
Title: Re: HRM "low freq short Post by: hywelg on April 05, 2010, 07:32:51 PM Like the problem I am having with my DZ-30 if you can't reliably replicate the problem its mighty tricky to find it. All I know is that my problem will only rear its head when i absolutely need it not to.........
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