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Post by slowburner on Sept 21, 2008 4:32:07 GMT -7
Hi folks
Recently saw the light and became a Z Head.
Gone and broke the bank ( maybe the world credit crunch is all my fault) these are not cheap in the UK, but I'm now the very proud owner of a Ghia with Z 2x10.
Having gigged it a few times I realize that I need an Airbrake.
I have been told that not only will the Airbrake reduce the tube life but also that of the output transformer.
Your comments please.
Slowburner
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Post by benttop (Steve) on Sept 21, 2008 9:56:25 GMT -7
Balderdash. I've had a Z Stingray for about two years (or ever since they came out, whichever is right) and used the Airbrake continuously while gigging and while recording. Nothing but good tones for the effort. These amps are Cathode biased, and as such run pretty doggone hot. Even when you aren't playing the tubes are wearing out. In fact they are wearing out less when you ARE playing, or so I've seen it said here on the forum several times. You don't have anything to worry about with an Airbrake, but you no doubt will hear this again and again from unschooled individuals. The way I like to put it is this: If you run your amplifier wide open, the only thing different about using an Airbrake is that you are not wearing out your hearing!
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Post by stuey222 on Sept 21, 2008 10:06:16 GMT -7
On other amps, it wears out the tubes and output transformers. With the Cathode bias (I think there may be one or two of Doc's creations that aren't) they're running hot all the time, which means you need good tubes or you'll be losing them like crazy. I've already had that problem with EF86s and I'm finally breaking down and getting a NOS. Doc's output transformers are massive, and I can't think of anything that would ruin them short of a bath or a 30 foot fall.
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Post by slowburner on Sept 22, 2008 6:50:03 GMT -7
Thanks for the reply guys.
I expect to replace output tubes whether using the Airbrake or not, was just a little concerned when I was told about the output transformer.
Thanks for putting my mind at rest.
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Post by nori22 on Sept 22, 2008 7:31:36 GMT -7
welcome. The Ghia loves the airbrake.
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Post by benttop (Steve) on Sept 22, 2008 8:43:06 GMT -7
On other amps, it wears out the tubes and output transformers. I think even this is debatable. It depends entirely on every specific situation. Take a guy playing say a Marshall 50 watt head wide open to get the tone he likes, but it's way too loud. But he still plays it wide open because of the tone. Now put an Airbrake in the signal path. He's still running it wide open, but not as much signal gets to the speakers. I don't think the amp is running any harder than it was, but his ears are sure getting a break. There's also the impedance change that the Airbrake introduces to the system. I've never seen Dr. Z publish anything on this, but I've seen some analysis in other quarters that suggest the load impedance goes up quite a bit. That would be considerably easier on the output tranny, although it would take a ton of analysis to make 100% accurate statements about it. In the end, experience with attenuators is my strong suit. I've been using an attenuator almost continuously since about 2002 when I got my THD Flexi-50. I gigged that Class A/B amp with a THD Hot Plate for three straight years (about 65 shows a year) and I've still got the original tubes in that amp (and they sound great). And I've gigged my SRZ-65 probably a dozen times with the Airbrake with no apparent problems, and had the same experience with my 6545 while I had it. The Stingray and RXES have both had the Airbrake on them every gig too, as has the Mazerati GT. I just find the Aibrake to be a product I can rely on and is safe for my equipment.
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Post by anacephalic on Sept 22, 2008 11:03:12 GMT -7
i've been using an airbrake with my Rx since they came out with no problems. I replaced power tubes once and that was more to preserve some life in an nice NOS set i had than real need.
That said lately i've taken more to running the amp volume about noonish plus or minus an hour and rolling the guitar volume waaaay back to about 2-3 without the airbrake. the dynamics are outstanding like that, the tone is a little more open and the volume isn't too out of control.
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Post by myles on Sept 23, 2008 8:03:47 GMT -7
The use of any "properly designed" attenuator will not have any adverse side effects. Tube wear will be faster but not because of the attenuator but because the attenuator lets the user crank up to higher levels. If you run a 100 watt at "2" the tube life will be longer than running it at "9" and if the attenuator lets you run at "9" then the tube wear will be faster.
In the past there were many poor designs that had issues but most of the problem was in the amp. A 50 watt Marshall could put out 70+ watts with ease and some 100 wattters could git 150 watts. Their output transformers were sized for their rated output .... 50 / 100 watts. Using an attenuator that lets the use crank a 50 watt to 70+ watts long term was just a problem waiting to happen.
There are some amps from back then and some today with marginal output transformers and even today Marshall has warnings against using attenuators on many of their amps.
Z amps have very stout transformers ... properly designed far beyond the rated wattage of the amp. As a side note, Fender had very few output transformer issues in the sixties when Marshall had issues that were more commonplace back in that era.
You will have no problems at all with an Airbrake and your Carmen Ghia .... happy playing.
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Post by benttop (Steve) on Sept 23, 2008 8:14:17 GMT -7
Well said Myles. I'm going to steal your answer for every time this comes up from now on.
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Post by slowburner on Sept 23, 2008 11:22:46 GMT -7
Thanks for sharing the benefit of your knowledge and wisdom. I'm gonna get one, i've made an offer in the buy,sell,trade section but to date have not had a reply.
I tied one out at the rehersal studio we use so i know how they sound. It will happen.
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Post by myles on Sept 23, 2008 12:12:53 GMT -7
Well said Myles. I'm going to steal your answer for every time this comes up from now on. Feel free to steal anything anytime.
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Post by detuned on Sept 25, 2008 9:05:44 GMT -7
I love that the Doc built an Airbrake into the Mini Z head. Sometimes I wish he'd think about that for some of the other amps too... But the Master knob on my Maz works so well, why mess with success?
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