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Post by myles on Aug 16, 2006 12:08:51 GMT -7
Hello Myles, I am re-asking a question that I did not state too clearly before. My Mazerati combo has a loose tone knob. It's not the small screw, or the 1/2" nut on the exterior of the amp. I have tightened that nut and there is no difference. If I move the knob up and down, there is a clear noise inside the amp. Should I try to drop the chassis and tighten something or leave it alone? It currently does not affect the amp's performance, but I would rather "fix" it now and avoid a bigger situation. thanks Myles. Go ahead and pull the chassis as there may be an inner nut on the shaft that became loose. |
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Post by abradpaisleyfan on Aug 16, 2006 16:01:16 GMT -7
hey myles, how are you? good I hope. I have a question for you. I have a vox ac30 custom classic. I re-glassed it about a month ago. I am now gettting a hum out of it you cant hear it hardly, but when the amp is miked its terrible. the tubes I used were groove tubes el84s in a 6 rating. and ecc83's and the gz34, the hum has just started? what could be going on. sounds like a filter cap? I hear no hum when the amp is on standby. I even put my ear on the cab near the power transformer and I hear nothing. the hum comes out of the speakers. let me know what you think? thankyou much
matt
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Post by blanketeer on Aug 17, 2006 9:14:34 GMT -7
Haya! I've heard a lot about mis-matched EL84 action - but am not sure what range of mis-match I should be looking for. Like... 2's and 7's or 4's and 6's... Aces and 8's, bwah. I like the rock and roll, generally play a Paul through a Mazerati, use ZVex Super Duper for overdrive/distortion and was interested in perhaps trying this out (or not). Suggestions would be super appreciated! Time to replace the tubes and wanted to see what the story is - take it easy and thanks thanks!  cooper www.blanketeer.netwww.myspace.com/blanketeerwww.sonicbids.com/blanketeer |
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Post by myles on Aug 17, 2006 10:40:50 GMT -7
hey myles, how are you? good I hope. I have a question for you. I have a vox ac30 custom classic. I re-glassed it about a month ago. I am now gettting a hum out of it you cant hear it hardly, but when the amp is miked its terrible. the tubes I used were groove tubes el84s in a 6 rating. and ecc83's and the gz34, the hum has just started? what could be going on. sounds like a filter cap? I hear no hum when the amp is on standby. I even put my ear on the cab near the power transformer and I hear nothing. the hum comes out of the speakers. let me know what you think? thankyou much matt Matt, Do you have the old set of output tubes you can put in for a moment? You may have had an output tube go bad and drift too far out of match if the hum is moderate. If it is severe then tube was farther out of match or failed. If you want, call Rick Benson toll free at GT at 1-800-459-5687 and have GT warranty replace the quad. This is usually an output tube issue and probably not a cap at all. |
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Post by myles on Aug 17, 2006 10:42:02 GMT -7
Haya! I've heard a lot about mis-matched EL84 action - but am not sure what range of mis-match I should be looking for. Like... 2's and 7's or 4's and 6's... Aces and 8's, bwah. I like the rock and roll, generally play a Paul through a Mazerati, use ZVex Super Duper for overdrive/distortion and was interested in perhaps trying this out (or not). Suggestions would be super appreciated! Time to replace the tubes and wanted to see what the story is - take it easy and thanks thanks! cooper www.blanketeer.netwww.myspace.com/blanketeerwww.sonicbids.com/blanketeerI keep the ratings within two points but use two different duet types such as EL84S #6 and a set of NOS mid range tubes or a set of EL-84Y #5's. |
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Post by blanketeer on Aug 17, 2006 12:34:12 GMT -7
Thanks, boss - I'll give it a shot!
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Post by abradpaisleyfan on Aug 17, 2006 13:24:28 GMT -7
hey myles I put the org power tubes back in. I dont have a hum but I can see the blue gas inside the tubes and they are pulsing. I can hear it through the speakers. its like a whushing sound. I even put the org rectifier tube back in. still does it. im not sure whats going on. I have a heath kit tube checker and I checked my el84s and they all read different percentages. where as when I tested them before I put them in the amp they all read the same. somethings messed up inside the amp. its still under warrenty. anyways thanks for your help. should I still call Rick Benson to replace the tubes. even though it prob was the amp that messed the tubes up? thanks much for your replay myles
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Post by myles on Aug 18, 2006 10:17:43 GMT -7
hey myles I put the org power tubes back in. I dont have a hum but I can see the blue gas inside the tubes and they are pulsing. I can hear it through the speakers. its like a whushing sound. I even put the org rectifier tube back in. still does it. im not sure whats going on. I have a heath kit tube checker and I checked my el84s and they all read different percentages. where as when I tested them before I put them in the amp they all read the same. somethings messed up inside the amp. its still under warrenty. anyways thanks for your help. should I still call Rick Benson to replace the tubes. even though it prob was the amp that messed the tubes up? thanks much for your replay myles You cannot really use an old tube tester for testing output tubes as they do not develop proper voltages. Preamp tubes are fine though. But ... if they read the same originally and do not now that could be an indication of something. Before I blame the amp I'd blame the tubes. I would call Rick Benson and say one of the set failed and have him replace them under warranty. Blue glow is quite normal by the way. Swirling purple gas clouds are not normal. Once you have a good set of tubes we can go from there. |
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Post by abradpaisleyfan on Aug 18, 2006 18:25:44 GMT -7
I did some researing and I guess my amp use the bias for vibrato. so that would explaning the tube flashing purple gas? the org tube are electro harmonix el84eh. no hums at all. and the only time I see the gas in the powetubes is when im useing the vibrato. I think it is just a tube problem. but I got my recept out and they are more than 90 days old. i dont think they are under warrenty anymore. anyways I do thankyou much for replying back.
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Post by James on Aug 22, 2006 11:47:57 GMT -7
Myles,
I need new Power tubes for my Rt 66. What's my best bet for purchasing them. Are the chineese versions that GT sells good enough? Brent Fergusen says Doc is using them lately and having great success.......that they actually sound sweeter than the HP's.
As always, your response is much appreciated!
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Post by myles on Aug 23, 2006 9:53:14 GMT -7
I did some researing and I guess my amp use the bias for vibrato. so that would explaning the tube flashing purple gas? the org tube are electro harmonix el84eh. no hums at all. and the only time I see the gas in the powetubes is when im useing the vibrato. I think it is just a tube problem. but I got my recept out and they are more than 90 days old. i dont think they are under warrenty anymore. anyways I do thankyou much for replying back. If the vibrato modulates bias what you are seeing is quite normal. |
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Post by myles on Aug 23, 2006 9:55:59 GMT -7
Myles, I need new Power tubes for my Rt 66. What's my best bet for purchasing them. Are the chineese versions that GT sells good enough? Brent Fergusen says Doc is using them lately and having great success.......that they actually sound sweeter than the HP's. As always, your response is much appreciated! Lots of folks are using the KT66C in a #6 rating in the Route 66. In the original Steve Carr Mercury he played with the HP and the C and preferred the C sonically and used that tube. In the end it is personal taste. The HP was good to over 525 plate volts and the C was good until 450 but is now is OK to 490 or so depending on plate dissapation via bias. The Z amps are fine and dandy with the C by a nice margin. |
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Post by Curt on Aug 23, 2006 10:59:50 GMT -7
Myles,
I have a '68 Pro Reverb that has original tubes except for the power tubes, they are German made 6L6's and are screened with "Realistic" and "Lifetime". the amp seemed weak, I checked bias and it was at 24mA, checked the GT chart and looks like 40 would be more like it.
Plate volts check out to 450v, I set the bias at 33 and it is much improved.
What would you suggest I set the bias at?
Thanks,
Curt
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Post by BW on Aug 24, 2006 3:43:57 GMT -7
Radio Shack 6L6's
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Post by billyguitar on Aug 24, 2006 4:48:40 GMT -7
Those Radio Shacks were always the worst! Any of those that said Lifetime Guarantee anyway.
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Post by Curt on Aug 24, 2006 8:53:35 GMT -7
Well I knew Realistic was a Radio Shack brand but was unsure if these tubes were from there.
They actually are not bad, of course I had not tried any others in this amp.
I need a nice fresh set and a bias point to know for sure. Overall the Pro is VERY cool.
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Post by myles on Aug 25, 2006 11:06:25 GMT -7
Myles, I have a '68 Pro Reverb that has original tubes except for the power tubes, they are German made 6L6's and are screened with "Realistic" and "Lifetime". the amp seemed weak, I checked bias and it was at 24mA, checked the GT chart and looks like 40 would be more like it. Plate volts check out to 450v, I set the bias at 33 and it is much improved. What would you suggest I set the bias at? Thanks, Curt Curt, BF Fender 6L6 amps seem to love 30-32mA without much regard to plate voltage. |
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Post by myles on Aug 25, 2006 11:07:41 GMT -7
Those Radio Shacks were always the worst! Any of those that said Lifetime Guarantee anyway. Actually Radio Shack when having tubes labelled Realistic were generally great. Lots of gold pin Mullards and Telefunkens in the old days. |
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Post by myles on Aug 25, 2006 11:10:51 GMT -7
Well I knew Realistic was a Radio Shack brand but was unsure if these tubes were from there. They actually are not bad, of course I had not tried any others in this amp. I need a nice fresh set and a bias point to know for sure. Overall the Pro is VERY cool. The Fender Black Face Pro Reverb in my mind may be the best all around amp that Fender ever made. You can get them to break up nicely at rational levels as they are only a 6L6 duet. They are tube rectified and the 2x12's are cool too. Tony from Mother Jones, Jeff Smith, Doug McCaskill are three of my clients off the top of my head that play these. They are all spectacular. I think I have over six of them that I maintain. |
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Post by billyguitar on Aug 25, 2006 11:48:52 GMT -7
I'm surprised about the Radio Shack tubes. maybe the ones I had were just worn out. I never bought any, they would just come in some of the old amps.
I learn something every day! (I think I forget more than I learn though. Someday I'll be blank!)
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Post by Curt on Aug 25, 2006 16:34:03 GMT -7
Thanks very much Myles as I'm new to Biasing my own stuff, looks like I was lucky here ! 33 seemed to sound really nice to me, really woke her up from the 24mA she was at. I'd take several more of these if I could find them for the $800 I paid for this'n  It's a '68 First year SF with the Drip edge, can't recall the circuit right now and don't know if they changed from BF by then, and don't care as it is a fantastic amp. I've never been a reverb guy but this one is insane...really nice. Thanks for your feedback Myles. God Bless, Curt |
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Post by guitarboy02451 on Aug 25, 2006 21:27:06 GMT -7
Myles, in my sr /nr I have 3 svetlana 12ax7's. Should I put a 12ax7LPS in V3?
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Post by myles on Aug 26, 2006 7:23:12 GMT -7
Thanks very much Myles as I'm new to Biasing my own stuff, looks like I was lucky here ! 33 seemed to sound really nice to me, really woke her up from the 24mA she was at. I'd take several more of these if I could find them for the $800 I paid for this'n It's a '68 First year SF with the Drip edge, can't recall the circuit right now and don't know if they changed from BF by then, and don't care as it is a fantastic amp. I've never been a reverb guy but this one is insane...really nice. Thanks for your feedback Myles. God Bless, Curt Curt, The Black Face Pro Reverb was circut AA165 from 1965-1967. The Silver face actually had two variants and was built from 1968-1976 (AB668) and 1976 (changed in 1976) to 1982 was AA1069. 1976-1982 had a master volume. Yours is more desirable. The AA1069 has a bias balance pot rather than a conventional bias pot as yours has. The balance bias pots are not as preferred and many folks change these to a conventional bias pot arrangement. Your amp may have a few minor differences from the AA165 circuit such as swamper resistors in the output section but these are no biggie and I would not even go to the trouble of removing or changing anything on the AB668 circuit. It is a great circuit. Great amp ... play it in good health.... Myles The circuit is |
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Post by myles on Aug 26, 2006 7:25:19 GMT -7
Myles, in my sr /nr I have 3 svetlana 12ax7's. Should I put a 12ax7LPS in V3? It is hard to say. I prefer long plates in the PI position but it also depends on how well the Svet in there now is matched and whether it has good current output (which most of them that I have looked at seem to have). If you are anywhere near me I would be happy to test the tube and spec it at no charge. (Same offer for any of the folks in this forum). |
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Post by RC on Aug 26, 2006 20:01:17 GMT -7
Myles,
Could you recommend a good A/B/dual amp switcher for me to use with my Ghia and Maz 18 jr. Any thoughts you have on avoiding some of the common issues with tone loss and phasing would be really appreciated.
Thanks,
Russ
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Post by myles on Aug 28, 2006 13:18:03 GMT -7
Myles, Could you recommend a good A/B/dual amp switcher for me to use with my Ghia and Maz 18 jr. Any thoughts you have on avoiding some of the common issues with tone loss and phasing would be really appreciated. Thanks, Russ Russ, The one I use is a red box and I do not even remember who made it. Danny Jacob is currently using mine so I cannot even look. But .... I'd ask this quest of Carl Verheyen in the ask Carl area as he switches amps and has one that works better than anything I have ever seen. It may be a Lehle but I am not sure of it's specifics as it may have been a custom design for him. |
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Post by guitarboy02451 on Aug 29, 2006 12:15:38 GMT -7
Myles, I'm going to replace the tubes in my Maz Sr. The local GC (Nashua NH) only has GT6l6 5's or 7's but no 6's. I'm opting to go with the 5's. Any issues?
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Post by Curt on Aug 29, 2006 12:45:39 GMT -7
Myles, I'm going to replace the tubes in my Maz Sr. The local GC (Nashua NH) only has GT6l6 5's or 7's but no 6's. I'm opting to go with the 5's. Any issues? Uhh..errr...Froidian?  Don't you mean EL-84's? ? IMO going from a 6 to a 5 or a 7 is negligeable (sp?) |
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Post by Danny on Aug 29, 2006 13:01:17 GMT -7
Russ, I'm not Myles, but FWIW I use Lehle switchers. They are wonderfully made and involved no tone loss whatsoever. Phase issues are also not a problem. Either the '1@3' or the 'Dual' should work for you. Check out www.lehle.com for details. Good luck, Daniel |
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Post by RC on Aug 29, 2006 15:45:56 GMT -7
Myles and Daniel,
Thanks guys I think the Lehle switcher is going to do the trick for me.
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