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Tubey Goodness
- Thread starter Kronde
- Start date
phishaholik said:
phishaholik,
I think you ended up with my old D-180 (I owned it for years). It's easy to tell. I installed a green power light in the front panel from the original blue one. It was built in 1986
But agreed, the Mesa D-180 is a very loud and powerful amp, and for the going prices it's the best deal. In college and such, I used to be able to use it at loud outdoor heavy-rock gigs pushing two 2x15 cabs and with no PA support...that's how great it is!
cheezewiz said:
It doesn't take much. All you have to do is have some idea what you're talking about and disagree with him.
luckily he's still nothing more than an irritant, the worst damage he can do is indirect... as in someone spends money based on his input...
SM
seamonkey said:
On this I have to agree. If you overcap a power supply too much, the inrush current when powering on can easily exceed the rating of the rectifiers (solid state in this case - since tube rectifiers come up to power slowly as they warm up, they tend to self limit) and can cause rectifier diode failures. As long as the output power is clean from the PS, there really is very little merit in increasing power supply capacitance, and in many cases (such as this), too much of a supposed "good thing" can actually become a problem.
This is one of the reasons that large SS power amps (PA amps typically) run a thermistor or other inrush limiter in the front end. Not only does it minimize the chance of having breakers blow due to power on surge, it makes life a lot easier on the power supplies.
- Tim
Upping the capacitance in a bass tube amp from the 70's realistically isn't going to cause diode rectifier failure. That would require an excess amount of capacitance AND voltage which would also destabilize the output section and send it into oscillation. What Shrimp-boy is describing is a slight increase in power supply damping and certainly nowhere near enough to blow a rectifier diode. He also still has yet to explain how this is supposedly going to damage a power transformer.
tadawson said:
Great - thanks for the clarification.
Let me ask you a question. I've read that bass cabinets some 30+ years ago were not designed to go very low, maybe 90hz. So in general would somebody picking up an old amp, and trying it with a new cabinet find that the bass may not be as stiff as the cabinet the amp was designed for? Maybe this is what encourages people to up the power supply capacitance?
Plain Old Me said:
My Mesa Bass 400 is from 1982, and it works great.
...oh yeah, someone said they also came with 6L6's instead of 6550's sometimes; you're right. Mine came from GC with 6L6's when I purchased it last year..
I called Mesa, and they said the correct range 6550 would work fine...and they were right -kudos to them for suggesting a tube they don't carry..
LOL!
I'm not about to let Shrimp-boy's garbage go unchallenged. He can play cute and ignore my posts all he likes, but as long as he keeps posting BS, I'm going to expose it.
Here's the latest installment, complete with highlights.
That's a common trick for him. When Shrimpy can't use actual facts, he makes up his own, and 'innocently' intones that he "read" or "heard" them somewhere. The fact of the matter is that 30+ years ago cabinets were designed to go just as low as they do now, but high powered drivers and amplifiers were not common. Amplifiers were NEVER designed to purposefully omit lows as this would compromise their operational stability.
Shrimpy can pretend he never read my refutations of his previous lies about power supply filtering, but the FACT of the matter is that Shrimpy is inventing a mythical 'historical' scenario in order to rationalize his disdain for tubes and vintage amps. The most important thing to remember is that things were NEVER as he says, and however he may try to split technical hairs to obscure that, vintage amps are and were not the engineering failures he claims they are.
And this statement is equally false, but it is also designed to 'innocently' support his PREVIOUS lie about power supplies in old amps. It's crap. Ignore it.
And yet again, another false statement designed to shore up his lie that all old tube amps have inadequate filtering, one his first lies in this thread: more crap.
Here's the latest installment, complete with highlights.
seamonkey said:
That's a common trick for him. When Shrimpy can't use actual facts, he makes up his own, and 'innocently' intones that he "read" or "heard" them somewhere. The fact of the matter is that 30+ years ago cabinets were designed to go just as low as they do now, but high powered drivers and amplifiers were not common. Amplifiers were NEVER designed to purposefully omit lows as this would compromise their operational stability.
Shrimpy can pretend he never read my refutations of his previous lies about power supply filtering, but the FACT of the matter is that Shrimpy is inventing a mythical 'historical' scenario in order to rationalize his disdain for tubes and vintage amps. The most important thing to remember is that things were NEVER as he says, and however he may try to split technical hairs to obscure that, vintage amps are and were not the engineering failures he claims they are.
And this statement is equally false, but it is also designed to 'innocently' support his PREVIOUS lie about power supplies in old amps. It's crap. Ignore it.
And yet again, another false statement designed to shore up his lie that all old tube amps have inadequate filtering, one his first lies in this thread: more crap.
FaithNoMan said:My Mesa Bass 400 is from 1982, and it works great.
Uhhh FaithNM, all Mesa Bass tube heads say "1982" on the back of them. You actually have to remove the bottom lid and written in black pen on one of the caps the the real date.
In 1982, only the early D-180 without the graphic eq was available, then in '84 the D-180 got the graphic eq section. The Bass400 made its debut in later '86.
The Buster was the ONLY Mesa tube bass head that I didn't like, so it's fair to say nobody should buy it without trying it. The D-180 can sound quite like the 400+, but with slightly less fulness. But it can also make any guitar amp tuck its power cord between its casters and scuttle on home. Truly one of the few amps that excels at both guitar and bass, no pedals needed.
4Mal said:
I must have missed this part the first time around.
"In need of a re-tube/recap"????
The V4, otherwise known in its original form as the V-Type, was only introduced in 1995. *None* of these amps should be anywhere near due for a recap, and in many cases, not even tube replacement. My V-Type is still on its original tubes and still sounds great.
Now, I don't play this amp for ten hours a day every day, but still...
And the one I sold was also on its original tubes and still sounded great when I sold it a couple of years ago. I can't vouch for what happened to it after that, but when I got it and its associated 1248H cabinet, they looked like they had seen some serious gigging action.
Yes, 650-700 is a more likely price for a V-Type head or V4 head in good working condition, but if you look around, there are deals to be had.
Psycho Bass Guy, quick question for you. Many modern capacitors utilize "self healing" materials and construction. Do you happen to know if the old style caps pre 1980's could do the same?
Most old can caps are wax paper wrapped inside the outer shell and once they get too hot, they begin degrading. I think the first "modern" electrolytics you'll see will be Elna and LCR's from the 80's. Mallory changed later IIRC.
Jeff A said:
I dunno . . . I can't recall my reference exactly, but I am an EE by degree, and definitely have seen a credible reference to power supplys that were designed for a certain filter capacitance having rectifier failures if the filter caps are later made too large. Not due to oscillation or anything long term like that, but rather due to the surge currents when the caps charge when the amp is first powered up. A diode can carry it's rated current forever, but powerup surge is many orders of magnitude higher than that, and diodes can only carry their surge rating for very short periods, and increased capacitance will cause both the duration and magnitude of the initial powerup surge to increase . . . If the diodes were not very overrated to start with, it CAN cause failures . . . .
Now, having said that, please recognize that this does NOT mean that I agree with a lot of the other meritless crap that has come from seamonkey . . . I am just agreeing on this ONE point . . . .
- Tim
These amp sound great with EV 15's. They really kick when you hook them up to two 15's.amper said:
