Availability of lateral MOSFETs for repairs

[skier 913]

There are parts that are no longer available (obsolete) for these as well…

I have a chance to pick up a prodigy.
Is there any perceivable part replacement issues with this model?

 

[agedhorse]

I have a chance to pick up a prodigy.
Is there any perceivable part replacement issues with this model?

Some, but not nearly as many and obviously not MOSFETs. It's mostly issues with things like pots with pull switches, eq slide pots and a few switches. This is because some component manufacturers have stopped producing specific parts due to low volume demand. I have to deal with this all the time on our legacy products, many of which have been in production for many years or even decades. Sourcing replacement parts for production is very frustrating and time consuming.

 

[Overdiver]

Dear dudes and dudettes, most amps are not time bombs so… more play - less panic? If you’re a proud amp owner, you’re propably the kind of person who likes to play music and have a good time. Manufacturers like to make new stuff to make more money.

 

[Geri O]

Dear dudes and dudettes, most amps are not time bombs so… more play - less panic? If you’re a proud amp owner, you’re propably the kind of person who likes to play music and have a good time. Manufacturers like to make new stuff to make more money.

If that were really the case, there would be new amplifiers being introduced, thereby leaving MOSFET manufacturers with warehouses stacked full of perfectly good MOSFET parts going unused because of being abandoned for the latest, greatest thing in amplifier technology.

Sounding preposterous yet?

 

[agedhorse]

Dear dudes and dudettes, most amps are not time bombs so… more play - less panic? If you’re a proud amp owner, you’re propably the kind of person who likes to play music and have a good time. Manufacturers like to make new stuff to make more money.

You are completely missing the point…

I was pointing out the challenges that are developing because of key components that were used in this industry are being discontinued.

IF an amp using these parts needs service, it’s going to be more expensive if even possible/practical to complete many repairs. Knowing this in advance is useful for those who own these amps so that they can make informed decisions. It has nothing to do with playing more or having a good time.

 

[Overdiver]

You are completely missing the point…

I was pointing out the challenges that are developing because of key components that were used in this industry are being discontinued.

IF an amp using these parts needs service, it’s going to be more expensive if even possible/practical to complete many repairs. Knowing this in advance is useful for those who own these amps so that they can make informed decisions. It has nothing to do with playing more or having a good time.

Nah, not really. I get your point and this is great info to all of us. My ”between the lines” point is that there’s a lot of great techs out there who can do the job even if some parts are hard to find. All used amps are great for parts so no shortage in the next 50 years for those who want to drive a Big Block with style + have good time. More and more stuff is getting repaired, recycled and upcycled these days - at least in Europe.

 

[baxter_x]

Nah, not really. I get your point and this is great info to all of us. My ”between the lines” point is that there’s a lot of great techs out there who can do the job even if some parts are hard to find. All used amps are great for parts so no shortage in the next 50 years for those who want to drive a Big Block with style + have good time. More and more stuff is getting repaired, recycled and upcycled these days - at least in Europe.

Your statement is a bit laughable.
I live in Europe and when one of my Mesa Titan failed back in 2017, the tech in charge of it gave me a call telling me he didn't know of he could repair the amp as some parts were very hard to find. Especially the power transistors. Some needed to be replaced.

He finally could find them at a very high price but warned me about the fact they would probably be no longer be available very soon.
This thread proves his point.

Feel free to stick to your beliefs but refusing the reality is a recipe to some disappointments. You've been warned.

I recently found an interesting add for a Titan. While I am very very tempted by owning again this great amp, I'll probably won't buy it for the reasons mentioned here.

 

[timmus]

Your statement is a bit laughable.
I live in Europe and when one of my Mesa Titan failed back in 2017, the tech in charge of it gave me a call telling me he didn't know of he could repair the amp as some parts were very hard to find. Especially the power transistors. Some needed to be replaced.

He finally could find them at a very high price but warned me about the fact they would probably be no longer be available very soon.
This thread proves his point.

Feel free to stick to your beliefs but refusing the reality is a recipe to some disappointments. You've been warned.

I recently found an interesting add for a Titan. While I am very very tempted by owning again this great amp, I'll probably won't buy it for the reasons mentioned here.

This is how I ended up with my Tube Works RT-3300 amp. I am an amp tech...mostly retired now. A client brought me one to repair many moons ago..blown final mosfets. I mentioned this in the 2nd post in this thread.

I told the client that the mosfets for this amp have been discontinued and may be hard to find. I did find some eventually but they were going to be hellishly expensive. I wrote him up a quote and he balked (I couldn't blame him really).

It was months before I heard back from him, even after repeatedly trying to contact him. He finally said I could keep it for parts as it was going to be too expensive to fix. It ended up on a shelf and I bought the parts to repair it myself. I eventually got around to fixing it and it sounded so good, I decided to keep it, though I rarely use it.

After I fixed it, I found I was able to repair it for a little less than I quoted so I called him back (this was about 6 months later), and asked him if he still wanted it at a slightly better price than I quoted. By that time he had bought a new amp and had moved on.

 

[agedhorse]

Nah, not really. I get your point and this is great info to all of us. My ”between the lines” point is that there’s a lot of great techs out there who can do the job even if some parts are hard to find. All used amps are great for parts so no shortage in the next 50 years for those who want to drive a Big Block with style + have good time. More and more stuff is getting repaired, recycled and upcycled these days - at least in Europe.

Yeah really, and it’s dismissive comments and assumptions like yours being the reason why I posted this thread.

Too many customers getting surprised at the cost of a repair because of the scarcity of certain parts and the labor involved in sourcing them.

Then there’s the whole counterfeit and knock-off part market which results in unreliable repairs. This is true in Europe you, I talk with service centers there all the time.

 

[thebandcircle]

I sure love my M-Pulse 600 & Walkabout scout. If the power section fails in the future, could they still be used as preamps using effects loop send? Maybe even removing power section to save some weight? I've used both of these sent into crest power amp and was very impressed. I've been interested in the Subway line for a while but really need to play one on a gig to cement my decision. @agedhorse, you have been a wellspring of helpful information for me through out the years and I sincerely thank you for that..Ryan

 

[micguy]

I think people outside of manufacturing / repair ( of any industry ) rarely think about the "extinction" of components.
We tend to think the underlying technology , once invented, just remains and is not subject to market pressure like a finished project.

Of course we can still get spring loaded phone dials, 2 inch 16 track audio tape, and Roman concrete, why wouldn't we?

Roman concrete is made from common materials that you can likely still get. Leaded solder, however…..

 

[agedhorse]

I sure love my M-Pulse 600 & Walkabout scout. If the power section fails in the future, could they still be used as preamps using effects loop send? Maybe even removing power section to save some weight? I've used both of these sent into crest power amp and was very impressed. I've been interested in the Subway line for a while but really need to play one on a gig to cement my decision. @agedhorse, you have been a wellspring of helpful information for me through out the years and I sincerely thank you for that..Ryan

Depending on the failure, you can probable use the effects send as a preamp output unless the power supply as also failed (which would require additional repair work).

 

[HelpImaRock]

Here's a question nobody can predict the answer to: in what timeframe are we likely to repeat this process again with today's technology?

 

[agedhorse]

Here's a question nobody can predict the answer to: in what timeframe are we likely to repeat this process again with today's technology?

That’s the question I deal with every day when designing new gear. Speaking for myself, I try very hard to choose components that I think will have long active lifetimes (maybe 20-30 years) and multiple sources, but alas I am not a mind reader and occasionally get blindsided myself.

I also spend a fair amount of time researching alternative sources for components that are at their end of life within the supply chain. Sometimes, we have to tool replacement parts from alternate vendors.

I work very little in the digital world, but things become obsolete in this environment more quickly. Often, it happens with little warning too. In this regard, I’m glad that I am an old analog road dog.

 

[Bill the Cat]

Exicon still produces lateral Mosfets. Older ECW20 ( double die) series announced end of life. Double Die or Double Disaster series still in production with new W6 family. So same old devices ECW20P20 and ECW20N20 now just have additional suffix W6.

 

[agedhorse]

Note that Exicon doesn’t produce this technology, the wafers are (or were) produced by Renasis and the wafers are converted to die and packaged for Exicon by a contract packaging firm.

My understanding is that when the lateral process is fully shut down, whatever end of life wafer buys happen, that inventory will become end of life finished semiconductor inventory.

Purchasing in production quantities (5,000- 10,000 pieces) has been challenging for many years, no matter who marketed the devices based on Hitachi’s unique process. It’s very much a niche, boutique device with low demand.too much trouble and risk to continue with IME.

 

[Pontiac Thrasher]

Note that Exicon doesn’t produce this technology, the wafers are (or were) produced by Renasis and the wafers are converted to die and packaged for Exicon by a contract packaging firm.

My understanding is that when the lateral process is fully shut down, whatever end of life wafer buys happen, that inventory will become end of life finished semiconductor inventory.

Purchasing in production quantities (5,000- 10,000 pieces) has been challenging for many years, no matter who marketed the devices based on Hitachi’s unique process. It’s very much a niche, boutique device with low demand.too much trouble and risk to continue with IME.

Makes me really appreciate the old Hammond organs, my Hammond Model A's are from 1935 and still played well as of when they went into storage. Would love to hear them through the Subway's, the Model A's have pure sinewave bass on the pedal board, unlike the B3's burpy sounding complex tonewheels, and as I witnessed once, the A's can sound very much like an upright bass when played by an expert, that also plays upright bass. Gotta get those out of California someday...

: )

 

[Bill the Cat]

Correct old fab on 4" wafers, most mass production moved to 8" or 12" for higher precision low count production runs.
4" could be considered completely extinct for a long long time for anything.
New fab has been moved to 6" wafers with higher precision new fabrication machines for lateral production.

As with any lateral once you start to parallel multiple devices for high power applications. Very good matching and dedicated gate and source resistors must be used. Parasitic Oscillation and current sharing becomes big issue. As noted the whole industry including Hitachi abandoned the tech in the 90's
for this very reason. Thermal behavior, speed and low drive current always the huge advantage.

Exicon will never say publicly, for high power solutions multiple dual die packages are bad idea.
We match them very well, but dedicated gate and source transistors are not possible.
They did recommend external source resistors for parallel dual dies which actually works well, but people like to insist that they are not needed for lateral.

HiFi industry doesn't fully keep the doors open since 1993 they lasted to all this time to other industry sales.
But replacement T03 packages or more common to HiFi those were EOL few years ago.
People just use copper plate adaptors for new plastic devices so the old heatsinks can be used. Basically any older TO3 lateral easily repairable and done by many.

 

[agedhorse]

Correct old fab on 4" wafers, most mass production moved to 8" or 12" for higher precision low count production runs.
4" could be considered completely extinct for a long long time for anything.
New fab has been moved to 6" wafers with higher precision new fabrication machines for lateral production.

As with any lateral once you start to parallel multiple devices for high power applications. Very good matching and dedicated gate and source resistors must be used. Parasitic Oscillation and current sharing becomes big issue. As noted the whole industry including Hitachi abandoned the tech in the 90's
for this very reason. Thermal behavior, speed and low drive current always the huge advantage.

Exicon will never say publicly, for high power solutions multiple dual die packages are bad idea.
We match them very well, but dedicated gate and source transistors are not possible.
They did recommend external source resistors for parallel dual dies which actually works well, but people like to insist that they are not needed for lateral.

HiFi industry doesn't fully keep the doors open since 1993 they lasted to all this time to other industry sales.
But replacement T03 packages or more common to HiFi those were EOL few years ago.
People just use copper plate adaptors for new plastic devices so the old heatsinks can be used. Basically any older TO3 lateral easily repairable and done by many.

View attachment 7400778

New fab is 12” wafers now, and the focus is on high volume devices.

Screwing around with adapters like that isn’t really practical in a regular repair scenario, especially when you consider the thermal resistance difference and Pd difference of the T03P devices compared with the metal TO3 devices.

 

[skier 913]

I keep telling myself I should buy an acoustic bass because no F.A when S.H.T.F.