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Post by rhythmeister on Nov 22, 2006 16:40:14 GMT -7
Hi Guys,
Well, I've still got one thing I'm trying to resolve with this amp. (Thanks to tips from this forum, I eliminated some annoying hum. etc. by replacing all 12AX7 tubes and tightening the screws to the chassis. It is now almost perfect...)
Here's the issue. This amp cannot be played when sitting on a cabinet. It seems clear to me that the vibrations are causing a degradation in the sound, such that over the course of a practice at good volume, the amp becomes unlistenable if placed atop a Z-Best cabinet. On the other hand, it performs fine and sounds great if placed on the floor and played in the same manner over the same time.
This is just not practical. Who wants to perform with the head on the floor? So I'm thinking there must be something within the amp (maybe a tube) that is causing this sensitivity. I did not replace the EF86 (Dario), or the output tubes GT EL34 #5, or the tube rectifier after I got the amp.
Any thoughts that would allow the head to sit where it should on the cabinet?
Cheers, Blair
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Post by yinielin on Nov 22, 2006 20:27:14 GMT -7
I have to do the same thing with my ghia head. Not really that big of a deal maybe look for something of similar height of the cab and place it on that??? Ive always found out you care way more about the way ur amp looks then people ever notice. Unless of course if its red which a weird color and have had countless people ask about.
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crikey
Junior Member
Posts: 57
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Post by crikey on Feb 9, 2007 0:29:05 GMT -7
I've started running all my amp heads either on the floor or on some inert non-vibrating surface. I noticed the problem that you describe with a great Plexi reproduction I have, and cleared it up by moving the amp to the floor. I then A-Bed two other amps and found they all sound better on the floor than atop a speaker cabinet. Funny that I played for decades before noticing this. I don't think I've ever played my 6545 on a cabinet, having only recently bought it.
Someday I'll probably buy some closed-cell foam to put under the heads, and repeat my testing.
Crikey
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Post by Phil (aka Phil) on Feb 9, 2007 7:03:07 GMT -7
I've had the same problem that was caused by either a bad power tube (EL84) or rectifier (5Y3-Ghia). I wouldn't put it past a EL34 to become sensitive to vibrations.
PDW
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Post by myles on Feb 11, 2007 11:33:56 GMT -7
In the 6545 first try to replace the EF86. This is the usual culprit.
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Post by rhythmeister on Feb 13, 2007 16:22:05 GMT -7
Thanks for the tips, folks! I appreciate your help and experiences.
Cheers, Blair
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Post by skydog958 on Feb 17, 2007 11:41:42 GMT -7
Maybe putting a strip of that tempurpedic stuff under the head would do it. It doesn't transfer motion, right?
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