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Post by bigben55 on Mar 7, 2012 11:56:48 GMT -7
So whats a good NOS 5AR4 that won't destroy the budget?
I think I will stay with the 5751. Thats whats in it right now(a Sovtek), and I plan to use my FD2 for extra dirt, so I'd just assume keep the amp a little louder cleaner. Whats the best bang for the buck 5751, NOS or otherwise?
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Post by myles on Mar 7, 2012 12:02:16 GMT -7
Those are outstanding and even nicer. |
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Post by myles on Mar 7, 2012 12:03:16 GMT -7
So whats a good NOS 5AR4 that won't destroy the budget? I think I will stay with the 5751. Thats whats in it right now(a Sovtek), and I plan to use my FD2 for extra dirt, so I'd just assume keep the amp a little louder cleaner. Whats the best bang for the buck 5751, NOS or otherwise? Look at some of the links I provided. The Sovtek 5751 is NOT a 5751. |
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Post by bigben55 on Mar 7, 2012 13:11:13 GMT -7
What IS the Sovtek 5751 then?
What, if any, are the best 5AR4 rectifier tubes being made today? Don't think I can currently afford a NOS one, yet.
Look at some of the links I provided.
The Sovtek 5751 is NOT a 5751.
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Post by myles on Mar 7, 2012 17:00:04 GMT -7
What IS the Sovtek 5751 then? What, if any, are the best 5AR4 rectifier tubes being made today? Don't think I can currently afford a NOS one, yet. Look at some of the links I provided. The Sovtek 5751 is NOT a 5751. What I said in the piece is that current production tubes called 5751s are nothing more than sub standard and out of spec 12AX7s. Use your Sovtek rectifier but have a ss backup. I have a piece on the 5751 on my blog website as a side note. |
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Post by bigben55 on Mar 7, 2012 17:13:17 GMT -7
Ok, gotcha. I have a few 12AX7s and 12 AT7s lying around. Might experiment before buying a NOS 5751
Is there a ss rectifier that is plug and play without rebiasing? If not, I will just get another Sovtek until I can get me a NOS one.
Thank you Myles
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Post by myles on Mar 7, 2012 17:58:58 GMT -7
Ok, gotcha. I have a few 12AX7s and 12 AT7s lying around. Might experiment before buying a NOS 5751 Is there a ss rectifier that is plug and play without rebiasing? If not, I will just get another Sovtek until I can get me a NOS one. Thank you Myles As long as your amp is properly biased and under about 65% in the case of a Z-28 you can plug in a SS rectifier and not have to rebias. The plate voltage will not increase that much over the GZ34/5AR4. You might even prefer the feel of the SS unit. Some folks like it. Michael Burks uses SS plugins in many of his amps and he is a monster player with monster tone - www.michaelburks.comExperimenting is the name of the game. There is no right or wrong. If you take a cheap scrap tube, plug it in and love it then that is perfect-o and very cool. |
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Post by John on Mar 9, 2012 18:59:07 GMT -7
Myles, I just picked up a Ghia. My first tube amp without a standby switch.
When taking breaks at a gig, do you recommend turning the amp off, or unplugging the guitar? Or something different. (turning the volume to zero?) I remember you saying that a cathode biased amp is harder on the power tubes when nothing is being played. So I would think because of that, it would be better to turn the amp off during breaks.
What's best?
And also, what kind of phase inverter does this amp have?
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Post by myles on Mar 10, 2012 10:02:05 GMT -7
Myles, I just picked up a Ghia. My first tube amp without a standby switch. When taking breaks at a gig, do you recommend turning the amp off, or unplugging the guitar? Or something different. (turning the volume to zero?) I remember you saying that a cathode biased amp is harder on the power tubes when nothing is being played. So I would think because of that, it would be better to turn the amp off during breaks. What's best? And also, what kind of phase inverter does this amp have? If a break is going to be more than ten minutes or so turn off the amp. The amp with no guitar plugged in or the volume all the way down is still running at 100%. No standby switch is needed as the 5Y3 has a slow warm up. Think of it this way .... In the 40s, 50s, 60s there were millions of American cars that had radios that used tubes. I never saw a single one with a standby switch (and I am old enough to have turned on those radios thousands of times). My TV or home radio had no standby switch. Come to think of it, I never saw a McIntosh tube amp or tube preamp with a standby switch either. I think I have made some sort of point. Standby switches are more desirable with designs and rectifiers that can supply high voltage to the output tubes very quickly. Your amp may have a 5751 or may have a 12AX7. Look at V2 in the amp. If it is a new production 5751 get a proper NOS tube in there. If you tell me what is in V1 and V2 I will be happy to comment. Happy playing ... you have a great amp, one of the classics of all time. |
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Post by John on Mar 10, 2012 11:58:14 GMT -7
It's basically a brand new Ghia. New logo, so that means it's from last summer or more recent. I don't know why the guy sold it. He says he bought 2 of them new in January. Sold one to me. So I would assume it's got whatever the Doc put in there.
I remember you saying any modern production 5751 is really a 12ax7 that didn't meet the specs.
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Post by myles on Mar 10, 2012 16:45:04 GMT -7
It's basically a brand new Ghia. New logo, so that means it's from last summer or more recent. I don't know why the guy sold it. He says he bought 2 of them new in January. Sold one to me. So I would assume it's got whatever the Doc put in there. I remember you saying any modern production 5751 is really a 12ax7 that didn't meet the specs. Look and see what is really in there. Don't guess or assume. |
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Post by John on Mar 11, 2012 8:38:21 GMT -7
It arrives tomorrow, I'll take a look.
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Post by John on Mar 12, 2012 11:55:10 GMT -7
Myles, my Ghia just arrived. V1 is a JJ labeled: "ECC83S" V2 is a 12ax7a...here it is:  It reads: 12 ax7a USA That's it. No other identification. USA? Could this be a NOS? Power tubes are JJ's. |
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Post by myles on Mar 12, 2012 13:16:29 GMT -7
The photo is too fuzzy to see what the tube is.
The ECC83S is probably a JJ. They have too much of a mid bump for my taste. I'd use a medium plate NOS tube or if you can find a nice smooth plate Ei that is not microphonic those are amazing in a Ghia.
For V2 get a real NOS 5751.
If that V2 tube in the blurry photo is an NOS USA tube which it might be, either send a better shot or have somebody look at the tube, it could make a cool V1.
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Post by mickey on Mar 12, 2012 14:17:15 GMT -7
Hi, last September I bought a spare NOS GE 5Y3GT for my Ghia, same as what's already in there. I noticed at the time that the top "disc"....(don't know what it's called but it has two sets of serrations on opposite sides, it's in a plane parallel to the base and I guess it holds the plates in place)....is bent down on one side, between the plates and the glass, and I guess it shouldn't be. The tube works fine, as far as I can tell. Is this an issue or purely cosmetic? The (eBay) seller, Elderly Electronics, seems OK, lots of positive feedback, and he's still trading. Thanks.
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Post by myles on Mar 12, 2012 17:58:02 GMT -7
Hi, last September I bought a spare NOS GE 5Y3GT for my Ghia, same as what's already in there. I noticed at the time that the top "disc"....(don't know what it's called but it has two sets of serrations on opposite sides, it's in a plane parallel to the base and I guess it holds the plates in place)....is bent down on one side, between the plates and the glass, and I guess it shouldn't be. The tube works fine, as far as I can tell. Is this an issue or purely cosmetic? The (eBay) seller, Elderly Electronics, seems OK, lots of positive feedback, and he's still trading. Thanks. Purely cosmetic. No worries. |
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Post by mickey on Mar 13, 2012 0:49:58 GMT -7
Excellent, thanks Myles!
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Post by thatstatuemoved on Mar 13, 2012 6:41:53 GMT -7
Hello--I would like to know the current brand of El-84 tubes you would recommend--I have always used JJ's and really like them but they seem to be having some issues. Please advise as I am in need of new ones for my ray--I like good strong cleans, punchy and a chimey sound--thanks  |
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Post by myles on Mar 13, 2012 16:54:22 GMT -7
Hello--I would like to know the current brand of El-84 tubes you would recommend--I have always used JJ's and really like them but they seem to be having some issues. Please advise as I am in need of new ones for my ray--I like good strong cleans, punchy and a chimey sound--thanks I continue to use the JJs but am testing other brands. After I do my bench tests I will send sets out with some folks so they can report back their own sonic and tone thoughts. When tests are done I will publish the link here to the test results. |
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Post by randalp3000 on Mar 13, 2012 17:20:48 GMT -7
Very much look forward to those results.
thanks Myles
rp
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Post by myles on Mar 13, 2012 17:42:00 GMT -7
You are quite welcome
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Post by John on Mar 14, 2012 8:56:22 GMT -7
From a few posts ago:
That PI tube in my Ghia....I emailed Brent. He said it's a mislabeled tube. It says USA 12ax7...but in fact is a NOS 5751. Nice! Took the JJ out of V1 like you suggested, I have Svetlana 12ax7 I popped in there.
But I also have a Sovetek 12ax7 LPS. Would that be better or worse than the Svetlana?
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Post by boptometrist(david) on Mar 14, 2012 9:45:17 GMT -7
Myles,
I have an NOS Mullard EF86 tube. On the box is a sticker that reads "5.0/2.9". Assuming it is a test result, what is the test that would produce those numbers?
Thanks as always for sharing you knowledge and expertise.
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Post by mickey on Mar 14, 2012 15:18:38 GMT -7
Yet another Ghia V1 question....I just replaced the JJ ECC83S in V1 with a NOS Jan Phillips 12AX7WA. To be honest it didn't do much for me, and I put the JJ back in. Am I missing something here, or is the Jan Phillips really nothing special? I suppose the main difference I noticed was that it had a bit less gain than the JJ. I tried hard to hear a tonal advantage, but it certainly wasn't obvious.
Thanks!
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Post by myles on Mar 14, 2012 16:52:46 GMT -7
From a few posts ago: That PI tube in my Ghia....I emailed Brent. He said it's a mislabeled tube. It says USA 12ax7...but in fact is a NOS 5751. Nice! Took the JJ out of V1 like you suggested, I have Svetlana 12ax7 I popped in there. But I also have a Sovetek 12ax7 LPS. Would that be better or worse than the Svetlana? One will be better than the other. Which one will depend on your ears It is a matter of personal preference. As a side note, many times the stronger tube will be preferred in most cases if it is closer to design spec so keep that in mind and try to listen for things like definition and balance. |
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Post by myles on Mar 14, 2012 17:01:45 GMT -7
Myles, I have an NOS Mullard EF86 tube. On the box is a sticker that reads "5.0/2.9". Assuming it is a test result, what is the test that would produce those numbers? Thanks as always for sharing you knowledge and expertise. Numbers can me manipulated pretty easily by changing the plate or bias voltage from standard. Standard expectations when measured at standard test voltages for the EF86: 250 plate volts 140 screen volts -2.0 volt bias would be 3.0mA of plate current 1800-1850 transconductance 2.5 Meg Ohms plate resistance Actual gain 38 Those numbers are not close to design spec parameters other than the 2.9 which may be plate current. I would ask the supplier what his numbers mean and ask what machine they used to test the tubes and what are the plate, screen and bias voltages. Here is a link to one of the EF86 datasheets - www.guitaramplifierblueprinting.com/files/PhilipsEF86.pdf |
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Post by myles on Mar 14, 2012 17:06:20 GMT -7
Yet another Ghia V1 question....I just replaced the JJ ECC83S in V1 with a NOS Jan Phillips 12AX7WA. To be honest it didn't do much for me, and I put the JJ back in. Am I missing something here, or is the Jan Phillips really nothing special? I suppose the main difference I noticed was that it had a bit less gain than the JJ. I tried hard to hear a tonal advantage, but it certainly wasn't obvious. Thanks! You are not missing anything at all ;D Tube preference is just that, a matter of personal taste and preference. This is no right or wrong, better or worse. If you prefer the short plate JJ ECC83S then it is a great choice for you. It has a strong midrange which indicates to me that there is a possibility that you are more of a hard rocker than a traditional blues player, but I might be off base here, just a general sort of guideline that seems to apply to folks that like a bump in the mids and a fast rise time, quick response and earlier compression. Bottom line ... happy playing! |
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Post by mickey on Mar 15, 2012 0:57:55 GMT -7
Yet another Ghia V1 question....I just replaced the JJ ECC83S in V1 with a NOS Jan Phillips 12AX7WA. To be honest it didn't do much for me, and I put the JJ back in. Am I missing something here, or is the Jan Phillips really nothing special? I suppose the main difference I noticed was that it had a bit less gain than the JJ. I tried hard to hear a tonal advantage, but it certainly wasn't obvious. Thanks! You are not missing anything at all ;D Tube preference is just that, a matter of personal taste and preference. This is no right or wrong, better or worse. If you prefer the short plate JJ ECC83S then it is a great choice for you. It has a strong midrange which indicates to me that there is a possibility that you are more of a hard rocker than a traditional blues player, but I might be off base here, just a general sort of guideline that seems to apply to folks that like a bump in the mids and a fast rise time, quick response and earlier compression. Bottom line ... happy playing! Thanks, as always, for your reply. Interesting, maybe what I heard as less gain was actually less mids with the Jan Phillips. Is there generally a correlation between plate length and mids? I'd be interested to know your take on that tube, compared to the choices out there? I put it back in my Ghia today, and what I'm hearing now is that it's smoother, maybe not as grainy as the JJ, not as flappy on the low notes with the volume at about 2 o' clock. Actually I've been running a blues rock trio for the last twenty years, I'm not what I would call a hard rocker  Also, I don't generally mess with different tubes too much, prefering to use what was in the amp originally. I just thought I'd try this one. In any case, usually during the few seconds it takes to change a tube over, I've forgotten what the first one sounded like |
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Post by myles on Mar 15, 2012 8:50:06 GMT -7
Hearing less gain and mids is accurate. The JJECC83S had a mid bump and at one time they were the highest actual gain tubes on the market. It is the tube I used to use when I built the GT MHG kits for V1 and V2. In one of my blog posts I believe I talk about that subject in a bit of detail. Tubes are personal preference. In my own Carmen Ghia I use a Telefunken smooth plate in V1. I generally find Telefunken's too bright for my taste in most amps but the tone filter network in the Ghia is outstanding with the Telefunken. In V2 I currently have either a GE 5 star 5751 or and RCA Command Series 5751. Each of those came from Mike at www.kcanostubes.com. My output tubes are 48mA JJ EL84S tubes. I typically run my volume at 10 o'clock and tone at 2 o'clock or so. |
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Post by mickey on Mar 15, 2012 9:33:33 GMT -7
Very interesting, and thanks for including your settings and tube preferences. I still have the NOS 5751 which the amp came with in V2, and JJ EL84's rating 6. I'm going to stick with the Jan Phillips in V1 for a while as it does actually sound a bit sweeter, but I might look into the Telefunken, though it seems to be more difficult to source in the UK. Thanks again for your valuable insight!
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Also, I don't generally mess with different tubes too much, prefering to use what was in the amp originally. I just thought I'd try this one. In any case, usually during the few seconds it takes to change a tube over, I've forgotten what the first one sounded like 
