Mark Levinson No 334 Repair Manual
I've heard it said that older amps, such as Levinson ML-2s and such, generally benefit by a comprehensive capacitor replacement after they've been used for a while. I have a pair of Levinson 334's that seem to sound fine, but I get concerned by all the talk on various forums that these amps are 'headed for a re-cap'. I found a service that can recap my amps, but at a cost of over $1k each. Have there been issues with capacitors 'wearing out' on audio amplifiers or is this all hype? How could i tell if my amps need a new set of capacitors, and what's the right way to do this repair?
Mark Levinson No 334 Reviews
For customer service and product. Terms in This Manual These terms may appear in this manual. Mark Levinson® tradition of home theater excellence. Mark Levinson No-334. Below you will find the Mark Levinson No 334. The owners manual is used as an reference guide, instruction manual and instruction. I have never listened to a Mark Levinson amp, but am curious as to what sound. 334 (and X150.5 to a lesser degree) are for all evening all genre music. ML service center and ask if you can buy a service manual.
The re-capping perception for ML amps is strong enough that it directly affects their resale value. I had a pair of 334s myself, and found this out the hard way when I sold them. Some non-trivial fraction of the ML 300 series amps have had caps that failed, that's a fact. Most of them are in the 331-332-333 series, though there are some cases, fewer of them it seems, in the later 334-335-366 models. This might be just because of age. I talked to Levinson about my amps, which were from 1999, and they told me that the caps were spec'd to have a 20 year lifespan. Of course, that probably means there will be some failures due to age after 10 years, and by 15 years it would be much more visible.
Mark Levinson 334 Review
Lots of these 3xx amps are now 20 years old. Levinson also told me that 'recreational' re-capping is not recommended or necessary, and that most 3xx amps won't need new caps until they are more than 20 years old. I'm not sure I believe them, because as caps age they lose their energy storage capability gradually over time.
It's not a simple failure or ok scenario. Capacitors, especially the soda can sized things in older Levinson amps (and Thresholds, Krell, etc),do indeed age and eventually need replacement. Both environmental and usage factors can affect aging, and it's always been my suspicion that older high-end amps have a usage model that these high-power capacitors weren't designed for. Specifically, most audiophiles turn their amps on and off, because these amps idle at 100-300 watts even in Class AB mode. The high-end audio industry is using off-the-shelf caps, and most high power caps are designed for equipment that is never turned off, like computers and telecom equipment. When you turn on those 334s what happens?
Levinson didn't use soft-start circuitry, so all of the lights in the house dim as a huge, 50+amp transient of current charges those caps. It's just my conjecture, but I'm guessing that surge performed a couple of hundred times per year for ten years could prematurely age the caps that weren't designed for that usage model. Many of the latest high-power amps use a soft start function that charges the caps over ten seconds or more. Conceived for multichannel amps to prevent tripping circuit breakers, I also suspect these soft start functions improve cap life. Finally, most amp manufacturers are now using arrays of smaller capacitors to achieve the same energy storage as a couple of big ones, and smaller caps seem to age better than large ones. (Though my understanding is that the cap arrays are really intended to lower the series resistance the output stage sees, making the power supply faster.
I've never heard of aging as a design criteria.) There's a guy on audiogon who sells replacement upgraded caps for $745 for each amp, and factoring in labor to disassemble and reassemble one of those monsters means that $1K seems reasonable. The only way to tell if your amp really needs re-capping is to have it bench tested, preferably at rated power into 4 ohms. It might be a bit of a trick finding someone who can do that without shipping them somewhere. That's a good question, and the bottom line is that I don't know. The 33x series uses simple passive heat sink cooling, and the 334s idle at about 2.5 amps at 120v, so the components inside that chassis are going to be quite warm if you leave that amp powered up all the time.
Will that age the overall amp worse than just turning it on and off? I don't know. I doubt there's any data on this, even from Harman. You'll also run up your electric bill with a constant 5 amp electrical load. My advice - as long as the amps sound fine just enjoy the 334s and ignore the background noise on other forums like Audiogon.
Remember, many of those people worry about what the right power cord to use is, and buy cryogenic-treated electrical outlets thinking they will improve a system's sound. If I may offer my $0.02 I'd talk to a factory certified tech. He/she would be able to zero in on pattern failures, etc. There are many variables, excessive heat, operating too close to a cap's rated voltage, and the type of cap in question. (I'll have to look around for the exact formula to help estimate life span.) A simple rule or law is that the life of a capacitor doubles for every 10 degree Celsius decrease in temperature.
For example aluminum electrolytic caps don't have nearly as long a life span as a ceramic or tantalum cap. EDIT: I found the calculator: EDIT: #2 I saw your question about leaving the amp on all the time. The short answer: absolutely not. Mark Levinson 331/332/333/334/335/336/33H Capacitors Levinson 334 and 331 uses four 46000uF/75V for Filter supply and four 1900uF/150V for regulator supply. It will not cost $1000 to replace the caps. The original Philips can be replaced with 46000uF/75V Cornell Dubilier caps also 1900uF/250V caps for regulator supply. The big caps are 2 inches in diameter and 5.7 inches long.
The smaller 1900uf/250V caps must be 35mm or 1.37 inches in diameter. Total cost 500 dollars. Very easy to replace caps on levinson 334 and 331. Levinson repair center uses United Chemicon caps.
I only uses USA made Cornell dubilier. When the original China made Philips caps fail it will take out the surge resistors on the Slow start VSMB board. The newer Levinson 334 have the updated surge resistors these resistors are there to protect the amp in case if there is a short or cap failure. The older 331/332/333 used a epoxy based surge resistors it is very good idea to replace these resistors with new Nichrome 0.024 wire with 10 Ohms to handle the inrush current and heat. I have these also custom made.
Mark Levinson No.334
The levinson 336/333/332 uses 50kuF/125V caps with 150v surge these Philips caps can be replaced with Cornell 50000uF/125V or 51000uF/160V caps these caps are more expensive. I do agree caps need to be replaced after being use for 20+ years, or a little sooner when there are visible signs. Just would like to point out that the lights dim because of the transformer inrush current that can be as high as 12 to 20 times or more the rated current.
For example, a 1200 VA transformer at 120V, the primary winding current inrush could be as high as 120A or higher for the first few cycles. Of course some amps do employ some sort of soft start circuitry.
You can remove all those huge filter caps and the lights will still dim. How high the inrush can go depends on a couple of things, one being the timing, it will be maximum when the incoming voltage happens to be crossing 0 power is turned on, the other is the polarity of the residual magnetic flux in the transformer core. I do agree caps need to be replaced after being use for 20+ years, or a little sooner when there are visible signs. Just would like to point out that the lights dim because of the transformer inrush current that can be as high as 12 to 20 times or more the rated current.
For example, a 1200 VA transformer at 120V, the primary winding current inrush could be as high as 120A or higher for the first few cycles. Of course some amps do employ some sort of soft start circuitry. You can remove all those huge filter caps and the lights will still dim.
How high the inrush can go depends on a couple of things, one being the timing, it will be maximum when the incoming voltage happens to be crossing 0 power is turned on, the other is the polarity of the residual magnetic flux in the transformer core. When using an old amplifier and starting it up after it has been OFF for an extended period. Use a variac and slowly bring up the AC voltage.
Also contrary to the above comment. As required by CSA, UL and CE the power transformer has an internal, built-in circuit breaker and we have experienced power transformer failure if the amplifier has not been activated for an extended period and then suddenly exposed to a high, in-rush voltage/current surge. As mentioned above use a variac and bring up the amplifier's AC input voltage slowly. Just my $0.02. When using an old amplifier and starting it up after it has been OFF for an extended period.
Use a variac and slowly bring up the AC voltage. Also contrary to the above comment. As required by CSA, UL and CE the power transformer has an internal, built-in circuit breaker and we have experienced power transformer failure if the amplifier has not been activated for an extended period and then suddenly exposed to a high, in-rush voltage/current surge. As mentioned above use a variac and bring up the amplifier's AC input voltage slowly.
Just my $0.02. All Levinson amps 334/331/335/332/336/333 amps have soft slow start circuit built in already. When you power up these beasts with two massive transformers with over 200kuF capacitance high inrush the surge resistor with Nichrome wire will see about 1000c for a second. This wire will melt if it reaches over 1400c.This is how the amp is protected from any damage.
Tidak semua orang kuasa menghadirkan kecintaan itu. Resensi buku biografi.
The reason the original Philips caps are failing the internal constructon of the cap is very poor. Just sold a set of caps for a gentlemen in Germany with Mark levinson 333.
He replaced the original Philips 50kuF/125v and United chemicon 1900uF/150V caps with Cornell 50kuf/125v and 1900uF/250v caps. The amp is running lot cooler now with outstanding results the reason the voltage is higher on regulator caps. According to senior design Engineer at Cornell Dubilier he told me using a higher value capacitor,higher capacitance and higher voltage the cap will run cooler and also last longer.
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