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Post by nixpix on Feb 25, 2011 16:29:55 GMT -7
It's time for a retube for my Ghia and I'd like to hear what you all suggest. I've had it for about 4 years and I replaced the power tubes a year ago. Now I want to do a full swap of all the tubes. I'm leaning toward the stock tube choices as the replacements - JJ EL84 & ECC83 and NOS 5751. Any other suggestions?
One other question I have is this: Is it necessary to change the rectifier tube as well when doing a tube replacement such as this? If so what do you suggest?
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Post by helmi on Feb 25, 2011 17:55:22 GMT -7
no, it's not necessary. usually a rectifier tube is going to work or it's not. if it's the stock recto from the doc, i believe it is already a NOS 5y3 tube. personally, i love mazda nos rectifier tubes. (expensive, and hard to find) for your other tubes, buy a couple 12ax7's, nos 5751's, and a 12bh7 for v2, and have fun and experiment. good luck
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Post by zdogma on Feb 25, 2011 17:56:45 GMT -7
I wouldn't replace the rectifier unless its rattling. They do that fairly often. NOS 5Y3's are still relatively plentiful and cheap.
I like long plate NOS telefunkens or seimens in V1, but the jj is quite good.
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Post by nixpix on Feb 26, 2011 11:28:57 GMT -7
I thought the same about the rectifier tube - either it works or not kinda thing. I'll buy some extra preamp tubes to swap out and experiment with. Thanks for your help!
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Post by myles on Mar 2, 2011 17:03:31 GMT -7
It is all personal taste and preference.
In my own Ghia I use ....
V1 - Telefunken long smooth plate. The Carmen Ghia is the only amp that makes me like the Telefunken. It is normally a tube too bright for my taste. If you can find an old Ei long smooth plate that does not rattle and tests properly that works just as nicely.
V2 - RCA command series 5751
Output tubes - JJ EL84S that spec at 48mA at 250 plate volts and -7.3 volt bias.
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Post by myles on Mar 2, 2011 17:05:28 GMT -7
It's time for a retube for my Ghia and I'd like to hear what you all suggest. I've had it for about 4 years and I replaced the power tubes a year ago. Now I want to do a full swap of all the tubes. I'm leaning toward the stock tube choices as the replacements - JJ EL84 & ECC83 and NOS 5751. Any other suggestions? One other question I have is this: Is it necessary to change the rectifier tube as well when doing a tube replacement such as this? If so what do you suggest? Side note ... In Brad Paisley's amps the output tubes in the EL84 amps are replaced every 10 shows, about every 30 hours. You can hear and feel the difference. You do NOT need to change preamp tubes unless they are giving you some sort of problem or if you want to change the tone. They take a long time to wear out. Good NOS preamp tubes will last decades.
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Post by nixpix on Mar 3, 2011 8:46:43 GMT -7
Awesome! I didn't realize preamp tubes last so long. And I've put way more than 30 hrs on this current set of EL84's. I thought I was going crazy when they started sounding sub par a few months ago. Thanks, Myles, for your always informative information!
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Post by myles on Mar 3, 2011 11:49:31 GMT -7
Awesome! I didn't realize preamp tubes last so long. And I've put way more than 30 hrs on this current set of EL84's. I thought I was going crazy when they started sounding sub par a few months ago. Thanks, Myles, for your always informative information! You are very welcome
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Post by nisaacs7 on May 12, 2015 10:29:37 GMT -7
I would like to resurrect this forum to talk more about the tube changes in the Ghia. I currently have 12ax7's in V1 and V2 from the previous owner. I have changed the tubes but kept the same specs as I loved the tone I was getting. Now I have a brake lite and want to run my amp a little hotter than before and on the edge of breakup. What I'm wondering is how would I benefit from changing V2 to a 5751? I know about gain values and understand it should give me a bit more clean headroom, but I want to understand how the tone will change if it changes at all.
I've also read about people using a 12AU7, 12BH7, and 12AT7 in the V2 position. Besides giving more headroom, how would that change the tone? Also, would that widen the adjustments for breaking up? Right now I'm getting breakup around 10 o'clock, but from there it is not a very gradual increase in gain. From 10-10:30/11 it's pretty drastic of a gain change.
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Post by Mark (Basement Enthusiast) on May 12, 2015 11:04:58 GMT -7
My 2014-model Ghia came stock with 12AX7's in V1 & V2. I switched V1 to NOS 12AX7 (can't recall which) and V2 to NOS 5751. To my ears, the amp felt less congested and the breakup was a tad more relaxed. Maybe a 5-10% drop in perceived gain/grit (which I'm attributing to the 5751 in V2.) YMMV, though.
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Post by nisaacs7 on May 12, 2015 11:22:03 GMT -7
I believe mine was made in 2006 if that makes a difference.
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Post by myles on Jun 7, 2015 17:00:14 GMT -7
I would like to resurrect this forum to talk more about the tube changes in the Ghia. I currently have 12ax7's in V1 and V2 from the previous owner. I have changed the tubes but kept the same specs as I loved the tone I was getting. Now I have a brake lite and want to run my amp a little hotter than before and on the edge of breakup. What I'm wondering is how would I benefit from changing V2 to a 5751? I know about gain values and understand it should give me a bit more clean headroom, but I want to understand how the tone will change if it changes at all. I've also read about people using a 12AU7, 12BH7, and 12AT7 in the V2 position. Besides giving more headroom, how would that change the tone? Also, would that widen the adjustments for breaking up? Right now I'm getting breakup around 10 o'clock, but from there it is not a very gradual increase in gain. From 10-10:30/11 it's pretty drastic of a gain change. The Carmen Ghia is one of the few amps made where the phase inverter is grid biased rather than cathode biased as are most preamp tubes. The original design in the first series of amps calls for a 5751 which is different than a 12AX7. I prefer the 5751 but that is just me. A 12AT7 will run hotter and to me sounds harsh. A 12BH7 to me is really nice and fun. In the end, they all will safely work, it's just V2 is not "self biasing" as are cathode biased tubes. That is also one reason why the PI in the CG will last forever as a side benefit. In the end I prefer the 5751 for some things and a 12BH7 for some things, but that is just my preference.
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