Billy Zoom's Jet Set

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For the record: I used to work for Fender. I traveled the world as a product specialist. I spent 3 years playing guitar in the Fender booth at NAMM. I LOVE Fender, no one loves Fender more than I do. Bill Schultz was a friend of mine. I just expect more. They of all companies should know better.


that clears a lot of stuff up billydlight. thanks for explaining the whole CBS thing.


Back in the 60s the two biggest names in drums were Ludwig and Rogers with Gretsch probably a distant third. CBS bought Rogers and ran them into the ground. If there had been another company with a good full line of amps top to bottom we probably wouldn't have Fender today. In the early 70s, it was probably the amp line more than guitars that saved them. That's back when guitar store and pawn shops had cordwood sales with Fender guitars.


I always appreciate the insight BZ can provide on subject so clouded in mystery. I never quite know what tubes to buy.

I've had good luck with the old Winged C 6L6, the General Rohren EL84, and the Tung Sol 12AX7.


Most old 12X7 tubes were designed and manufactured with tight tolerances so "balance" of a single tube was really never an issue.

This has not always been the case with modern tubes although they have got better.

I really don't think that it's worth paying more to get a 12AX7 tube that's been checked for balanced output if it's a good quality modern one such as the Russian Tung Sol "replicas" but you may think otherwise.

Personally, I'd rather spend that cash on a solid NOS tube!


Ellengtrgrl: danrhh said: CBS did to Fender what FME did to Harley Davidson. Actually, it was AMF that owned Harley.

I can't believe I said that. I had FME on the brain that day. I am a printing coordinator. FME sells printing equipment. Believe it or not I actually Have an HD and have had different ones since the 70's. Shamefull. Thanks for the correction.


I assume you all realize that a modern Tung Sol is just a Sovtek with the Tung Sol name on it. There's no effort to copy the old tube designs...they just own the names - Tung Sol, Mullard, etc.
Sovtek has a 12AX7 called a Mullard because they own that name, but Groove Tubes actually owned the original Mullard tooling, but couldn't use the Mullard name. Expecting a modern Tung Sol to sound or work like a real one is like expecing a Fender reissue amp to be made like the original.


BillyZoom - I'd like to ask you a question about the Phase Inverter tube in a MusicMan 130W amp.

Last weekend I had my MM out in the sunshine, looked in the back and noticed a small diagram glued onto the inside which showed it had a 5th valve, which I didn't know even existed after 35 years of ownership!!! It's kind of hidden inside an outer alum cover. Mojave said that there's probably no need to replace it anyway, and he may be right as it's gone for 35 years, but I've got a feeling the amp has lost some tone.

Last night I read on the net that MusicMan changed the design of their amps after 2 years because in some cases there was a failure between the pre-amp and the PI tube which resulted in a major melt down of the power amp. They took out the PI tube and went solid state.

Should I replace the PI tube and can if affect the tone of the amp? I wouldn't like to blow up the power amp by overlooking the replacement of the PI tube if that was the problem which brought about the change by MM. I usually use the amp on low power, 8-10 pre-amp volume and 3 power amp volume.


I don't think many users of this page doubt that there are differences between the original Tung-Sol tubes and the Russian "re-issues." However, CITA won't go wrong with one of the new tubes in his Music Man as the PI.

Now, can the PI tube change the tone of the amp? Yes, primarily due to the way that it's output drives the power tubes. It is, however, a minor difference by comparison with other tube changes.

Lastly, Music Man did change to a solid state PI around 1979. The way the amp was designed, with its' solid state pre-amp, could cause serious power amp issues although I personally have never witnessed the "melt down" scenario. If this is the reason for changing that tube then get a good solid new tube like the Tung-Sol or JJ. If you want a GOOD NOS tube that will do the job without being riduculously expensive then try something like a JAN Philips 12AX7WA.


Early MM amps had a 12AX7. The first half was for bad overdrive, the second half was a Cathodyne phase splitter. That's also the model that runs around 700 volts on the plates. DON'T use JJ's or anything else cheap. Try to find some nos 6CA7's. They can handle the voltage. If you HAVE to use a Russian tube, keep the amp on low power...that works on lower plate voltage.
And...You should expect a new Tung Sol to differ from an original in the same ways that you'd expect a new Sovtek or Electro-Harmonix to differ from an original Tung Sol. You SHOULDN'T expect a new Tung Sol to be more like an original than you would expect a new Sovtek to be like an original Tung Sol. They only bought the names...not the tooling or the designs. This doesn't work like guitars, where they try to copy the original. They just bought the names and the logos. BZ


Billy...the way we're going CITA is going to be more confused than he was when this thread started!


1) Use a good NOS 12AX7 for the phase splitter if you really want to be safe and get good output but get it from a quality supplier like KCA NOS Tubes.

2) Replace your power tubes ONLY with NOS 6CA7 models. The original tubes were made by Sylvania.

3) If you don't want to spend that much money, get the best new tubes you can and keep the power down. Since that amp is so damned loud that shouldn't be a problem!


Thank you BillyZ and Mojave. You haven't confused me too much, well a bit with the acronym NOS. I would have thought that modern tubes would use better technology than the older tubes and would therefore be a better choice?

I live in Australia and in the end, as always, it will come down to what I can source on the local market. Thanks again.


Manufacturing technology appears to have gone backwards since the 1950's. We can't make a vacuum tube at an acceptable price in a Western, first world style economy. Oddly, we could make them fifty years ago, when most families relied on a SINGLE wage earner. Now working couples are the norm, as the earnings of a single worker won't cover household expenses. Is there something amiss with this equation?

One wonders if our problems aren't deeper than a simple lack of decent vacuum tubes.


"We can't make a vacuum tube at an acceptable price in a Western, first world style economy."

Viper, how right you are, such are the economies of mass production. In my street there are 35 homes. Fifty years ago every one of them would have had a radio set and a tv, each one stuffed with valves (OK, tubes if you prefer) — not all the same valves as in a guitar amp, granted, but all the products of valve manufacturing production lines nontheless. Repeat that all over the country and that's a hell of a lot of valves — therefore an industry thrived.

That had all just faded away by the 70s — our homes were transistorised, whether we liked it or not. The guitar valve amp market (now, just as then) is pretty small in the overall manufacturing scheme of things — no matter how important we might like to think it it — so the stuff has to be made in appropriately 'small' quantities in places where manufacturing costs (presumably including labour costs) are much lower.

I don't have any update on valve manufacturing restarting/continuing at the former Mullard plant in Blackburn Lancashire (with its four thousands holes!). Nice to think we could buy UK-made 12AX7 and EL34 valves again.

Edit: there are numerous books out there on the history of Fender amps. I found this one worth reading, primarily for its account of what happens to a small company that gets successful and is then bought by a huge organisation. It's even funny in places:


Oz! I should have guessed.

NOS is simply old stock that hasn't been used. (New Old Stock)

Most of us expected vacuum tube technology to have been long gone by now but it seems that in some aspects it just gets better results than transistor technology.

So, as the older production plants were phased out in favor of the new technology, only the eastern block factories remained. Their quality control was never that good so the "NOS tubes are now sought after by "purists."

However, quality of production in Russia, China and the Slovak Republic has improved so don't be afraid to try tubes friom there.


But surely a new, high tech, modern tube should sound better than something from 50 years ago, or am I too drug damaged to tell the diff?

Yea Mojave, Oz, here's a story for you, I took an amp into a repair shop, it turned out to be a tube. When I got it back, they'd soldered a transistor on the base plate where the valve used to be and thought they'd done me a great favour as it was now transistorized! No more pesky tubes to deal with!


This thing has got 1500 tubes — and some of them are the originals, 60-plus years old but still working. The secret is no secret — like lightbulbs, they'll last indefinitely if you don't keep switching them on and off. I appreciate this isn't exactly practical with guitar amps!

On this link, scroll down to item four, the Colossus. You'd have great fun fixing this, Proteus:


Hey billydlight - sorry, wasn't picking you out specifically, just commenting on the general drift of the conversation. And you aren't the only current or ex-Fender employee that thinks Fender can do more - and a few of them are still there trying. Just sometimes what seems like a good business decision turns into a mess. And the current economy is very unforgiving for even good decisions. Let's hope things get better for everyone. Cheers.


Joel...Me and you's....friends for life man! I don't know how stupid Americans can really be. Nothing is made in the USA anymore. No wonder we have no jobs and no economy. To me the China thing is a huge joke and the joke's on us, or should I say the US.


We'll just make milkshakes for each other, shine each other's shoes, and keep passing our last remaining five dollar bill to the right.

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