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Post by jzguitar on Jun 23, 2005 21:02:19 GMT -7
Hey everyone!
Is it true that you should change your PI tube whenever you change power tubes? If so, why? I just retubed my Mazerati with JJ EL84s but I didn't change the PI. Is this bad? Thanks!
jz
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Post by myles on Jun 24, 2005 12:56:23 GMT -7
Hey everyone! Is it true that you should change your PI tube whenever you change power tubes? If so, why? I just retubed my Mazerati with JJ EL84s but I didn't change the PI. Is this bad? Thanks! jz This is a good practice to follow on amps such as Marshalls, Bogners, etc. An EL84 is pretty easy to drive. I generally change PI's on the Z EL84 amps every few output tube changes but I measure the PI and see how much it's current output has dropped since it was new and measured / recorded. The drop is in proportion to hours and how hard it was driven during those hours. On master volume amps you also have to look at whether the master is pre or post PI. .... and how you use the amp. On my clients amps the PI is always checked and noted for it's balance, gain, output, transconductance, and plate resistance. If you are anywhere close to L.A I would be happy to trace your PI on a weekend as a general favor.
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Post by jzguitar on Jun 26, 2005 18:48:55 GMT -7
Hey Myles
Thanks for the info. I'm in Nashville, so it's a bit of a drive to LA! If I'm playing there anytime, I'll be sure to shoot you an email, though. I gigged this weekend with JAN GE 5751's in both positions (Mazerati combo) and I really liked it. Take care.
jz
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Post by bluzsteel on Jun 26, 2005 19:33:32 GMT -7
Hi Myles, Dave Millsap here in FT Worth I will be calling you this week. time to re tube the Maz. need some of your hand pics
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Post by myles on Jun 27, 2005 12:52:06 GMT -7
Hey Myles Thanks for the info. I'm in Nashville, so it's a bit of a drive to LA! If I'm playing there anytime, I'll be sure to shoot you an email, though. I gigged this weekend with JAN GE 5751's in both positions (Mazerati combo) and I really liked it. Take care. jz Jz At the Brad Paisley Christmas show in L.A. he was using my MAZ 38 with 5751's in V1 and V5 to compliment his RxES. In Nashville you can hit up Todd Sharp at Nashville Amp service. If he orders anything from Rick Benson over at GT have him tell Rick to have me pick out some stuff for you if you ever need anything. I support a lot of Nashville folks and you may know some of them. If so, you could always get something from some of them if you know them and I can resupply them.
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Post by myles on Jun 27, 2005 12:52:44 GMT -7
Hi Myles, Dave Millsap here in FT Worth I will be calling you this week. time to re tube the Maz. need some of your hand pics I can be reached at GT M-F, 8am to about noon at 1-800-459-5687.
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Post by taswegian on Aug 21, 2005 4:34:35 GMT -7
Miles, I run a Route 66 with Genelex kt66's (clear bottle brown base) a GEC EF86 and a Mullard steel based Gz34 (1954). However, the phase inverter is still stock. I wanted to NOS the amp up for my latest album and maybe niavely I figured the PI was the "least" important to change. I also ran out of money. Is there any particular PI you recommend for the Route 66? I find your website extremely helpful too, thank you for all the great info.
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Post by telefunken on Aug 21, 2005 13:15:02 GMT -7
Hey JZguitar. I got a Mazerati 212 combo a while ago. It sounded pretty harsh, didn't have the sparkle and just didn't feel right. I was thinking of selling it, and then decided to try swaping a few tubes. I also have a Maz jr head. I switched the 5ar4's and couldn't believe the difference!. Tha Mazerati came with a very crappy sounding 5ar4. The amp sounds awsome now.
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Post by taswegian on Aug 22, 2005 16:38:35 GMT -7
I think we may need to start a "Ask Miles" thread on the general board. Poor guy is getting bombarded from every direction!
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Post by jzguitar on Aug 22, 2005 18:49:03 GMT -7
Hey telefunken!
Cool - I just won a Mullard 5AR4 on eBay (I know - but the seller had great feedback and seemed ok), so I can't wait to pop it in my Mazerati. There seems to be some varying opinions on the effect of rectifier tubes on the tone of an amp - so I'm curious to take a listen. My main concern is reliability. I've already had a JJ go bad after a few months (not a good feeling when your amp just dies!) Take care.
jz
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Post by myles on Aug 25, 2005 20:29:46 GMT -7
Miles, I run a Route 66 with Genelex kt66's (clear bottle brown base) a GEC EF86 and a Mullard steel based Gz34 (1954). However, the phase inverter is still stock. I wanted to NOS the amp up for my latest album and maybe niavely I figured the PI was the "least" important to change. I also ran out of money. Is there any particular PI you recommend for the Route 66? I find your website extremely helpful too, thank you for all the great info. I prefer the longer plate tubes for PI use. They have a different overload character and how the PI breaks down is actually much, if not most of what is passed on and amplified by the output tubes. Short plates such as the Sovtek 12AX7WA, WB, WC, the 12AX7C, the 12AX7EH and JJ ECC83S don't curve trace under load as many of the longer plate tubes. I prefer tubes such as the Sovtek 12AX7LPS, 12AX7M, and even an Ei long plate if you can find one with decent current output on a tester. Many of the NOS medium and medium long plate tubes are great. One guy that has lots of these generally at new tube costs in a lot of cases is Mike at www.kcanostubes.com
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Post by myles on Aug 25, 2005 20:33:26 GMT -7
Hey telefunken! Cool - I just won a Mullard 5AR4 on eBay (I know - but the seller had great feedback and seemed ok), so I can't wait to pop it in my Mazerati. There seems to be some varying opinions on the effect of rectifier tubes on the tone of an amp - so I'm curious to take a listen. My main concern is reliability. I've already had a JJ go bad after a few months (not a good feeling when your amp just dies!) Take care. jz Jz.... If you ever sell the amp pull the rectifier first. It will improve any amp and will still work to pass on to your grandkids. There are really no current GZ23/5AR4's that exceed book spec for voltage and current output. The Mullard does this consistantly. If it works at all it will be great. Other NOS GZ34 rectifiers were also quite a cut above any new production unit. Considering they generally do not really wear out or weaken as output tubes a few bucks more can be a great investment in tone (as you will have higher plate voltage) and reliability.
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Post by jzguitar on Aug 25, 2005 22:01:07 GMT -7
Thanks for the info Myles! I put the Mullard rectifier in tonight and it seems fine, so I'm really looking forward to cranking it at my gig Friday! I also posted about finding an old Mullard 12AX7 in a reel-to-reel recorder. I tried it out tonight and it sounds great. It was made in '56 so I guess it's fairly old. I think I'll save that one for studio work. Thanks again for all your help on this board! Take care,
jz
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Post by myles on Aug 31, 2005 10:45:05 GMT -7
Thanks for the info Myles! I put the Mullard rectifier in tonight and it seems fine, so I'm really looking forward to cranking it at my gig Friday! I also posted about finding an old Mullard 12AX7 in a reel-to-reel recorder. I tried it out tonight and it sounds great. It was made in '56 so I guess it's fairly old. I think I'll save that one for studio work. Thanks again for all your help on this board! Take care, jz jz - happy playing. By the way .... if you get out to Los Angeles I will be happy to give you a few things to try in your amp. New set of output tubes too.
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Post by guitarman1 on Aug 31, 2005 11:51:13 GMT -7
I recently came across a Valvo GZ34. I'm not familiar with this company. Anybody know anything about Valvo tubes? I'm going to try it out in my MAZ Sr.
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Post by myles on Sept 1, 2005 11:28:29 GMT -7
It is a great rectifier .... better than current production. Valvo generally rebranded tubes as did companies such as National. Sometimes everybody helped everybody when Phillips owned Mullard and made tubes that were even sold by GE as an example in some types.
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